Noncommercial forests need type- and age-differentiated conservation measures: A case study based on 600 plots in Zhejiang Province in eastern China

Global climate change and unprecedented human activities have significantly endangered forest biodiversity and productivity. Understanding the biodiversity-ecosystem functioning (BEF) relationship is the basis for forest management and the formulation of biodiversity conservation strategies. Forest productivity is one of the most important ecosystem functions. In this study, multiple stepwise linear regression methods were used to model the biomass and environment factors of 600 plots in the Qiantang River Basin in eastern China. We used seven types of linear models to simulate the BEF relationships with three age stages (age stage 1:60 yr old) of pine forests, mixed forests and broad-leaved forests. Our results showed that the biomass of pine and mixed forests was significantly correlated with elevation and canopy density, and that of broad-leaved forest was correlated with canopy density. Furthermore, we found that the BEF relationships of pine forests and mixed forests are positive, while that of broad-leaved forests are negative, especially in old-growth broad-leaved forests. Thus, our results recommend some differentiated management plans: for pine forests and mixed forests, positive management is recommended, such as replanting some broadleaf species, while for those broad-leaved forests, keeping them maintaining natural succession state (avoid any management measures) is recommended. Our study provides more detailed data and references for carbon storage capacity and management of subtropical forests.