COMMUNITY COMPOSITION AND STRUCTURE ALONG THE ENVIRONMENTAL GRADIENTS OF LARIX GMELINII FOREST IN NORTHEAST CHINA

Larix gmelinii forest is one of the most important cold-temperate conifer forests which plays a crucial role on national ecological security in China. Understory plants of Larix gmelinii forest has different distribution and ecological strategy. This paper quantitatively explored the relationship between community composition and environmental factors in natural Larix gmelinii forest in Northeast China. The regional sample plots (n=175, size=30 mx30 m) were classified into 6 plant associations by two-way indicator species analysis (TWINSPAN), and different plant associations showed different habitat preferences. Species richness and diversity showed a similar trend. Both of them had significantly negative correlation with elevation, isothermality, temperature seasonality, showing significantly positive correlation with mean annual temperature and annual precipitation. Species evenness had significantly negative correlation with mean annual temperature and annual precipitation, showing significant positive correlation with elevation and isothermality. Species richness and diversity in Asso.II (Larix gmelinii-Spiraea chamaedryfolia + Corylus heterophylla-Eriophorum vaginatum) and Asso.VI (Larix gmelinii-Carex Larix gmelinii-Sorbaria sorbifolia-Geranium wilfordii) showed higher index than others. However, species evenness in Asso.III (Larix gmelinii-Ledum palustre+Vaccinium vitis-idaea-Deyeuxia angustifolia) and Asso.IV (Larix gmelinii-Rhododendron dauricum-Pyrola dahurica) showed higher index than others. Canonical correspondence analysis (CCA) claimed that mean annual temperature, annual precipitation and elevation were primary environmental factors affecting species association distribution. The study can be used as a reference for Larix gmelinii forest ecosystem protection and a theoretical basis for scientifically sustainable management in similar areas.

Automated summary

This study quantitatively explored the relationship between community composition and environmental factors in natural Larix gmelinii forest in Northeast China, revealing that different plant associations have different habitat preferences. The findings suggest that mean annual temperature, annual precipitation, and elevation are the primary environmental factors affecting species association distribution.