ALBERT

Description: In Nepal, forest management priority is shifting to scientific management from conventional management. Though, the forest officials claims that scientific management is beneficial to the forest user groups, comparative financial assessment with conventional management remains unexplored. Following a case study approach, this study compares financial efficiency of two forest management systems in the community forests, focusing on benefit-cost ratio. The study conducted documents review, focus group discussions, and rapid survey to quantify costs and benefits from each forest management system. Conventional management gave a higher benefit-cost ratio to the forest user groups, irrespective of whether forest products are sold at a subsidized price or par with the market price. However, scientific management required high forest management costs and thus had a lower benefit-cost ratio. Sensitivity analysis between two systems revealed that conventional management gave a higher benefit-cost ratio in all cases. The study concludes that forest user groups would bear financial loss if they do not fix the price of the timber at par with the market in scientific management, and in such a case, the tagged price will be beyond affordability of the forest users. Furthermore, scientific management has discouraged kind contribution of users in managing forest. Besides, social and environmental consequences of scientific management cannot be ignored. Hence, the study argues for reconsidering current scientific management considering likely economic and social consequences to the forest user groups.

Description: Forest biomass is an important ecological indicator for the sustainable management of forests. The aim of this study was to estimate forest aboveground biomass (AGB) by integrating SPOT-6 data with field-based measurements using the random forest (RF) algorithm. In total, 52 remote sensing variables, including spectral bands, vegetation indices, topography data, and textures, were extracted from SPOT-6 images to predict the forest AGB of Xuan Lien Nature Reserve, Vietnam. To determine the optimal predictor variables for AGB estimation, 10 different RF models were built. To evaluate these models, 10-fold cross-validation was applied. We found that a combination of spectral and vegetation indices and topography variables offer the highest prediction results (Radj2  = 0.74 and RMSE = 61.24 Mg ha−1). Adding texture features into the predictor variables did not improve the model performance. In addition, the SPOT-6 sensor has the potential to predict forest AGB using the RF algorithm.

Description: Agroecology was born as a competing theory to sciences derived from the Green Revolution like conventional agronomy or modernized animal husbandry. In recent years, several theoretical models or approaches have been developed in order to explain this science. However, any of them can explain its change or difference with its rival theories in a rational manner that allows assessment of its success. As a result, the aim of this study was to propose a rational model of scientific change based on main and auxiliary hypotheses. We found that seven basic principles have been formulated throughout theoretical books and papers as well as several auxiliary hypotheses that can be derived from them. These principles are as follows: (1) characteristic systemic principle of agroecology, (2) principle of biomimicry, (3) principle of biodiversity, (4) principle of specificity of agroecosystems, (5) principle of governance, (6) principle of socioecological resilience, and (7) principle of vulnerability. Also, three principles for food systems approach were retrieved. This model shows agroecology more like an organic theory that moves in different scales than a set of rival theories competing for success. However, a proper articulation and discussion of these basic principles is yet to be done.

Description: Background and Aims. An excessive and prolonged use of fertilizers undermines soils’ quality and, consequently, that of the crops they support, thus reducing the content of organic matter and generating environmental damages and problems to human health. Therefore, the use of biofertilizers such as cyanobacteria becomes a promising alternative. However, it is not always possible to generalize these fertilizers’ applicability, because microorganisms may be impacted by the physical and chemical variations of their environment. We will describe the action mechanisms or the characteristics of cyanobacteria involved in plant growth promotion for different crops in situ through a systematic review of scientific literature. Methods. A comprehensive search for original articles in two different databases, ScienceDirect and Scopus, was performed. We included in our search documents published from 2009 to 2018. After the screening process and the addition of gray literature publications, we obtained 23 articles for theoretical analysis. Results. The studies were distributed mainly in Asia and part of Africa, without any important temporal variation. They also showed a tendency to describe the use of cyanobacteria genera such as Anabaena sp., Nostoc sp., and Calothrix sp., besides mechanisms as N2 fixation, phosphate solubilization, phytohormone production, bioactive compounds excretion, and symbiotic associations, mainly on rice, wheat and corn crops. Conclusions. Cyanobacteria fertilizers used in situ are a widespread strategy, mainly in cereal crops. Their use is predominant in countries where cereal crops make an important contribution to their national economy. The great variety of mechanisms and characteristics of cyanobacteria used to promote plant growth in the field demonstrate the dramatic influence that physical, chemical, and biological variables have in their development.

Description: Empirical evidence shows complementarity between maize and soybean as a sustained agricultural system across North and South America as well as Eastern Europe. The potential application to sub-Saharan Africa motivates this literature review. Maize is one of the most important crops on the African subcontinent, accounting for over half of daily caloric intake in some regions. However, continuous cropping of maize has led to extensive degradation of soil and decrease in crop productivity and endangers household food and nutritional security. The cultivation of soybean holds great promise in improving agricultural systems in sub-Saharan Africa. Introducing soy into rotation with maize is a method to diversify diets, better nutritional status, reduce abiotic and biotic stresses, and improve soil fertility, while enhancing crop productivity and generating more income for farmers. However, limited access to extension services and other sources of technical support constrains adoption of the more complex rotation cropping system involving a new crop, soybean. Rotating soybean with maize too challenges farmers as there is not a specific prescription that can guide farmers operating across Africa’s diverse agroecological environments. Finally, soybean is an input-intensive crop requiring significant investment at planting, which may not allow small holders with limited resources and no access to credit.

Description: The extract of Nicotiana tabacum L. var Virginia origin of Ponorogo (EHRE-Nt) was applied under field conditions against the coffee borer beetle Hypothenemus hampei (CBB). Three extract formulations containing 150, 300, and 450 ml of EHRE-Nt in 100 liters of water were prepared and sprayed on 0.5 hectares each. A nontreatment was applied as a control on 0.5 hectares of plantation. The intensity of the CBB attacks was observed for six weeks on a Robusta coffee plantation in the Kalibening area, South Semarang, Central Java, Indonesia. An extract formulation containing 450 ml of EHRE-Nt resulted in the lowest intensity of CBB attacks from weeks one to six (1.6% to 2.2%). The attacks of the control field were 11.3% to 13.5%. The highest efficacy level of 85.4% was obtained with the 450 ml EHRE-Nt formulation. These results demonstrate that EHRE-Nt has potential as a bioinsecticide for coffee berries from CBB attacks.

Description: An experiment was conducted to examine the performance of pearl millet under different nitrogen (N) fertilizer rates in two locations in the semiarid zone of Nigeria. The objective was to evaluate the effects of different N rates on pearl millet yields, water- and nitrogen-use efficiency, and profitability. Grain yield increased by 23, 26, 32, 32, and 27% and by 38, 41, 54, 58, and 56% compared to unfertilized plots when applying 20, 40, 60, 80, and 100 kg Nha−1 in Minjibir and Gambawa, respectively. Similarly, stalk yield increased by 4, 3, 9, 9, and 9% and by 16, 24, 36, 40, and 37% compared to unfertilized plot when applying 20, 40, 60, 80, and 100 kg Nha−1 in Minjibir and Gambawa, respectively. The variations in GY that could be explained by TWU and NUE were 28% and 26% in Minjibir and 46% and 41%, respectively, in Gambawa. There was a strong and positive correlation (R = 0.81 and R = 0.95) between WUE and GY across N-fertilizer rates and pearl millet varieties in both locations. An increase in N-fertilizer levels increased WUE, confirming the optimal application of 60 kg Nha−1 in Minjibir and of 80 kg Nha−1 in Gambawa. Similarly, the highest net economic return (NER) of US$610 ha−1 was obtained at 60 kg Nha−1 in Minjibir and the highest NER of US$223 ha−1 was obtained at an application rate of 80 kg Nha−1 in Gambawa. Break-even yield was above 1000 kg ha−1, signifying that average farmer with a mean yield of less than 1000 kg ha−1 produces millet at a loss.

Description: Forestry related projects fail due to the lack of participation by the community during the initiation stage. This further leads to unsustainable management of forests. This study was undertaken to examine how participatory project initiation influences sustainable forest management in Saboti forest in Trans-Nzoia County, Kenya. Participatory Development Theory guided this study. The explanatory research design was adopted. The target population was 2600 community forest association (CFA) members and 15 Kenya Forest Officers. Census sampling was used in the sampling of Kenya forest Officers and simple random sampling to select community forest management members. The sample size was 347 community forest management members and 15 Kenya forest Officers. Data were collected using questionnaires and through interview. Data were analyzed using descriptive and inferential statistics. Presentation of findings was carried out using tables. There was a significant influence of participatory project initiation on sustainable forest management (SFM) (r = 0.700, p=0.00). This implies that an increase in participatory project initiation improved sustainable forest management in Saboti. Participatory project initiation had a significant influence on sustainable forest management. The community participation in initiation had a significant influence on sustainable forest management. There is need for forest management to involve the community members during the initiation stage of the projects in order to achieve sustainable forest management.

Description: Tomato production is constrained by fungal diseases especially the early and late blight caused by Alternaria solani and Phytophthora infestans, respectively. Control of the two diseases is usually by use of synthetic fungicides which have a long residue effect and also contribute to environmental pollution. Innovative use of biocontrols may offer an eco-friendly and more sustainable solution. This study tested the in vitro efficacy of crude extracts and essential oils of ginger, garlic, tick berry, and Mexican marigold in inhibition of radial growth of A. solani and P. infestans. Extraction of the crude extracts was done using distilled water, ethanol, and methanol solvents, while essential oils were extracted using the dry steam distillation method. The extracts and essential oils were used to amend the growth media of the test pathogens before introducing the precultured pathogens. Sterile distilled water and synthetic fungicide, Ridomil Gold®, were used as positive and negative controls, respectively. Fungal growth inhibition was determined by measuring the radial growth of the test pathogens. Both the crude extracts and the essential oils portrayed some efficacy against the test pathogens. Garlic crude extracts were found to be the most effective, while ethanol was the most suitable extraction solvent. Essential oils were more effective in restricting the pathogen growth than crude extracts. Ginger and garlic oil was found to be as effective as the synthetic fungicide, and thus it was concluded that the two plants have strong antifungal properties with high potential of being utilized as biofungicides. However, effective utilization of these products in farmers’ fields may require industrial formulation to improve their efficiency.

Description: Passion fruit (Passiflora edulis (Sims)) is currently ranked third among fruit exports from Kenya and has great potential since the demand for both fresh fruit and processed juice is on a continuous increase. Passion fruit production in Kenya is constrained by a lack of healthy, clean planting material, poor seed viability, and low germination rates. To address this, the present study reports an in vitro plant regeneration protocol for passion fruit using leaf disc and nodal explants and genetic fidelity analysis of the regenerated plants. The highest number of shoot regeneration was obtained on Murashige and Skoog (MS) medium supplemented with 2 mg·L−1 6-Benzyl amino purine (BAP) (shoot induction medium). The multiplication of shoots was optimum in MS medium supplemented with 3 mg·L−1 BAP. To eliminate the requirement of an additional step of in vitro rooting, exogenous application of putrescine induced the formation and development of roots on nodal explants. Genetic fidelity analysis of the in vitro regenerated and macropropagated plants with that of the mother plant was carried out by sequence-related amplified polymorphism (SRAP) markers, and monomorphic banding profile for 80% of the regenerants confirmed the genetic uniformity of the in vitro regenerated and macropropagated plants. The in vitro regeneration system developed can be utilized for mass clonal propagation for the economic commercial exploitation of this important tropical fruit.

Description: Agricultural soils in the tropics have undergone significant declines in their native carbon stock through the long-term use of extractive farming practices. However, these soils have significant capacity to sequester CO2 through the implementation of improved land management practices. This paper reviews the published and grey literature related to the influence of improved land management practices on soil carbon stock in the tropics. The review suggests that the implementation of improved land management practices such as crop rotation, no-till, cover crops, mulches, compost, or manure can be effective in enhancing soil organic carbon pool and agricultural productivity in the tropics. The benefits of such amendments were, however, often short-lived, and the added organic matters were usually mineralized to CO2 within a few cropping seasons leading to large-scale leakage. We found that management of black carbon (C), increasingly referred to as biochar, may overcome some of those limitations and provide an additional soil management option. Under present circumstances, recommended crop and land management practices are inappropriate for the vast majority of resource constrained smallholder farmers and farming systems. We argue that expanding the use of biochar in agricultural lands would be important for sequestering atmospheric CO2 and mitigating climate change, while implementing the recommended crop and land management practices in selected areas where the smallholder farmers are not resource constrained.

Description: Pine wood and barley straw biochar amendments to Kettering and Cameroon sandy silt loam soils (15, 30, or 150 mg biochar g−1 soil) caused significant reductions (up to 80%, ) in concentrations of substrate and extractable product in soil dehydrogenase and phosphomonoesterase enzyme assays. Likely this was caused by increased solid-phase sorption of the chemicals in the presence of the biochars under assay conditions. The relationship between assay chemical sorption and biochar concentration depended on the chemical, soil type, biochar type, and their interactions; hence, no uniform correction factor could be derived. This biochar impact on assay constituents will limit the identification of genuine biochar effects on soil enzymes. It is recommended that the assumption of saturating substrate concentrations be checked and that product standards be matrix-matched when conducting enzyme assays with biochar-amended soil.

Description: Total petroleum hydrocarbon (TPH) concentrations and their fractional composition (medium fraction: n-alkane chain-length C15 to C27, heavy fraction: 〉C27) were determined at distances from 1 to 60 m from roads and at soil depths from 0.5 to 15 cm. The traffic intensities were up to 25000 vehicles per day. Soil TPH concentrations were highest within 15 m distance (665 and 3198 mg kg−1 at the windward and leeward sides, resp.), followed by a rapid drop to background values beyond (196 and 115 mg kg−1 in 60 m distance at the windward and leeward sides, resp.). The data variability was lowest at distances of 1 m and highest within tree plantations at distances of 15 m from the road. The TPH concentrations decreased with depth but were significantly higher than the background at all depths investigated. A principal component analysis revealed a positive relation between the medium-to-heavy fraction ratio and soil depth. A fractional differentiation of hydrocarbons with distance from road was not observed. It was concluded that the assessment of the potential of hydrocarbons to translocate, accumulate, or degrade in soil necessitates their subdivision into fractions based on their physicochemical and metabolic properties.

Description: This study was designed to evaluate the effects of temperature on the potential leachable P pool and distribution of chemical P forms in a biosolids-amended soil. A P-deficient Spodosol was incubated with seven biosolids and inorganic P fertilizer at 20 and 32°C for 90 days. Amendments were applied to provide a total P concentration of 112 mg kg−1 soil, which correspond to a field application of ~224 kg P ha−1. Cumulative P mass leached during the 90 d study for any P source was

Description: Transfer of Pb and As into vegetables grown on orchard soils historically contaminated by Pb arsenate pesticides was measured in the greenhouse. Lettuce, carrots, green beans, and tomatoes were grown on soils containing a range of total Pb (16.5–915 mg/kg) and As (6.9–211 mg/kg) concentrations. The vegetables were acid-digested and analyzed for total Pb and As using ICP-mass spectrometry. Vegetable contamination was dependent on soil total Pb and As concentrations, pH, and vegetable species. Arsenic concentrations were the highest in lettuce and green beans, lower in carrots, and much lower in tomato fruit. Transfer of Pb into lettuce and beans was generally lower than that of As, and Pb and As were strongly excluded from tomato fruit. Soil metal concentrations as high as 400 mg/kg Pb and 100 mg/kg As produced vegetables with concentrations of Pb and As below the limits of international health standards.

Description: I analyze the effect of post-fire burnt wood management on herbivore attack on a woody plant species (Ulex parviflorus). Two experimental plots of ca. 20 hectares were established at two elevations in a burnt area in a Mediterranean mountain (Sierra Nevada, Spain). Three replicates of three treatments differing in post-fire burnt wood management were established per plot: “no intervention” (NI, all trees remained standing), “partial cut plus lopping” (PCL, felling the trees, cutting the main branches, and leaving all the biomass in situ), and “salvage logging” (SL; removal of logs and elimination of woody debris). Risk of herbivory and damage intensity were monitored for two years. The pattern of attack by ungulate herbivores varied among treatments and years. In any case, there was an overall reduction in the risk of herbivory in the PCL treatment, presumably because the highest habitat complexity in this treatment hampered ungulate movement and foraging. As a result, the burnt logs and branches spread over the ground acted as a physical barrier that protected seedlings from herbivores. This protection may be used for the regeneration of shrubs and trees, and it is of interest for the regeneration of burnt sites either naturally or by reforestation.

Description: Peanut (Arachis hypogaea L.) has the potential to become a major source of biodiesel, but for market viability, peanut oil yields must increase. Oil yield in peanut is influenced by many different components, including oil concentration, seed mass, and mean oil produced per seed. All of these traits can potentially be improved through selection as long as there is sufficient genetic variation. To assess the variation for these traits, a diallel mating design was used to estimate general combining ability, specific combining ability, and heritability. General combining ability estimates were significant for oil concentration, weight of 50 sound mature kernels (50 SMK), and mean milligrams oil produced per SMK (OPS). Specific combining ability was significant for oil concentration. Reciprocal effects were detected for OPS. Narrow-sense heritability estimates were very high for oil concentration and 50 SMK and low for OPS. The low OPS heritability estimate was caused by the negative correlation between oil concentration and seed size. Consequently, oil concentration and seed mass alone can be improved through early generation selection, but large segregating populations from high oil crosses will be needed to identify progeny with elevated oil concentrations that maintain acceptable seed sizes.

Description: In this study, a total of ten essential elements for plants growth in the Guinea savanna region of Niger State in Northern Nigeria have been identified in the soils using instrumental neutron activation analysis. The experimental results show good agreement with certified or literature values within the agreed percentage range of ±2.35% to ±8.69%. However, the concentration distributions of the ten identified elements in the soil samples within the studied area for plants growth revealed the following: Fe (123.4 ppm), Mn (2100.7 ppm), K (5544.3 ppm), Al (54752.4 ppm), Ti (3082.9 ppm), Ca (4635 ppm), V (54.3 ppm), Na (857.5 ppm), Mg (13924.1 ppm), and Dy (12.1 ppm). A further analysis of the two fundamental soil physical parameters for healthy growth of some common crops like egusimelon, groundnut, rice, yams, soybeans, cassava, and potato analyzed in this work revealed a pH range of 4.0 pH–8.0 pH and a temperature range of 28.0°C to 29.3°C, which are optimal for plant nutrients availability in the soils within the study area.

Description: This paper seeks to analyze the dynamical structure of the Indian stock market by considering two major Indian stock market indices, namely, BSE Sensex and CNX Nifty. The recurrence quantification analysis (RQA) is applied on the daily closing data of the two series during the period from January 2, 2002, to October 10, 2013. A Rolling Window of 100 and step size 21 are applied in order to see how both the series behave over time. The analysis based on three RQA measures, namely, % determinism (DET), laminarity (LAM), and trapping time (TT), provides conclusive evidence that the Indian equity market is chaotic in nature. Evidences for phase transition in the Indian equity market around the time of financial crisis are also found.

Description: A study was conducted on the impact of forest clearance on discharge from newly established Hopea odorata plantations catchment (14.4 ha). The stands were two years old when this study commenced in year 2006 and the data collection was carried out for two years. The forested catchment (C3) was clear-cut during the preparation of the forest plantation and catchment C1 was left undisturbed. Discharge and rainfall were measured continuously for two years. The discharge measured from years 1997 to 2003 was used also to determine the water yield before and after forest clear-cut. This study showed that the plantation catchment is more responsive to storm with higher total water yield than in the forested catchment. The effect of forest clear cutting to discharge was clearly shown by the increment in the amount following the clear-cut activities and time taken for the recovery of the discharge back to its original state was almost three years. The peak discharge in C3 also was affected in which the biggest change was obtained during the forest clear-cutting period compared with during calibration and after clearing periods. This study is useful as basis for improving the existing guidelines on forest plantation establishment.

Description: Broadcast fertilization with an array of amendments was investigated for its capacity to stimulate growth and enhance nutrition of a three-year-old Jeffrey pine (Pinus jeffreyi Grev. & Balf.) plantation growing on an acidic Sierra Nevada surface mine. Four formulations that differed in N source, duration of release, and the suite of nutrients provided were evaluated, with each applied using four rates. Free Flow 29-3-4, a conventional amendment featuring urea as its near exclusive N source, and High N 22-4-6, a controlled release formulation containing ammoniacal, nitrate, and urea N, were the most stimulatory while an organic formulation relying exclusively on a municipal biosolid N source, Milorganite 6-2-0, was the least so. The lowest application rates employed were inadequate while the most advantageous was not the highest rate for any formulation. Foliar analysis revealed that improved N nutrition was probably critical in the favorable growth responses to fertilization, that of P was a likely contributor, and amelioration of potential Mn toxicity may have assumed an accessory role.

Description: Integrated crop-livestock systems have been purported to have significant agronomic and environmental benefits compared to specialized, single-enterprise production systems. However, concerns exist regarding the effect of livestock in integrated systems to cause soil compaction, thereby decreasing infiltration of water into soil. Such concerns are compounded by projections of more frequent high-intensity rainfall events from anticipated climate change, which would act to increase surface runoff and soil erosion. A study was conducted to evaluate the effects of residue management, frequency of hoof traffic, season, and production system (e.g., integrated annual cropping versus perennial grass) on infiltration rates from 2001 through 2008 in central North Dakota, USA. Imposed treatments had no effect on infiltration rate at three, six, and nine years after study establishment, implying that agricultural producers should not be concerned with inhibited infiltration in integrated annual cropping systems, where winter grazing is used. The use of no-till management, coupled with annual freeze/thaw and wet/dry cycles, likely conferred an inherent resistance to change in near-surface soil properties affecting soil hydrological attributes. Accordingly, caution should be exercised in applying these results to other regions or management systems.

Description: To determine genotoxicity to coelomocytes, Pheretima peguana earthworms were exposed in filter paper studies to cadmium (Cd) and lead (Pb) for 48 h, at concentrations less than the LC10—Cd: 0.09, 0.19, 0.38, 0.75, and 1.50 μg cm−2; Pb: 1.65, 3.29, 6.58, 13.16, and 26.32 μg cm−2. For Cd at 0.75 μg cm−2, in the micronucleus test (detects chromosomal aberrations), significant increases (P<.05) in micronuclei and binucleate cells were observed, and in the comet assay (detects DNA single-strand breaks), tail DNA% was significantly increased. Lead was less toxic with minimal effects on DNA, but the binucleates were significantly increased by Pb at 3.29 μg cm−2. This study shows that Cd is more acutely toxic and sublethally genotoxic than Pb to P. peguana. Cadmium caused chromosomal aberrations and DNA single-strand breaks at 45% of the LC10 concentration. Lead, in contrast, did not induce DNA damage but caused cytokinesis defects.

Description: Selected farmlands in southern Baja California, Mexico, were surveyed to determine the levels and the causes of salinization/sodication in irrigated agricultural soil. The salt dynamics observed in profiles differed from farm to farm. Low EC and high pH levels were observed in the profiles of sandy fields, because the salt composition of these soils can easily change when salts are leached by irrigation water that contains carbonates of sodium. On the other hand, high levels of salinity and sodicity were observed in the soils of clayey fields. Soil salinization/sodication is complexly interrelated with soil characteristics, the amount and composition of salts in the soil, the quantity and quality of irrigation water applied, and the irrigation methods used. Our findings indicate that irrigation water in Baja California should be supplied at a rate that is sufficient to meet crop requirements without exacerbating salt accumulation.

Description: Concentrations of Cu, Cr, and As in soils surrounding 26 Douglas Fir Chromated Copper Arsenate (CCA) treated utility poles and in rainwater runoff from a new CCA treated utility pole segment (log) suspended outside in a cylinder were studied. The age of the utility poles, distances from the poles, rainfall amounts, and characteristics of soil samples including cation exchange capacity (CEC), pH, and total organic carbon (TOC) were considered. Heavier rainfall, damp conditions, and more weathered poles contributed to the greatest leaching of Cu, Cr, and As. The maximum measured soil concentrations of Cu, Cr, and As were 37.5, 65.5, and 38.9 mmol/kg and maximum Cu, Cr, and As concentrations in rainwater run-off were 14, 77.7 and 55.8 μmol/L. Metal concentrations decreased with distance from the poles and, except at one utility pole location, Cu was the most leached of the three elements. The As appeared to have greater mobility in the soil than the Cr. Along the transmission line nearest the coast and from which the greatest amount of samples was collected, soil CEC and TOC values were the highest and the CEC and TOC were directly and strongly correlated.

Description: The physical structure of a habitat (e.g., fragmentation) may affect the distribution of genetic diversity within a population, and genetic diversity may alter ecological function. This study investigates the population genetics of Humboldt Bay, California, eelgrass in light of the habitat’s fragmented physical structure. Historical and ongoing dredging operations in the bay maintain channels between fragmented tidal mudflats that are inhabited by eelgrass. A sample of 469 individuals, from 11 discrete fragments, was genotyped using microsatellite analysis. Ramets were collected at multiple points located at the edge and in the interior of each fragment. The sampling scheme was designed to detect evidence of population structure within and between fragments, as well as between edge and interior bed positions. Genetic diversity is not shown to differ among fragments and is not consistent with widespread clonality. Heterozygosity levels indicate that Hardy-Weinberg equilibrium predominates across loci in most instances. Comparisons of edge and interior bed positions also reveal similarities between positions for the metrics described above. Results suggest efficient gene flow between fragments and between bed positions. Such findings, which indicate the unstructured nature of the population, can guide resource managers in making evolutionarily informed conservation decisions by discouraging assumptions of low genetic diversity and insignificant sexual reproduction.

Description: Reduction in area of the southeastern temperate grasslands of Australia since European settlement has been accompanied by degradation of remaining remnants by various factors, including the replacement of native plant species by introduced ones. There are suggestions that these replacements have had deleterious effects on the invertebrate grassland community, but there is little evidence to support these suggestions. In the eastern Adelaide Hills of South Australia, four grassland invertebrate sampling areas, in close proximity, were chosen to be as similar as possible except for the visible amount of native grass they contained. Sample areas were surveyed in four periods (summer, winter, spring, and a repeat summer) using pitfall traps and sweep-netting. A vegetation cover survey was conducted in spring. Morphospecies richness and Fisher’s alpha were compared and showed significant differences between sample areas, mainly in the summer periods. Regression analyses between morphospecies richness and various features of the groundcover/surface showed a strong positive and logical association between native grass cover and morphospecies richness. Two other associations with richness were less strong and lacked a logical explanation. If the suggested direct effect of native grass cover on invertebrate diversity is true, it has serious implications for the conservation of invertebrate biodiversity.

Description: Existing theory for invasive nonnative species emphasizes the role of escaping specialist enemies. A useful approach is to reciprocally transplant enemies in a controlled and common experiment to quantify the interaction specificity of enemies from plant's native and nonnative ranges. Quantitative measures of interaction specificity, from two experiments with three host genotypes (Belgium, Louisiana, and Pennsylvania) and 37 Pythium isolates (10 Europe and 27 USA), revealed that Pythium pathogens from populations of Prunus serotina in its native range were not host genotype specific while Pythium pathogens from its nonnative range vary with host genotype. This study provides empirical evidence suggesting that Pythium from the nonnative range are either preadapted to or are actively adapting to this host. Although only for a single pathosystem, this study illustrates the importance of understanding enemy impact and host-specificity to assess whether an invader has escaped its natural enemies.

Description: Eucalyptus species have been planted in Angola since the early twentieth century. The species introduction experiment of Tchianga, in the Angolan Highlands, was established in 1966/1967. The experiment included several tropical pines and eucalypts. The plots were 43 years old when measured in 2009. Species included Eucalyptus saligna Sm., E. camaldulensis Dehnh., E. macarthurii H. Deane & Maiden, E. resinifera Sm., E. siderophloia Benth., and E. grandis Hill ex. Maiden. E. saligna had the highest stand volume at 43 years (1427 m3 ha−1), followed by E. grandis (1006 m3 ha−1). E. macarthurii and E. camaldulensis had the lowest stand volume (423 and 511 m3 ha−1, resp.). Using X-ray analyses of increment cores, it was possible to study the temporal development of the stand characteristics. An analysis of the mean annual increment showed that the optimal rotation length for most of the studied eucalypts is around 22 years with the exception of E. resinifera, for which 12–15 years is the best. E. saligna had the highest maximum mean annual increment (MMAI) of 37 m3 ha−1 attained at 22 years of age. E. grandis reached its MMAI of 25 m3 ha−1 at 28 years. The results suggest that E. saligna is the most recommended Eucalyptus species for new plantations in Angola.

Description: Allophane and imogolite neogenesis in soils may occur in the presence of organic matter. To understand this process under conditions relevant to soils, the influence of dissolved organic carbon (DOC) as humic acid (HA), on aluminosilicate formation was studied at 25C∘, pH 6, and low-DOC concentrations. For solutions with initial Al/Si ratios of 1–2.1, and 0–6 mg/L DOC, precipitates recovered after 20 h had Al/Si ratios of 2.2–2.7. The formation of allophane, imogolite-like material, and aluminosilicate gel was confirmed by XRD, FTIR, and NMR. The effect of DOC was to produce a small, but systematic increase in imogolite-like Si in the precipitate, and a decrease in the formation of aluminosilicate gel. Results suggest that the presence of DOC as HA slows the otherwise rapid polymerization of Al and Si at low temperature, and may also promote the formation of imogolite. The high C content of these precipitates indicates that this process may facilitate the sequestration of organic matter, slowing C cycling in soils.

Description: We investigated the effects of landscape features and forest structure on the avian community at the Reserva Florestal Adolpho Ducke near Manaus, in the Brazilian Amazon. We sampled the landscape and forest in 72 50 × 50 m plots systematically distributed in the reserve, covering an area of 6,400 ha. The avifauna was sampled using mist nets and acoustic surveys near the plots. We found no significant relationships between landscape features and forest components in the plots and the number of bird species and individuals sampled. Results of Principal Coordinate Analyses, however, showed that bird species composition changes along a topographic gradient (plateau-slope-valley), and also in relation to leaf litter depth and distance to forest streams. We also found compositional differences in the avian community on the eastern and western water basins that compose the reserve. Our results suggest that although most bird species occur throughout the reserve, many species track differences in the landscape and the forest structure.

Description: Agricultural drainage ditches can deliver high loads of phosphorus (P) to surface water. Installation of filter structures containing P sorbing materials (PSMs), including gypsum, is an emerging practice that has shown promise to reduce these P loads. The objective of this study was to evaluate what effect soil amendment with gypsum would have on soil P concentrations and forms in a laboratory incubation experiment. Gypsum was saturated at two levels with P, and applied to a silt loam and a sandy loam at two rates. The treated soils were incubated in the laboratory at 25°C, and samples were collected on eight dates between 0 and 183 days after amendment. Spent gypsum application did not significantly increase soil water-extractable or Mehlich 3 P when applied at typical agronomic rates. This appears to be a viable strategy to remove P from agricultural drainage waters but does not appear to provide any additional P fertilizer value.

Description: Development-perched watertables and subsurface lateral flows in texture-contrast soils (duplex) are commonly believed to occur as a consequence of the hydraulic discontinuity between the A and B soil horizons. However, in catchments containing shallow bedrock, subsurface lateral flows result from a combination of preferential flow from the soil surface to the soil—bedrock interface, undulations in the bedrock topography, lateral flow through macropore networks at the soil—bedrock interface, and the influence of antecedent soil moisture on macropore connectivity. Review of literature indicates that some of these processes may also be involved in the development of subsurface lateral flow in texture contrast soils. However, the extent to which these mechanisms can be applied to texture contrast soils requires further field studies. Improved process understanding is required for modelling subsurface lateral flows in order to improve the management of waterlogging, drainage, salinity, and offsite agrochemicals movement.

Description: We studied the ecological niche relations of native stream fish and an alien invader, brook trout (Salvelinus fontinalis), to examine if brook trout had located an underused environmental niche in our boreal study system. In both study years (1994 versus 2004), we found brook trout to have the most marginal niche position of all the fish species examined. The most important environmental variable affecting the distribution of brook trout was pH, with acid headwater sites being dominated by this species. Brown trout, in contrast, had relatively nonmarginal niche, occurring in average conditions across the sampled sites. Other fish species had niche positions between the two salmonids. Our results show that fish invasions may be strongly facilitated by the presence of suboptimally occupied environmental niche space in the recipient river system.

Description: Habitat has become one of the fundamentals for managing the environment. We report on synthesis of 30 habitat models for fish species that inhabit large streams and small rivers. Our protocol for integration of many species-level habitat models was to form a robust, general model that reflected the most common characteristics of the reviewed models. Eleven habitat variables were most commonly used in habitat models, and they were grouped by water quality, reproduction, and food and cover. The developed relations defined acceptable and optimal conditions for each habitat variable. Water quality variables were mid-summer water temperature, dissolved oxygen, pH, and turbidity. Other structural habitat variables were identified: riffle and pool velocity, riffle depth, and percent of the stream area with cover and pools. We conclude that it is feasible to consolidate species-level habitat models for fish that inhabit the same waterway type. Given the similarity among species models, our specification set will closely approximate the needs and optimal conditions of many species. These eleven variables can serve as design specifications for rehabilitating streams and small rivers in human dominated settings.

Description: This study evaluated the influence of planting sites on the establishment and ectomycorrhizal (ECM) colonization of American chestnut (Castanea denetata (Marsh.) Borkh.) on an abandoned coal mine in an Appalachian region of the United States. Root morphotyping and sequencing of the fungal internal transcribed spacer (ITS) region were used to identify the ECM species associated with the chestnut seedlings. Germination, survival, ECM root colonization, and growth were assessed in three habitats: forest edge, center (plots without vegetation), and pine plots (a 10-year-old planting of Pinus virginiana). Seedlings in pine plots had higher survival (38%) than the other plot types (center 9% and forest edge 5%;

Description: Nonnative plants threaten native biodiversity in landscapes where habitats are fragmented. Unfortunately, in developed areas, much of the remaining forested habitat occurs in fragmented riparian corridors. Because forested corridors of sufficient width may allow forest interior specializing native species to retain competitive advantage over edge specialist and generalist nonnative plants, identifying appropriate corridor widths to minimize nonnative plants and maximize ecosystem integrity is of habitat management concern. We measured the occurrences of 4 species of nonnative plants across the widths of 31 forested riparian corridors of varying widths in the White Clay Creek watershed of Pennsylvania and Delaware. Using repeated measures ANOVA, Japanese honeysuckle (Lonicera japonica) and multiflora rose (Rosa multiflora) prevalence did not significantly decline across buffer widths. However, garlic mustard (Alliaria petiolata) and oriental bittersweet (Celastrus orbiculatus) declined strongly within the first 15–25 m. Managing for riparian corridor widths a minimum of 15–25 m has the potential to enhance habitat quality but no corridor width (≤55 m) will exclude all invasive plants.

Description: We investigated predation rates of black grouse chicks during 1985–2007 in two localities in western Finland in light of three predation hypothesis: The Alternative Prey Hypothesis (APH) stating that vole-eating generalist predators cause a collapse in grouse reproduction after voles’ decline, the Main Prey Hypothesis (MPH), where grouse specialised predators by a lagged response cause an inversely density dependent predation for prey and the Predation Facilitation Hypothesis (PFH), where generalist and specialist predators act in concert. We also studied the effect of weather on grouse reproduction. We found that buzzard predation alone did not support APH, but did so when combined with goshawk predation. Kill rate by goshawks showed a linear response for black grouse chicks but was not density dependent. It, however, explained the losses of chicks but not their autumn density. Combined density of chicks with adults correlated with vole index in the latter study period (since 1994), thus, giving some support for APH. Weather seemed to have no effect on black grouse reproduction. Although buzzards and goshawks took, on average, only 10% of hatched grouse chicks we conclude that the among-year survival pattern of juvenile forest grouse may largely be determined by raptor predation.

Description: Seminatural grasslands are maintained by regular anthropogenic disturbance, usually grazing or mowing. Management action late in the growing season was historically more common than today. Two experimental grazing regimes, continuous stocking from May to September and late-onset grazing from mid-July, were compared in two Swedish grasslands. Effects on flowering and fruit production were studied and related to plant functional traits. Change in vegetation composition over six years was analysed in one grassland. Delayed onset of grazing enhanced fruit production up to four times. Phenology of reproduction was the most important plant trait explaining differences in reproduction among species. Diversity of vascular plant species was higher after six years of late-onset grazing. No differences in vegetation height or proportion of grazed shoots were found by the end of the season. The results suggest that early reproduction may function as an escape from damage and that late onset of grazing may be used as a substitute for labour-intense traditional mowing.

Description: Harpalus rufipes, a member of the Carabidae, is the most common granivorous invertebrate in Maine agroecosystems. While previous research demonstrated a positive correlation between H. rufipes activity-density and weed seed predation, little is known about the behaviour of this seed predator. We conducted mesocosm experiments to examine seed burial, soil surface conditions, and seed mass effects while tracking H. rufipes movement using a video camera, capture card, and EthoVision software. H. rufipes showed a preference (

Description: We present a geographic information system (GIS) framework to classify stream habitats and provide fish distribution predictions comprehensively at the landscape scale. Stream segments were classified into one of eighteen habitat types using three landscape attributes: stream size (three categories), stream quality (three categories), and water quality (two categories). An extensive literature search was undertaken to classify fish species into the same eighteen habitat types based on preferences for the three landscape attributes. We tested our framework in 39 sites throughout the upper Allegheny River basin in western New York. No difference was detected between observed and predicted numbers of fish species among stream habitats. Further, field collected bankfull width measurements, stream quality ratings, and water quality sampling results were largely consistent with predicted values. The habitat type expected to have the greatest fish species richness was large streams or small rivers with intact stream quality and suitable water quality. Our framework is rapidly applied, comprehensive, inexpensive, and built on widely available data thereby offering an efficient alternative to traditional field-based efforts for regional habitat classification and fish distribution prediction.

Description: The study site is currently retreating at a rate of 20 m y−1 due to severe coastal erosion and found to be highly polluted as revealed from the water, sediment and biological analysis. In an attempt to prevent coastal erosion, 14,000 Rhizophora mucronata (RM) trees were planted across a heavily eroded shoreline at Samut Sakhon, Thailand. The survival rate of RM was high at the landward area and decreased at the offshore area. The most landward plot showed the highest survival rate when measured 4 years after planting (63.5%), while only 26.7% of trees survived at the most offshore plot. NPK and coconut fiber were shown to be significantly effective to enhance initial tree growths in heavily eroded area.

Description: This paper reviews the bioeconomic literature on habitat-fisheries connections. Many such connections have been explored in the bioeconomic literature; however, missing from the literature is an analysis merging the potential influences of habitat on both fish stocks and fisheries into one general, overarching theoretical model. We attempt to clarify the nature of linkages between the function of habitats and the economic activities they support. More specifically, we identify theoretically the ways that habitat may enter the standard Gordon-Schaefer model, and nest these interactions in the general model. Habitat influences are defined as either biophysical or bioeconomic. Biophysical effects relate to the functional role of habitat in the growth of the fish stock and may be either essential or facultative to the species. Bioeconomic interactions relate to the effect of habitat on fisheries and can be shown through either the harvest function or the profit function. We review how habitat loss can affect stock, effort, and harvest under open access and maximum economic yield managed fisheries.

Description: Donor meadow recovery is important in deciding whether removal of material from natural seagrass meadows is a sustainable activity. Thus an investigation into meadow regrowth was undertaken as part of a large-scale seagrass rehabilitation effort in Cockburn Sound, Western Australia. Several plug extraction configurations were examined in Posidonia sinuosa and Posidonia australis meadows to monitor shoot growth into plug scars. No significant differences in shoot growth between extraction configurations were observed, and both species increased their shoot numbers over two years, with P. sinuosa showing a significantly better recovery rate than P. australis. P. sinuosa shoot recovery into extracted areas was 2.2±0.1 shoots over 24 months, similar to shoot changes in controls (2.3 shoots over the same period). P. australis shoot recovery for each configuration was 0.8 ± 0.3 shoots in 24 months compared with 1.5 shoots in the controls. Based on the number of regrowing shoots, the predicted recovery time of a meadow is estimated at 4 years for P. sinuosa and three years for P. australis. Different plug extraction configurations do not appear to affect meadow recovery, and it can be concluded that established meadows of both species are sustainable providers of planting units for rehabilitation measures.

Description: Natural stream channel design principles and riparian restoration practices were applied during spring 2010 to an agriculturally impaired reach of the Cacapon River, a tributary of the Potomac River which flows into the Chesapeake Bay. Aquatic macroinvertebrates and fishes were sampled from the restoration reach, two degraded control, and two natural reference reaches prior to, concurrently with, and following restoration (2009 through 2010). Collector filterers and scrapers replaced collector gatherers as the dominant macroinvertebrate functional feeding groups in the restoration reach. Before restoration, based on indices of biotic integrity (IBI), the restoration reach fish and macroinvertebrate communities closely resembled those sampled from the control reaches, and after restoration more closely resembled those from the reference reaches. Although the macroinvertebrate community responded more favorably than the fish community, both communities recovered quickly from the temporary impairment caused by the disturbance of restoration procedures and suggest rapid improvement in local ecological conditions.

Description: An increase in mesopredators caused by the removal of top-order predators can have significant implications for threatened wildlife. Recent evidence suggests that Australia’s top-order predator, the dingo, may suppress the introduced cat and red fox. We tested this relationship by reintroducing 7 foxes and 6 feral cats into a 37 km2 fenced paddock in arid South Australia inhabited by a male and female dingo. GPS datalogger collars recorded locations of all experimental animals every 2 hours. Interactions between species, mortality rates, and postmortems were used to determine the mechanisms of any suppression. Dingoes killed all 7 foxes within 17 days of their introduction and no pre-death interactions were recorded. All 6 feral cats died between 20 and 103 days after release and dingoes were implicated in the deaths of at least 3 cats. Dingoes typically stayed with fox and cat carcasses for several hours after death and/or returned several times in ensuing days. There was no evidence of intraguild predation, interference competition was the dominant mechanism of suppression. Our results support anecdotal evidence that dingoes may suppress exotic mesopredators, particularly foxes. We outline further research required to determine if this suppression translates into a net benefit for threatened prey species.

Description: Predator/prey interactions between copepods and balaenid (bowhead and right) whales were studied with controlled lab experiments using moving baleen in still water and motionless baleen in flowing water to simulate zooplankton passage toward, into, and through the balaenid oral cavity. Copepods showed a lesser escape response to baleen and to a model head simulating balaenid oral hydrodynamics than to other objects. Copepod escape response increased as water flow and body size increased and was greatest at distances ≥10 cm from baleen and at copepod density = 10,000 m−3. Data from light/dark experiments suggest that escape is based on mechanoreception, not vision. The model head captured 88% of copepods. Results support previous research showing hydrodynamic effects within a whale’s oral cavity create slight suction pressures to draw in prey or at least preclude formation of an anterior compressive bow wave that could scatter or alert prey to the presence of the approaching whale.

Description: Resistance to herbicides that inhibit protoporphyrinogen oxidase (PPO) has been slow to evolve and, to date, is confirmed for only four weed species. Two of these species are members of the genus Amaranthus L. Previous research has demonstrated that PPO-inhibitor resistance in A. tuberculatus (Moq.) Sauer, the first weed to have evolved this type of resistance, involves a unique codon deletion in the PPX2 gene. Our hypothesis is that A. tuberculatus may have been predisposed to evolving this resistance mechanism due to the presence of a repetitive motif at the mutation site and that lack of this motif in other amaranth species is why PPO-inhibitor resistance has not become more common despite strong herbicide selection pressure. Here we investigate inter- and intraspecific variability of the PPX2 gene—specifically exon 9, which includes the mutation site—in ten amaranth species via sequencing and a PCR-RFLP assay. Few polymorphisms were observed in this region of the gene, and intraspecific variation was observed only in A. quitensis. However, sequencing revealed two distinct repeat patterns encompassing the mutation site. Most notably, A. palmeri S. Watson possesses the same repetitive motif found in A. tuberculatus. We thus predict that A. palmeri will evolve resistance to PPO inhibitors via the same PPX2 codon deletion that evolved in A. tuberculatus.

Description: Commelina diffusa is a colonising species of banana orchard habitats in St. Vincent in the Windward Islands of the Caribbean. In the present study, the population dynamics of C. diffusa were investigated in response to mechanical weed management with either a rotary string trimmer or glufosinate in ruderal and banana habitats. The study focused on density and size distribution of the weed over time and their response to two weed management strategies. The population dynamics of C. diffusa differed between the two habitats. Seedling establishment appeared to be an important factor influencing the dynamics of C. diffusa in banana orchards as there was little recruitment of seeds with less flower production compared with ruderal habitats where plants produced more flowers. Plants of C. diffusa in the banana orchard habitat had a longer growth cycle. In the banana orchard habitat, the C. diffusa population was greater and the plants were shorter with mechanical management than in areas treated with glufosinate. The results suggest that it is possible to manipulate the dynamics of C. diffusa in banana orchards as there is less chance of seed recruitment. Further research is necessary to refine an IPM approach for the management of C. diffusa.

Description: Within existing literature, it is well known that people’s behavior in ultimatum game experiments cannot be explained by perfect rationality model. There is, however, evidence showing that people are boundedly rational. In this paper, we studied repeated ultimatum game experiments in which the pie size is only known to the proposer (player 1), but the transaction history is made known to both players. We found that subject’s behavior can be very well explained by the history-consistent-rationality model (HCR model) of Lee and Ferguson (2010), which suggests that people’s behavior is affected by what they observed in the past. The HCR model is able to yield point predictions whose errors are on average within 5% of the total pie size. The experimental results provide evidence that subjects' behavior is boundedly rational with respect to the transaction history.

Description: The Australian Red Cedar presents a great exploitation potential in Brazil, but works about the nutrient requirements and deficiency characterization in that species are still scarce. The objectives of this work were evaluating the effects of the omission of micronutrients and characterizing the nutrient deficiency symptoms in Australian Red Cedar saplings. The experiment was conducted in a greenhouse for a 90-day period. Australian Red Cedar cuttings were cultivated in pots with a nutrient solution under the missing element technique. The omission of the micronutrients B, Cu, Fe, Mn, and Zn affect negatively the height, diameter, and dry matter yield of the Australian Red Cedar plants. The micronutrient which affected the relative growth of the plants the most was B. Australian Red Cedar plants deficient in micronutrients present several visual symptoms characteristic of the metabolism disorders. The perception of the deficiencies through the visual diagnosis can be useful in the nutrient management of the culture of the Australian Red Cedar.

Description: Multivariate statistical techniques were used to compare the relationship between yield and its related traits under noninoculated and inoculated cultivars with mycorrhizal fungus (Glomus intraradices); each one consisted of three wheat cultivars and four water regimes. Results showed that, under inoculation conditions, spike weight per plant and total chlorophyll content of the flag leaf were the most important variables contributing to wheat grain yield variation, while, under noninoculated condition, in addition to two mentioned traits, grain weight per spike and leaf area were also important variables accounting for wheat grain yield variation. Therefore, spike weight per plant and chlorophyll content of flag leaf can be used as selection criteria in breeding programs for both inoculated and noninoculated wheat cultivars under different water regimes, and also grain weight per spike and leaf area can be considered for noninoculated condition. Furthermore, inoculation of wheat cultivars showed higher value in the most measured traits, and the results indicated that inoculation treatment could change the relationship among morphological traits of wheat cultivars under drought stress. Also, it seems that the results of stepwise regression as a selecting method together with principal component and factor analysis are stronger methods to be applied in breeding programs for screening important traits.

Description: Distribution modeling and vegetation suitability mapping were undertaken to assess (1) the role that past climate change played in fragmenting a subspecies of the endangered southern brown bandicoot Isoodon obesulus and (2) the impacts of land cover change on the subspecies following European settlement of Australia. Based on a selection of bioclimatic variables, disjunctions in the broad distribution of I. obesulus obesulus were found. Vegetation maps representing the time of European settlement revealed two clear features. First, vegetation that was unsuitable for the subspecies corresponded to climatic disjunctions in its distribution, and, second, substantial additional areas were predicted to have suitable vegetation but not suitable climate. Vegetation mapping showed considerable change over two centuries after European settlement, so that most places that formerly had suitable climate and vegetation were cleared. Our analysis demonstrates that clearing of native vegetation has masked naturally occurring disjunctions in the distribution of I. o. obesulus. This finding provides evidence that fragmented, regional-scale populations of I. o. obesulus existed prior to European settlement. Implications for conservation planning are discussed.

Description: Palmer amaranth is a very problematic weed in several crops in the southern USA due to its competitive ability and resistance to herbicides representing different mechanisms of action. Variation in growth and subsequent interference of North Carolina Palmer amaranth accessions has not been examined. A greenhouse experiment determined response of 15 North Carolina Palmer amaranth accessions to drought stress beginning 15 days after seedling emergence (DAE) for a duration of 3, 5, 7, and 9 days. Following exposure to drought, plants were grown under optimal moisture conditions until harvest at 30 DAE. Five accessions each of glyphosate-resistant (GR), acetolactate synthase inhibitor-resistant (ALSR), and acetolactate synthase inhibitor-susceptible and glyphosate-susceptible (ALSS/GS) were compared. Variation in response to drought stress, based on height and dry weight reduction relative to nonstressed controls, was noted among accessions. Stress for 3 or more days affected height and dry weight. Height and dry weight of GR and ALSR accession groups were reduced less by drought than the ALSS/GS accession group. Results suggest a possible relationship between herbicide resistance and ability of Palmer amaranth to withstand drought stress and thus a possible competitive advantage for resistant accessions under limited moisture availability.

Description: Terrestrial carbon (C) sequestration through optimizing land use and management is widely considered a realistic option to mitigate the global greenhouse effect. But how the responses of individual ecosystems to changes in land use and management are related to baseline soil organic C (SOC) levels still needs to be evaluated at various scales. In this study, we modeled SOC dynamics within both natural and managed ecosystems in North Dakota of the United States and found that the average SOC stock in the top 20 cm depth of soil lost at a rate of 450 kg C ha−1 yr−1 in cropland and 110 kg C ha−1 yr−1 in grassland between 1971 and 1998. Since 1998, the study area had become a SOC sink at a rate of 44 kg C ha−1 yr−1. The annual rate of SOC change in all types of lands substantially depends on the magnitude of initial SOC contents, but such dependency varies more with climatic variables within natural ecosystems and with management practices within managed ecosystems. Additionally, soils with high baseline SOC stocks tend to be C sources following any land surface disturbances, whereas soils having low baseline C contents likely become C sinks following conservation management.

Description: Eucalyptus is a fast-growing tree native to Australia and could be used to supply biomass for bioenergy and other purposes along the coastal regions of the southeastern United States (USA). At a farmgate price of $66 dry Mg−1, a potential supply of 27 to 41.3 million dry Mg year−1 of Eucalyptus could be produced on about 1.75 million ha in the southeastern USA. A proposed suite of indicators provides a practical and consistent way to measure the sustainability of a particular situation where Eucalyptus might be grown as a feedstock for conversion to bioenergy. Applying this indicator suite to Eucalyptus culture in the southeastern USA provides a basis for the practical evaluation of socioeconomic and environmental sustainability in those systems. Sustainability issues associated with using Eucalyptus for bioenergy do not differ greatly from those of other feedstocks, for prior land-use practices are a dominant influence. Particular concerns focus on the potential for invasiveness, water use, and social acceptance. This paper discusses opportunities and constraints of sustainable production of Eucalyptus in the southeastern USA. For example, potential effects on sustainability that can occur in all five stages of the biofuel life cycle are depicted.

Description: Interest in biomass-based energy in the southeastern Unites States has led to increased need for fast-growing tree species. Several Eucalyptus species exhibit characteristics that make them attractive in the bioenergy context. However, some of these also possess traits that suggest they could become invasive. To make a preliminary assessment of the risk of seedling establishment in the vicinity of Eucalyptus plantations, we conducted surveys at 3 sites in South Carolina and 16 sites in Florida. In South Carolina, no seedlings were detected in any sample transect. In Florida, we found seedlings within the boundaries of Eucalyptus plantations at 4 of the 16 sites surveyed. We also detected seedlings outside the boundaries of these same four plantations, but only two seedlings were detected at distances 〉45 m from plantation boundaries. All seedlings from Florida were either E. amplifolia, E. robusta, or E. grandis. The most predictive variable evaluated was latitude, with 27°N being the highest latitude at which seedlings established with regularity. Results of this survey indicate that, under current conditions, the spread of Eucalyptus spp. from plantations should be possible to manage with appropriate monitoring, but this should be evaluated further before Eucalyptus spp. are adopted for widespread planting.

Description: Renewed interest in short-rotation woody crops for bioenergy and bioproducts has prompted a reevaluation of the Eucalyptus species for the southern United States. One question that arises about the potential effects of introducing a nonnative species is what effect will there be on fire behavior. Our approximate answer based on modeling fire behavior using the Fuel Characteristic Classification System is that surface fire behavior in young stands differs little from surface fires common to pine plantations in the southern Coastal Plain. By the age of 9, the absence of a shrub layer, along with an increased height to live crown, reduced initiation potential despite increased bark shedding. When a shrub layer was introduced in the model, the initiation potential became equivalent to common Pinus fuelbeds. If a crown is ignited, however, the potentials for transmissivity and spread are very high, and the potential for crown fire behavior is more severe. Our modeling effort suggests that fire behavior at the stand level differs little from current conditions and points to the importance of avoiding the development of a shrub layer. Stands managed on short rotation (less than 10 years) will likely be harvested before bark shedding presents a significant spotting problem.

Description: Many agricultural species have undergone selection for traits that are consistent with those that increase the probability that a species will become invasive. However, the risk of invasion may be accurately predicted for the majority of plant species tested using the Australian Weed Risk Assessment (WRA). This system has been tested in multiple climates and geographies and, on average, correctly identifies 90% of the major plant invaders as having high invasion risk, and 70% of the noninvaders as having low risk. We used this tool to evaluate the invasion risk of 38 Eucalyptus taxa currently being tested and cultivated in the USA for pulp, biofuel, and other purposes. We predict 15 taxa to have low risk of invasion, 14 taxa to have high risk, and 9 taxa to require further information. In addition to a history of naturalization and invasiveness elsewhere, the traits that significantly contribute to a high invasion risk conclusion include having prolific seed production and a short generation time. Selection against these traits should reduce the probability that eucalypts cultivated in the USA will become invasive threats to natural areas and agricultural systems.

Description: Use of the Australian genus Eucalyptus in short rotation plantations in Africa and Madagascar has developed over the last century to such an extent that it is becoming the most frequently planted genus in Africa. In order to find ecologically well-adapted eucalypts, foresters have tested different species of various origins and the number of tested Eucalyptus species now exceeds 150 in Africa. Due to the ability of eucalypts to naturally form ectomycorrhizae, even in the absence of any controlled introduction of compatible ectomycorrhizal fungal partners, their introduction in new ecosystems has direct consequences for ectomycorrhizal fungus communities. A bibliographical compilation, together with original field observations on putative ectomycorrhizal fungi associated with eucalypts in Africa and in Madagascar, has been drawn up in two lists: one for Africa and one for Madagascar where surprisingly high fungal diversity was observed. The level of diversity, the putative origin of the fungi, and their potential impact on native ectomycorrhizal fungi are discussed. The development of eucalypts plantations will inexorably lead to the increase of exotic fungal species being potentially invasive in the considered region.

Description: Phenotypic plasticity was once seen primarily as a constraint on adaptive evolution or merely a nuisance by geneticists. However, some biologists promote plasticity as a source of novelty and a factor in evolution on par with mutation, drift, gene flow, and selection. These claims are controversial and largely untested, but progress has been made on more modest questions about effects of plasticity on local adaptation (the first component of ecological speciation). Adaptive phenotypic plasticity can be a buffer against divergent selection. It can also facilitate colonization of new niches and rapid divergent evolution. The influence of non-adaptive plasticity has been underappreciated. Non-adaptive plasticity, too can interact with selection to promote or inhibit genetic differentiation. Finally, phenotypic plasticity of reproductive characters might directly influence evolution of reproductive isolation (the second component of ecological speciation). Plasticity can cause assortative mating, but its influence on gene flow ultimately depends on maintenance of environmental similarity between parents and offspring. Examples of plasticity influencing mating and habitat choice suggest that this, too, might be an underappreciated factor in speciation. Plasticity is an important consideration for studies of speciation in nature, and this topic promises fertile ground for integrating developmental biology with ecology and evolution.

Description: The role of ecology in diversification has been widely investigated, though few groups have been studied in enough detail to allow comparisons of different ecological traits that potentially contribute to reproductive isolation. We investigated larval performance within a species complex of Lycaeides butterflies. Caterpillars from seven populations were reared on five host plants, asking if host-specific, adaptive larval traits exist. We found large differences in performance across plants and fewer differences among populations. The patterns of performance are complex and suggest both conserved traits (i.e., plant effects across populations) and more recent dynamics of local adaptation, in particular for L. melissa that has colonized an exotic host. We did not find a relationship between oviposition preference and larval performance, suggesting that preference did not evolve to match performance. Finally, we put larval performance within the context of several other traits that might contribute to ecologically based reproductive isolation in the Lycaeides complex. This larger context, involving multiple ecological and behavioral traits, highlights the complexity of ecological diversification and emphasizes the need for detailed studies on the strength of putative barriers to gene flow in order to fully understand the process of ecological speciation.

Description: Compared to the vast literature linking competitive interactions and speciation, attempts to understand the role of facilitation for evolutionary diversification remain scarce. Yet, community ecologists now recognize the importance of positive interactions within plant communities. Here, we examine how facilitation may interfere with the mechanisms of ecological speciation. We argue that facilitation is likely to (1) maintain gene flow among incipient species by enabling cooccurrence of adapted and maladapted forms in marginal habitats and (2) increase fitness of introgressed forms and limit reinforcement in secondary contact zones. Alternatively, we present how facilitation may favour colonization of marginal habitats and thus enhance local adaptation and ecological speciation. Therefore, facilitation may impede or pave the way for ecological speciation. Using a simple spatially and genetically explicit modelling framework, we illustrate and propose some first testable ideas about how, when, and where facilitation may act as a cohesive force for ecological speciation. These hypotheses and the modelling framework proposed should stimulate further empirical and theoretical research examining the role of both competitive and positive interactions in the formation of incipient species.

Description: Introduction of Eucalyptus spp. into the United States from Australia on a significant scale resulted from the gold rush into California in 1849. Numerous species were evaluated for fuel, wood products, and amenity purposes. The first recorded entry of eucalyptus into the southern United Stated was in 1878. Subsequent performance of selected species for ornamental purposes caused forest industry to visualize plantations for fiber production. That interest led the Florida Forestry Foundation to initiate species-introduction trials in 1959. The results were sufficiently promising that a contingent of forest products companies formed a cooperative to work with the USDA Forest Service, Lehigh Acres, FL, USA, on genetic improvement of selected species for fiber production. The Florida initiative caused other industrial forestry companies in the upper South to establish plantations regardless of the species or seed source. The result was invariably the same: failure. Bruce Zobel, Professor of Forestry, North Carolina State University, initiated a concerted effort to assess the potential worth of eucalyptus for plantation use. The joint industrial effort evaluated 569 sources representing 103 species over a 14-year period. The three levels of testing, screening, in-depth, and semioperational trials led to identification of some species and sources that offered promise for adaptation, but severe winter temperatures in late 1983 and early 1984 and 1985 terminated the project. Despite the failed attempt valuable silvicultural practices were ascertained that will be beneficial to other researchers and practitioners when attempts are again made to introduce the species complex into the US South.

Description: Colonist farmers have been largely ignored to date in national consultations on reducing emissions from deforestation and forest degradation (REDD+). Yet, good practices suggest that understanding all relevant stakeholders’ perspectives, goals, and issues is a precondition for the development of successful environmental policies. The present research documents perceptions of the civil society and the government on the possibility of successfully implementing REDD+ activities with colonist farmers. The focus is on Eastern Panama. The perceptions on REDD+ vary greatly depending on the stakeholders’ origins. The government perceives REDD+ as a possibility for improving laws, increasing control over the national territory, and investing more resources for conservation and public institutions, whereas respondents from colonist backgrounds mostly insist on the potential economic benefits and/or the negative implications that could encompass REDD+. Noncolonist participants from regional, national, and international organizations instead try to balance concerns of communities and conservation objectives. Because one of our results highlighted the difficulty of colonist farmers in speaking as a united voice, we carried out a case study of a successful colonists association in order to identify the characteristics and practices found to facilitate communal organization.

Description: A challenge in the development of renewable energy is the ability to spatially assess the risk of feedstock supply to conversion facilities. Policy makers and investors need improved methods to identify the interactions associated with landscape features, socioeconomic conditions, and ownership patterns, and the influence these variables have on the geographic location of potential conversion facilities. This study estimated opportunity zones for woody cellulosic feedstocks based on landscape suitability and market competition for the resource. The study covered 13 Southern States which was a segment of a broader study that covered 33 Eastern United States which also included agricultural biomass. All spatial data were organized at the 5-digit zip code tabulation area (ZCTA). A landscape index was developed using factors such as forest land cover area, net forest growth, ownership type, population density, median family income, and farm income. A competition index was developed based on the annual growth-to-removal ratio and capacities of existing woody cellulosic conversion facilities. Combining the indices resulted in the identification of 592 ZCTAs that were considered highly desirable zones for woody cellulosic conversion facilities. These highly desirable zones were located in Central Mississippi, Northern Arkansas, South central Alabama, Southwest Georgia, Southeast Oklahoma, Southwest Kentucky, and Northwest Tennessee.

Description: Eucalypts are being considered for biofuel production in the Lower Coastal Plain of the United States. The evolution of eucalypts in Australia has equipped some species to be successful in plantations and has also influenced their potential as invasive species. More than 200 eucalypt species have been evaluated in many countries around the world. Generally eucalypts have proved to have limited invasive potential for a number of reasons, including their poor dispersal capabilities. Two regions with climates similar to the Lower Coastal Plain of the United States are identified in Argentina and China. Frosts, particularly sudden frosts, are an important limitation for eucalypts in these regions, so existing plantations are very limited. However, invasive eucalypts do not appear to be a major problem in other regions of either country. The use of carefully selected frost-tolerant species and the development of genetically modified eucalypts may now open up more frost-affected areas for eucalypt plantations. Some control actions may be necessary and research needs are outlined, but it is concluded that experience in other regions around the world suggests that eucalypts are likely to be a relatively low risk as invasive species in the Lower Coastal Plain.

Description: Considering the wide variety of species and clones of Eucalyptus cultivated in Brazil, it is necessary to search for new information on wood properties, so that the selection of genetically superior material may be successful. The present study aimed to determine the properties of wood and charcoal from different clones of Eucalyptus spp. Six clones at the age of 7.5 years were evaluated and the samples were from a clonal, located in the city of Lassance, Minas Gerais, Brazil. Basic density, chemical composition, and higher heating value were determined. Carbonizations in a laboratory kiln were done and the levels of volatile matter, ash, and fixed carbon, higher heating value, and bulk density of the charcoal produced were determined. Evaluated genetic materials showed differences in their properties. According to research results, several properties of wood should be considered together for the selection of clones for charcoal production. However, basic density and chemical composition of wood, especially high contents of lignin and low contents of extractives, are the properties that had more influence on charcoal yield and its quality. Concerning charcoal production for steelmaking, clone 6 stood out and, conversely, clone 4 showed inferior properties to those of others.

Description: In the lignite mining region of Lower Lusatia (NE-Germany), Robinia pseudoacacia L. is an increasingly popular tree for the biomass production with short rotation coppices (SRCs) on reclamation sites. In order to evaluate biomass production, C and N allocation patterns in R. pseudoacacia stands between shoot, stump, coarse, and fine roots samples were collected from seedlings and three adjacent plantations and plants that were one, two and twelve years old. Results indicated that the summarized average dry matter production (DM) of the woody plant parts increased with plant age up to 7.45 t DM ha−1 yr−1 with a corresponding shoot increment of up to 4.77 t DM ha−1 yr−1 in the twelve-year-old stands. The shoot to root ratio changed from 0.2 for the one-year-old trees to 2.0 in the twelve-year-old plantation, whereby an average amount of 3.4 t C ha−1 yr−1 and 0.1 t N ha−1 yr−1 was annually bound in the living woody plant parts over the period of twelve years. Summing up, the results suggest a high potential for C and N storage of R. pseudoacacia what is also beneficial for land reclamation due to positive implications on soil humus and general site fertility.

Description: Increasing use of woody fuels requires that nontraditional types of raw materials are exploited, including logging residues and small-diameter trees. Although medium-scale combustors often use pellets, they could conceivably use dried chips of sufficiently narrow size distribution (henceforth pellet chips). The influence of the following factors on the relative cost-effectiveness of producing pellets and pellet chips was investigated for three plant sites in northern Sweden: (1) harvesting and transporting of forest residues; (2) the potential of existing energy plants to supply drying heat in periods of capacity surplus; (3) the distance to potential end-users. Data from the national forest inventory were used to estimate raw material costs. The resulting production costs were 144–176 $ per oven-dry tonnes (OD t) for pellets (27.4–33.5 $ MWh−1) and 143–173 $ OD t−1 (27.2–33.0 $ MWh−1) for pellet chips, with harvesting, forwarding, chipping, and transporting of logging residues to the sites amounting to 114–122 $ OD t−1 (21.7–23.2 $ MWh−1) for both fuels. Even though the differences in production costs were minor, the production of pellet chips requires significantly less electricity input per OD t of produced fuel. For cost reductions improved methods for wood fuel procurement, compacting and transporting of chips, small-scale low-temperature drying and foliage and bark separation are needed.

Description: Surveys of soil properties related to soil functioning for many regions of Kyrgyzstan are limited. This study established ranges of chemical (soil organic matter (SOM), pH and total N (TN)), physical (soil texture), and biochemical (six enzyme activities of C, N, P, and S cycling) characteristics for nine profiles from the Kukart watershed of Jalal-Abad region in Kyrgyzstan. These profiles represent different soil orders (Inceptisols, Alfisols, and Mollisols) and land uses (cultivated, nut-fruit forests, and pasture). The Sierozem (Inceptisols) soils had the highest pH and contained the lowest SOM and TN contents compared to the Brown, Black-brown, and Meadow-steppe soils (Alfisols and Mollisols). Enzymatic activities within surface horizons (0–18 cm) typically decreased in the following order: forest 〉 pasture 〉 cultivated. Enzyme activity trends due to land use were present regardless of elevation, climate, and soil types although subtle differences among soil types within land use were observed. The significant reductions in measured soil enzyme activities involved in C, N, P, and S nutrient transformations under cultivation compared to pasture and forest ecosystems and lower values under Inceptisols can serve as soil quality indicators for land use decisions in the watershed.

Description: This study addresses the indirect impacts of state-mandated workers' compensation benefits on workers' wages. The benefit structure of workers' compensation causes a fundamental estimation problem. I develop a new strategy to limit the biases inherent in earlier models. I utilize individual-level census data (between 1940 and 1990) to exploit benefit variation that occurs both across states and within the fifty states over time. The results suggest that wage offsets are not constant across time and may be larger for workers at lower-wage levels.

Description: This study intends to estimate the demand for indigenous chicken meat in Kenya, including other available meat products for comparison purposes. Data used was collected from six counties. A total 930 rural and urban households were sampled. Linear Approximated Almost Ideal Demand System (LA/AIDS) model was used to obtain the demand elasticities and to examine the socioeconomic and demographic factors influencing the meat budget shares. The results ascertain that the socio-demographic factors such as household location, the proportion of household members and the family size are important factors in explaining perceived variations in the consumption of meat products. Indigenous chicken meat, beef and mutton, were identified as necessities. Indigenous chicken meat and beef were identified as substitutes while indigenous chicken, goat and exotic chicken meats were complements. In view of the high expenditure elasticities, therefore, considering a policy option that would enhance consumer income is desirable, since it will result in high consumption thereby providing more incentives for production of meat products. The information generated would be more beneficial to the interest groups in the livestock sector as a whole. This would be utilised in the formulation of effective policies in line with food security and poverty alleviation.

Description: For the first time, and in a large spatial scale, the influence of ecological properties on the aquatic bird community of black water lakes in Brazilian Amazonia is evaluated. Bird surveys were conducted in 45 lakes. A total of 3626 individuals in 48 bird species were recorded; of these, 31 are aquatic, and 18 of these are primarily piscivorous. Bird richness and abundance were not significantly related to lake shape and productivity but were influenced by hydrological period (low versus high), water depth, transparency, lake isolation, and habitat richness. Matrices of bird species by lake were subjected to multivariate analyses (NMDS) to evaluate how these parameters influence bird community. The variation in bird species composition was positively correlated to lake depth and isolation and negatively correlated to water transparency and habitat richness. The results indicate that period, lake physical characteristics (depth, water transparency), isolation, and habitat richness are determinants of aquatic bird community composition in the black water lake systems of Amazonia.

Description: Handroanthus impetiginosus, pink lapacho, is a timber, ornamental, and medicinal tree. Experiments on the in vitro propagation of H. impetiginosus were conducted using nodal segments cultivated in both Murashige and Skoog salts with Gamborg vitamins (MSG) and Woody Plant Medium (WPM) with different concentrations of 6-benzylaminopurine (BA) and indole butyric acid (IBA). Morphogenic responses were differentially affected by salt compositions and their interactions with plant growth regulators in each micropropagation stage. According to response surface analysis, the optimum multiplication rate with 1 μM IBA ranged from 16.7 to 21.3 μM BA in WPM, and the inhibitors of endogenous auxins could increase multiplication rates. A pulse with 50 μM IBA in 1/2 MSG produced 83% rooting with 3.2 roots per shoots and higher fresh and dry weights of shoots and roots. In the acclimatisation stage, 50% of plants survived after 1 year. This methodology optimised the culture media for the in vitro propagation of the H. impetiginosus clonal pool and could be applied to related species, several of which are categorised as vulnerable on the International Union for the Conservation of Nature Red List.

Description: We tested the hypothesis that changes in leaf area index (LAI m2 m−2) and mean stand diameter following thinning are due to thinning type and residual density. The ratios of pre- to postthinning diameter and LAI were used to assess structural changes between replicated crown, dominant, and low thinning treatments to 33% and 50% residual density in even-aged Picea rubens and Abies balsamea stands with and without a precommercial thinning history in Maine, USA. Diameter ratios varied predictably by thinning type: low thinnings were <0.7, crown thinnings were >0.7 but <1.0, and dominant thinnings were >1.0 . LAI change was affected by type and intensity of thinning. On average, 33% density reduction removed <50% of LAI, whereas 50% density reduction removed >50% of LAI. Overall reduction of LAI was generally greatest in dominant thinnings (54%), intermediate in crown thinnings (46%), and lowest in low thinnings (35%). Upon closer examination by crown classes, the postthinning distribution of LAI between upper and lower crown classes varied by thinning history, thinning method, and amount of density reduction.

Description: Forest ecosystem dynamics are driven by a complex array of simultaneous cause-and-effect relationships. Understanding this complex web requires specialized analytical techniques such as Structural Equation Modeling (SEM). The SEM framework and implementation steps are outlined in this study, and we then demonstrate the technique by application to overstory-understory relationships in mature Douglas-fir forests in the northwestern USA. A SEM model was formulated with (1) a path model representing the effects of successively higher layers of vegetation on late-seral herbs through processes such as light attenuation and (2) a measurement model accounting for measurement errors. The fitted SEM model suggested a direct negative effect of light attenuation on late-seral herbs cover but a direct positive effect of northern aspect. Moreover, many processes have indirect effects mediated through midstory vegetation. SEM is recommended as a forest management tool for designing silvicultural treatments and systems for attaining complex arrays of management objectives.

Description: Distribution modeling and vegetation suitability mapping were undertaken to assess (1) the role that past climate change played in fragmenting a subspecies of the endangered southern brown bandicoot Isoodon obesulus and (2) the impacts of land cover change on the subspecies following European settlement of Australia. Based on a selection of bioclimatic variables, disjunctions in the broad distribution of I. obesulus obesulus were found. Vegetation maps representing the time of European settlement revealed two clear features. First, vegetation that was unsuitable for the subspecies corresponded to climatic disjunctions in its distribution, and, second, substantial additional areas were predicted to have suitable vegetation but not suitable climate. Vegetation mapping showed considerable change over two centuries after European settlement, so that most places that formerly had suitable climate and vegetation were cleared. Our analysis demonstrates that clearing of native vegetation has masked naturally occurring disjunctions in the distribution of I. o. obesulus. This finding provides evidence that fragmented, regional-scale populations of I. o. obesulus existed prior to European settlement. Implications for conservation planning are discussed.

Description: Within existing literature, it is well known that people’s behavior in ultimatum game experiments cannot be explained by perfect rationality model. There is, however, evidence showing that people are boundedly rational. In this paper, we studied repeated ultimatum game experiments in which the pie size is only known to the proposer (player 1), but the transaction history is made known to both players. We found that subject’s behavior can be very well explained by the history-consistent-rationality model (HCR model) of Lee and Ferguson (2010), which suggests that people’s behavior is affected by what they observed in the past. The HCR model is able to yield point predictions whose errors are on average within 5% of the total pie size. The experimental results provide evidence that subjects' behavior is boundedly rational with respect to the transaction history.

Description: The Australian Red Cedar presents a great exploitation potential in Brazil, but works about the nutrient requirements and deficiency characterization in that species are still scarce. The objectives of this work were evaluating the effects of the omission of micronutrients and characterizing the nutrient deficiency symptoms in Australian Red Cedar saplings. The experiment was conducted in a greenhouse for a 90-day period. Australian Red Cedar cuttings were cultivated in pots with a nutrient solution under the missing element technique. The omission of the micronutrients B, Cu, Fe, Mn, and Zn affect negatively the height, diameter, and dry matter yield of the Australian Red Cedar plants. The micronutrient which affected the relative growth of the plants the most was B. Australian Red Cedar plants deficient in micronutrients present several visual symptoms characteristic of the metabolism disorders. The perception of the deficiencies through the visual diagnosis can be useful in the nutrient management of the culture of the Australian Red Cedar.

Description: Multivariate statistical techniques were used to compare the relationship between yield and its related traits under noninoculated and inoculated cultivars with mycorrhizal fungus (Glomus intraradices); each one consisted of three wheat cultivars and four water regimes. Results showed that, under inoculation conditions, spike weight per plant and total chlorophyll content of the flag leaf were the most important variables contributing to wheat grain yield variation, while, under noninoculated condition, in addition to two mentioned traits, grain weight per spike and leaf area were also important variables accounting for wheat grain yield variation. Therefore, spike weight per plant and chlorophyll content of flag leaf can be used as selection criteria in breeding programs for both inoculated and noninoculated wheat cultivars under different water regimes, and also grain weight per spike and leaf area can be considered for noninoculated condition. Furthermore, inoculation of wheat cultivars showed higher value in the most measured traits, and the results indicated that inoculation treatment could change the relationship among morphological traits of wheat cultivars under drought stress. Also, it seems that the results of stepwise regression as a selecting method together with principal component and factor analysis are stronger methods to be applied in breeding programs for screening important traits.

Description: A predatory insect, Chrysopa sinica Tiedet (Neuroptera: Chrysopidae), and its taxis behavior were investigated in a tritrophic system that included a herbivore, Ceroplastes japonicus Green (Hemiptera: Coccidae), and a host plant, persimmon tree, Diospyros kaki L. (Ebenaceae). The results showed that this predator was attracted to the volatile compounds of persimmon trees that were infested with C. japonicus; however, the attraction varied with the growth season of the trees and the development stage of the wax scale. The strongest attraction occurred in the autumn and not in the late spring or summer. For the four time periods considered throughout the day, the most significant attraction rates were found at midnight and the early afternoon. The results indicated that the transformation of the chemical compositions of the volatiles of the persimmon tree might drive the taxis response of the predator in the three studied seasons. We mainly found differences in terpenoid emissions and propose that these compounds play a key part in the observed differences in attractiveness.

Description: We analyze the mutual relations among firms’ capital structure, ownership structure, and valuation. Through the estimation of a system of simultaneous equations for a sample of 1,130 firms from 16 countries from both the common law and the civil law environments, our results confirm the differential effect of ownership structure on firms’ value in each setting. Whereas in civil law firms the higher ownership concentration results in an entrenchment and an alignment effect, in the common law firms higher ownership concentration increases the value of the firm. Second, we corroborate the endogeneity of ownership structure since we find that ownership structure is affected by the value of the firm and by the capital structure. Third, our results suggest that corporate finance decisions are taken simultaneously with other mechanisms of corporate governance and conditional on firms’ valuation.

Description: Conditional expected shortfalls calculated for European insurance companies and banks under stressed market conditions are shown to be of similar magnitudes. Measured at 95% and 99% stress levels, on data covering the period from 1995 to 2011, the equity-return tail losses of insurance undertakings and banks are indistinguishable. Granger causality analysis, on all pairs of banks and insurance companies included in the sample, shows that banks and insurance companies have equal propensity to cause each others price movements. Even though the business model of insurance undertakings is different from the business model typically applied by banks, and even though insurance companies are not depending to a similar degree on short term funding as banks, the empirical results indicate that the financial equity markets in Europe do not differentiate their trading of banks and insurance companies in periods of stress.

Description: Total Factor Productivity (TFP) measures the growth in output which is not accounted for by inputs. Data Envelopment Analysis which forms the basis for the computation of Malmquist TFP index is used in this paper to study the performance of different river basins in Andhra Pradesh state, India. The results indicated that average technical efficiency of all the basins is only 66%. In all the basins there was a decline in growth of agricultural output during the first two decades, viz., 1979-1980 to 1988-1989 and it had picked in the last decade (1999-2000). All the river basins have TFP change greater than 1 indicating progress in agricultural productivity. Out of the 40 river basins, 14 river basins have technical efficiency change less than 1 indicating decline in TFP growth whereas all the basins have technical changes greater than 1 implying that there is shift in production frontier over years. In general, within the TFP, technical change contributed more than technical efficiency change. Looking at the future options for increasing the agricultural output in the river basins, it is important to focus on improving the TFP growth compared to increasing the quantities of physical inputs.

Description: This paper investigates the changes in cigarette demand in response to the changes in cigarette prices; smokeless tobacco prices; adoption of clean indoor air laws (CIALs). We used an error-correction econometric method to estimate the cigarette sales adjustment path in response to changes in prices and CIAL coverage in the United States by utilizing scanner data from supermarkets. Finding from this study indicates that smokeless tobaccos are not perfect substitutes for cigarettes, but increases in the price of cigarettes are associated with an increase in smokeless tobacco sales. The error-correction econometric method suggest that the demand for cigarettes and smokeless tobacco is related to each other; a price increase in either product leads to an increase in demand for the other product. However, the adjustment paths are quite different; an increase in cigarette prices lowers cigarette sales in relatively faster rate than decreases in smokeless tobacco prices or adoption of smoke-free laws. Changes in cigarette demand in response to changes in cigarette prices occur relatively quickly; but the full effects of smokeless tobacco price change and the adoption of 100% smoke-free laws on cigarette demand take a longer time.

Description: Repeated use of protox-inhibiting herbicides has resulted in a common waterhemp (Amaranthus rudis Sauer) biotype that survived lactofen applied up to 10 times the labeled rate. Field and greenhouse research evaluated control options for this biotype of common waterhemp. In the field, PRE applications of flumioxazin at 72 g ai ha−1, sulfentrazone at 240 g ai ha−1, and isoxaflutole at 70 g ai ha−1 controlled common waterhemp 〉90% up to 6 weeks after treatment. POST applications of fomesafen at 330 g ai ha−1, lactofen at 220 g ai ha−1, and acifluorfen at 420 g ai ha−1 resulted in

Description: Palmer amaranth (Amaranthus palmeri S. Wats.) has become difficult to control in row crops due to selection for biotypes that are no longer controlled by acetolactate synthase inhibiting herbicides and/or glyphosate. Early season interference in soybean [Glycine max (L.) Merr.] for 40 days after emergence by three glyphosate-resistant (GR) and three glyphosate-susceptible (GS) Palmer amaranth biotypes from Georgia and North Carolina was compared in the greenhouse. A field experiment over 2 years compared season-long interference of these biotypes in soybean. The six Palmer amaranth biotypes reduced soybean height similarly in the greenhouse but did not affect soybean height in the field. Reduction in soybean fresh weight and dry weight in the greenhouse; and soybean yield in the field varied by Palmer amaranth biotypes. Soybean yield was reduced 21% by Palmer amaranth at the established field density of 0.37 plant m−2. When Palmer amaranth biotypes were grouped by response to glyphosate, the GS group reduced fresh weight, dry weight, and yield of soybean more than the GR group. The results indicate a possible small competitive disadvantage associated with glyphosate resistance, but observed differences among biotypes might also be associated with characteristics within and among biotypes other than glyphosate resistance.

Description: This paper provides new insights into the calculation of trade potential between the EU and its Southern and Eastern Mediterranean partners (MPs). It is based on an econometric specification which takes into account some new explanatory variables which are not included simultaneously in the previous studies. These include trade costs (tariffs, NTBs, and logistics costs), factor movement (migration and FDI), as well as governance. In addition, specific estimators are implemented in order to account for zero trade flows, endogeneity and dynamics. The main conclusion of this study is that contrary to some results found in previous studies, MPs have reached their export potential with the EU. It is also shown that there is no specificity of the MP-EU trade potential in comparison with the other main PTAs (NAFTA, MERCOSUR, and ASEAN) which have also reached their trade potential. These results have strong policy implications.

Description: This study focuses on the influence of the 2008 ice storm in China and subsequent forest rehabilitation dynamics up until 2011. All seven plots studied exhibited significant damage, with the total number of damaged trees varying between 63 and 92%. In addition, most trees suffered stem bending in 2008 and the extent of damage varied with tree diameter at breast high (DBH). Relationships between loss of biomass as dead trees and stand characteristics were analyzed by multiple stepwise regression. The results showed that the decrease in biomass (Y) could be related to altitude (X1), slope (X2), and aboveground biomass (AGB) in 2008 (X5) according to the following formula:

Description: The purpose of this study is to investigate how earnings announcement event affects stock returns at Karachi Stock Exchange (KSE). For this purpose we use the KSE-100 Index as our sample. We use the CAR Analysis to analyze the impact of earnings announcement over the stock returns around announcement dates. Our results suggest that KSE experiences abnormal stock returns around earnings announcement dates for the overall market and for different categories which indicate that efficient market hypothesis does not hold in Pakistani market and point out the presence of informational dissemination inefficiencies in the market.

Description: In the past 50 years, a striking stylized fact has been the downward—or flat—trend of intra-African trade as a share of Africa’s total trade, while official development assistance (ODA) has experienced a noticeable expansion. During the same period, economic growth performances have not been consistent and robust enough to put a dent in the poverty level across the African continent in general and the Economic Community of West African States (ECOWAS) in particular. Using a two-stage least square (TSLS) estimation technique, this paper finds out that intra-ECOWAS trade stimulates per capita income growth substantially more than foreign aid, which rather constitutes an impediment to that growth in most specifications. Additionally, comparable results are obtained when the scope of the study is expanded to include trade of ECOWAS members with the rest of the world. As a result, it becomes appropriate to suggest policy recommendations encouraging increased cooperation among member states in an attempt to (i) expand and build new cross-states infrastructures, aimed at boosting communications and telecommunications networks, (ii) accelerate the trade facilitation process by addressing administrative red tapes that balloon both transaction costs and delays in the flows of goods across borders, seaports, and airports, and (iii) develop and diversify the industrial base in member states.

Description: Grain sorghum (Sorghum bicolor L.) has become a popular rotation crop in the Great Plains. The transition from conventional tillage to no-tillage production systems has led to an increase in the need for crop rotations. Some of the soils of the Great Plains are acidic, and there is concern that grain sorghum production may be limited when grown on acidic soils. The objective of this study was to evaluate the effect of soil pH for grain sorghum production. Potassium chloride-exchangeable aluminum was also analyzed to determine grain sorghum’s sensitivity to soil aluminum (Al) concentration. The relationship between relative yield and soil pH was investigated at Lahoma, Perkins, and Haskell, Oklahoma, USA with soil pH treatments ranging from 4.0–7.0. Soil pH was altered using aluminum sulfate or hydrated lime. Soil acidity reduced grain sorghum yield, resulting in a 10% reduction in yield at soil pH 5.42. Potassium chloride-exchangeable aluminum levels above 18 mg kg−1 resulted in yield reductions of 10% or greater. Liming should be considered to increase soil pH if it is below these critical levels where grain sorghum will be produced.

Description: Canola is grown mainly as an oil-seed crop, but recently the interest in canola has increased due to its potential as a biodiesel crop. The main objectives of this paper were to evaluate effects of abiotic factors and seed treatment on canola plant establishment and pest pressure in the Southern High Plains of Texas. Data was collected at two field locations during the first seven months of two field seasons. Based on multi-regression analysis, we demonstrated that precipitation was positively associated with ranked plant weight, daily minimum relative humidity and maximum temperature were negatively associated with plant weight, and that there may be specific optimal growth conditions regarding cumulative solar radiation and wind speed. The outlined multi-regression approach may be considered appropriate for ecological studies of canola establishment and pest communities elsewhere and therefore enable identification of suitable regions for successful canola production. We also demonstrated that aphids were about 35% more abundant on non-treated seeds than on treated seeds, but the sensitivity to seed treatment was only within four months after plant emergence. On the other hand, seed treatment had negligible effect on presence of thrips.

Description: A field experiment was conducted in a newly reclaimed soil at El-Saff region, El-Giza Governorate, Egypt to study the effects of different rates of nitrogen (N: 62 to 248 kg ha-1) with or without soil inoculation of sulfur- (S-) oxidizing bacteria (SoxB) and combined inoculation of SoxB and N-fixing bacteria (NFxB) on yield, quality and nutritional status of onion (Allium cepa L., “Giza 20”). Elemental S at 620 kg ha-1 was applied to all treatments. Application of N at 62, 124, and 248 kg ha-1 rates increased onion yield, plant height, and N uptake by 28 to 76%, 32 to 53%, and 61 to 145%, as compared to those of the plants that received no N. Inoculation of SoxB at various N rates increased onion yields by 47 to 69% and N uptake by 76 to 93%, as compared to those of the plants which received the respective rates of N but no SoxB inoculation. Inoculation with SoxB and NFxB increased onion yield by 221%, plant height by 62%, and N uptake by 629%, as compared to those of the plants grown without inoculation and no N applied.

Description: Cool-season grass species are commonly overseeded into bermudagrass turf for winter color. When the overseeded grass persists beyond the spring; however, it becomes a weed. The ability of perennial ryegrass, Italian (annual) ryegrass, intermediate ryegrass, and hybrid bluegrass to persist in bermudagrass one year after seeding was determined. Perennial ryegrass, intermediate ryegrass, and Italian ryegrass produced acceptable ground cover in the spring after fall seeding. Hybrid bluegrass did not establish well, resulting in unacceptable cover. Perennial ryegrass generally persisted the most one year after seeding, either because of summer survival of plants or because of new germination the following fall. Plant counts one year after seeding were greater in the higher seeding rate treatment compared to the lower seeding treatment rate of perennial ryegrass, suggesting new germination had occurred. Plant counts one year after seeding plots with intermediate ryegrass or Italian ryegrass were attributed primarily to latent germination and not summer survival. Applications of foramsulfuron generally did not prevent overseeded species stand one year after seeding, supporting the conclusion of new germination. Although quality is less with intermediate ryegrass compared to perennial ryegrass, it transitions out easier than perennial ryegrass, resulting in fewer surviving plants one year later.