Recovery of woody plant diversity in tropical rain forests in southern China after logging and shifting cultivation

Logging and intense shifting cultivation have caused major degradation of tropical forests and loss of biodiversity. Understanding the direct and indirect effects of those land uses on plant biodiversity is essential to the restoration of tropical forests. We compared the species diversity, community composition and basal area of all stems ⩾1 cm dbh among 18 1-ha tropical lowland and montane rain forest plots with a well-recorded long-term history of shifting cultivation and logging on Hainan Island, south China. We also explored the relative importance of disturbance and environmental factors in determining forest recovery. We found that the species density and diversity in old growth forests were higher than in shifting cultivation fallows (55 years old) but lower than in logged forests (35–40 years since logging). The species composition of shifting cultivation fallows was distinct from other forest types but logged forests were similar to old growth forests, especially in lowland forests. Disturbance intensity was the most frequently important factor in determining species composition, species density, diversity, and basal area accumulation. Soil nutrient availability explained some of the variation in species composition and diversity. Stem density was related to multiple factors including disturbance history, soil nutrients, and distance to old-growth forest. In general, we found that disturbance intensity was a better predictor of forest structure and diversity than edaphic environmental variables, highlighting the importance of human impacts in shaping tropical forest successional pathways.

We compared the woody species diversity recovery of all stems ⩾1 cm dbh (diameter at breast height) among 18 1-ha tropical rain forest plots with a well-recorded long-term history of shifting cultivation and logging in Bawangling Forest Region (BFR) on Hainan Island, south China. We demonstrated that forests recovery rate differs significantly between two vegetation types, and fallows from shifting cultivation lands remained distinct in terms of species diversity even after 55 years of recovery, especially in the lowland area. We found disturbance intensity was a better predictor of forest structure and diversity than environmental variables, highlighting the importance of human impacts in shaping tropical forest successional pathways.Figure optionsDownload as PowerPoint slideHighlights
► We compared the tropical rain forests after logging and shifting cultivation in southern China.
► The species composition of shifting cultivation fallows was distinct from other forest types.
► Disturbance intensity was a better predictor of forest recovery than environmental variables.
► We highlighted the importance of human impacts in shaping tropical forest successional pathways.