Effects Of Environmental Factors On Functional Traits Of Wetland Plants In The Lhasa River Basin On The Qinghai-Tibet Plateau

The Lhasa River Basin is a typical distribution area of the alpine wetlands on the Qinghai-Tibet Plateau.It plays an important role in regulating surface runoff,providing drinking and irrigation water sources,improving the ecological environment,regulating climate,and maintaining biodiversity.It is closely related to human survival and sustainable economic and social development.However,the interference of climate change and human activities are seriously affecting the wetland ecosystem of the Qinghai-Tibet Plateau in recent years.As one of the primary producers of the wetland ecosystem,wetland plants are an important part of the wetland ecosystem.And changes in functional traits of wetland plants are recognized as responses and adaptions of wetlands plants to changes in ambient environments.In order to study the impact of environmental factors on the functional traits of wetland plants in the Qinghai-Tibet Plateau,the Lhasa River Basin was selected as the study area.Wetland plants in the Lhasa River Basin were collected through field surveys and sampling,and Pearson correlation analysis was used to elucidate the relationships between functional traits and environmental factors,and then we compared this study with other studies on functional traits of wetland plants in the Qinghai-Tibet Plateau to further explore how wetland plants adapt to the harsh environment of the Qinghai-Tibet Plateau.The main results are as follows:(1)In this field survey sampling work,a total of 25 water samples and soil samples were collected from 25 sampling sites in the Lhasa River Basin,and 145 wetland plant samples were collected.They belongs to 26 families,47 genera,and 55 species.Among them,the more frequent species are Potentilla anserina,Plantago depressa,Potentilla bifurca,Cynoglossum wallichii,Astragalus laxmannii,Dysphania schraderiana,Taraxacum mongolicum,Polygonum sibiricum,Rumex acetosa,Aster gouldii,Youngia simulatrix.The special river orientation and topography of the Lhasa River Basin on the Qinghai-Tibet Plateau resulted in a very significant positive correlation between altitude,longitude and latitude of this region.Altitude,longitude and latitude are all related to the mean annual temperature and the mean growing season temperature.Total soil organic carbon concentration and total soil nitrogen concentration are extremely significantly positively correlated with altitude,longitude,and latitude,and extremely significantly negatively correlated with mean annual temperature and mean growth season temperature,which indicates that altitude,longitude and latitude indirectly affect the total soil organic carbon concentration and total soil nitrogen concentration by affecting the mean annual temperature and the mean growing season temperature.The growth of wetland plants in the Lhasa River Basin on the Qinghai-Tibet Plateau is mainly limited by nitrogen.The functional traits of wetland plants in the Lhasa River Basin are significantly affected by altitude,latitude,mean annual temperature,mean growth season temperature,and total soil phosphorus concentration.Among them,functional traits such as plant height,leaf area,leaf perimeter,specific leaf area and total leaf phosphorus concentration decreased significantly with the increase of altitude and latitude,and increased significantly with the increase of the mean annual temperature and the mean growing season temperature.In addition to temperature,UV radiation and water availability also play an important role in this process.(2)With the increase of altitude,the plant height and total leaf phosphorus concentration of wetland plants on the Qinghai-Tibet Plateau decreased significantly.With the increase of latitude,the specific leaf area and total leaf phosphorus concentration of wetland plants on the QinghaiTibet Plateau decreased significantly.With the increase of mean annual temperature,the specific leaf area of wetland plants increased significantly.The correlations between the specific leaf area of wetland plants in the Qinghai-Tibet Plateau and altitude,total leaf organic carbon concentration and temperature,total leaf nitrogen concentration and altitude,total leaf nitrogen concentration and latitude,total leaf nitrogen concentration and temperature,total leaf phosphorus concentration and temperature,are quite different from this study,which may be caused by the different types of wetland plants studied by different research.In addition,the integration of different studies on the one hand may weaken the correlation between the functional traits of wetland plants and environmental factors,and on the other hand may reveal correlations that were originally insignificant in various studies.The difference between the results of this study and other studies may be due to the unique geographical location,complex topographical conditions and special climatic environment of the Qinghai-Tibet Plateau.Wetland plants living in different regions had made plastic changes in plant morphology in order to adapt to the local environment.In addition,different research focused on different wetland plant species,and the phylogeny of different species was quite different,which may lead to different results in research carried out in different regions.