Study on the Relationship Between Leaf Functional Traits and Soil Factors of Rhododendron aganniphum var. Schizopeplum at Different Altitude Gradients in Sejila Mountain

Abstract

The study of plant leaf functional traits and environmental factors is of great significance for understanding the formation of plant communities under different altitude gradients and their adaptation mechanisms to the environment. This study takes Rhododendron aganniphum var. Schizopeplum in Sejila Mountain, Tibet as the research object, analyzes the different leaf functional traits of Rhododendron aganniphum var. Schizopeplum under different altitude gradients, and investigates the main soil factors that affect the changes in leaf functional traits of Rhododendron aganniphum var. Schizopeplum, attempting to reveal the adaptation strategies of Rhododendron aganniphum var. Schizopeplum in soil environment of high altitude areas. The results showed that: (1) With the increase of the altitude gradient, the leaf area (LA), dry weight (DW), dry matter content (LDMC), leaf length (LL) and specific leaf area (SLA) of Rhododendron aganniphum var. Schizopeplum decreased, while leaf N content (N), N:P, leaf thickness (LT), leaf P content (P) and leaf tissue density (LD) presented an upward trend with the increase of elevation gradient. The variation coefficient of leaves ranges between 4.60%~57.78%, variation coefficient of P is the lowest (4.60%), and variation coefficient of SLA is the highest (57.78%). Where, variation of P, N, N:P, LT, and LL is weak, that of LDMC, LA and DW is moderate, and that of LD and SLA is strong. (2) There is certain correlation between leaf functional traits, and it adapts to the harsh external environment changes in the high-altitude areas of southeastern Tibet through its own relevant adjustments. Leaf DW, LDMC, and LA can be used as the main indicators for changes in leaf functional traits of Rhododendron aganniphum var. Schizopeplum. (3) The leaf functional traits of Rhododendron aganniphum var. Schizopeplum are affected by various soil factors. Among the soil factors, TP, AK, and AP are the main soil factors that affect leaf functional traits. The above research results deepen our understanding of the leaf functional traits of Rhododendron aganniphum var. Schizopeplum at different altitude gradients, and provide scientific basis for the scientific protection and utilization of the germplasm resources and biodiversity of Rhododendron aganniphum var. Schizopeplum in this area.