Effects of abiotic factors on plant diversity and species distribution of alpine meadow plants

Abstract

The alpine meadow is a type of vegetation with significant ecological and economic values. Plant diversity and species distribution are affected by ecological environment. To study the influence of abiotic factors (topographic factors and soil chemical and physical properties), it can understand plant communities' formation and the adaptation of plants to abiotic factors. Here, we explored the influence of the abiotic factors on the plant diversity and species distribution through the investigation of alpine meadow vegetation and abiotic factors at the northeast Tibetan Plateau, the results of the laboratory experiments, and the representative difference analysis (RDA) to find the ordination differences. Our results revealed that 11 ordered abiotic factors explained the 25.5% of the distribution of the alpine meadow species. The slope, soil total nitrogen (STN), and soil organic matter (SOM) have a significant influence on the distribution of the alpine meadow species. According to the RDA analysis of the correlation between plant diversity and abiotic factors, the cumulative interpretation value of the four ordination axes was 39.0%. Slope and STN has a strong correlation with plant diversity, respectively. STN, soil total phosphorus (STP), soil total potassium (STK), and soil water content (SWC) has positive relationships with the plant diversity index, respectively, suggesting that those factors above mentioned are the main factors affecting the diversity of species in alpine meadows. Slope, aspect, and soil temperature (ST) has negative relationships with the Partrick index, Simpson's diversity index, and Shannon-Wiener diversity index, indicating that with the slope increases, the plant diversity decreases, and the plant diversity also decrease at the sunward aspect. The soil has a more significant impact on the Pielou's evenness index, but the topography has a weaker influence on the Pielou's evenness index. The plant diversity and species distribution of alpine meadow in Tibet Plateau are affected by many abiotic factors. In our study, we found that slope and STN were the main factors affecting the plant diversity and species distribution in alpine meadows.