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Yang X.-D.,East China Normal University | Yang X.-D.,Tiantong National Forest Ecosystem Observations and Research Station | Zhang X.-N.,Xinjiang University | Zhang X.-N.,Xinjiang Key Laboratory of Oasis Ecology | And 4 more authors.
PLoS ONE | Year: 2014

The hydraulic redistribution (HR) of deep-rooted plants significantly improves the survival of shallow-rooted shrubs and herbs in arid deserts, which subsequently maintain species diversity. This study was conducted in the Ebinur desert located in the western margin of the Gurbantonggut Desert. Isotope tracing, community investigation and comparison analysis were employed to validate the HR of Populus euphratica and to explore its effects on species richness and abundance. The results showed that, P. euphratica has HR. Shrubs and herbs that grew under the P. euphratica canopy (under community: UC) showed better growth than the ones growing outside (Outside community: OC), exhibiting significantly higher species richness and abundance in UC than OC (p<0.05) along the plant growing season. Species richness and abundance were significantly logarithmically correlated with the P. euphratica crown area in UC (R2 = 0.51 and 0.84, p<0.001). In conclusion, P. euphratica HR significantly ameliorates the water conditions of the shallow soil, which then influences the diversity assembly in arid desert communities. © 2014 Yang et al. Source

Ali A.,East China Normal University | Ali A.,Tiantong National Forest Ecosystem Observations and Research Station | Ali A.,Abdul Wali Khan University Mardan | Xu M.-S.,East China Normal University | And 11 more authors.
Silva Fennica | Year: 2015

Species-specific allometric equations for shrubs and small trees are relatively scarce, thus limiting the precise quantification of aboveground biomass (AGB) in both shrubby vegetation and forests. Fourteen shrub and small tree species in Eastern China were selected to develop species-specific and multispecies allometric biomass equations. Biometric variables, including the diameter of the longest stem (D), height (H), wet basic density (BD), and crown area and shape were measured for each individual plant. We measured the AGB through a non-destructive method, and validated these measurements using the dry mass of the sampled plant components. The AGB was related to biometric variables using regression analysis. The species-specific allometric models, with D and H as predictors (D-H models) accounted for 70% to 99% of the variation in the AGB of shrubs and small trees. A multispecies allometric D-H model accounted for 71% of the variation in the AGB. Although BD, as an additional predictor, improved the fit of most models, the D-H models were adequate for predicting the AGB for shrubs and small trees in subtropical China without BD data. © 2015 Istanbul Universitesi. All rights reserved. Source

Yang X.-D.,East China Normal University | Yang X.-D.,Tiantong National Forest Ecosystem Observations and Research Station | Yan E.-R.,East China Normal University | Yan E.-R.,Tiantong National Forest Ecosystem Observations and Research Station | And 5 more authors.
Trees - Structure and Function | Year: 2015

Abstract: Linking temporal pattern of tree architecture with changing light conditions through forest succession is important for understanding plant adaptive strategies. We determined vertical (canopy, sub-canopy, and understory species) and temporal (pioneer, mid-successional, and climax species) patterns of tree height, stem basal area, crown area and depth, leaf coverage, leaf convergence (clumped vs. dispersed leaves) and stretch direction of branches (vertical, leaned and horizontal branches) and their relationship with crown exposure index (CEI) for woody plants among three successional series in subtropical evergreen broad-leaved forests in eastern China. The series included three stages: secondary shrub (early-), young (mid-) and climax forests (late-successional stage). Tree height, crown area and depth, stem basal diameter and leaf coverage were the greatest in canopy trees, intermediate in sub-canopy trees, and the smallest in understory plants among the three successional stages; the above parameters and the proportions of dispersed leaves and leaned branches were climax > mid-successional > pioneer species. In contrast, the proportions of clumped leaves and vertical branches were pioneer > mid-successional > climax species. Between canopy and understory species, the patterns of branch stretch direction and leaf convergence were not consistent among the three successional stages. Tree height, crown area and depth, leaf coverage, and stem basal diameter were positively correlated with CEI for both vertically different species and successional species. Tree architectural traits were interactively affected by forest age and CEI (p < 0.01). In conclusion, tree architecture varies with changes in both forest vertical structure and successional status. The large variability of tree architectural traits in relation to CEI and forest age reflects a strong control of light availability that affects biomass allocation strategies of trees. Our study demonstrated that light induced shift in tree architecture may result in species coexistence through divergence of vertical space, as well as species replacement through forest succession.Key message: Vertical and temporal patterns of tree architecture and their relationship with woody plant crown exposure index varied with succession in evergreen broad-leaved forests in eastern China. © 2014, Springer-Verlag Berlin Heidelberg. Source

Ali A.,East China Normal University | Ali A.,Tiantong National Forest Ecosystem Observations and Research Station | Ma W.J.,East China Normal University | Ma W.J.,Tiantong National Forest Ecosystem Observations and Research Station | And 8 more authors.
Journal of Forest Science | Year: 2014

Quantitative relationships between stand indices and carbon dioxide (CO2) stocking are missing in the evergreen broadleaved forests (EBLFs) in eastern China and this hinders to estimate carbon (C) budget in the subtropical region. We determined the vegetation-soil C pool and CO2 stocking using stand indices [diameter at breast height (DBH), total height (H) and wood density] in Schima superba dominated EBLFs in the Tiantong National Forest Park in eastern China. Vegetation biomass was determined by a non-destructive method using the tree volume and wood density approach while soil C concentration was determined using the oil bath-K2CrO 7 titration method. Finally, multiple regression and one-way ANOVA with LSD test were used for data analysis. Results showed that total C stocks in the vegetation and the 0-20 cm surface soil were 90.53 t·ha-1 and 116.24 t·ha-1, respectively. The study revealed that the total amount of CO2 stocks in the studied forest is 331.87 t·ha-1. One-way ANOVA with LSD test showed that CO2 stocks varied significantly (P < 0.05) between the tree growth stages. There was a significant variation in CO2 stocking capacity within sapling and pole growth stages but no significant variation within standard stage. The stepwise multiple regression analysis showed that DBH, BA and H were related to the C stocking while wood density had no significant effect. The significant amount of C stocking in EBLFs in the Tiantong National Forest Park of eastern China showed the potential and significant C stocks by trees. As the C pool structure changes due to a change in the forest type and location, therefore this study is important to estimate C stocks and predict CO2 stocks from stand indices in EBLFs which serve as a scientific basis for sustainable forestry operations, rational utilization of forest resources and global warming reduction in EBLFs in subtropical regions of China. Source

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