The environmental interpretation of Pinus yunnanensis community differentiation after the invasion of Ageratina adenophora in Panxi region, China

Abstract

The relationship between plants and the environment is the foundation of plant community composition. It is urgent to clarify the distribution pattern and influencing factors of community biodiversity, especially the driving patterns of environmental factors under the conditions of invasive alien species. In this study, we investigated the effects of various environmental factors, especially altitude and Ageratina adenophora invasion, on forest community differentiation in Pinus yunnanensis forest in Panxi region, providing a strong theoretical basis for forest management and natural resource protection in this area. Based on the field survey data of 40 sample sites, a total of 18 environmental factors, including climate, terrain, soil and biology are selected, which may affect Pinus yunnanensis community. The methods of Two-way indicator species analysis (TWINSPAN), Redundancy analysis and Locally weighted linear regression are adopted by quantitative ecology. The effects of environmental factors on forest community type, species distribution pattern and species diversity were discussed. The results show that: (1) The Pinus yunnanensis community was divided into 4 types by TWINSPAN. (2) Altitude, annual mean temperature, soil pH, soil total phosphorus, Ageratina adenophora invasion were significantly correlated with forest community types and species distribution. (3) With the increase in altitude, the species diversity of Pinus yunnanensis community decreased firstly and then increased, and reached its lowest point at about 1800–2000 m a.s.l. With the increase in Ageratina adenophora invasion, the species diversity index of the community showed a downward trend. (4) The species diversity index of the tree layer was negatively correlated with the altitude. The species diversity index of herbaceous layer was negatively correlated with the Ageratina adenophora invasion intensity. Environmental factors had little influence on the species diversity index of shrub layer. It is suggested that the next research focus should be on setting up experimental areas for the invasion area of Ageratina adenophora, exploring scientific and effective removal methods, strengthening the restoration research and demonstration construction of the invaded ecosystem. By simulating and reconstructing the historical distribution dynamics of Ageratina adenophora, analyzing its diffusion trend and environmental interpretation, predicting the suitable areas in China under the background of climate change. We will conduct long-term monitoring and risk assessment of invaded and potential spread areas, and formulate and implement prevention and control policies.