Aims The monsoon evergreen broad-leaved forest (MEBF) is the dominant vegetation type in the subtropics of Eurasian continent. It provides vital ecosystem services and supports the socioeconomic development of the societies. Recent literature indicated that the MEBF had been greatly affected by the changing climate and other disturbances such as outbreaks of insects and, consequently, shifted its species composition and structure. In this study, we aim at the long-term changes of plant species and community structure in the MEBF.
Methods Species names, diameters at breast height (DBH), and tree heights of all trees with DBH ≥ 1.0 cm were recorded in 1992, 1994, 1999, 2004, 2008, 2010 and 2015 in a 1-hm 2 monitoring plot in the Dinghushan Biosphere Reserve. We quantified the long-term changes over this 24-year study period by species composition, biological diversity, aboveground biomass, DBH frequency table, and stand density by species.
Important findings Important findings From 1992 to 2015, the stand density increased by 42.7% while the total biomass decreased by 5.1%. The β diversity based on biomass and stand density indicated that the diversity increased by 37.4% and 65.6%, respectively, from 1992 to 2015. More importantly, the number of small arbor and shrubs, and smaller trees (DBH < 15 cm) also increased sharply, with major contributions from Aidia canthioides, Macaranga sampsonii and Blastus cochinchinensis. In contrast, the change in stand biomass was more from biomass decrease of Castanopsis chinensis, Schima superba and Cryptocarya concinna, but increase of Gironniera subaequalis and Pterospermum lanceifolium. We conclude that the changes on community composition and structure in the MEBF were significant, which was resulted from a combined influence of succession, changes in climate, and insect outbreaks.