Investigating Elevation Pattern Of Woody Plants Leaf Economics Spectrum In Cangshan Mountain

Plant functional traits centrally reflect its ecological strategies for long-term adaptation to different environments.Leaves have high plasticity and environmental sensitivity.Their functional traits and economic spectrum characteristics can be used to characterize the resource utilization strategies of plant leaves.The altitude gradient concentrates different environmental conditions and community types within a small space range,which provides an ideal place to study the responses of the altitude pattern of plant leaf functional traits and economic spectrum to environmental factors.In this study,six sampling plots were established in the altitude ranging from 2200 m to 3200 m in Cangshan Mountain,and the leaves of all woody plants in the six sampling plots were collected;Leaf area,specific leaf area,specific leaf weight,leaf thickness,leaf dry matter content,nitrogen content,carbon content and phosphorus content were measured.Seven environmental factors such as the average annual temperature of the atmosphere,the average temperature of the warmest month and the coldest month,the content of soil nitrogen,phosphorus and total carbon,and altitude were monitored.On this basis,explore the altitude pattern of different leaf functional traits at the species and community level and their response strategies to various environmental factors,reveal the characteristics of leaf economic spectrum,altitude pattern and its control factors,and elucidate the resource utilization strategy of woody plants in Cangshan Mountain.The main results and conclusions are as follows.(1)At the species level,only the specific leaf weight of woody plants in Cangshan Mountain had a significant positive correlation with altitude(p < 0.05),showing an obvious altitude pattern that specific leaf weight increased with altitude.At the community level,there was no obvious altitude pattern of leaf functional traits.(2)At the species level,the main controlling factors of leaf functional traits of woody plants in Cangshan Mountain are greatly affected by species and trait types.Among them,the response of specific leaf weight to environmental change is the most sensitive,and its main control factors are atmospheric annual average temperature and soil nitrogen content.Soil nutrients were significantly correlated with specific leaf area,leaf dry matter content,specific leaf weight and the content of carbon and phosphorus of leaf(p < 0.05).At the community level,soil phosphorus content had the greatest impact on leaf functional traits,and the response of specific leaf weight and leaf carbon content to the environment was significant.(3)There are resource trade-off strategies among woody plants in Cangshan Mountain.The trade-off relationship between leaf traits is universal,but it is adjusted to varying degrees due to environmental changes.Woody plants at higher altitudes tend to be resource conservative strategies with thick leaves,large specific leaves,high leaf dry matter content,small leaf area and specific leaf area,and low leaf nitrogen,phosphorus and carbon content.However,the variation of leaf economic spectrum characteristics with altitude at the community level is not obvious,and the correlation with environmental factors is not significant.(4)Petiole has no significant impacts on the altitude pattern of leaf functional traits and its relationship with environmental factors,as well as the overall trade-off relationship among leaf traits in the leaf economic spectrum,but it has a significant effect on the trade-off relationship among some traits in some environments.Therefore,it is suggested that it is necessary to indicate whether petiole is included in the determination of leaf functional traits in the study of leaf economic spectrum,so as to help readers obtain more comprehensive information.