ALBERT

Description: Publication year: 2012 Source: Dendrochronologia Kathryn Allen, David M. Drew, Geoffrey M. Downes, Robert Evans, Patrick Baker, Michael Grose The great majority of dendroclimatological work in Australia has thus far relied on ring-width chronologies only. We report novel results from a pilot study that show the potential to develop density-based climatically sensitive chronologies from two long-lived conifers endemic to Tasmania: Pencil Pine and Celery Top Pine. Cross-dating of average ring density profiles within each of the two sites examined was comparable with the better replicated ring-width chronologies from the sites. Cross-dating potential for maximum density was also indicated. Correlations between density and climate for both species were stronger and more persistent across a window of several months than correlations between ring width and climate. These stronger correlations suggest that temperature reconstructions based on average density may be possible. The ability to develop high resolution temperature-sensitive chronologies would allow for spatial comparisons across regions such as Tasmania that are affected by multiple broad-scale climate systems. A particularly novel result was the finding that maximum density was significantly related to stream-flow at the end of the growing season. Further work is required to assess the potential to reconstruct temperature, and to reconstruct stream-flow for important Tasmanian catchments over the past 500–800 years.

Description: Publication year: 2012 Source: Dendrochronologia Hannu Hökkä, Hannu Salminen, Erkki Ahti The climate conditions of the current and previous growing seasons have been shown to influence growth of coniferous trees in mineral soils sites. These dependencies may be different in peatlands where growth is generally more dependent on variations in soil water conditions. In the Nordic and Baltic countries, millions of hectares of peatlands and wetlands have been drained in order to enhance forest production. These drainage networks do not guarantee stable soil water conditions for the whole stand rotation. It is thus likely that precipitation in particular may have a different influence on annual growth in peatland to that in mineral soil sites. We studied the effect of precipitation and temperature on the inter-annual diameter growth of Scots pine ( Pinus sylvestris L.) in Finland in drained peatland forests. The diameter growth data were limited to periods when growth response to drainage had levelled out. For comparison, growth data were also collected from adjacent mineral soil trees. The climate variables were monthly mean temperature and precipitation in a given location estimated from observations at the nearest weather stations by means of spatial smoothing. We used mixed linear models in describing the annual diameter growth of individual trees as a function of tree size and stand properties and expressed the residual variation as a function of climate parameters. The peatland and mineral soil growth variations showed different dependence on climate parameters. Peatland trees within 5 m of a ditch showed different climate responses compared to those located further away. Precipitation in July was negatively correlated with the diameter growth of peatland trees but there was no correlation with temperature. Growth of trees in mineral soils was positively correlated with March and April mean temperatures and May and June mean precipitation. The residual growth indices showed largely similar patterns in peatlands and mineral soil sites.

Description: Publication year: 2012 Source: Dendrochronologia Keyan Fang, Xiaohua Gou, Fahu Chen, Yingjun Li, Fen Zhang, Miklos Kazmer Individual tree-ring series may show changed growth trends and divergent climate–growth associations even within a site, highlighting the need to examine tree growth and its climate association before building a chronology. We provided a case study for the stratification and temporal variability of tree growth and its climate associations of individual cores for three mountain ranges in north central China. Tree growth is mainly limited by moisture conditions in previous July–September and current June–August. Repeated sampling and field investigations of Picea wilsonii at Xinglong Mountain over a growth year of 2004 suggested that the growing season is from about the end of April to the end of September. It appears that the moisture conditions in previous and current growing seasons are crucial for tree growth in this region. However, a decrease in drought limitation was observed for a few tree-ring series. We thereby built the pooled chronology and sub-site chronologies with only drought-sensitive tree rings similar climate–growth relationships from the three mountain slopes. Growth disturbances of tree-ring series are detected by checking the occurrence of successively low values of the biweight series, which are treated by fitting a flexible curve.

Description: Publication year: 2012 Source: Dendrochronologia Esther Jansma, Rowin J. van Lanen, Kit Sturgeon, Steve Mohlke, Peter W. Brewer Dendrochronological data formats in general offer limited space for recording associated metadata. Such information is often recorded separately from the actual time series, and often only on paper. TRiDaBASE has been developed to improve metadata administration. It is a relational Microsoft Access database that allows users to register digital metadata according to TRiDaS, to generate TRiDaS XML for uploading to TRiDaS-based analytical systems and repositories, and to ingest TRiDaS XML created elsewhere for local querying and analyses.

Description: Publication year: 2012 Source: Dendrochronologia Igor Drobyshev, P. Charles Goebel, Yves Bergeron, R. Gregory Corace The study of forests dominated by red pine ( Pinus resinosa Ait.), one of the few fire-resistant tree species of eastern North America, provides an opportunity to reconstruct long-term fire histories and examine the temporal dynamics of climate forcing upon forest fire regimes. We used a 300-year long spatially explicit dendrochronological reconstruction of the fire regime for Seney National Wildlife Refuge (SNWR, 38,531 ha), eastern Upper Michigan to: (1) identify fire size thresholds with strong vs. weak climate controls, (2) evaluate effect of landform type (outwash channel vs. sand ridges) in modifying climate–fire associations, and (3) check for the presence of temporal changes in the climate control of large fire events over the time period 1700–1983. We used a summer drought sensitive red pine chronology (ITRDB code can037 ) as a proxy of past fire-related climate variability. Results indicated that fires 〉60 ha in sand-ridge-dominated portions of SNWR and 〉100 ha in outwash channels were likely climatically driven events. Climate–fire associations varied over time with significant climate–fire linkages observed for the periods 1700–1800 (pre-EuroAmerican), 1800–1900 (EuroAmerican settlement) and 1900–1983 (modern era). Although an increase in fire activity at the turn of 20th century is commonly associated with human sources of ignitions, our results suggest that such an increase was also likely a climatically driven episode.

Description: Publication year: 2012 Source: Dendrochronologia Maxim Yermokhin This article presents for the first time Scots pine tree-ring chronology created from historical timber (XVII–XIX cc.) from central Belarus. The chronology includes 59 tree-ring series which were collected from the different wood structures in the Nesvizh castle. This samples show different stages of the castle renovations. The chronology presented in this paper embraces 222 years covering the period between 1608 and 1829.

Description: Publication year: 2012 Source: Dendrochronologia Pavel Pavlovich Silkin, Natalia Victorovna Ekimova This study addressed distribution of calcium and strontium in Siberian spruce ( Picea obovata Ledeb.) and Siberian fir ( Abies sibirica Ledeb.) tree-rings and its dependence on these woody species cell structure. Calcium concentration was found to decrease gradually from earlywood to latewood, whereas strontium showed an opposite trend. However, their trends at the scale of several rings are co-directed in the samples analyzed. A strong linear relationship was identified between the distribution of Sr/Ca concentration ratio and tree-ring density profile for both woody species. Radiographic density of Siberian spruce tree-ring cell walls and Ca and Sr concentrations in them were determined to have negative correlation with cell wall thickness. In earlywood of annual rings of a spruce the radiographic density of cell wall reaches 2.0 g/cm 3 and decreases to 1.2 g/cm 3 in latewood. The hypothesis put forward in this study to explain these strontium and calcium distributions in the tree-rings is that the concentrations of the element ions change with development of different cell wall layers. The high value of radiographic density of a cellular wall in earlywood and its relationship with cell wall thickness can be explained by the presence of ions of calcium in a cellular wall. Ions of calcium absorb X-ray radiation more strongly in comparison with light chemical elements. It can become the reason of observable relationship between radiographic density of cell wall and cell wall thickness.

Description: Publication year: 2012 Source: Dendrochronologia Xiaohua Gou, Fen Zhang, Yang Deng, Gregory J. Ettl, Meixue Yang, Linlin Gao, Keyan Fang Tree-line ecotones are strongly climatically limited and serve as potential monitors of climate change. We employed annual growth increment from tree-rings, and tree density and age structure data derived from two Juniperus przewalskii tree-line sites in the eastern part of the Qilian Mountains, northeastern Tibetan Plateau, to detect the responses of tree growth and population dynamics to climate change. High temperature favors tree growth and is associated with increased tree density at tree-line, and an advance in tree-line position. Significantly positive correlations were found between ring-width and mean monthly air temperatures in current and previous June, July and August. Tree recruitment began to increase rapidly at the two sites after the Little Ice Age, but then decreased starting in the 1970s. The number of trees established coincides with temperature changes. The warming trend after the Little Ice Age favors increases of tree density and an advance of tree-line. The majority of trees established during the period of 1931–1970, which coincides well with the rapid radial growth of the trees.

Description: Publication year: 2012 Source: Dendrochronologia, Volume 30, Issue 1 X. Arnan, B.C. López, J. Martínez-Vilalta, M. Estorach, R. Poyatos Trees can reach ages that in some cases amount to thousands of years. In the Mediterranean region, olive trees ( Olea europaea ) have traditionally been considered a particularly long-lived species. The main objective of this study was to assess the age of large olive trees considered to be millenarian and classified as monumental trees in northeastern Spain. We extracted cores of 14 individuals and obtained 8 sections of trees which had already been cut in the area where the largest olive trees in the northeastern Iberian Peninsula are found. The age of the sampled olive trees was assessed by counting the number of annual growth rings. Tree rings did not cross-date well, neither within nor between individuals, but boundaries between likely annual rings were clearly distinct. We found a linear relationship between DBH and tree age (in years) (Age = 2.11 × diameter(cm) + 88.93, R 2 = 0.80), which was used to estimate the age of unsampled olive trees. The maximum estimated age (627 ± 110 years) is among the greatest ages reported for olive trees around the world (700 years) and among the oldest trees in Mediterranean ecosystems.

Description: Publication year: 2012 Source: Dendrochronologia Marc Macias-Fauria, Aslak Grinsted, Samuli Helama, Jari Holopainen Proxy data forms natural time series used to lengthen instrumental climatic records, and may contain a significant portion of autocorrelation. Increased serial correlation limits the number of independent observations, not satisfying the assumptions of conventional statistical methods. We estimate the significance of calibration and verification statistics used in dendroclimatic reconstructions by combining Monte-Carlo iterations with frequency (Ebisuzaki) or time (Burg) domain time series modelling. Significance tests are presented for Coefficient of Determination ( R 2 ), Coefficient of Correlation ( r 2 ), Reduction of Error (RE) and Coefficient of Error (CE) for time series ranging from very low to very high autocorrelation. Increased autocorrelation implies higher occurrences of relatively high but spurious reconstruction statistics. Ebisuzaki time series modelling shows greater robustness and its use is recommended over Burg's method, which penalizes the restriction in the number of autocorrelation coefficients imposed by the Akaike Information Criterion. Positive RE and CE values, traditionally viewed as successful reconstruction statistics, are not necessarily significant and depend on the temporal structure of the time series used. This approach is further implemented successfully to compute confidence intervals based on the temporal structure of the residuals of the transfer function. A Matlab ® package and a Windows executable file for non-Matlab ® users are provided to perform the described analyses.

Description: Publication year: 2012 Source: Dendrochronologia, Volume 30, Issue 1 Kristof Haneca, Vincent Debonne A detailed dendrochronological survey was performed on the medieval roofs of the Church of Our Lady (CoOL) in Damme, Belgium. Seen its complex architectural history, special attention was paid to the identification of consecutive building phases, based on combined architectural historical research and tree-ring dating. In total 64 increment cores were taken throughout the roof structures of the CoOL. All roof timbers are made of European oak ( Quercus robur / petraea ), of which only few have surviving sapwood or bark. Tree-ring dating confirms the late 13th/early 14th century construction date of the roofs. For all chronologies that were composed, the highest correlation values are found with reference chronologies covering the catchment area of the river Meuse. From the dating results of the timbers of the CoOL it becomes clear that the same timber source was used for nearly a century. On several of the examined roof timbers, rafting joints were observed, demonstrating that the timbers were indeed tied together as a raft and floated down the river. By implementing sapwood estimates in a Bayesian chronological model (OxCal), tree-ring series with surviving sapwood from coeval roof structures were combined in order to narrow down the time range for the felling date. Based on the refined interpretation of the felling dates, several consecutive building phases can now be identified and dated, leading to a new interpretation of the architectural history of the CoOL. Intriguingly, a marked interruption in building activities is observed around 1300. Probably this is related to the instable political situation at that time, caused by the armed conflict that emerged between the Count of Flanders and the king of France. Since Damme served as the outport of the riotous city of Bruges, it was alternately seized by the French and Flemish, both consuming considerable amounts of timber and other building materials for military fortifications. Potentially this led to a shortage in building materials and provoked a stop in building activities. This paper demonstrates the power of Bayesian models to refine the interpretation of dendrochronological dates in architectural analyses of medieval historical buildings.

Description: Publication year: 2012 Source: Dendrochronologia, Volume 30, Issue 1 Kristina Sohar, Adomas Vitas, Alar Läänelaid Pedunculate oak ( Quercus robur L.) is one of the widely used and dendrochronologically investigated species in Europe. Still, it is a problematical dating object if its outermost section is missing partly or totally. Thus, we need sapwood estimation of living trees. As sapwood amount varies geographically, numbers of sapwood rings have been published for different regions in Europe but no such estimation has been done for the Baltic States yet. Therefore, this paper deals with the estimation of pedunculate oak sapwood growing in the eastern Baltic region, i.e. in Finland, Estonia, Latvia, and Lithuania. In total, 668 oak core samples of living trees from 43 stands were investigated. Ring widths were measured and the number of sapwood rings was determined according to two criteria: difference of colour and absence of tyloses in earlywood vessels. The samples were divided into two sets, according to the t H -values between site chronologies and the major geobotanical sub-provinces. Thus, the nine Finnish and western Estonian sites were attributed to the western region and the 34 eastern Estonian, Latvian and Lithuanian sites to the eastern region. As the result of a statistical analysis, we explain that the number of oak sapwood rings ranges from 4.09 to 20.85 and 6.45 to 18.02 within 95% confidence limits in the western and eastern regions, respectively. For the three Baltic countries and southern Finland in general, we recommend to consider a sapwood estimate of 6.18–18.71 rings. Regarding earlier studies, the general European trend of decreasing sapwood ring number towards the east was confirmed. A geographical pattern of eastward decrease of the median sapwood ring number was noticed in the Baltics as well. The chronology based upon 668 samples of living oak trees from all sites covered the period of 1631–2008.

Description: Publication year: 2012 Source: Dendrochronologia, Volume 30, Issue 1 Julia Bartens, Henri D. Grissino-Mayer, Susan D. Day, P. Eric Wiseman Live oak ( Quercus virginiana Mill.) is a long lived, broadleaf, evergreen species native to the lower Coastal Plain of the southern and southeastern United States and is frequently planted in the urban environment. However, live oak has received limited attention for its potential for dendrochronological analyses possibly because its growth-ring boundaries may be less defined due to the absence of a distinct dormancy period. The objective of this explorative study was to determine whether live oak rings in both urban and historic trees could be accurately identified and measured for dendrochronological applications. One hundred urban live oaks were assessed as well as four cross-sectional specimens from historic sites in the southeastern United States. Age of all cored live oak ranged from 7 to 29 (average = 16.8 rings), while cross-sections were taken from trees with an average age of 175 years. A chronology was created from cores that had the highest interseries correlations ( n = 27), resulting in an average interseries correlation of 0.654. The analysis of live oak cross sections revealed that the rings on live oak are very faint and barely discernible, delimited mainly by a faint row of earlywood vessels with no or barely visible terminal parenchyma. Rings on these sections were erratic (i.e., fading out along the circumference) and non-concentric (i.e., a particular ring could be both wide and narrow at certain points along the circumference) so that any attempt to measure the rings on opposing radii would have produced meaningless results. However, based on the results of this study, we conclude that the dendrochronological analysis of live oak is possible with careful sample preparation and analysis and that results would be reliable, even for urban trees. Results of this study suggest that urban tree-ring series with higher interseries correlations were more vigorous than those with lower values, suggesting that urban environmental stresses related to individual sites may decrease the usefulness of crossdating techniques for evaluating annual rings on younger, urban trees.

Description: Publication year: 2012 Source: Dendrochronologia, Volume 30, Issue 1 Rob Wilson, C. Richard Bates Following the successful utilisation of lake preserved sub-fossil woody material to extend living Scots pine chronologies in Scandinavia, ongoing research in the Scottish Highlands aims to build a similar multi-millennial long climatically sensitive pine chronology. This paper details explorative research testing the use of sonar methods to facilitate the search for sub-fossil material in lake environments. Although the method clearly identifies elongate anomalies that are consistent with submerged tree stems in water depths 〉1.5 m, it does not allow the identification of sub-fossil wood remnants in shallow water (〈1.0 m) or heavily vegetated bays. Therefore, for the successful survey of lakes, a combination of traditional and sonar methods must be applied. Ongoing research will now explore the utilisation of these methods to more remote locations where boat access is not possible.

Description: Publication year: 2011 Source: Dendrochronologia, Volume 29, Issue 4 Yongxiang Zhang, Xuemei Shao, Martin Wilmking Knowledge of the spatial pattern and temporal relationships between tree-growth and climatic factors are important not only for the projection of forest growth under varying climate but for dendroclimatology in general. Here, we systematically investigated tree-growth climate relationships of Picea crassifolia at upper treeline in the Qilian Mts., northwestern China. 297 trees from eleven sites, covering a large part of the natural range of this species, show increasing and partly divergent correlations with temperature in the most recent decades. The dominant signal at all sites was a strengthening of negative correlations of annual radial growth with summer temperature. In a subset of trees at six sites, a strengthening positive correlation with summer temperatures existed as well. Wetter and high altitude sites tended to show a higher percentage of trees that are positively correlated with warming temperatures, indicating that some individuals there may take advantage of warmer conditions. Divergent responses between the two sub-populations clustered by their response to climate factor were significantly stronger in the last 30 years compared to earlier time slices. In the same time frame, hydrothermal conditions of the investigation area changed to a drier and warmer combination. Drought conditions, most likely affecting the radial growth of most P. crassifolia , have been intensifying over time and expanding spatially from the middle Qilian Mts. to most of our study area during the last half century. While explanations such as methodological effects due to trend removal or human disturbance at the sampling sites might be able to explain the result at single sites, the spatial and temporal co-occurrence of large scale changes in climate and tree growth suggests a causal link between them.

Description: Publication year: 2011 Source: Dendrochronologia, Volume 29, Issue 3 Martin de Luis, Klemen Novak, José Raventós, Jožica Gričar, Peter Prislan, Katarina Čufar Research was carried out on the wood formation process and the intra-annual density fluctuations (IADFs) in Mediterranean Aleppo pine ( Pinus halepensis Mill.) trees from the coastal site of Guardamar, and inland Maigmo in south-eastern Spain. Samples taken at breast height of the trees were inspected to define the frequency of tree rings with latewood-like cells in earlywood (E-ring) and with earlywood-like cells in latewood (L-ring). L-rings were generally more frequent, especially on the warmer, dryer, coastal site of Guardamar. Dendrochronological techniques using tree-ring features vs. climate showed that L-rings were formed in Guardamar when August and/or September precipitation was higher than normal and in Maigmo when August precipitation was higher than normal. The formation of E-rings was promoted when winter and early spring were warmer than long term average. By studying intra-annual tree-ring formation at a cellular level, we found that at Maigmo in 2004 (MAI2004) all monitored trees presented a normal ring with normal earlywood and latewood and gradual transition between both. At Guardamar in 2005 (GUA2005) a typical L-ring was formed in the majority of monitored trees. In GUA2005 the wood formation started before February and the transition from early- to latewood occurred in late spring. In summer, the cambial cell production occurred at a very low rate, but an increased production of xylem cells took place in September when the amount of precipitation was twice as high as the long term average. During this period, a band of earlywood-like cells was formed, followed by the production of latewood-like cells that continued until the end of December. The normal ring in MAI2004 was formed because climatic factors triggering IADF did not occur (no precipitation in August 2004). After a modest cell production of cambium in September, only few latewood-like cells were produced. According to the strong agreement of results obtained from studying long-term dendrochronological series and intra-annual information on wood formation, such combined study indicates a high potential for use in explaining the environmental signals registered by a tree during different phases of wood formation.

Description: Publication year: 2011 Source: Dendrochronologia, Volume 29, Issue 1 Peter H. Nishimura, Colin P. Laroque Despite their suitability for dendroclimatological research, the boreal regions of central and western Labrador remain under-researched. In an attempt to evaluate the growth trends and climatic response of this region's trees, master chronologies have been developed for its four dominant conifer species. Balsam fir ( Abies balsamea (L.) Mill.), white spruce ( Picea glauca (Moench) Voss), black spruce ( Picea mariana (Mill.) Britton, Sterns, Poggenb.) and eastern larch ( Larix laricina (DuRoi) K. Koch) were sampled systematically within a 3 × 4 grid of twelve sites at the intersection of 62°W, 64°W and 66°W longitude, and latitudes 52°N, 53°N, 54°N and 55°N. The two most dominant species at each site were sampled, yielding a total of twenty-four master chronologies, all of which reflected a highly significant common signal at each site. The chronologies were subjected to a response function analysis to determine the nature of the growth–climate relationships in the region. Summer temperature proved to be the predominant limiting factor with regard to radial growth at most sites. The onset of the optimum temperature regime, however, varies across the network of sites, revealing evidence of a gradient of continentality in the data. Growth–temperature correlations indicated a significant relationship with July temperature at most eastern sites, while western sites tended to correlate with May, June and August temperatures. Central sites tended to correlate with June–July temperatures. We interpret these results as demonstrating the bioclimatic gradient of change between coastally proximal, maritime-influenced sites and inland, continentally influenced locales. This transition occurs approximately 330 km inland from the open Labrador Sea.

Description: Publication year: 2011 Source: Dendrochronologia, Volume 29, Issue 4 S. Szymczak, M.M. Joachimski, A. Bräuning, T. Hetzer, J. Kuhlemann Stable isotopes in tree rings have widely been used for palaeoclimate reconstructions since tree rings record climatic information at annual resolution. However, various wood components or different parts of an annual tree-ring may differ in their isotopic compositions. Thus, sample preparation and subsequent laboratory analysis are crucial for the isotopic signal retained in the final tree-ring isotope series used for climate reconstruction and must therefore be considered for the interpretation of isotope–climate relationships. This study focuses on wood of Corsican Pine trees ( Pinus nigra ssp. laricio ) as this tree species allows to reconstruct the long-term climate evolution in the western Mediterranean. In a pilot study, we concentrated on methodological issues of sample preparation techniques in order to evaluate isotope records measured on pooled whole tree-ring cellulose and whole tree-ring bulk wood samples. We analysed 80-year long carbon and oxygen chronologies of Corsican Pine trees growing near the upper tree line on Corsica. Carbon and oxygen isotope records of whole tree-ring bulk wood and whole tree-ring cellulose from a pooled sample of 5 trees were correlated with the climate parameters monthly precipitation, temperature and the self-calibrating Palmer Drought Severity Index (sc-PDSI). Results show that the offsets in carbon and oxygen isotopes of bulk wood and cellulose are not constant over time. Both isotopes correlate with climate parameters from late winter and summer. The carbon and oxygen isotope ratios of cellulose are more sensitive to climatic variables than those of bulk wood. The results of this study imply that extraction of cellulose is a pre-requisite for the reconstruction of high-resolution climate records from stable isotope series of P. nigra ssp. laricio .

Description: Publication year: 2011 Source: Dendrochronologia, Volume 29, Issue 3 Annie Deslauriers, Sergio Rossi, Audrey Turcotte, Hubert Morin, Cornélia Krause Continuous measurements of stem radius variation in trees are obtained with automatic dendrometers that provide time series composed of seasonal tree growth and circadian rhythms of water storage and depletion. Several variables can be extracted from the raw data, such as amplitude and duration of radius increase and contraction, which are useful for understanding intra-annual tree growth, tree physiology and for performing growth–climate relationships. These measurements constitute a large dataset whose manipulation needs numerous algorithms and automatic procedures to efficiently and rapidly extract the information. This paper presents a three-step procedure using two SAS routines to extract the time series describing radius variation and associate them with environmental parameters. The first routine organizes and corrects data and generates outputs in the form of files and plots to visualize the results and improve data correction (first step). The second step consists of a reclassification of the hours of contraction or expansion that have been misclassified by the automatic process. The second routine classifies the daily patterns of stem variation into the three phases of contraction, expansion and radius increment and associates the environmental parameters (third step). An example of the procedure is given, with an explanation of the outputs generated. The advantages and shortcomings of the procedure and its importance for the intra-annual analyses of tree growth are discussed.

Description: The ability to restore American chestnut (Castanea dentata) through the planting of blight-resistant (Cryphonectria parasitica) trees is currently being tested. Forest-based research on the species’ silvicultural requirements and chestnut blight development are lacking. Pure American chestnut seedlings were planted in a two-age shelterwood forest with low residual basal area and in a midstory-removal treatment with high residual basal area. Survival did not differ between silvicultural treatments and averaged 67 percent across both treatments by the fifth year. Trees in the two-age shelterwood were 2.36 m and 16.8 mm larger in height and ground-line diameter, respectively, compared to trees in the midstory-removal by the fifth growing season. Blight occurrence was not affected by silvicultural treatment. Exploratory analyses indicated that seedling grading at planting and keeping trees free-to-grow through competition control would have resulted in a two-year gain in height and GLD growth in the two-age shelterwood treatment. The two-age shelterwood represented the most efficacious prescription for chestnut restoration, but the midstory-removal prescription may offer a reasonable alternative in areas where harvesting must be delayed.

Description: Available online 3 October 2012 Publication year: 2012 Source: Dendrochronologia In order to detect the response of trees to environmental pollution in Shenyang during the last century, tree rings of two 100+ year old Chinese pine ( Pinus tabulaeformis Carr.) were analyzed for nine trace element concentrations (K, Ca, Mg, Mn, Cu, Zn, Al, Pb and Cd) and compared to local environmental change. The concentrations of Cu, Zn and Al had significant ( p 〈 0.01) increasing trends after 1940s and correlated significantly ( p 〈 0.01), with increasing production of nonferrous metal from local industrial processing. Concentrations of nutrient element (K, Ca and Mg) showed significant ( p 〈 0.01) increasing trend from heartwood to sapwood with declines in the last three decades. Significant correlation between climatic factors and element concentration in tree rings were also found, in which the temperature (November to May) and relative humidity in April and May showed significant positive correlation with Ca, Zn and Cu ( p 〈 0.05) as well as Al ( p 〈 0.01) concentrations in tree rings. April rainfall showed significant positive correlation with K and Zn ( p 〈 0.05) as well as Al ( p 〈 0.01) concentration in tree rings. The results suggest that tree rings from Chinese pine in Shenyang are sensitive to environmental change and have the potential to be used as a biomonitor for the environmental pollution. The results also demonstrate the feasibility of applying dendrochemical techniques to areas with limited samples.

Description: Available online 3 September 2012 Publication year: 2012 Source: Dendrochronologia To understand the effect of climate on tree-ring features, such as width or density, tree-ring data have to be calibrated against instrumental records. The high degree of multicollinearity among monthly time series of climate data violates the assumption of independent predictor variables in ordinary least squares regression. Bootstrapped confidence intervals of parameter estimates via regression against the principle components of the predictor variables are a possible solution to that problem. Package bootRes for R implements a flexible interface for bootstrapped response and correlation function analysis and tackles some shortcomings of currently available software. Given the increasing popularity of the free R software for statistical analysis, bootRes should facilitate both using R as a computational environment among tree-ring scientists and implementing new approaches to dendroclimatic calibration.

Description: Available online 23 September 2012 Publication year: 2012 Source: Dendrochronologia The opening of the Silk Road vigorously promoted economic and cultural exchanges between Central Asia, Europe, northern India and China. The easternmost section of the ancient trade route was established during the Qin-Han period (221 BC to 220 AD). Previous research has shown that there were three routes: the first is known as the “Hexi Route”, the second is known as the “Juyan Route” or “Prairie Route”, and the third is known as the “Qinghai Route”. The Qinghai Route has long been viewed as merely an auxiliary line of the Hexi Route which was used when the main Hexi Route was blocked by warfare. Others believe that the Qinghai Route was used during the 5th to 6th century when it was controlled by Tuyuhun Kingdom. Yet, by the 7th to 8th century, after the Tibetan occupation of the region, it was no longer a main trade route. Dendrochronology, the study of tree-rings, is a precise dating method that can be accurate to the year. In this study, wood remains excavated from tombs along the ancient Qinghai Route were studied by the means of dendrochronology in order to determine the date and better understand when Qinghai Route was used. In the tombs a lot of commercial goods such as silk products, pottery, lacquer carpentry were found. The date of the tombs determined by dendrochronology when viewed together with other archaeological data, showed that from the early Tang Dynasty to the High Tang Dynasty (early 7th century to late 8th century), the Qinghai Route was one of the routes of communication between the West and China. This disproves the hypothesis that this route was only used during the 5th to 6th century.

Description: Available online 25 August 2012 Publication year: 2012 Source: Dendrochronologia In dendrochronological dating, we encounter the trouble that some samples cannot be dated due to the occurrence of anomalies in the tree-ring series. When dating subfossil wood for the extension of existing master chronologies, this may be an especially unwanted circumstance as subfossil wood is scarce and each sample is valuable. In Moravia (Czech Republic) outbreaks of the cockchafer ( Melolontha sp.) used to appear with a disastrous effect on agricultural crops, and, for a dendrochronologist, on samples of wood to be dated. Oak ring width reduction caused by cockchafer induced defoliation can superimpose climate induced growth variations and may complicate dating of historical or subfossil samples. For this study, 33 samples of sub-fossil trunks were assessed; 19 of which were attacked by cockchafer. For comparison, we analysed a total of nine living oak trees from the forest district Strážnice-Vracov, recently attacked by the cockchafer. Occurrence of the cockchafer was reported there in 1999, 2003 and 2007. We found clear growth patterns with cyclic narrow rings every 4 years. This allowed us to create an artificial curve expressing the recurring cycles of cockchafer outbreaks which assisted us in the detection of the same pattern in subfossil tree growth. The tree-ring series of the attacked living oak stand as well as the 19 individual tree-ring series from subfossil oak trunks could not be dated using standard chronologies and showed a high resemblance to the cockchafer life cycle. Additionally, we found out that the living oak stand was attacked in 1983, 1987, 1991 and 1995 as well. The results support the hypothesis that the periodical reduction observed in tree-rings at regular increments is caused by cockchafer infestation. This evidence is further supported by characteristic anatomical features in early wood. A mean tree-ring series was created from the individual tree-ring series of subfossil oaks even though radiocarbon dating showed completely different ages of samples. This means that the affected tree-ring series cannot be used for dendrochronological dating and dendroclimatological analyses. These series cannot be used without preceding mathematical and statistical modification.

Description: Publication year: 2012 Source: Dendrochronologia Shuzhi Wang, Xiuhai Zhao The opening of the Silk Road vigorously promoted economic and cultural exchanges between Central Asia, Europe, northern India and China. The easternmost section of the ancient trade route was established during the Qin-Han period (221 BC to 220 AD). Previous research has shown that there were three routes: the first is known as the “Hexi Route”, the second is known as the “Juyan Route” or “Prairie Route”, and the third is known as the “Qinghai Route”. The Qinghai Route has long been viewed as merely an auxiliary line of the Hexi Route which was used when the main Hexi Route was blocked by warfare. Others believe that the Qinghai Route was used during the 5th to 6th century when it was controlled by Tuyuhun Kingdom. Yet, by the 7th to 8th century, after the Tibetan occupation of the region, it was no longer a main trade route. Dendrochronology, the study of tree-rings, is a precise dating method that can be accurate to the year. In this study, wood remains excavated from tombs along the ancient Qinghai Route were studied by the means of dendrochronology in order to determine the date and better understand when Qinghai Route was used. In the tombs a lot of commercial goods such as silk products, pottery, lacquer carpentry were found. The date of the tombs determined by dendrochronology when viewed together with other archaeological data, showed that from the early Tang Dynasty to the High Tang Dynasty (early 7th century to late 8th century), the Qinghai Route was one of the routes of communication between the West and China. This disproves the hypothesis that this route was only used during the 5th to 6th century.

Description: Imperata cylindrica is an invasive plant species that threatens diversity and forest productivity in southeastern ecosystems. We examined the effects of disturbance events, particularly fire and hurricane/salvage harvesting, to determine the effects on I. cylindrica abundance in longleaf pine (Pinus palustris) forests in the Florida panhandle. Areas that were burned or had greater biomass removal following a hurricane had a greater number of I. cylindrica patches and larger patch size. These results highlight the importance of disturbance events on expanding invasive species populations in this region and are likely applicable for other invasive species as well. Monitoring and treatment should follow disturbance events to ensure that invasive species populations do not exceed unmanageable levels.

Description: A recent policy response to halting global forest deforestation and degradation, and any resulting greenhouse gas emissions is REDD+, which also includes the role of conservation, sustainable management of forests and enhancement of forest carbon stocks. Although still in its infancy, the success of REDD+ will depend significantly on whether it can be economically viable and if any resulting payments are sufficient to cover the opportunity cost plus any transaction cost. Where tenure security over forest is weak, REDD+ can pose a risk for forest communities, who could be dispossessed, excluded and marginalized. This review of existing studies explores how payment for avoided deforestation, and forest tenure impact the success of REDD+ projects in terms of effectiveness, efficiency and equity. Effectiveness refers to the difference between deforestation with and without REDD+, efficiency refers to avoiding deforestation at minimal cost, and equity refers to the implication of REDD+ on benefit sharing. We conclude that the potential success or failure of REDD+ as a means to reduce deforestation and carbon emission on forest commons depends critically on designing projects that work within existing informal tenure institutions to ensure that carbon storage benefits align with livelihood benefits.

Description: Publication year: 2012 Source: Dendrochronologia Pierre Mérian, Jean-Claude Pierrat, François Lebourgeois Regional chronology and climate–growth relationships assessment are known to be sensitive to sampling effort. To disentangle the respective benefits of increasing whether the number of plots or the number of trees per plot when investigating climate–growth relationships under temperate conditions, we propose to simulate samples from a set of 84 plots established in plantations of Corsican pine ( Pinus nigra Arnold ssp. laricio Poiret var. Corsicana ), within which 10 dominant trees were cored in 1992. The effect of sampling effort was investigated through 20 modalities of sampled plots (from 3 to 84) and 10 modalities of sampled trees per plot (from 1 to 10). Regional chronology was studied using the mean effective correlation and the expressed population signal, while climate–growth relationships were evaluated through correlation functions. The calculation of the correlation functions also allowed testing the effect of sampling effort on various climatic regressors presenting different climate–growth correlation strengths. The accuracy of the dendroecological investigations increased with increasing sample size: estimating climate sensitivity with a regional chronology built from a small sample led to a general under-estimation of the climate–growth correlations. Decreasing sample size also increased the risk of estimating (i) “false” non-significant correlations for the most influencing climatic regressors, and (ii) “false” significant correlations for the less influencing ones. Increasing the number of plots was found of a greater interest than increasing the number of trees per plot to improve the climate–growth relationships assessment. Finally, the analysis revealed that the improvement of the expressed population signal with increasing sampling effort did not linearly mirror the bettering in the climate–growth correlations assessment.

Description: Publication year: 2012 Source: Dendrochronologia Mingxing Cui, Xingyuan He, Nicole Davi, Zhenju Chen, Xianliang Zhang, Junjie Peng, Wei Chen In order to detect the response of trees to environmental pollution in Shenyang during the last century, tree rings of two 100+ year old Chinese pine ( Pinus tabulaeformis Carr.) were analyzed for nine trace element concentrations (K, Ca, Mg, Mn, Cu, Zn, Al, Pb and Cd) and compared to local environmental change. The concentrations of Cu, Zn and Al had significant ( p 〈 0.01) increasing trends after 1940s and correlated significantly ( p 〈 0.01), with increasing production of nonferrous metal from local industrial processing. Concentrations of nutrient element (K, Ca and Mg) showed significant ( p 〈 0.01) increasing trend from heartwood to sapwood with declines in the last three decades. Significant correlation between climatic factors and element concentration in tree rings were also found, in which the temperature (November to May) and relative humidity in April and May showed significant positive correlation with Ca, Zn and Cu ( p 〈 0.05) as well as Al ( p 〈 0.01) concentrations in tree rings. April rainfall showed significant positive correlation with K and Zn ( p 〈 0.05) as well as Al ( p 〈 0.01) concentration in tree rings. The results suggest that tree rings from Chinese pine in Shenyang are sensitive to environmental change and have the potential to be used as a biomonitor for the environmental pollution. The results also demonstrate the feasibility of applying dendrochemical techniques to areas with limited samples.

Description: Publication year: 2012 Source: Dendrochronologia M. Wilmking, M. Hallinger, R. Van Bogaert, T. Kyncl, F. Babst, W. Hahne, G.P. Juday, M. de Luis, K. Novak, C. Völlm Woody plants growing in seasonal climates normally form one growth ring each year. However, under severe stress conditions they may not complete annual wood production all the way down to the root collar resulting in continuously missing outer rings at lower stem sections (CMORs). Here we test whether CMORs occur at different distributional margins of woody plant species, where stress levels are expected to be high. We tested 13 species (202 individuals) of trees and shrubs growing at elevational and latitudinal shrub- and tree-lines, under conditions that are normally associated with a reduction of radial growth such as drought, cold or nutrient deficiency. Samples were collected from Alaska, north western Russia, Central Europe, Scandinavia and south eastern Spain. Annual radial growth was measured along several disks or cores of each individual applying the serial sectioning technique. Individuals of nine species showed CMORs. The proportion of individuals with CMORs within a sampled species and site ranged from 0% to 80%. The number of CMORs within an individual increased with decreasing sampling height on the stem. Significant correlations existed between the amount of CMORs and (i) cambial age, (ii) stem length, (iii) stem proportion/length below peat surface, and (iv) herbivore-caused defoliation intensity depending on the species and sampling location. Our results suggest that CMORs can be associated with a cambium that may be inactive, yet functional, for up to 18 years. We conclude that CMORs can occur in a wide variety of species, growth forms and biomes, suggesting a general strategy of woody plant growth. To avoid miss-dating in dendrochronological studies, we further recommend the use of the serial sectioning technique for woody plants growing in unfavorable environments, above all, when sample size is limited and when no established chronology for cross-dating is available.

Description: Publication year: 2012 Source: Dendrochronologia Martin Worbes, Nils Raschke The rising discussion on carbon balance of tropical forests often does not consider the sequestration potential of secondary dry forests, which are becoming an increasing importance due to land use change and reforestation. We have developed an easy applicable tool for the estimation of biomass increment of tropical secondary forest stands on the base of tree ring analysis. The existence of annual rings was shown by a combination of anatomical examination and radiocarbon estimations. With tree ring analysis, forest inventories and destructive sampling the above-ground biomass increment of secondary forest stands of age between 9 and 48 years in the dry forest region of Guanacaste, Costa Rica were estimated. The above-ground biomass increment of the tree layer varies between 2.4 and 3.2 Mg/ha yr in different stands. Lianas contribute with up to 23% additional production. Differences in productivity among the stands along a chronosequence were not significant. The measured carbon allocation potential of 1.7–2.1 Mg C/ha yr lies in the range of reported values from other tropical dry forests and old growth humid forests as well.

Description: Visitor information often serves as the basis for the management plan of parks. However, there exist few scientific and fundamental surveys for parks and open spaces in Japan. We analyzed the correlation between the number of visitors and the various factors in a suburban open space in a northern Japanese city, Takino Park. To explain the fluctuations in the number of visitors in Takino Park, multiple regression analyses with the stepwise method were conducted. The analyses employed social factors and meteorological factors, such as the day of the week, school vacations, temperature and the weather. The results show that the most influential factor is the day of the week, i.e., Sundays and holidays. The weather is also influential as the number of visitors decreases on rainy and snowy days. Comparing different seasons of the year, we found that influential factors varied from one season to the other. A key distinguishing finding of our results is that the weather conditions at the departure site and the weather forecast are also determining factors. These findings will help park managers understand the current situations and examine future management strategies to maintain and enhance visitor satisfaction, and improve information services.

Description: Publication year: 2012 Source: Dendrochronologia D.M. Brown, M.G.L. Baillie In the course of building the 7000 year Belfast long oak chronology a series of depletion problems were encountered. These problems were overcome by 1984 when the completion of the Long Chronology was announced. The solution to the bridging of the various ‘gaps’ in the Irish chronology lay in the use of long sections of oak chronology from Britain. Now that a quarter of a century has elapsed and large numbers of additional oak samples, and site assemblages, have been accumulated it seems reasonable to review the ‘gaps’ in order to see if the Irish chronology could now be constructed without the use of British material. That is, are the depletion periods in the Irish chronology still evident, and if so, what might they imply about past conditions and human populations? The perhaps surprising conclusion is that the original depletions are still evident after 25 years of quasi-random sampling by archaeologists and palaeoecologists throughout Ireland.

Description: Publication year: 2012 Source: Dendrochronologia Nesibe Köse, Ünal Akkemik, Hasan Nüzhet Dalfes, Mehmet Sinan Özeren, Doğanay Tolunay Pinus nigra Arn. subsp. pallasiana (black pine) is one of the most widely grown tree in Turkey. It is the third most widely distributed tree species after Quercus L. and Pinus brutia Ten. Black pine grows in 20% of all forested areas in Turkey. In this dendroecological study, we identified the most important climate factors affecting radial growth of black pine in western Anatolia and classified its responses to climate. Twenty-eight site chronologies developed by different researchers were used in the analysis. Response functions were calculated for each chronology to identify the effect of climate on radial growth. Hierarchical cluster analysis was used to sort response functions and to classify the chronologies into groups based on climate responses. The individual responses of these chronologies to temperature and precipitation were classified in four main groups. Climatic and phytogeographic differences were the major factors influencing the formation of clusters. The results suggest that the major limiting factor is drought caused by low precipitation, especially in May, in almost all sites. The drought effect is much stronger in the transition region to the steppe, Central Anatolia and Mediterranean Regions than the Black Sea Region. Black pine trees respond positively to higher temperature at the beginning of growing season in almost all areas except in transition region to the steppe.

Description: Long-term changes for invasive trees and shrubs presence in 16 floras encompassing four remnant urban forests of the coastal northeastern United States were examined for relationships with arboricultural introductions’ residence time and planting intensity, and state level recognition of regional invasive woody taxa. The number of invasive woody taxa significantly increased over the period 1818 to 2011 which encompasses the 16 floras. No significant Pearson product moment correlations were found for residence time as the year of introduction to arboriculture with presence in the 16 floras as well as with the 4 most recent floras. In contrast to residence time, planting intensity from the North American flora and two botanical gardens floras of the region from 1811 to 1818 and New York and Philadelphia parks floras from 1857 to 1903 did have significant correlations with the 16 floras and the 4 most recent floras. State level recognition of regional invasive woody taxa showed significant correlations with presence in all 16 floras as well as the 4 most recent floras. Monitoring for range expansion by the regional invasive woody taxa is essential because only 18% of the 98 taxa are present in all 4 of the most recent floras.

Description: Forest management strategies and policies such as REDD (reduced emissions from deforestation and forest degradation) may have unintentional implications for forest sectors in countries not targeted by such policies. The success of a policy effort like REDD would result in a significant reduction in deforestation and forest degradation and an ensuing reduction in the supply of natural forest timber production within participating countries. This could in turn result in price increases, inducing a supply response outside project boundaries with possible implications for forest management as well as global carbon emissions. This paper reviews the literature to discern potential timber market implications for countries sourcing wood products from developing countries affected by REDD related conservation efforts. The literature reviewed shows varying degrees of market effects leakage—policy actions in one place creating incentives for third parties to increase timber harvesting elsewhere through the price mechanism—ranging from negligible to substantial. However, wood products in the studies reviewed are dealt with on quite an aggregated scale and are assumed to be more or less perfect substitutes for wood products outside conservation effort boundaries. The review suggests that a thorough mapping of the end-uses of tropical timber is needed to comprehensively analyze impacts on wood-product markets in regions such as Europe from conservation efforts in tropical developing countries. The types of tropical timber expected to be affected, in which applications they are used, which are the most likely substitutes and where they would be sourced, are issues that, along with empirical analysis of supply and demand price elasticities and degree of substitutability, should be investigated when assessing the overall effectiveness of REDD.

Description: Understanding the spatial pattern of ecosystem services is important for effective environmental policy and decision-making. In this study, we use a geospatial decision-support tool (Marxan) to identify conservation priorities for habitat and a suite of ecosystem services (storage carbon, soil retention and water yield) in the Upper Paraná Atlantic Forest from Misiones, Argentina—an area of global conservation priority. Using these results, we then evaluate the efficiency of existing protected areas in conserving both habitat and ecosystem services. Selected areas for conserving habitat had an overlap of carbon and soil ecosystem services. Yet, selected areas for water yield did not have this overlap. Furthermore, selected areas with relatively high overlap of ecosystem services tended to be inside protected areas; however, other important areas for ecosystem services (i.e., central highlands) do not have legal protection, revealing the importance of enforcing existing environmental regulations in these areas.

Description: Publication year: 2012 Source: Dendrochronologia Steen Magnussen, René I. Alfaro Aerial surveys provide valuable information on the scale and severity of defoliation and mortality caused by forest insects. However, methods to estimate the losses in growth using aerial survey data are not available. This study presents a method to link aerial survey data of location and severity of insect defoliation to tree ring series of radial growth in order to quantify potential growth losses due to defoliation. The method includes estimation of potentially confounding effects of climate. As an example we used aerial surveys of hemlock looper defoliation in the Mt. Revelstoke region of British Columbia, and tree ring series of radial growth of 351 western hemlock trees located in 22 plots and exposed to various levels of periodic defoliation. An autoregressive conditional heteroskedasticity time-series model (ARCH) of standardized growth indices identified significant direct and lagged effects of climate and defoliation on radial growth between 1930 and 2005. Defoliation effects were statistically significant in all plots ( P 〈 0.05). The variation in both timing and strength of estimated growth reductions varied considerably among plots. During years of observed defoliation the radial growth was reduced by an average of 10%. Growth reductions attributed to defoliation were most pronounced in the second and third year of a looper outbreak. Our modelling approach linked tree ring data to aerial survey data of defoliation through a logistic distance dependent threshold function and affords a quantitative estimation of regional growth losses.

Description: Publication year: 2012 Source: Dendrochronologia Marina Gurskaya, Martin Hallinger, Jayendra Singh, Leonid Agafonov, Martin Wilmking Tree core samples of larch ( Larix sibirica Ledeb.), spruce ( Picea obovata Ledeb.) and pine ( Pinus sibirica Du-Tour.) from the northern taiga of West Siberia were collected to assess their potential for summer temperature reconstructions in the Ob River region. Bootstrapped response functions showed that annual growth was mainly influenced by May to June temperatures in pine and by June to July temperatures in spruce and larch. Spruce and pine chronologies showed high positive correlations with previous October temperature. June–July temperatures were reconstructed based on spruce (1795–1996) and larch (1615–1999) tree ring chronologies. The pine chronology could not be used for a reliable temperature reconstruction, due to low values of explained May–June temperature variance (11–15%) but the species has a high potential to help clarify the May–June and October climatic influence on ring width observed in all three species. We explained the effect of the early vegetation period (May–July) and the differences in the temperature signals between spruce and larch tree ring chronologies with the influence of previous September and October temperature on tree growth with the warming effect of the Ob River and differences of the species’ photosynthetic possibilities and the activity of chloroplasts and bud meristem tissues.

Description: Publication year: 2012 Source: Dendrochronologia Christian Zang, Franco Biondi To understand the effect of climate on tree-ring features, such as width or density, tree-ring data have to be calibrated against instrumental records. The high degree of multicollinearity among monthly time series of climate data violates the assumption of independent predictor variables in ordinary least squares regression. Bootstrapped confidence intervals of parameter estimates via regression against the principle components of the predictor variables are a possible solution to that problem. Package bootRes for R implements a flexible interface for bootstrapped response and correlation function analysis and tackles some shortcomings of currently available software. Given the increasing popularity of the free R software for statistical analysis, bootRes should facilitate both using R as a computational environment among tree-ring scientists and implementing new approaches to dendroclimatic calibration.

Description: Publication year: 2012 Source: Dendrochronologia Tomáš Kolář, Michal Rybníček, Willy Tegel In dendrochronological dating, we encounter the trouble that some samples cannot be dated due to the occurrence of anomalies in the tree-ring series. When dating subfossil wood for the extension of existing master chronologies, this may be an especially unwanted circumstance as subfossil wood is scarce and each sample is valuable. In Moravia (Czech Republic) outbreaks of the cockchafer ( Melolontha sp.) used to appear with a disastrous effect on agricultural crops, and, for a dendrochronologist, on samples of wood to be dated. Oak ring width reduction caused by cockchafer induced defoliation can superimpose climate induced growth variations and may complicate dating of historical or subfossil samples. For this study, 33 samples of sub-fossil trunks were assessed; 19 of which were attacked by cockchafer. For comparison, we analysed a total of nine living oak trees from the forest district Strážnice-Vracov, recently attacked by the cockchafer. Occurrence of the cockchafer was reported there in 1999, 2003 and 2007. We found clear growth patterns with cyclic narrow rings every 4 years. This allowed us to create an artificial curve expressing the recurring cycles of cockchafer outbreaks which assisted us in the detection of the same pattern in subfossil tree growth. The tree-ring series of the attacked living oak stand as well as the 19 individual tree-ring series from subfossil oak trunks could not be dated using standard chronologies and showed a high resemblance to the cockchafer life cycle. Additionally, we found out that the living oak stand was attacked in 1983, 1987, 1991 and 1995 as well. The results support the hypothesis that the periodical reduction observed in tree-rings at regular increments is caused by cockchafer infestation. This evidence is further supported by characteristic anatomical features in early wood. A mean tree-ring series was created from the individual tree-ring series of subfossil oaks even though radiocarbon dating showed completely different ages of samples. This means that the affected tree-ring series cannot be used for dendrochronological dating and dendroclimatological analyses. These series cannot be used without preceding mathematical and statistical modification.

Description: Site index (SI) curves for H20 (dominant height at 20 years total age) were constructed for hybrid larch (Larix × eurolepis Henry) growing in 26 stands on former farmland in southern and central Sweden (Latitude 56–60° N.). The mean total age of the stands was 23 ± 10 (range 17–49) years; the mean diameter at breast height (ob) was 16 (7–34) cm; the mean height was 14 (8–29) m; and the stands had a mean density of 993 (266–2195) stems ha−1. A model derived by Cieszewski (2001) performed best for the data. The model explained 99% of the observed variation in height development. No apparent bias across the range of predicted site indices was found. SI was examined in relation to soil types. Multiple samples were available for three soil types: light clay, medium clay and till. There were no significant differences between these soil types with respect to the choice of SI curve.

Description: Publication year: 2012 Source: Dendrochronologia, Volume 30, Issue 3

Description: Eastern forests of the US are valued both as a carbon sink and a wood resource. The amount of biomass that can be harvested sustainably from this biome for bioenergy without compromising the carbon sink is uncertain. Using past literature and previously validated models, we assessed four scenarios of biomass harvest in the eastern US: partial harvests of mixed hardwood forests, pine plantation management, short-rotation woody cropping systems, and forest residue removal. We also estimated the amount and location of abandoned agricultural lands in the eastern US that could be used for biomass production. Greater carbon storage was estimated to result from partial harvests and residue removals than from plantation management and short-rotation cropping. If woody feedstocks were cultivated with a combination of intensive management on abandoned lands and partial harvests of standing forest, we estimate that roughly 176 Tg biomass y−1 (~330,000 GWh or ~16 billion gallons of ethanol) could be produced sustainably from the temperate forest biome of the eastern US. This biomass could offset up to ~63 Tg C y−1 that are emitted from fossil fuels used for heat and power generation while maintaining a terrestrial C sink of ~8 Tg C y−1.

Description: In 2002, the Biscuit Wildfire burned a portion of the previously established, replicated conifer unthinned and thinned experimental units of the Siskiyou Long-Term Ecosystem Productivity (LTEP) experiment, southwest Oregon. Charcoal C in pre and post-fire O horizon and mineral soil was quantified by physical separation and a peroxide-acid digestion method. The abrupt, short-term fire event caused O horizon charcoal C to increase by a factor of ten to 〉200 kg C ha−1. The thinned wildfire treatment produced less charcoal C than unthinned wildfire and thinned prescribed fire treatments. The charcoal formation rate was 1 to 8% of woody fuels consumed, and this percentage was negatively related to woody fuels consumed, resulting in less charcoal formation with greater fire severity. Charcoal C averaged 2000 kg ha−1 in 0–3 cm mineral soil and may have decreased as a result of fire, coincident with convective or erosive loss of mineral soil. Charcoal C in 3–15 cm mineral soil was stable at 5500 kg C ha−1. Long-term soil C sequestration in the Siskiyou LTEP soils is greatly influenced by the contribution of charcoal C, which makes up 20% of mineral soil organic C. This research reiterates the importance of fire to soil C in a southwestern Oregon coniferous forest ecosystem.

Description: We investigated the sprouting capacity of poplar stumps in ten 8–21-year old stands growing on former farmland in Sweden situated between 55°N and 60°N. Seven of the stands were planted with the clone OP-42 (Populus maximowiczii Henry × Populus trichocarpa Torr. and Gray), one with black cottonwood (Populus trichocarpa Torr. and Gray) and two with unidentified clones. The poplars’ mean age was 17 years (range 8–21); six of the stands were growing on clay soils, two on tills and two on loam. The studied sprouts were 1–7 years old. Stump sprouting was observed in all studied stands. The number of sprouts per living stump decreased as sprout age increased. The mean dry mass of all sprouts stump−1 was 16.1 ± 14.0 (range 3.3–37.2) kg. A biomass equation was constructed for estimating sprout biomass from the sprouts’ diameter at 10 cm above the ground (D10). The mean total sprout weight per hectare for sprouts amounted to 16.9 ± 14.6 (range 1.2–41.3) tons ha−1 when calculated for the actual living stumps in the studied areas.

Description: Biological activity and the physical environment regulate greenhouse gas fluxes (CH4, N2O and NO) from upland soils. Wildfires are known to alter these factors such that we collected daily weather records, fire return intervals, or specific fire years, and soil data of four specific sites along the Colorado Front Range. These data were used as primary inputs into DAYCENT. In this paper we test the ability of DAYCENT to simulate four forested sites in this area and to address two objectives: (1) to evaluate the short-term influence of fire on trace gas fluxes from burned landscapes; and (2) to compare trace gas fluxes among locations and between pre-/post- fire suppression. The model simulations indicate that CH4 oxidation is relatively unaffected by wildfire. In contrast, gross nitrification rates were reduced by 13.5–37.1% during the fire suppression period. At two of the sites, we calculated increases in gross nitrification rates (〉100%), and N2O and NO fluxes during the year of fire relative to the year before a fire. Simulated fire suppression exhibited decreased gross nitrification rates presumably as nitrogen is immobilized. This finding concurs with other studies that highlight the importance of forest fires to maintain soil nitrogen availability.

Description: Distribution models of invasive plants are very useful tools for conservation management. There are challenges in modeling expanding populations, especially in a dynamic environment, and when data are limited. In this paper, predictive habitat models were assessed for three invasive plant species, at differing levels of occurrence, using two different habitat modeling techniques: logistic regression and maximum entropy. The influence of disturbance, spatial and temporal heterogeneity, and other landscape characteristics is assessed by creating regional level models based on occurrence records from the USDA Forest Service’s Forest Inventory and Analysis database. Logistic regression and maximum entropy models were assessed independently. Ensemble models were developed to combine the predictions of the two analysis approaches to obtain a more robust prediction estimate. All species had strong models with Area Under the receiver operator Curve (AUC) of 〉0.75. The species with the highest occurrence, Ligustrum spp., had the greatest agreement between the models (93%). Lolium arundinaceum had the most disagreement between models at 33% and the lowest AUC values. Overall, the strength of integrative modeling in assessing and understanding habitat modeling was demonstrated.

Description: Species-specific and mixed-species volume and above ground biomass allometric equations were developed for 15 indigenous tree species and four tree fern species in New Zealand. A mixed-species tree equation based on breast height diameter (DBH) and tree height (H) provided acceptable estimates of stem plus branch (〉10 cm in diameter over bark) volume, which was multiplied by live tree density to estimate dry matter. For dead standing spars, DBH, estimated original height, actual spar height and compatible volume/taper functions provided estimates of dead stem volume, which was multiplied by live tree density and a density modifier based on log decay class from field assessments to estimate dry matter. Live tree density was estimated using ratio estimators. Ratio estimators were based on biomass sample trees, and utilized density data from outerwood basic density surveys which were available for 35 tree species sampled throughout New Zealand. Foliage and branch ( 〈 10 cm in diameter over bark) dry matter were estimated directly from tree DBH. Tree fern above ground dry matter was estimated using allometric equations based on DBH and H. Due to insufficient data, below ground carbon for trees was estimated using the default IPCC root/shoot ratio of 25%, but for tree ferns it was estimated using measured root/shoot ratios which averaged 20%.

Description: The Glentress Trial Area is an extensive research area in southern Scotland of 117 ha where a long-term trial of the transformation of even-aged plantations to continuous cover has been in progress since 1952. During the assessment of permanent sample plots in 1990 information on the species and spatial position of saplings (trees taller than 1.3 m with a diameter at breast height of 〈 7 cm) was recorded. This provided a unique opportunity to investigate the long-term survival of saplings during the transformation process when the Trial Area was reassessed in 2009. The main finding was that 37% of saplings survived the 19-year period and the majority developed into trees (≥7 cm diameter at breast height). There was considerable variation between species, the lowest survival of saplings was European larch (Larix decidua Mill.) (13%) and the highest European beech (Fagus sylvatica L.) (55%); however differences between species were not significant. There were, however, significant differences between the six management areas with three with high sapling survival (55% to 61%) but others much lower (27% to 32%). If this result is confirmed by other studies, covering a broader range of sites, management guidance that assumes 90% survival will need to be revised.

Description: Invasive plant species have long been known to cause extensive damage, both economically and ecologically, to native ecosystems. They have historically been introduced by the public, both intentional and not, for a variety of reasons. Many of the woody shrubs, such as Lonicera maackii and Rosa multiflora were introduced for wildlife cover, forage, and ornamental value. These invasives have quickly out-competed native flora, in many cases drastically impacting and changing the environment they inhabit. In this review, chosen species characteristics have been described, their pathway to invasion explained, and their impacts to native wildlife highlighted. Based on a review of the scientific literature, we determined that not all effects by invasive plants are negative. Many positive impacts can be seen throughout the literature, such as native frogs utilizing Microstegium vimineum for cover and nesting habitat. However, some important invasive plant species were not included in this review due to a lack of literature on the subject of the effects on fauna. While much is known about their economic impact and the impact on native plant species, additional work needs to be done in the field of wildlife research to determine current impacts and future implications of non-native, invasive plants on native fauna.

Description: Publication year: 2012 Source: Dendrochronologia Donald K. Youngblut, Brian H. Luckman We present a network of thirteen annual ring-width chronologies from high elevation whitebark pine ( Pinus albicaulis Engelm.) sites in the western Canadian Cordillera in order to assess the dendroclimatic potential of this long-lived tree species. The temperature signal within the chronologies is complex and strongly influenced by diverging trends in the summer temperature and ring-width records from across the region. A first differences transformation of the tree-ring and temperature records illustrates a loss of frequency coherence in growth response to summer temperatures following reduced radial growth in the 1950s. Prior to reduced growth, we note a positive association with summer temperatures for both first differenced ( r d = 0.60) and traditional ( r = 0.50) records. Following reduced growth, the association at first differences is maintained ( r d = 0.49) whereas there is a change in the lower frequency component of tree growth response to summer temperatures ( r = −0.34). We suggest the cause of this reduced temperature sensitivity is related to the interaction between diurnal temperature and cloud cover patterns, the hydrological regime of snowpack, and site conditions which have been amenable to the initiation of moisture stress during the latter half of the 20th century. Reduced radial growth is coincident with the arrival of white pine blister rust ( Cronatium ribicola J.C. Fisch. ex Raben) into the study region which suggests this infestation may be related to the observed reduction in radial growth. Whitebark pine has considerable potential for the field of dendroclimatology. Unfortunately, the decline of the species due to the combined effects of climate change, white pine blister rust, mountain pine beetle ( Dendroctonus ponderosae Hopk.), and forest fire exclusion practices indicate this potential may remain unfulfilled.

Description: To quantify the climate change impacts of forestry and forest management options, we must consider the entire forestry system: the carbon dynamics of the forest, the life cycle of harvested wood products, and the substitution benefit of using biomass and wood products compared to more greenhouse gas intensive options. This paper presents modelled estimates of the greenhouse gas balance of two key native forest areas managed for production in New South Wales for a period of 200 years, and compares it to the option of managing for conservation only. These two case studies show that forests managed for production provide the greatest ongoing greenhouse gas benefits, with long-term carbon storage in products, and product substitution benefits critical to the outcome. Thus native forests could play a significant part in climate change mitigation, particularly when sustainably managed for production of wood and non-wood products including biomass for bioenergy. The potential role of production forestry in mitigating climate change, though substantial, has been largely overlooked in recent Australian climate change policy.

Description: Publication year: 2012 Source: Dendrochronologia Ana I. García-Cervigón Morales, José Miguel Olano Mendoza, Màrcia Eugenio Gozalbo, J. Julio Camarero Martínez In contrast to most high elevation areas, plant growth at Mediterranean mountains is exposed to a summer drought period, which represents an additional climatic constraint to low temperatures. Although arboreal and shrubby conifers coexist at high altitudes, most dendroecological studies have focused on climatic responses of tree species, whereas those of shrubby species remain mostly unexplored. We built tree-ring width chronologies for two conifer species, a shrub ( Juniperus sabina ) and a tree ( Pinus sylvestris ), coexisting at three high-altitude localities of the Iberian System mountains, eastern Spain. We analyzed their climate–growth relationships for the period 1950–2009 using correlation analyses and multiple regressions. Coexisting species responded to year-to-year climatic variability in different ways. Radial growth in junipers and pines responded positively to April and May temperatures, respectively. Summer drought constrained growth in both cases, although its impact was stronger on junipers than on pines. Our findings suggest that junipers respond earlier than pines to spring temperatures due to their prostrate morphology which may enhance a fast warming of their cambial meristems after snowmelt. The higher dependence of J. sabina on summer rainfall as compared with co-occurring pines confirms that drought stress negatively impacts secondary growth in Mediterranean mountains. This sensitivity to water availability may be caused by the juniper shallow root systems, which mainly use superficial soil water. The climatic signal registered in J. sabina allows studying the response of other similar shrubby woody species growing in Mediterranean alpine areas to the ongoing climate warming, which could also reduce water availability.

Description: In dry western Unites States forests where past resource management has altered the ecological role of fire and stand characteristics alike, mechanical thinning and prescribed burning are commonly applied in wildfire hazard abatement. The reduced surface fuel loads and stand structures resulting from fuels modifications are temporary, yet few studies have assessed the lifespan of treatment effects. We sampled forest fuels and vegetation following fuels reduction in a chronosequence of time since treatment in the northern Sierra Nevada and southern Cascade regions of California. Treatments altered overstory characteristics including stand density, basal area, and species composition. These effects were still present on the oldest treatment sites (8–15 years post-treatment). Other stand characteristics, particularly timelag fuel loads, seedling density, and shrub cover, exhibited substantial variability, and differences between treatment age classes and between treatment and control groups were not statistically significant.

Description: Longleaf pine has been classified as very shade intolerant but leaf physiological plasticity to light is not well understood, especially given longleaf pine’s persistent seedling grass stage. We examined leaf morphological and physiological responses to light in one-year-old grass-stage seedlings and young trees ranging in height from 4.6 m to 6.3 m to test the hypothesis that young longleaf pine would demonstrate leaf phenotypic plasticity to light environment. Seedlings were grown in a greenhouse under ambient levels of photosynthetically active radiation (PAR) or a 50% reduction in ambient PAR and whole branches of trees were shaded to provide a 50% reduction in ambient PAR. In seedlings, shading reduced leaf mass per unit area (LMA), the light compensation point, and leaf dark respiration (RD), and increased the ratio of light-saturated photosynthesis to RD and chlorophyll b and total chlorophyll expressed per unit leaf dry weight. In trees, shading reduced LMA, increased chlorophyll a, chlorophyll b and total chlorophyll on a leaf dry weight basis, and increased allocation of total foliar nitrogen to chlorophyll nitrogen. Changes in leaf morphological and physiological traits indicate a degree of shade tolerance that may have implications for even and uneven-aged management of longleaf pine.

Description: This paper compares carbon (C) and nutrient contents in soils (Alfisols derived from andesite), forest floor and vegetation in a former fire (1960) and an adjacent forest in the Sagehen Watershed in the Sierra Nevada Mountains of California. Soils from the former fire (now occupied predominantly by Ceanothus velutinus, a nitrogen-fixing shrub) had significantly lower contents of extractable SO42− and P (both Bray and bicarbonate) but significantly greater contents of exchangeable Ca2+ than the adjacent forested site (dominated by Pinus jeffreyii). 15N data suggested that N fixation had occurred in the former fire site, but N contents did not differ between the two sites. O horizon C and nutrient contents did not differ between the two sites, but vegetation C and nutrient contents were significantly greater in the forested than former fire site. These results contrast with those from a nearby, previous study at Little Valley Nevada, also dominated by P. jeffreyii growing on a different soil type (Entisols derived from granite). In the Little Valley study, soil C, N, Ca2+, Mg2+, and K+ contents within the former fire (1981, now also occupied predominantly by Ceanothus velutinus) were greater than in the adjacent forest (Pinus jeffreyii) but soil extractable P contents either did not differ or were greater in the former fire. We conclude that soil parent material is an indirect but strong mediator of the effects of post-fire vegetation on soils in this region, especially with respect to soil P changes, which vary substantially between andesite- and granite-derived soils.

Description: Many scientists and managers have an interest in describing the environment following a fire to understand the effects on soil productivity, vegetation growth, and wildlife habitat, but little research has focused on the scientific rationale for classifying the post-fire environment. We developed an empirically-grounded soil post-fire index (PFI) based on available science and ecological thresholds. Using over 50 literature sources, we identified a minimum of five broad categories of post-fire outcomes: (a) unburned, (b) abundant surface organic matter (〉85% surface organic matter), (c) moderate amount of surface organic matter (≥40 through 85%), (d) small amounts of surface organic matter (

Description: Based on theoretical underpinnings and an empirical review of forest laws and regulations of selected countries throughout the Americas, we examine key components of natural forest management and how they are addressed in the legal frameworks of Argentina, Brazil, Chile, Costa Rica, Guatemala, Nicaragua, Paraguay, Uruguay, and the U.S. We consider forest policy directives in terms of legislative, planning, operational, environmental/ecological, social, and economic aspects and classify them by the type of policy obligation: (1) non-discretionary laws or rules; or (2) discretionary, voluntary directives; and, further, by the type of policy approach: (1) a specific technology or practice required or recommended; (2) a process or system requirement or recommendation; or (3) a performance or outcome based requirement or recommendation. Protection of at-risk species and riparian buffers are required in all countries and include specific prescriptions in most; forest management planning and secure, legal land title or tenancy are commonly required; and mandatory processes to protect soil and water quality are customary. Less common requirements include forest monitoring and social and economic aspects, and, when in place, they are usually voluntary. Implications for improved policies to achieve sustainable forest management (SFM) are discussed.

Description: As part of its efforts to curb greenhouse gas emissions, China has committed to expanding the country’s forest area by 40 million hectares and stocking volume by 1.3 billion m3 from 2006 to 2020. Our analysis suggests that it is very likely that China will realize its goal of forest area expansion; but the target of volume increase represents only a modest gain, which may absorb about 2% of its cumulative carbon emissions. However, China’s forests can be a much more significant carbon sequester and ecosystem services provider if its forest growth rate and stocking level are boosted by improving forest quality and productivity. To that end, however, the civil cultural practices and governance structure must be transformed.

Description: Forest carbon stocks—both in terms of the standing biomass and the soil organic carbon (OC)—were monitored in the mangrove plantation reforested from an abandoned shrimp pond for the 10 years following land excavation. Excavation to a level of 25 cm below the existing ground level increased the inundation time of tidal water from 463 to 7,597 hours per year, resulting in a significant increase of survival/growth rates for planted mangrove species, Rhizophora mucronata (RM) and Bruguiera cylindrica (BC), and of carbon stocks as well. RM showed high rates of standing biomass accumulation with 98.7 ton/ha while 28.8 ton/ha for BC was measured over 10 years in the excavated area. In contrast, the unexcavated area showed low rates of biomass accumulation, 1.04 ton/ha for RM and 0.53 ton/ha for BC in the same period. The excavated area recorded a twofold increase of soil OC in the upper 5 cm of the surface soil from 71.8 to 154.8 ton/ha in 10 years, however it decreased to 68.3 ton/ha in the unexcavated area where soil OC is susceptible to decomposition. These results imply that the potential of carbon sinks in reforested land from abandoned areas cannot be developed unless hydraulic conditions are properly recovered. The fast growing species Avicennia marina (AM) grew quickly for the first two years after colonization but its growth slowed down afterwards, showing a limited ability of carbon capture.

Description: Longleaf pine (Pinus palustris) ecosystems have been reduced dramatically throughout their range. Prescribed burning is considered the best way to restore and maintain plant communities associated with longleaf pine, but little is known about its effects on coarse woody debris and associated organisms. We conducted a 5-year study on the Osceola National Forest in northeastern Florida to determine how dormant-season prescribed burns at different frequencies (annual, biennial, quadrennial or unburned) applied over a 40-year period affected coarse woody debris volume, decomposition and nitrogen content, and subterranean termite (Reticulitermes spp.) activity. Burn frequency had no effect on standing dead tree or log volumes. However, freshly cut longleaf pine logs placed in the plots for four years lost significantly less mass in annually burned plots than in unburned plots. The annual exponential decay coefficient estimate from all logs was 0.14 yr−1 (SE = 0.01), with the estimated times for 50 and 95% loss being 5 and 21.4 years, respectively. Termite presence was unaffected by frequent burning, suggesting they were able to survive the fires underground or within wood, and that winter burning did not deplete their food resources.

Description: Enhancement of forest growth through silvicultural modification of stand density is one strategy for increasing carbon (C) sequestration. Using the Fire and Fuels Extension of the Forest Vegetation Simulator, the effects of even-aged, uneven-aged and no-action management scenarios on C sequestration in a southern Appalachian red spruce-Fraser fir forest were modeled. We explicitly considered C stored in standing forest stocks and the fate of forest products derived from harvesting. Over a 100-year simulation period the even-aged scenario (250 Mg C ha−1) outperformed the no-action scenario (241 Mg C ha−1) in total carbon (TC) sequestered. The uneven-aged scenario approached 220 Mg C ha−1, but did not outperform the no-action scenario within the simulation period. While the average annual change in C (AAC) of the no-action scenario approached zero, or carbon neutral, during the simulation, both the even-aged and uneven-aged scenarios surpassed the no-action by year 30 and maintained positive AAC throughout the 100-year simulation. This study demonstrates that silvicultural treatment of forest stands can increase potential C storage, but that careful consideration of: (1) accounting method (i.e., TC versus AAC); (2) fate of harvested products and; (3) length of the planning horizon (e.g., 100 years) will strongly influence the evaluation of C sequestration.

Description: Today there is an increasing demand for biomass for use in energy production. In this study we investigated stumps and roots from six poplar (Populus sp.) stands growing on former farmland in Sweden, situated between latitudes 55 and 60°N. The mean age of the poplar was 20 years (range 16–23), the mean stand density 1151 stems ha−1 (range 361–3279), and the mean diameter at breast height (over bark) 288 mm (range 81–574). All poplar stands were on clay soils (light and medium clay and light clay tills).The mean dry mass weight of the 72 excavated stumps was 45 ± 39 kg (range 1–185), with the roots ≥ 50 mm weighing 14 ± 16 kg (range 0.2–87). Dry mean stump weight represented 21% (by dry weight) of the stem. The mean total dry weight per hectare for stumps amounted to 34.9 ± 21.8 (range 12.9–66.9) tons and the equivalent value for roots was 12.0 ± 9.6 (range 4.7–10.9) tons. The excavation of below-ground biomass can either focus on the stump or the stump and parts of the root system. Depending on the combination of soil type and soil moisture the weight of soil adhering to stumps and the cleaning requirements will vary.

Description: The documented role of United States forests in sequestering carbon, the relatively low cost of forest-based mitigation, and the many co-benefits of increasing forest carbon stocks all contribute to the ongoing trend in the establishment of forest-based carbon offset projects. We present a broad analysis of forest inventory data using site quality indicators to provide guidance to managers planning land acquisition for forest-based greenhouse gas mitigation projects. Specifically, we summarize two condition class indicators of site productivity within the FIA forest inventory database—physclcd and siteclcd—as they relate to current aboveground live tree carbon stocks. Average carbon density is higher on more productive sites, but compared to the overall variability among sites, the differences are relatively small for all but the highest and lowest site classes. Some minor differences in eastern- versus western-forests were apparent in terms of how carbon on the least productive sites differed from most other forest land over time. Overall results suggest that xeric sites in most regions as well as sites that correspond to the lowest, non-productive classifications of forest land should preferentially not be used forestry-based greenhouse gas mitigation projects, but all other forest areas appear to be suitable.

Description: Sector sampling is a new and simple approach to sampling objects or borders. This approach would be especially useful for sampling objects in small discrete areas or “polygons” with lots of internal or external edge, but it may be extended to sampling any object regardless of polygon size. Sector plots are wedge-shaped with a fixed sector angle. The probability of object selection is constant and equal to the sector angle in degrees divided by 360°. A unique property of sector sampling is that the point from which the angle originates may be located subjectively when the sector direction is at random. Another advantage over traditional sampling (such as fixed or variable area plots) is that there is no edge effect; that is, there is no altering of selection probabilities of objects close to polygon boundaries. Various approaches are described for deriving polygon means and totals with their associated variances. We review the genesis of sector sampling and develop two new components: sub-sampling using fixed area plots and line sampling using the sector arcs as transects. Sector sampling may be extended to measuring a variety of objects such as trees, shrubs, plants, birds, animal trails and polygon borders.

Description: The objective of REDD+ is to create incentives for the reduction of emissions from deforestation and forest degradation and for the increase of carbon stocks through the enhancement, conservation and sustainable management of forests in developing countries. As part of the international negotiations under the United Nations Framework Convention on Climate Change (UNFCCC), compensation would be estimated in relation to national performance but how these incentives will be channeled within countries has not been specified and there are concerns about how the benefits will be shared among different stakeholders. One central issue is that under the national approach good performance in one region can be offset by underperformance in other regions of the country thus preventing the generation of predictable local incentives. Other issues relate to the need to provide incentives to a wide range of stakeholders and to avoid perverse reactions. To address these and other issues we propose separating the accounting of reduced deforestation, reduced degradation and enhancement of forests. The local attribution of credits would be easier for carbon enhancement, and possibly reduced degradation, than for reduced deforestation, since carbon gains can, in principle, be measured locally in the first two cases, while estimating achievements in reduced deforestation requires a regional approach. This separation in attribution of rewards can help to create adequate incentives for the different stakeholders and overcome some of the problems associated with the design and implementation of national REDD+ programs.

Description: This paper assesses quantification methods for carbon leakage from forestry activities for their suitability in leakage accounting in a future Reducing Emissions from Deforestation and Forest Degradation (REDD) mechanism. To that end, we first conducted a literature review to identify specific pre-requisites for leakage assessment in REDD. We then analyzed a total of 34 quantification methods for leakage emissions from the Clean Development Mechanism (CDM), the Verified Carbon Standard (VCS), the Climate Action Reserve (CAR), the CarbonFix Standard (CFS), and from scientific literature sources. We screened these methods for the leakage aspects they address in terms of leakage type, tools used for quantification and the geographical scale covered. Results show that leakage methods can be grouped into nine main methodological approaches, six of which could fulfill the recommended REDD leakage requirements if approaches for primary and secondary leakage are combined. The majority of methods assessed, address either primary or secondary leakage; the former mostly on a local or regional and the latter on national scale. The VCS is found to be the only carbon accounting standard at present to fulfill all leakage quantification requisites in REDD. However, a lack of accounting methods was identified for international leakage, which was addressed by only two methods, both from scientific literature.

Description: This study analyzes the latent demand to outdoor recreation participation and identifies what factors are constraining people from realizing this demand. In Sweden, recreation in the outdoors is seen as a public right as articulated in public policy and much of the outdoor recreation centre around forested landscapes—over 60 percent of the land area is classified as forest. Using data from a nationwide survey of 43 recreation activities, the study takes a time-contextual approach to reveal variations in recreation constraints across weekdays, weekends and holidays. Results show that almost half the population has a latent demand to increase their participation in outdoor recreation. Three categories of time contextual constraints are identified and several of the constraints studied show variations across outdoor activities and socio-economic factors. Practical implications for the promotion of outdoor recreation participation by public agencies, recreation managers and tourism businesses are discussed based on the study findings.

Description: Bhutan was an inhabited wilderness until 1961, when road construction started after the closure of the Tibetan border. Since then, the road network has expanded from the Indian boarder, often tracing traditional trails. This has accelerated commerce as well as movement of people from India, benefitting both the Bhutanese and foreign tourists. At the same time, dependence on imported automobiles and fossil fuel has risen, and roadless areas have begun to shrink. This brought an inevitable loss of traditional environmental knowledge, such as the care of mules for packing, and reduction in physical and mental health among the Bhutanese. People who lost jobs as horsemen moved into towns to find jobs. Road extension is also a double-edged sword for visitors. It has resulted in shrinking trekking areas and loss of traditional culture, both of which have been sacrificed for easy access. Protected areas often function as fortifications against mechanical civilization. However, protected-area status or its zoning does not guarantee that an area will remain roadless where there is considerable resident population. An analysis in Jigme Dorji National Park showed the gradual retreat of trailheads and increasing dependence on automobiles among residents and trekkers. B. MacKaye, a regional planner in the Eastern United States, proposed using trails as a tool to control such mechanical civilization. His philosophy of regional planning suggests two measures; one is consolidated trailheads as dams, and the other is confinement of roads by levees, consisting of new trails and wilderness belts. According to case studies, the author proposed six options for coexistence of trails with roads.

Description: Despite the widespread agreement on the importance of preserving ecological integrity in conservation and outdoor recreation decision-making processes, traditional metrics analyzing the supply of and demand for conservation and recreation resources have focused on geographical and population-centric units of measurement rather than ecological ones. One tool past researchers have used to inform recreation resource planning is the recreation location quotient (RLQ). While simple park-to-population ratios or acres-per-capita metrics provide a base measure of carrying capacity and are often useful to set broad recreation supply standards, the RLQ offers a more nuanced snapshot of supply and demand by comparing regional ratios to a standardized reference region. The RLQ is thus able to provide a statistic or quotient that highlights regions where recreation resources are particularly abundant and/or scarce relative to a reference area. This project expands the past RLQ analyses by investigating the distribution of recreation resources across the 10 ecological sections found within the US state of Minnesota. RLQs were calculated using recreation trail mileage, natural resource and recreation area acreage data, and recreation facility data from federal, state, and local agencies. Results found notable differences in supply of recreation resources across ecological sections. Some sections were considerably underrepresented in recreation resources-per area (e.g., Red River Valley and North Central Glaciated Plains) while others were underrepresented in recreation resources-per capita (e.g., Minnesota and Northeast Iowa Morainal). The RLQ statistics and resulting maps illustrating relative surplus or deficiencies can inform future land acquisition decisions and highlight the need for cross-jurisdictional planning in order to ensure outdoor recreation systems are ecologically representative. Possible implications and recommendations for future planning decisions are discussed.

Description: Cyclaneusma needle-cast has a major impact on the New Zealand forest industry. The causal agent, Cyclaneusma minus, causes most severe damage to 11–20 year-old trees and currently there are no economically viable procedures for control of the disease in New Zealand. Here we present a method for genetic transformation of C. minus using protoplasts generated by incubation with Glucanex™ enzyme. C. minus was transformed with a gene encoding green fluorescent protein (GFP) and expression was stable after successive sub-culturing of the strain in the absence of selective pressure. Expression of the gfp gene allowed us to utilize an in vitro GFP-based screening method to identify strains of Trichoderma with potential for biocontrol of this disease. The strain that showed the most promise as a potential biocontrol candidate exhibited a low level of inhibition by uncharacterized metabolite(s) that C. minus secretes into the medium, and consistently caused a loss of GFP expression from the GFP-labeled C. minus strain. The interaction between C. minus and the biocontrol strain, in the interaction zone where GFP expression was lost, was determined to be fungicidal. The utility of such biocontrol strains is discussed. This study represents the first genetic manipulation of C. minus and will pave the way for further studies of the life cycle and infection biology of this organism.

Description: Forest biomass is an important energy source in Sweden and some other European countries. In this paper we estimate the physically available (i.e., total potential) forest biomass for energy from annual forest harvesting (1970–2008) or in the total standing stock (2008) in Sweden. To place Sweden’s forest resources into perspective we relate this to an estimated need for renewable energy sources in Europe. As Swedish forests supply a range of goods and ecosystem services, and as forest biomass is often bulky and expensive to procure, we also discuss issues that affect the amount of forest biomass that is actually available for energy production. We conclude that forests will contribute to Sweden’s renewable energy potential, but to a limited extent and expectations must be realistic and take techno-economical and environmental issues into consideration. To meet future energy needs in Sweden and Europe, a full suite of renewable energy resources will be needed, along with efficient conversion systems. A long-term sustainable supply of forest resources for energy and other uses can be obtained if future harvest levels are increased until they are equal to the annual growth increment. Delivering more than this would require increasing forest productivity through more intensive management. The new management regimes would have to begin now because it takes a long time to change annual production in temperate and boreal forests.

Description: Coping or adaptation following large-scale disturbance may depend on the political system and its preparedness and policy development in relation to risks. Adaptive or foresight planning is necessary in order to account and plan for potential risks that may increase or take place concurrently with climate change. Forests constitute relevant examples of large-scale renewable resource systems that have been directly affected by recent environmental and social changes, and where different levels of management may influence each other. This article views disturbances in the forest sectors of Sweden and Canada, two large forest nations with comparable forestry experiences, in order to elucidate the preparedness and existing responses to multiple potential stresses. The article concludes that the two countries are exposed to stresses that indicate the importance of the governing and institutional system particularly with regard to multi-level systems including federal and EU levels. While economic change largely results in privatization of risk onto individual companies and their economic resources (in Canada coupled with a contestation of institutional systems and equity in these), storm and pest outbreaks in particular challenge institutional capacities at administrative levels, within the context provided by governance and tenure systems.

Description: New diseases in forest ecosystems have been reported at an increasing rate over the last century. Some reasons for this include the increased disturbance by humans to forest ecosystems, changed climatic conditions and intensified international trade. Although many of the contributing factors to the changed disease scenarios are anthropogenic, there has been a reluctance to control them by legislation, other forms of government authority or through public involvement. Some of the primary obstacles relate to problems in communicating biological understanding of concepts to the political sphere of society. Relevant response to new disease scenarios is very often associated with a proper understanding of intraspecific variation in the challenging pathogen. Other factors could be technical, based on a lack of understanding of possible countermeasures. There are also philosophical reasons, such as the view that forests are part of the natural ecosystems and should not be managed for natural disturbances such as disease outbreaks. Finally, some of the reasons are economic or political, such as a belief in free trade or reluctance to acknowledge supranational intervention control. Our possibilities to act in response to new disease threats are critically dependent on the timing of efforts. A common recognition of the nature of the problem and adapting vocabulary that describe relevant biological entities would help to facilitate timely and adequate responses in society to emerging diseases in forests.

Description: Our objective was to compare and evaluate the practical applicability to REDD+ of ten forest management, social, environmental and carbon standards that are currently active worldwide: Climate, Community and Biodiversity (CCB), CCB REDD+ Social and Environmental Standards (CCBA REDD+ S&E), CarbonFix Standard (CFS), Forest Stewardship Council (FSC), Global Conservation Standard (GCS), ISO 14064:2006, Plan Vivo Standard, Programme for Endorsement of Forest Certification (PEFC), SOCIALCARBON Standard and the Voluntary Carbon Standard (VCS). We developed a framework for evaluation of these standards relative to each other using four substantive criteria: (1) poverty alleviation, (2) sustainable management of forests (SMF), (3) biodiversity protection, (4) quantification and assessment of net greenhouse gas (GHG) benefits; and two procedural criteria: (5) monitoring and reporting, and (6) certification procedures. REDD programs require assessment of GHG benefits, monitoring, reporting and certification. Our analysis shows that only the Voluntary Carbon Standard (VCS) treats these three criteria comprehensively. No standard provides comprehensive coverage of the social and other environmental criteria. FSC, PEFC and CarbonFix provide comprehensive assessments of the sustainable forest management criterion. CCBA REDD+ S&E, CCB, and GCS provide comprehensive coverage of the biodiversity and poverty alleviation criteria. Experience in using these standards in pilot projects shows that projects are currently combining several standards as part of their strategy to improve their ability to attract investment, but costs of implementing several certification schemes is a concern. We conclude that voluntary certification provides useful practical experience that should feed into the design of the international REDD+ regime.

Description: One of the main issues regarding the implementation of REDD+ in Latin America has been the growing concern that such projects may infringe upon the rights and negatively affect the livelihoods of forest-dependent communities. Various indigenous and civil society organizations are ardently opposed to the initiative. Such is the case in Ecuador, where indigenous opposition to REDD+ represents a considerable obstacle in the creation of a national strategy since more than 60% of the country’s remaining forest cover is on indigenous land or under indigenous occupation. Thus one of the most critical challenges remaining for Ecuador will be the construction of a strong legal, financial, and institutional framework—one that the greater indigenous community might be willing to accept. Closer examination of this topic however, reveals just how difficult this may become. Lack of information, a recent political split between national authorities and the indigenous sector, and the dissimilar organizational capacity levels of indigenous communities make the feasibility of carrying out REDD+ projects on these lands extremely complex. However, the biggest obstacle may be ideological. Many indigenous groups view REDD+, with its possible emphasis on international markets and neoliberal mechanisms, as a continuation of the type of policies that have impeded their quest for sovereignty and self determination. As such, indigenous people are only willing to consider such projects if they clearly see preconditions in place that would safeguard their cultures, territories, and autonomy.

Description: We evaluated the effects of site preparation treatments on growth of lodgepole pine and white spruce in north-eastern British Columbia, Canada. These treatments can provide yield gains of up to 10 percent for lodgepole pine and white spruce at 60 and 80 years, respectively (estimated using TASS). Stands of these two species are showing a Type 1 response. Using growth multipliers, based on measurements collected at ages 10 to 20 results in inflated estimates of potential yield responses while the age-shift method provides the most appropriate estimates of yield gains when measured during the first 20 years of growth.

Description: The Lake Tahoe basin, located along the California and Nevada border between the Carson and Sierra Nevada mountain ranges, represents a complex forested ecosystem consisting of numerous sub-watersheds and tributaries that discharge directly to Lake Tahoe. This synthesis focuses on historical and current nutrient pools and the effects of biomass management in watersheds of the basin relative to their potential impacts on nutrient (N, P) related discharge water quality. An accumulating forest floor as a result of fire suppression has resulted in the build-up of large nutrient pools that now provide a “natural” source of long term nutrient availability to surface waters. As a consequence, stand and forest floor replacing wildfire may cause a large magnitude nutrient mobilization impact on runoff water quality. Hence, mechanical harvest and controlled burning have become popular management strategies. The most ecologically significant long-term effects of controlled fire appear to be the loss of C and N from the forest floor. Although the application of controlled fire may have some initial impact on overland/litter interflow nutrient loading, controlled burning in conjunction with mechanical harvest has the potential to improve runoff water quality by reducing N and P discharge and improving the overall health of forest ecosystems without the danger of a high intensity wildfire.

Description: Temporal changes in plant tissue non-structural carbohydrates (NSC) may be sensitive to climate changes that alter forest phenology. We examined how temporal fluctuations in tissue NSC concentrations of Populus grandidentata and Quercus rubra relate to net and gross primary production (NPP, GPP) and their climatic drivers in a deciduous forest of Michigan, USA. Tissue NSC concentrations were coupled with NPP and GPP phenologies, declining from dormancy until GPP initiation and then increasing following NPP cessation. Warmer autumns extended the temporal gap between NPP and GPP cessation, prolonging the period of NSC accumulation. These results suggest that tissue NSC concentrations may increase with climate change.

Description: This research explores the intersection between the various federal and state forestry incentive programs and the adoption of sustainable forestry practices on non-industrial private forest (NIPF) lands in the US. The qualitative research reported here draws upon a series of eight focus groups of NIPF landowners (two each in Minnesota, Oregon, Pennsylvania, and South Carolina). Despite minor regional variations, the dominant theme that emerged is that these landowners’ purchase and management decisions are motivated by the “trilogy” of forest continuity, benefit to the owner, and doing the “right thing.” This trilogy is quite consistent with notions of sustainable forestry, but somewhat more at odds with the objectives of many financial incentive programs, as well as specific tactics such as third-party certification. A series of policy recommendations that emerge from this research is presented.

Description: Visitor information often serves as the basis for the management plan of parks. However, there exist few scientific and fundamental surveys for parks and open spaces in Japan. We analyzed the correlation between the number of visitors and the various factors in a suburban open space in a northern Japanese city, Takino Park. To explain the fluctuations in the number of visitors in Takino Park, multiple regression analyses with the stepwise method were conducted. The analyses employed social factors and meteorological factors, such as the day of the week, school vacations, temperature and the weather. The results show that the most influential factor is the day of the week, i.e., Sundays and holidays. The weather is also influential as the number of visitors decreases on rainy and snowy days. Comparing different seasons of the year, we found that influential factors varied from one season to the other. A key distinguishing finding of our results is that the weather conditions at the departure site and the weather forecast are also determining factors. These findings will help park managers understand the current situations and examine future management strategies to maintain and enhance visitor satisfaction, and improve information services.

Description: Of the more than 300 species of Psocoptera described in North America, 44 species have been documented on eastern hemlock, Tsuga canadensis (L.) Carrière, in the southern Appalachians. However, the distribution and co-occurrence patterns of these species throughout the tree canopy are unknown. This study was initiated to evaluate specimen abundance, species richness and species composition among three designated strata in the canopy of eastern hemlock, assess species for vertical stratification patterns, and determine if co-occurrence patterns of Psocoptera species are random or non-random. During this study, 27 species representing 18 genera and 10 families were evaluated. Psocopteran specimen abundance, species richness and composition differed among the lower, middle, and upper strata. Unique assemblages were identified in each stratum, indicating vertical stratification. The upper stratum of the canopy had five exclusive species, the middle had four exclusive species, and the lower stratum had 14 exclusive species. The co-occurrence pattern of Psocoptera species in the canopy of eastern hemlock was non-random.

Description: Despite the importance of protected areas (PAs) worldwide to protect biodiversity, reduce poverty and promote sustainable development, throughout the world governments struggle to adequately fund PAs to meet conservation goals. Tourism is seen as a viable financial option for PAs, with tourism concessions through private sector partnerships gaining momentum that allows the overarching goal of preservation and conservation to remain with the state. However, without appropriate planning or best practices in place, tourism concessions can lead to such problems as waste, habitat destruction and the displacement of local people and wildlife. We analyzed tourism concession agreements in government documents from 22 countries to provide an overview of what best practices for tourism concessions are being established and what practices might need to be better incorporated into agreements. The greatest weaknesses of best practices appear to be with concession qualifications, legal, and financial responsibilities, while the strengths included environmental and empowerment/social responsibilities. This initial assessment of contract components will provide a baseline to further develop best practices and assist protected area managers, local communities, and conservation practitioners working with tourism in PAs to ensure that tourism has a positive impact on protected area management.

Description: Forestry, as a large industry, has significant impacts on the quality of nature-based tourism landscapes in boreal forests. In Finland, the rapid growth of nature-based tourism has expanded outdoor recreation activities from protected areas into timber production forests; this is particularly so in northern Finland. This paper focuses on assessing balanced local net impacts of three alternative land-use scenarios, in which the level of integration between nature-based tourism (NBT) and traditional forestry is varied. The study is located in northern Finland in the area between two top-rated tourist resorts, Ylläs and Levi. The results of the case study support the idea of an eligible integration between NBT and forestry, which takes into account scenic qualities of forested landscapes by restricting traditional management practices. In our case, the increased number of tourists (due to a more attractive forest environment) offset the losses accrued in forestry (due to restricted forest management).

Description: This research analyzes the relationships between off-highway vehicle (OHV) riders’ patterns of prior experience and the social-psychological benefits they desire from the activity; it also examines the relationships between patterns of prior experience and environmental attitudes. The sample consists of 600 OHV riders in Utah drawn from the entire population of OHV owners within the state. The sample was segmented into experience use history groups based upon respondents’ number of OHV trips within the past 12 months and the total number of years they have been riding OHVs. Results show that patterns of prior experience are related to certain desired social-psychological benefits. Personal achievement benefits were significantly more important for more frequent riders when compared to those who rode less often. The analysis also reveals no relationship between patterns of prior experience and general environmental attitudes.

Description: The growing interest in US biofuels has been motivated by two primary national policy goals, (1) to reduce carbon emissions and (2) to achieve energy independence. However, the current low cost of fossil fuels is a key barrier to investments in woody biofuel production capacity. The effectiveness of wood derived biofuels must consider not only the feedstock competition with low cost fossil fuels but also the wide range of wood products uses that displace different fossil intensive products. Alternative uses of wood result in substantially different unit processes and carbon impacts over product life cycles. We developed life cycle data for new bioprocessing and feedstock collection models in order to make life cycle comparisons of effectiveness when biofuels displace gasoline and wood products displace fossil intensive building materials. Wood products and biofuels can be joint products from the same forestland. Substantial differences in effectiveness measures are revealed as well as difficulties in valuing tradeoffs between carbon mitigation and energy independence.

Description: Developing adaptation measures in forestry is an urgent task because the forests regenerated today will have to cope with climate conditions that may drastically change during the life of the trees in the stand. This paper presents a comprehensive review of potential adaptation options in forestry in Europe based on three pillars: a review of the scientific literature, an analysis of current national response strategies, and an expert assessment based on a database compiled in the COST Action ECHOES (Expected Climate Change and Options for European Silviculture). The adaptation measures include responses to both risks and opportunities created by climate change and address all stages of forestry operations. Measures targeted to reduce vulnerability to climate change may either aim to reduce forest sensitivity to adverse climate change impacts or increase adaptive capacity to cope with the changing environmental conditions. Adaptation measures mitigating drought and fire risk such as selection of more drought resistant species and genotypes are crucial. For adaptation to be successful it is of the utmost importance to disseminate the knowledge of suitable adaptation measures to all decision makers from the practice to the policy level. The analysis of the ECHOES database demonstrates that this challenge is well recognized in many European countries. Uncertainty about the full extent of climate change impacts and the suitability of adaptation measures creates a need for monitoring and further research. A better understanding of how to increase adaptive capacity is also needed, as well as regional vulnerability assessments which are crucial for targeting planned adaptation measures.

Description: Recently, tree planting has become popular under NAPA. For decades, many tree planting projects were implemented to reduce the vulnerability of ecosystems and societies. Despite all of these, tree-dependent livelihoods remain vulnerable, which leaves doubt on the benefit of tree planting to enhance the resilience of livelihoods to climatic shocks. This suggests that much can be learned from the past to improve future tree planting adaptation projects. This paper draws on the experience of farmers involved in gum arabic agroforestry in Sudan in order to understand the needs of tree-related adaptation projects that should be addressed. Surveyed farmers appreciated the different environmental services rendered by trees. Their priority areas for an adaptation project however, remain issues tied to gum producer price, rainfall pattern, and locust attacks as well as extension services and to a lesser extent access to micro credits. Moreover, Sudan’s Gum Arabic Company (GAC) and Forests National Corporation play key roles in governance but are not yet considered as key adaptation players particularly the unsupportive role of the monopoly of gum exportation by GAC to tree planting as an adaptation activity. By focusing the design and implementation on tree related livelihood obstacles, adaptation projects are likely to be more responsive to the needs of vulnerable groups.

Description: In 2010, thousand cankers disease (TCD) was documented in Tennessee, representing the first confirmation of this disease in the native range of black walnut and the first known incidence of TCD east of Colorado. Tennessee Department of Agriculture personnel conducted surveys to determine the extent of TCD in counties in eastern Tennessee. Samples of symptomatic black walnuts were sent to the University of Tennessee for processing. The causative agents, walnut twig beetle, Pityophthorus juglandis, and the fungal pathogen Geosmithia morbida, were documented on the same trees in four counties. Tree mortality was observed in two counties, and tree decline was observed in at least 10 counties although it may be attributed to previous droughts or to TCD. In 2010, four confirmed counties were quarantined by TDA, and 10 buffer counties were also regulated. Research is underway to further assess the incidence and impact of TCD on black walnut in Tennessee.

Description: In this study we analyzed the effects of silvicultural treatments on carbon (C) budgets in Pinus taeda L. (loblolly pine) plantations in the southeastern United States. We developed a hybrid model that integrated a widely used growth and yield model for loblolly pine with published allometric and biometric equations to simulate in situ C pools. The model used current values of forest product conversion efficiencies and forest product decay rates to calculate ex situ C pools. Using the model to evaluate the effects of silvicultural management systems on C sequestration over a 200 year simulation period, we concluded that site productivity (site quality), which can be altered by silviculture and genetic improvement, was the major factor controlling stand C density. On low productivity sites, average net C stocks were about 35% lower than in stands with the default average site quality; in contrast, on high quality sites, C stocks were about 38% greater than average productivity stands. If woody products were incorporated into the accounting, thinning was C positive because of the larger positive effects on ex situ C storage, rather than smaller reductions on in situ C storage. The use of biological rotation age (18 years) was not suitable for C sequestration, and extended rotation ages were found to increase stand C stock density. Stands with an 18-year-rotation length had 7% lower net C density than stands with a 22-year-rotation length; stands with a 35-year-rotation length had only 4% more C than stands harvested at age 22 years. The C sequestered in woody products was an important pool of C storage, accounting for ~34% of the average net C stock. Changes in decomposition rate, associated with possible environmental changes resulting from global climate change, affected C storage capacity of the forest. When decay rate was reduced to 10% or increased to 20%, the C stock in the dead pool (forest floor and coarse woody debris) was reduced about 11.8 MgC∙ha−1 or increased about 13.3 MgC∙ha−1, respectively, compared to the average decay rate of 15%. The C emissions due to silvicultural and harvest activities were small (~1.6% of the gross C stock) compared to the magnitude of total stand C stock. The C model, based on empirical and biological relationships, appears appropriate for use in regional C stock assessments for loblolly pine plantation ecosystems in the southern U.S.

Description: The use of woody biomass feedstocks for bioenergy and bioproducts involves multiple sources of material that together create year round supplies. The main sources of woody biomass include residues from wood manufacturing industries, low value trees including logging slash in forests that are currently underutilized and dedicated short-rotation woody crops. Conceptually a ton of woody biomass feedstocks can replace a barrel of oil as the wood is processed (refined) through a biorefinery. As oil is refined only part of the barrel is used for liquid fuel, e.g., gasoline, while much of the carbon in oil is refined into higher value chemical products-carbon in woody biomass can be refined into the same value-added products.

Description: Climate change is projected to profoundly influence vegetation patterns and community compositions, either directly through increased species mortality and shifts in species distributions or indirectly through disturbance dynamics such as increased wildfire activity and extent, shifting fire regimes, and pathogenesis. Mountainous landscapes have been shown to be particularly sensitive to climate changes and are likely to experience significant impacts under predicted future climate regimes. Western white pine (Pinus monticola), a five-needle pine species that forms the most diverse of the white pine forest cover types in the western United States, is vulnerable to an interacting suite of threats that includes climate change, fire suppression, white pine blister rust (Cronartium ribicola), and mountain pine beetles (Dendroctonus ponderosae) that have already caused major changes in species distribution and abundance. We used the mechanistic simulation model FireBGCv2 to simulate effects of climate change and fire management on western white pines in a mountainous watershed in Glacier National Park, Montana, USA. Our results suggest that warming temperatures favor increased abundance of western white pine over existing climax and shade tolerant species in the study area, mainly because warmer conditions potentiate fire dynamics, including increased wildfire frequency and extent, which facilitates regeneration. Suppression of wildfires reduced the area dominated by western white pine, but fire suppression was less effective at limiting burned area extent and fire frequency in a warmer and drier climate. Wildfires created canopy gaps that allowed for western white pine regeneration at a high enough rate to escape local extirpation from white pine blister rust. Western white pine appears to be a resilient species even under fairly extreme warming trajectories and shifting fire regimes, and may provide a hedge against vegetation community shifts away from forest types and toward grass and shrublands.

Description: Forests play a key role in the global carbon cycle, and programs aimed at mitigating greenhouse gas emissions through the protection and enhancement of forest carbon stocks are growing in number. Adding greenhouse gas mitigation as a management objective presents managers with a considerable challenge, because data and guidelines are scarce. Long-term inventory datasets have the potential to serve as a useful resource, providing data on carbon accumulation over time, as well as offering insight on strategies for managing forests for the objective of climate mitigation in the face of changing climate and disturbance regimes. We present long-term estimates of carbon accumulation developed from biometric measurements from two northern hardwood forests in the northeastern USA. The Bartlett Experimental Forest in central New Hampshire, USA, stored an estimated net average annual 0.53 tC/ha/yr between 1932–2001, for an increase of 50% in carbon stock per unit area; there were significant differences in accrual rates between age classes (38% for old unmanaged stands and 78% for younger unmanaged stands). The Kane Experimental Forest in northwestern Pennsylvania, USA, exhibited a 140% increase in carbon stored per unit area between 1932 and 2006, with an average annual accumulation rate of 0.89 tC/ha/yr. While both forests have experienced management activity and natural disturbances and differ in species composition, the average age of the forests is an important factor driving the differences in net accumulation rates.

Description: Forests deliver multiple ecosystem services to society. Management of forests must be able to deal with trade-offs when the delivery of different ecosystem services comes in conflict with each other. The research program Future Forests (http://www.futureforests.se) attempts to form a scientific basis for managing such trade-offs between conflicting interests in northern boreal forests. Some key characteristics of the research program are interdisciplinary and participatory research and a clear communication agenda for stakeholders. This paper gives a brief overview of the underlying ideas behind the program, and an introduction to the papers published in this Special Issue.

Description: The physiological principles predicting growth (3-PG) model is generally used to estimate gross primary productivity (GPP) in forest plantations. All existing parameter values in the 3-PG model for GPP estimation have been set as the standard values for eucalyptus and pine plantations. We propose that the 3-PG model can be applied to deciduous broadleaf forests dominated by Betula platyphylla via appropriate parameterization of their structure and functions. The allometric relationships between stem biomass and stem diameter, and between foliage biomass and stem biomass, were determined for the biomass partitioning ratio. Additionally, a temperature modifier was considered appropriate because it affected canopy quantum efficiency. After parameterization, the model showed a good correlation between the estimated results and the data from experimental plots in central and northern Japan. At both sites, GPP peaked around August and was 0 during the winter, when the canopy is bare of leaves. Furthermore, a sensitivity analysis was conducted to determine the most influential parameter relative to the output. GPP was sensitive to changes in canopy quantum efficiency and optimum temperature. Among the meteorological data used, solar radiation and temperature had great impacts on GPP, therefore, these parameters should be carefully considered to produce accurate results.

Description: Uncertainty related to inventory data, growth models and timber price fluctuation was investigated in the assessment of forest property net present value (NPV). The degree of uncertainty associated with inventory data was obtained from previous area-based airborne laser scanning (ALS) inventory studies. The study was performed, applying the Monte Carlo simulation, using stand-level growth and yield projection models and three alternative rates of interest (3, 4 and 5%). Timber price fluctuation was portrayed with geometric mean-reverting (GMR) price models. The analysis was conducted for four alternative forest properties having varying compartment structures: (A) a property having an even development class distribution, (B) sapling stands, (C) young thinning stands, and (D) mature stands. Simulations resulted in predicted yield value (predicted NPV) distributions at both stand and property levels. Our results showed that ALS inventory errors were the most prominent source of uncertainty, leading to a 5.1–7.5% relative deviation of property-level NPV when an interest rate of 3% was applied. Interestingly, ALS inventory led to significant biases at the property level, ranging from 8.9% to 14.1% (3% interest rate). ALS inventory-based bias was the most significant in mature stand properties. Errors related to the growth predictions led to a relative standard deviation in NPV, varying from 1.5% to 4.1%. Growth model-related uncertainty was most significant in sapling stand properties. Timber price fluctuation caused the relative standard deviations ranged from 3.4% to 6.4% (3% interest rate). The combined relative variation caused by inventory errors, growth model errors and timber price fluctuation varied, depending on the property type and applied rates of interest, from 6.4% to 12.6%. By applying the methodology described here, one may take into account the effects of various uncertainty factors in the prediction of forest yield value and to supply the output results with levels of confidence.

Description: Changing and competing land use, where we make use of a growing share of resources, potentially undermines the capacity of forests to provide multiple functions such as timber, biodiversity, recreation and pasture lands. The governance challenge is thus to manage trade-offs between human needs and, at the same time, maintain the capacities of forests to provide us with these needs. Sweden provides a clear example of this kind of challenge. Traditionally, timber has been the most apparent contribution of the forest to Swedish national interests. However, due to competing land use, the identification of the wider role of forests in terms of multifunctionality has been recognized. Today, a number of functions, such as water quality and biodiversity together with cultural and social activities related to forests, are increasingly included as potential demands on forests in competition with traditional functions such as timber production. The challenge is thus related to trade-offs between different functions. How to balance the relationship and guide trade-offs between different functions of forests is, to a large extent, a matter of policy choice and the design of appropriate governance institutions and pro-active management activities. Based on perceptions among stakeholders on future competing demands and a literature review, the paper explore the multifunctionality of the Swedish forests and how it is affected by competing demands for land use; how multifunctionality is currently governed; and concludes by suggesting promising decision support methods to manage trade-offs between different functions.

Description: Land tenure and carbon rights constitute critical issues to take into account in achieving emission reductions, ensuring transparent benefit sharing and determining non-permanence (or non-compliance) liabilities in the context of REDD+ strategies and projects. This is so because tenure systems influence who becomes involved in efforts to avoid deforestation and improve forest management, and that land tenure, carbon rights and liabilities may be linked or divorced with implications for rural development. This paper explores these issues by looking at tenure regimes and carbon rights issues in Mexico, Brazil and Costa Rica. It is effectively shown that complex bundles of rights over forest resources have distinct implications for REDD+ design and implementation, and that REDD+ strategies in selected countries have to date failed in procedurally addressing land-use conflicts and carbon rights entitlements and liabilities.

Description: We investigated the relationship of stem diameter to tree, site and stand characteristics for six major tree species (trembling aspen, white birch, balsam fir, lodgepole pine, black spruce, and white spruce) in Alberta (Canada) with data from Alberta Sustainable Resource Development Permanent Sample Plots. Using non-linear mixed effects modeling techniques, we developed models to estimate diameter at breast height using height, crown and stand attributes. Mixed effects models (with plot as subject) using height, crown area, and basal area of the larger trees explained on average 95% of the variation in diameter at breast height across the six species with a root mean square error of 2.0 cm (13.4% of mean diameter). Fixed effects models (without plot as subject) including the Natural Sub-Region (NSR) information explained on average 90% of the variation in diameter at breast height across the six species with a root mean square error equal to 2.8 cm (17.9% of mean diameter). Selected climate variables provided similar results to models with NSR information. The inclusion of nutrient regime and moisture regime did not significantly improve the predictive ability of these models.