黄土丘陵区生物多样性与生态系统功能响应关系的分析

Analysis on the Relationship between Biodiversity and Ecosystem Function in Loess Hilly Region

为探究黄土高原植物群落生物多样性与生态系统功能的关系,本研究以黄土丘陵区不同环境条件下稳定的自然植物群落为对象,采用3个物种多样性指数(Shannon-Wiener指数、Simpson优势度指数、Pielou均匀度指数)和4个功能多样性指数(FRic功能丰富度、FDiv功能趋异指数、FEve功能均匀度和FDis功能离散度),选取地上生物量(Aboveground biomass,AGB)、土壤全氮(Soil total nitrogen,STN)、土壤有机碳(Soil organic carbon,SOC)和土壤全磷(Soil total phosphorus,STP)作为生态系统功能指标,运用冗余分析和全因子回归的方法对影响生态系统功能的因素进行分析。结果表明:Shannon指数、STP随降雨量和气温递增呈现先递增后递减的趋势,FRic呈递减趋势,FDiv,AGB,SOC,STN呈递增趋势(P<0.05);年均降雨量Pa对生态系统功能的贡献值达到21.5%,功能多样性指数(FDiv,FDis,FEve)对生态系统功能的贡献值要高于物种多样性(Shannon指数),且显著影响AGB和STP(P<0.05)。综上所述,在黄土丘陵区降雨量主要影响着生态系统功能,功能多样性对生态系统功能的影响程度比物种多样性更大。本研究可为黄土高原生物多样性和生态系统功能的恢复提供理论依据。

Under different environmental conditions in Loess Hilly Region,we analyzed three species diversity indexes(Shannon-Wiener index,Simpson index,Pielou index),four functional diversity indexes(functional richness,functional divergence,functional evenness,functional dispersion)in the stable natural plant communities,and four ecosystem function indicators(aboveground biomass,soil total nitrogen,soil organic carbon,soil total phosphorus),to examine the relationship between the biodiversity of plant communities and ecosystem function in Loess Hilly Region.The redundancy analysis and full factor regression were used to identify the factors which affect ecosystem functions.The results showed that the Shannon index and STP had a trend of increasing first and then decreasing with the increasing of precipitation and temperature(P<0.05).Under different environmental conditions,FRic showed a decreasing trend,while FDiv,AGB,SOC and STN an increasing trend(P<0.05).According to redundancy analysis,the contribution value of average annual precipitation to ecosystem function reached to 21.5%.The contribution value of functional diversity index to ecosystem function was higher than that of species diversity,and significantly affected the aboveground biomass and soil total phosphorus.In summary,precipitation mainly affected the ecosystem function in Loess Hilly Region,and functional diversity had a greater impact on ecosystem functions than species diversity.This study could provide theoretical basis for the restoration of biodiversity and ecosystem functions in the Loess Plateau.