title: Substantial reorganization of China's tropical and subtropical forests: based on the permanent plots.
abstract: There is evidence that climate change induced tree mortalities in boreal and temperate forests and increased forest turnover rates (both mortality and recruitment rates) in Amazon forests. However, no study has examined China's tropical and subtropical evergreen broadleaved forests (TEBF) that cover >26% of China's terrestrial land. The sustainability of this biome is vital to the maintenance of local ecosystem services (e.g., carbon sequestration, biodiversity conservation, climatic regulation), many of which may influence patterns of atmospheric circulation and composition at regional to global scales. Here, we analyze time-series data collected from thirteen permanent plots within China's unmanaged TEBF to study whether and how this biome has changed over recent decades. We find that the numbers of individuals and species for shrub and small tree have increased since 1978, whereas the numbers of individuals and species for tree have decreased over this same time period. The shift in species composition is accompanied by a decrease in the mean diameter at breast height (DBH) for all individuals combined. China's TEBF may thereby be transitioning from cohorts of fewer and larger individuals to ones of more and smaller individuals, which shows a unique change pattern differing from the documented. Regional-scale drying is likely responsible for the biome's reorganization. This biome-wide reconstitution would deeply impact the regimes of carbon sequestration and biodiversity conservation and have implications for the sustainability of economic development in the area.
authors.affiliation: South China Botanical Garden, Chinese Academy of Sciences, Guangzhou, 510650, China.
authors.forename: Guoyi
authors.initials: G
authors.lastname: Zhou
authors.forename: Benjamin Z
authors.initials: BZ
authors.lastname: Houlton
authors.forename: Wantong
authors.initials: W
authors.lastname: Wang
authors.forename: Wenjuan
authors.initials: W
authors.lastname: Huang
authors.forename: Yin
authors.initials: Y
authors.lastname: Xiao
authors.forename: Qianmei
authors.initials: Q
authors.lastname: Zhang
authors.forename: Shizhong
authors.initials: S
authors.lastname: Liu
authors.forename: Min
authors.initials: M
authors.lastname: Cao
authors.forename: Xihua
authors.initials: X
authors.lastname: Wang
authors.forename: Silong
authors.initials: S
authors.lastname: Wang
authors.forename: Yiping
authors.initials: Y
authors.lastname: Zhang
authors.forename: Junhua
authors.initials: J
authors.lastname: Yan
authors.forename: Juxiu
authors.initials: J
authors.lastname: Liu
authors.forename: Xuli
authors.initials: X
authors.lastname: Tang
authors.forename: Deqiang
authors.initials: D
authors.lastname: Zhang
mesh_terms: D044822:Biodiversity; D002681:China; D012987:Soil; D014197:Trees / Q000254:growth & development*; D014329:Tropical Climate
chemical_list: D012987:Soil
keywords: China; demography; directional change; evergreen broadleaved forests; individual size; species composition; tropical and subtropical area