功能多样性对典型阔叶红松林生产力的影响

Effects of functional diversity on productivity in a typical mixed broadleaved-Korean pine forest

为比较生物量比率假说与生态位互补假说在解释生产力变异的相对重要性,探讨生物多样性和生产力之间的关系是否受到生物和非生物因素的影响,该研究依托小兴安岭9 hm^2阔叶红松(Pinus koraiensis)林动态监测样地,通过计算群落初始生物量、物种多样性、功能多样性、植物性状的群落加权平均值和测定环境因子,运用线性回归模型、结构方程模型,比较了物种多样性和功能多样性与生产力的相关性。结果表明:(1)物种多样性和功能多样性均对生产力有显著作用,功能多样性比物种多样性与生产力的关系更为密切;(2)功能多样性指数比群落加权平均值能更好地解释生产力变异,说明生态位互补假说更适用于解释阔叶红松林群落内生产力的变异;(3)生物多样性与生产力的关系受生物因素与非生物因素的共同作用,相较于多样性和功能性状组成(植被质量),初始林分生物量(植被数量)能更有效地解释生产力的变异。生物多样性与生产力关系的研究应从植被质量与植被数量同时出发,评估生态系统过程的多种非生物和生物驱动因素,同时维护森林功能多样性,加强植物与土壤环境的保护,对有效增加生产力和维持生物多样性具有重要意义。

Aims Exploring the relationship between biodiversity and ecosystem productivity has become a hot topic in ecological research.The results support the mass ratio hypothesis and niche complementarity hypothesis,but their relative importance is still controversial.Our aim is to test the relative importance of these two hypotheses in explaining the variability of productivity,and to explore whether the relationship between biodiversity and productivity is influenced by both biotic and abiotic factors.Methods We used the data of woody plants in a 9 hm2 typical mixed broadleaved-Korean pine forest.By calculating the initial biomass,species diversity,functional diversity,community-weighted mean functional traits and measuring environmental factors,we analyzed the relationship between diversity and productivity by the linear regression model and structural equation model.Important findings The results showed that:(1)Both species diversity and functional diversity played a significant role in productivity,and functional diversity was more closely related to productivity than species diversity;(2)the functional diversity index could better explain the variation of productivity than community-weighted mean functional traits.It suggested that the niche complementarity hypothesis was more suitable for explaining the variation of productivity in the mixed broadleaved-Korean pine forest;(3)the relationship between biodiversity and productivity was affected by biotic and abiotic factors,and compared with diversity and functional character composition(vegetation quality),initial stand biomass(vegetation quantity)could explain the variation of productivity more effectively.Our study suggests that,it is important to maintain forest functional diversity and strengthen the protection of plants and soil environments to increase productivity and biodiversity effectively.