Ecological restoration in the source region of Lancang River: Based on the relationship of plant diversity, stability and environmental factors

Ecosystem stability is the interaction result of species diversity, environmental conditions and external disturbances, the research on diversity and stability of plant community and their relationship with environmental factors is the prerequisite of establishing a self-organized ecosystem with adaptability and resilience. Taking Nangqian County in the source region of Lancang River as study area, this paper empirically analyzed the influence and mechanism of plant diversity and environmental factors on community stability through Spearman correlation test, regression analysis and redundancy analysis (RDA), so as to provide scientific basis for ecological restoration and construction of stable plant community. The results showed that the descending order of community stability was N₈ > N₃ > N₅ > N₄ > N₂ > N₉ > N₆ > N₇ > N₁ (N₁-N₉ respectively represent the nine sampling sites selected in this study). Community stability index (S) tended to decrease first and then increase with the increase of Species richness index (R) and Pielou evenness index (J), but had no significant correlation with Simpson dominance index (D) and Shannon-Wiener diversity index (H). Plant diversity mainly affected stability through mechanism channels such as improving performance effect, species evenness and interspecific competition. Topsoil organic carbon (T_OC), pH (T_PH) and sodicity (T_ESP) had important influence on community stability. Temperature (TEMP) and precipitation (PRCP) influenced the distribution pattern of plant communities, while topographic factors including elevation (ELEV), slope (SLOPE) and aspect (ASPECT) affected mean value of species abundance (μ) and Species richness index (R) through solar radiation intensity, temperature, precipitation and soil conditions. In the source regions of Lancang River and other similar areas, ecological restoration should pay attention to the adaptation of species to moisture, heat and soil conditions, give full play to the important role of dominant species in maintaining stability, take into account species evenness and weaken intensity of interspecific competition while increasing diversity.