Diversity-biomass relationships are shaped by tree mycorrhizal associations and stand structural diversity at different spatial scales  

作　　者：Rui Zhang Shuaifeng Li Xiaobo Huang Cong Li Chonghua Xu Jianrong Su 

机构地区：[1]Institute of Highland Forest Science,Chinese Academy of Forestry,Kunming,650224,China [2]Pu'er Forest Ecosystem Research Station,National Forestry and Grassland Administration,Kunming,650224,China [3]Pu'er Forest Ecosystem Observation and Research Station of Yunnan Province,Pu'er,665000,Yunnan,China [4]Nanjing Forestry University,Nanjing,210037,China [5]Taiyanghe Provincial Nature Reserve,Pu'er,665000,Yunnan,China

出　　处：《Forest Ecosystems》2024年第6期781-792,共12页森林生态系统(英文版)

基　　金：funded by Fundamental Research Funds of Chinese Academy of Forestry(No.CAFYBB2021ZA002).

摘　　要：Diversity-biomass relationships(DBRs)in terrestrial ecosystems tend to vary across spatial scales,but,particularly in hyperdiverse forests,the mechanisms driving these trends remain uncertain.Until now,few have simultaneously investigated the connections between tree species diversity,stand structural diversity,mycorrhizal associations,and ecosystem functioning.In addition,DBRs have only been studied at limited spatial scales,with limited focus on the direct and indirect effects of environmental factors.We addressed these research gaps using a 30-ha forest dynamics plot located in Pu'er City,Southwest China.Through piecewise structural equation models,we quantified the direct effects of tree species diversity(α,β,γ),stand structural diversity,mycorrhizal associations(AM,EcM),and the environmental factors(soil fertility and topography),as well as the indirect effects of the environmental factors on aboveground tree biomass across spatial scales ranging from 400 to 230,400 m^(2).We hypothesized that complex interactions among these factors underpin the variation in DBRs in natural ecosystems across spatial scales.Our results showed that environmental conditions indirectly affected the tree biomass via changes in tree species diversity,and these effects became stronger as the spatial scale increased.At small to moderate spatial scales,environmental factors were more predictive of tree biomass than tree species diversity(or its components);the effects of stand structural diversity on biomass also gradually increased with spatial scale.Conversely,from the intermediate to the largest spatial scales,mycorrhizal associations gradually became the best predictors of DBR dynamics.Our research offers novel empirical evidence demonstrating the importance of environmental conditions,structural diversity,and mycorrhizal associations in shaping cross-scale DBRs.Future comprehensive studies should consider these factors to assess the mechanisms shaping scale-dependent DBRs in complex natural ecosystems.

关 键 词：Spatial scales Mycorrhizal dominance Aboveground biomass Environmental factors Stand structural diversity Biodiversity-ecosystem functioning Monsoon evergreen broad-leaved forest 

分 类 号：TP3[自动化与计算机技术—计算机科学与技术]