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.

Knowledge about agricultural ecosystems, as well as about ecological and social interactions that occur in an agricultural context, is essential to promote a balanced environment for production. Incorporating the forest landscape into farming systems has promoted the development of integrated production systems such as agroforestry. However, many aspects of the relationship between farming and the forest landscape have changed since the modernization of agriculture introduced by the Green Revolution. The objectives of this review are: (1) to contribute to the understanding of the changes in cultivation strategies and in the dynamics of agricultural systems, particularly in the context of farming in Santa Catarina State, Brazil; (2) to contribute to the understanding of agroforestry systems as a strategy to reintroduce the element of forestry into agricultural production systems; and (3) to compile a list of forest plant species that could be used in agroforestry. The approach adopted in this manuscript seeks to highlight the potential of agroforestry systems to conserve natural resources and thereby to support agricultural development by connecting environmental conservation with income for farmers.

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.

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.

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.

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.

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.

The interior forest of protected area (PA) recover quickly in terms of greater diversity and structural complexity than peripheral and outsides, which may be due to high plant-frugivore interactions in the interior forest than the disturbed outsides. To describe the structural and functional differences in tree communities from interior to outside forests with in small PA, we quantitatively analyzed the vegetation of Trishna Wildlife Sanctuary, a rich primate habitat of Northeast India. Vegetation was sampled at ≥10 cm girth at breast height by 10 m × 500 m sized 20 line transects (10 ha) laid in the interior (N = 7), peripheral (N = 7) and outside (N = 6) zones of this sanctuary. All transects were ordinated by Principal Component Analysis based on correlation between diversity and existing disturbance indices. We found significant differences (P < 0.05) in taxonomic richness and diversity indices between the habitat. Van diagram confirmed greater unique species richness in the interior zone (64) than peripheral (28) and outside (6) zones. Overall density (ha⁻¹) did not differed across the zones, but basal area (m² ha⁻¹) was significantly (P < 0.01) high in peripheral zone. Vertical distribution of stem density was linearly declined across zones ($ r_{\text{adj}}^{2} $ > 0.70; P < 0.01) with increase in the canopy height. Horizontal distribution of adult stems showed significant inverse quadratic relationship ($ r_{\text{adj}}^{2} $ > 0.80; P < 0.001), which suggests very low density of canopy forming voluminous trees in the interior zone. Immediate protection, restoration and management of interior regions are required to preserve local plant genetic diversity and also to maintain suitable habitat for threatened wildlife.

Canopy gaps play a significant role in maintaining structure and composition of tropical forests. This study was carried out in tropical evergreen forests of central Western Ghats in India to understand the influence of canopy gap size and the relationship of gap regime attributes to diversity measures and regeneration. The average gap size in the study area was found to be 396 m² and around half of gaps were 4–8 years old. Gaps created by natural single tree fall were smaller in size but significantly higher in number. Diversity and regeneration of woody species were compared with canopy gaps and intact vegetation. Species richness and diversity was higher in gaps than in intact vegetation. Macaranga peltata, a shade intolerant species dominated gaps while intact vegetation was dominated by shade tolerant Kingiodendron pinnatum. Gap size significantly influenced species diversity and regeneration. Gap area and age were significantly and negatively correlated with diversity measures but positively correlated with regeneration. Among all the attributes of gaps, regeneration was significantly positively correlated with light intensity. Gaps maintained species diversity and favored regeneration of woody species. In addition to gap size and age, other gap ecological attributes also affected species diversity and regeneration.

We investigated the correlation of large fires (>300 ha) from 1992 to 2013 within the borders of the Antalya Regional Directorate of Forestry using the Keetch–Byram drought index (KBDI). Daily KBDI values were calculated for each year, and values for the period before the year 2000 differed significantly from those after 2000. After 2000 (large fires occurred in 2004, 2006, 2007, 2008, 2010, and 2013), when KBDI values increased, the KBDI, but not the number of fires, was inversely correlated with the natural log of the burned area (NLBA). While there were both high and low KBDI values when the NLBA was small, only high KBDI values were associated with high NLBA values. Particularly for logarithmic values of 4 and higher, KBDI values increased in parallel with increases in NLBA values. On the basis of a Mann–Whitney U test done in addition to a Pearson correlation test, we found that when the burned areas were grouped according to small and large areas, the KBDI could be used to distinguish the two groups. Using a conditional probability analysis, we found that 4th, 5th and 6th class KBDI values may lead to large fires at the 60 % possibility. Similarly, the possibility of large fires greater than the median burned area in any given 6 years was found to be 48 %. In addition, while the mean value of KBDI is 390.51 for the period from May to September for these 6 years, it is 359.93 for the other years. Consequently, the area burned also increased as the KBDI classes (Class 0: 0–99, Class 1: 100–199, Class 2: 200–299, Class 3: 300–399, Class 4: 400–499, Class 5: 500–599, Class 6: 600–699, and Class 7: 700–800) increase.

The most common scientific approach to numerical landscape-level forest management planning is combinatorial optimization aimed at finding the optimal combination of the treatment alternatives of stands. The selected combination of treatments depends on the conditions of the forest, and the objectives of the forest landowners. A two-step procedure is commonly used to derive the plan. First, treatment alternatives are generated for the stands using an automated simulation tool. Second, the optimal combination of the simulated treatment schedules is found by using mathematical programming or various heuristics. Simulation of treatment schedules requires models for stand dynamics and volume for all important tree species and stand types present in the forest. A forest planning system was described for Northeast China. The necessary models for stand dynamics and tree volume were presented for the main tree species of the region. The developed models were integrated into the simulation tool of the planning system. The simulation and the optimization tools of the planning system were described. The optimization tool was used with heuristic methods, making it possible to easily solve also spatial forest planning problems, for instance aggregate cuttings. Finally, the use of the system is illustrated with a case study, in which nonspatial and spatial management plans are developed for the Mengjiagang Forest District.

We determined a suitable amount of fertilizer for konara oak (Quercus serrata) and Japanese zelkova (Zelkova serrata) planted in a harvested pitch pine (Pinus rigida) plantation. Two-year-old bare-root seedlings of konara oak and one-year-old containerized seedlings of Japanese zelkova were planted in April 2011. Three plots were established for each tree species to evaluate each of three fertilization applications. Solid compound fertilizer (N:P:K = 3:4:1) was applied yearly in three amounts (control: no fertilization, F1: 180 kg ha⁻¹, and F2: 360 kg ha⁻¹), every May from 2011 to 2013. We measured the root collar diameter and height, and analyzed the compartmental N and P concentrations. Compartmental N concentrations of konara oak and Japanese zelkova were not consistent based on amount of fertilization. However, the compartmental P concentrations of konara oak and Japanese zelkova were significantly different in the order of F2, F1, and control. Although the differences in growth of konara oak appeared after 3 years of fertilization, Japanese zelkova showed differences after only 2 years of fertilization owing to differences in seedling type. Growth of konara oak was affected by fertilization at F1 and F2 in 2013. However, growth of Japanese zelkova was affected only at F2. Nutrient demand of Japanese zelkova appeard to be higher than that of konara oak, at least during the early growing period. Results from this study could be practically used in harvested pitch pine plantations to determine appropriate fertilization regimes.

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.

Modeling height–diameter relationships is an important component in estimating and predicting forest development under different forest management scenarios. In this paper, ten widely used candidate height–diameter models were fitted to tree height and diameter at breast height (DBH) data for Populus euphratica Oliv. within a 100 ha permanent plots at Arghan Village in the lower reaches of the Tarim River, Xinjiang Uyghur Autonomous Region of China. Data from 4781 trees were used and split randomly into two sets: 75 % of the data were used to estimate model parameters (model calibration), and the remaining data (25 %) were reserved for model validation. All model performances were evaluated and compared by means of multiple model performance criteria such as asymptotic t-statistics of model parameters, standardized residuals against predicted height, root mean square error (RMSE), Akaike’s information criterion (AIC), mean prediction error (ME) and mean absolute error (MAE). The estimated parameter a for model (6) was not statistically significant at a level of α = 0.05. RMSE and AIC test result for all models showed that exponential models (1), (2), (3) and (4) performed significantly better than others. All ten models had very small MEs and MAEs. Nearly all models underestimated tree heights except for model (6). Comparing the MEs and MAEs of models, model (1) produced smaller MEs (0.0059) and MAEs (1.3754) than other models. To assess the predictive performance of models, we also calculated MEs by dividing the model validation data set into 10-cm DBH classes. This suggested that all models were likely to create higher mean prediction errors for tree DBH classes >20 cm. However, no clear trend was found among models. Model (6) generated significantly smaller mean prediction errors across all tree DBH classes. Considering all the aforementioned criteria, model (1): $ {\text{TH}} = 1.3 + {\text{a}}/\left( {1 + {\text{b}} \times {\text{e}}^{{ - {\text{c}} \times {\text{DBH}}}} } \right) $ and model (6): $ {\text{TH}} = 1.3 + {\text{DBH}}^{2} /\left( {{\text{a}} + {\text{b}} \times {\text{DBH}} + {\text{c}} \times {\text{DBH}}^{2} } \right) $ are recommended as suitable models for describing the height–diameter relationship of P. euphratica. The limitations of other models showing poor performance in predicting tree height are discussed. We provide explanations for these shortcomings.

Bamboo forest is an important land use in the traditional village of Penglipuran, Bali Indonesia. Bamboo growing in the rural areas can be a good choice for capturing CO₂. I harvested selected culms to determine biomass content, and 50 % of dry weight biomass was calculated as carbon content. The Penglipuran bamboo forest supported six bamboo species in a one hectare sampling plot, all of the genus Gigantochloa. The clump and culm densities were 339 and 7190 ha⁻¹, respectively. Total above- plus below-ground biomass was 87.35 Mg ha⁻¹, and carbon storage was 43.67 Mg ha⁻¹. Carbon storage estimated in the bamboo forest at Penglipuran offers insight into the opportunity for PES (payment for ecosystem services) through emission trading mechanisms.

Mid-subtropical forests are the main vegetation type of global terrestrial biomes, and are critical for maintaining the global carbon balance. However, estimates of forest biomass increment in mid-subtropical forests remain highly uncertain. It is critically important to determine the relative importance of different biotic and abiotic factors between plants and soil, particularly with respect to their influence on plant regrowth. Consequently, it is necessary to quantitatively characterize the dynamic spatiotemporal distribution of forest carbon sinks at a regional scale. This study used a large, long-term dataset in a boosted regression tree (BRT) model to determine the major components that quantitatively control forest biomass increments in a mid-subtropical forested region (Wuyishan National Nature Reserve, China). Long-term, stand-level data were used to derive the forest biomass increment, with the BRT model being applied to quantify the relative contributions of various biotic and abiotic variables to forest biomass increment. Our data show that total biomass (t) increased from 4.62 × 10⁶ to 5.30 × 10⁶ t between 1988 and 2010, and that the mean biomass increased from 80.19 ± 0.39 t ha⁻¹ (mean ± standard error) to 94.33 ± 0.41 t ha⁻¹ in the study region. The major factors that controlled biomass (in decreasing order of importance) were the stand, topography, and soil. Stand density was initially the most important stand factor, while elevation was the most important topographic factor. Soil factors were important for forest biomass increment but have a much weaker influence compared to the other two controlling factors. These results provide baseline information about the practical utility of spatial interpolation methods for mapping forest biomass increments at regional scales.

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.

The influence of aryl amide compounds (TMB) as β-nucleating agents, on the non-isothermal crystallization of a wood-flour/polypropylene composite (WF/PP) prepared by compression molding was investigated by wide-angle X-ray diffraction and differential scanning calorimetry. TMB was proved to be an effective β-crystalline nucleating agent for WF/PP. The DSC data showed that the crystallization peak temperature (T _p) increased and the half-time (t _1/2) decreased with the addition of TMB. Three theoretical models were used to analyze the non-isothermal crystallization process. The modified Avrami method and Mo method successfully explained the non-isothermal crystallization behavior of PP and its composites. Their activation energies for non-isothermal crystallization were determined basing on the Kissinger method.