ALBERT

Description: In order to improve environment and relieve poverty, China has launched a series of major ecological engineering programs since the 1980s. These include the Natural Forest Conservation Program, the Sloping Cropland Conversion Program, the Desertification Combating Program, and the Protection Forest System Construction Program. There is a growing need to quantify the contributions of these programs to regional carbon stocks. However, the lack of widely accepted, robust methods is one of the key obstacles to quantification. The objective of this study was to review existing methods for quantifying regional carbon stocks and then recommend suitable ones for the Chinese ecological engineering programs. We expect that the recommended methods can be applied to elsewhere in the world where there are similar characteristics and objectives.

Description: The ethylene-responsive factor family is one of the largest families of plant-specific transcription factors that are involved in plant development and stress responses. Previously, we demonstrated that the gene ThERF1 , encoding a novel ethylene-responsive factor from Tamarix hispida , negatively modulates abiotic stress tolerance. In the present study, Arabidopsis plants overexpressing ThERF1 had decreased oxidative tolerance and increased transpirational water loss rate compared with wild-type plants, leading to sensitivity to abiotic stress. Real-time RT-PCR showed that the upstream regulator of ThERF1 , ThWRKY2 , is involved in responses to different abiotic stresses. Furthermore, both ThWRKY2 and ThERF1 shared similar expression patterns in the stems and leaves of T. hispida when exposed to salinity, drought and abscisic acid. Chromatin immunoprecipitation assays further confirmed that ThWRKY2 can directly bind to the promoter of ThERF1 and regulate its expression. This study revealed the regulatory mechanism of ThERF1 expression in response to abiotic stresses in T. hispida .

Description: Insufficient knowledge of the germination ecology of local species is one of the main constraints to restoration of degraded rural lands. We tested seeds from fourteen Sudanian savanna species targeted for restoration for their response to two different pretreatments (conventional and prolonged acid pretreatments) and two different storage conditions (ambient room conditions and refrigerator at 4 °C). For 6 of the studied species, longer soaking in sulphuric acid significantly improved germination rates and also reduced the germination time of some species. Storage condition, in general did not affect germination rates except for two species where cool storage depressed germination. The practical implication is that, for the species tested, when mature seeds are collected for plantation in the upcoming rainy season, there is no need to invest in infrastructure and energy for storing in cold conditions. The study also revealed that in general when seeds are stored in ambient conditions from the time of collection up to seeding time, although germination rate does not increase, germination time is shortened and this could be of great interest in synchronizing germination in real field conditions.

Description: Subalpine dark coniferous forests in the western Sichuan Province of China play an important role in the hydrological processes in the upper reaches of the Yangtze River. Second-growth forests, with different stand successional stages, have developed as a result of logging over the past 50 years. Forest cover and stand structure changed greatly with concomitant degradation of forest ecosystem functions. To understand how the stand structures of the second-growth forests change during the stand succession process, we analyzed stand structure characteristics and an old-growth state index of the bamboo and moss-forest types. We found that stand structure at the young successional stage featured one-third of the structure characteristics of the old-growth dark coniferous forests, while the structure of the medium-aged stage had reached half the structure of the old-growth state. The two forest types were similar in the rate of development at the young successional stage but differed at the medium-aged stage; the moss-forest type had more advanced development than the bamboo-forest type at the medium-aged successional stage.

Description: Assessment of regional forest carbon stocks and underlying controls is critical for guiding forest management in the context of carbon sequestration. We investigated the variations in tree biomass carbon stocks relating to forest types, and estimated the total tree biomass carbon stocks and projected gains through natural stand development by 2020 and 2050 in the Daqing Mountain Nature Reserve based on Category II data of the Forest Inventory of Inner Mongolia for the period ending 2008. Over a total area of 388,577 ha, this nature reserve currently stores an estimated 2221 GgC in tree aboveground biomass alone, with potential to grow by more than 30 % to reach 2938 GgC by 2020 and nearly double to 4092 GgC by 2050 through natural development of the existing forest stands. The tree biomass carbon density and potential gain in tree biomass carbon stocks vary markedly among forest types and with stand development. The variations in the potential change of tree biomass carbon density for the periods 2008–2020 and 2008–2050 among forest types partly reflect the varying relationships of tree biomass carbon density with stand age for different tree species, and partly are attributable to variations in the stand age structure among different forest types. Of the major forest types, the ranking of projected changes in tree biomass carbon density are not consistent with variations in the relationship between tree biomass carbon density and stand age, neither are they explainable by variations in stand age structures, implying the interactive effect between forest type and stand dynamics on temporal changes in tree biomass carbon density. Birch rank highest for future biomass carbon sequestration because of its dominance in cover area and better age structure for potential gain in tree biomass carbon stocks. Poplar and larch were out-performers compared to other forest types given their greater contribution to total tree biomass carbon stocks relative to their distributional areas. Findings in this study illustrate that protection and proper management of under-aged forests can deliver marked gains in biomass carbon sequestration. This is of great importance to policy-makers as well as to scientific communities in seeking effective solutions for adaptive forest management and mitigation of anthropogenic greenhouse gases emissions using forest ecosystems.

Description: Peroxidase plays important roles in many stress-related interactions and catalyzes important reactions in various physiological processes. Since peroxidase played critical roles in the evolution of almond ( Prunus dulcis Miller (D.A Webb) syn P. amygdalus Batsch), peroxidase-gene-based analyses may increase the understanding of evolution of this species. Peroxidase gene polymorphism (POGP) markers were used to determine genetic diversity and relationships among 69 Turkish genotypes/cultivars and 27 foreign almond cultivars by using unweighted pair group method with arithmetic mean (UPGMA) analysis. This study is the first evaluation of the use of POGP markers for diversity analysis in almond. Totally, 83 fragments were obtained from eight peroxidase primer pairs, and polymorphism was identified as 94 %. Similarity level among the genotypes ranged between 0.63 and 0.93, and all materials were distinguished. In general, Turkish and foreign genotypes were mixed in clusters since they share a common genetic background and gene migration among the sites. Clusters were not based on geographic regions except for some minor groupings. This study indicated that peroxidase gene markers can be reliably used to determine genetic relationships in almonds.

Description: Thus far, measurements and estimations of actual evapotranspiration (ET) in extremely arid areas are still insufficient. Based on successive observations from June–September 2014, we simulated ET of a Populus euphratica Oliv. forest during the growing season in an extremely arid region of northwest China using the Shuttleworth–Wallace (S–W) model. Simulated ET values were compared to those of the eddy-covariance (EC) method on a 1 h interval. With a root mean square error (RMSE), relative error (RE) and mean absolute error (MAE) of 0.192, 3.100 and 0.165 mm h −1 , respectively, model performance was not satisfactory. In particular, on days with strong winds (Sep. 11–13), deviations between simulated and observed ET values increased to 0.275, 0.878 and 0.251 mm h −1 , RMSE, RE and MAE respectively. These values were significantly greater than those in other study periods and were most likely owing to sharp increases in wind speed. As a result, there were substantial advective effects, which is not consistent with the assumption of the S–W model that there are no advective effects or mesoscale circulation patterns induced by surface discontinuities.

Description: Hevea brasiliensis is a commercially cultivated species for its natural rubber (NR) latex in South East Asian countries. To meet the ever-increasing demand, NR cultivation has been extended to non-traditional regions due to the limited scope of further expansion in traditional rubber-growing areas in India. These areas are often confronted with various abiotic stresses, especially high and low temperatures, which cause reduction in plant growth, thereby increasing its uneconomical immaturity period. Eighteen wild Hevea accessions along with two modern clones RRII 203 and PB 235 and two check clones RRIM 600 and Haiken 1 were evaluated in the early mature growth phase. The site was at Nagrakata, West Bengal, the sub-Himalayan cold-prone region of India. In Hevea , crop production is governed by two major factors, growth-vigor and production capacity. Growth-vigor is of special importance because the production of rubber is a process linked with the early growth of the plant, which results in early tappability and early economic gains. The genotypes exhibited highly significant clonal differences (P = 0.05) for all the growth traits. Tappability percentage in the seventh year, ranged from 0.33 % (AC 3074, AC 3075, AC 3293) to 89.67 % (RO 2727). The most vigorously growing accession (RO 2727) reached tappabile girth early in the seventh year when the girth of plant ranged from 22.38 cm (AC 3293) to 53.12 cm (RO 2727). The general mean was 43.32 cm, and the similar growth trend was exhibited by these accessions in the tenth year also. Annual girth increment (cm a −1 ) over 3 years ranged from 1.81 cm (AC 3075) to 6.80 cm (RO 2727). The mean winter girth increment (cm a −1 ) over 4 years ranged from 0.13 cm (AC 3075) to 0.96 cm (RO 2727) as compared to the check clone RRIM 600 (1.11 cm) and Haiken 1 (1.10 cm). Wide differences between the phenotypic coefficient of variation (50.29) and genotypic coefficient of variation (24.82) were observed for winter girth increment. Girth in the tenth year recorded the highest heritability (87 %). Girth was significantly correlated with the other growth traits. The top 30 % of the potential accessions showing high growth vigour and early tappability under cold stress were identified. These ecotypes/selections have high potential value for the development of cold-tolerant clones for these regions and also in broadening the genetic base of the present-day cultivated rubber.

Description: We collected acorns from selected Quercus robur and Quercus petraea mother trees growing at stations with different depths to the water table. We produced pairs of micro-cuttings from these single acorns. The obtained pairs of cuttings represented phenotypes of high similarity according to photosynthetic parameters. These pairs of cuttings were used to test the plasticity of response to contrasting water regimes. For each pair, one cutting was submitted to drought and the other was submitted to waterlogging. Drought response was recorded according to gas exchange traits (stomatal closure and water use efficiency). The response to waterlogging was recorded according to the capacity to form hypertrophied lenticels and to maintain the CO 2 assimilation rate. Intermediary phenotypes presenting both high water use efficiency and the capacity to develop hypertrophied lenticels were expected.

Description: MADS-box transcription factors show highly diverse regulatory functions in a wide variety of organisms. In this study, we characterized a MADS-box gene ( BpMADS12 ) from the white birch ( Betula platyphylla Suk). This gene is a member of the suppressor of overexpression of CO 1/tomato MADS 3 class of MADS-box genes. We generated lines overexpressing BpMADS12 and found that these had higher levels of lignin compared to that observed in nontransgenic lines. Transcriptome analysis revealed numerous changes in gene expression patterns. In total, 8794 differentially expressed genes were identified, including 5006 upregulated unigenes and 3788 downregulated unigenes in BpMADS-overexpression lines. Differentially expressed genes involved in the pathways for lignin and brassinosteroid biosynthesis were significantly enriched and may have contributed to phenotypic changes. The results from a quantitative RT-PCR analysis were consistent those obtained with the transcriptome analysis. Our transcriptome analysis, in combination with measurement of lignin level, indicated that BpMADS12 promotes lignin synthesis through regulation of key enzymes in response to brassinosteroid signaling. These results suggest that this MADS-box protein is crucial to all subsequent structural events and provide a good foundation for studies aiming to elucidate the developmental mechanisms underlying formation of wood.