Land-cover change alters stand structure, species diversity, leaf functional traits, and soil conditions in Cambodian tropical forests

Abstract

Given the severe land-use and land-cover change pressure on tropical forests and the high demand for field observations of ecosystem characteristics, it is crucial to collect such data both in pristine tropical forests and in the converted deforested land-cover classes. To gain insight into the ecosystem characteristics of pristine tropical forests (EFs), regrowth forests (RFs), and cashew plantations (CPs), we established an ecosystem monitoring site in Phnom Kulen National Park, Cambodia. Here, we present the first observed datasets at this site of forest inventories, leaf area index (LAI), leaf traits of woody species, a fraction of intercepted photosynthetically active radiation (fPAR), and soil and meteorological conditions. Using these data, we aimed to assess how land-cover change affects stand structure, species diversity, leaf functional traits, and soil conditions among the three land-cover classes and to evaluate the feasibility of locally calibrated diameters at breast height (DBHs) and tree height (H) allometries for improving aboveground biomass (AGB) estimation. We found significant differences in these ecosystem characteristics, caused by the anthropogenic land-cover conversion, which underlines land-cover change’s profound impact on stand structure, species diversity, leaf functional traits, and soil conditions in these tropical forest regions. Our results further demonstrated the feasibility of locally updating aboveground biomass estimates using power-law functions based on relationships between DBH and H. These datasets and findings can contribute to enriching tropical forest research databanks and supporting sustainable forest management.