Relationships between tree diversity and biomass/productivity and their influence factors in a lower subtropical evergreen broad-leaved forest

Abstract

www.biodiversity-science.net 研究报告 indirectly. Therefore, it is a critical issue of ecology. The aim of this study is to quantitatively explore the relationship between tree diversity and biomass or productivity of subtropical natural forest ecosystems in late successional stages. Methods: Based on long-term community surveys of topographies and soil nutrients from permanent forest ecosystems in the subtropical evergreen broad-leaved forest, we analyzed the relationship between tree diversity and productivity/biomass and their influencing factors. In this analysis, the correlations between tree diversity and each factor were evaluated using a Pearson correlation analysis. The single and shared effects of each factor were quantified by variance partitioning analysis (VPA). In addition, the relationships between soil nutrients and topographies and their effects on productivity and biomass were further evaluated, either directly or indirectly, through species and structural diversity by using a structural equation model (SEM). Result: Species diversity displayed a negative correlation with biomass and a positive correlation with productivity. Contrarily, structural diversity was positively correlated with biomass and negatively correlated with productivity. The effects of environment factors on tree diversity and biomass/productivity were varied. Specifically, soil moisture had a significant effect on productivity, species diversity was correlated with soil nutrients and topographies, and structural diversity was strongly related to soil nutrients. The variance partitioning analysis results indicated that the single effect of structural diversity explained the largest portion of variance in biomass (35.39%) and productivity (5.21%), followed by the shared effect of structural and species diversity on biomass (13.66%) and productivity (3.53%). Soil nutrients and topographies explained less variation in productivity and biomass. The structural equation results analysis indicated that structural diversity had a direct positive effect on biomass, and biomass had a strong direct negative effect on productivity. Structural diversity indirectly reduced productivity by increasing biomass. Soil nutrients and topographies were mainly affected by biomass, while productivity indirectly affected tree species and structural diversity. Conclusions: These results indicate that (1) species diversity had the greatest direct effect on productivity, and structural diversity had the greatest direct effect on biomass in southern subtropical evergreen broad-leaved forests; (2) species diversity explained productivity better than structural diversity, while structural diversity explained biomass accumulation better than species diversity; and (3) both species diversity and structural diversity can be affected by soil nutrients and topographies.

Topography and Soil Properties Determine Biomass and Productivity Indirectly via Community Structural and Species Diversity in Karst Forest, Southwest China

“…In this study, it was found that the community structure was complex in the environment with high content of soil phosphorus and soil available potassium in karst primeval forest. While the environment with high soil organic carbon and soil nitrogen content reduced community structure, which was similar to the results of Zhu Jie et al's study [50]. The possible causes: soil nitrogen deposition affects the changes of species diversity and structural diversity, and the more nitrogen in soil, the lower the community species diversity and structural diversity, and the lower the biodiversity will affect the growth of forest productivity.…”

“…Species in natural communities have evolved over a long period of time, forming a specific community structure of interdependence and interaction between species and the environment. The results of showed that topographic factors had no significant effect on biomass and productivity, which was consistent with the results of Zhu Jie et al's study on evergreen broad-leaved forests in the subtropical region [50], and different from the results of Wu Chuping' s study on secondary forest in Dinghai, Zhejiang [15], this indicates that the structure of the community is influenced by region and forest type. Elevation was positively correlated with species diversity, while slope was negatively correlated with species diversity.…”

“…It is also that when the individual species distribution is more uneven, productivity is higher [44]. However, species diversity was negatively correlated with biomass, which is consistent with Zhu, J. et al [50], and contrary to Wu, C. et al [15]. The total biomass of the community mainly depends on the species with high carbon storage.…”

Scale‐dependent effects of species diversity on aboveground biomass and productivity in a subtropical broadleaved forest on Mt. Huangshan

“…In a grassland ecosystem, Adler et al ( 2011 ) found that species diversity was not a good predictor of community productivity at different sampling scales. A possible explanation is that the available resources not only affect the maximum biomass that can be achieved by species in the area but also cause biomass to stop increasing (Zhu et al, 2021 ). On the other hand, scale can also lead to resource competition among species, thereby affecting the number of species.…”

“…Stands with high species diversity often have more complex stand structures and edge effects, and such stands can better utilize sunlight and soil fertility, thereby changing the microclimate in the forest and improving the growth environment in forest areas (Zhu et al, 2021 ). Furthermore, this can increase the nutrient content of the soil, improve the speed of nutrient flow and circulation, and continuously improve soil fertility, resulting in more new tree species in a given plot, decreased tree mortality, and allowing existing trees to obtain higher biomass (Wu et al, 2018 ; Zhu et al, 2021 ). Future studies should explore the effects of soil nutrients, light, and other environmental factors on biomass, productivity, and species community structure.…”