Informations et ressources scientifiques
sur le développement des zones arides et semi-arides

Titre : Relationship between Plant Community Diversity and Productivity in Desert Steppe under Controlled Precipitation

Auteur : 郭亚飞

Grade : Master 2022

Université : Northwest Normal University

Résumé partiel
The relationship between biodiversity and ecosystem function has been one of the hot topics in ecology.Ecosystem can provide human beings with a variety of services such as material basis and living environment.As an important factor of controlling ecosystem stability,productivity,carbon sequestration,nutrient cycle and other functions and processes,biodiversity plays an important role in the realization of ecosystem functional services.Since the industrial revolution,it is an indisputable fact that the intensification of human activities has changed the global precipitation pattern.The change of precipitation pattern will affect plant growth and community diversity,and ultimately have influence on the structure and function of ecosystem.The desert grasslands of the western Loess Plateau are characterized by scarce precipitation,sparse vegetation and fragile ecosystems,and are highly sensitive to changes in precipitation patterns.Therefore,researching the relationship between plant community diversity and ecosystem function under precipitation change is of great significance for the maintenance and scientific management of ecosystem service function in this region.Based on the field precipitation control test platform of desert grassland in the west of the Loess Plateau,according to the precipitation variability of the study area in recent50 years（-41.1%-39.2%）,five precipitation gradients（40%precipitation reduction,20%precipitation reduction,control,20%rainfall increase and 40%rainfall increase）are set to simulate the possible precipitation changes in the future.Through the field investigation and laboratory analysis of plant communities and plant functional traits,the data of species diversity,functional diversity and productivity were obtained to explore the relationship between plant community species diversity,functional diversity and functional traits and community productivity under the background of precipitation change.The main results are as follows :（1）The change of precipitation had a significant effect on aboveground biomass The aboveground biomass of the precipitation-reduced group was significantly lower than that of the control and rainfall-increased groups（P＜0.05）.The aboveground biomass of grasses in the 40%precipitation-reduced group was significantly lower than that in the rainfall-increased group（P＜0.05）,and that of forbs in the 40%rainfall-increased group was significantly higher than that in the remaining groups（P＜0.05）.The 40%precipitation-reduced treatment significantly decreased the importance value of grasses（P＜0.05）.To sum up,the negative effect of precipitation-reduced treatment on above-ground biomass was significant,and extreme rainfall increase and precipitation reduction had a greater effect on community composition

Mots clés : Precipitation change ;Desert steppe ;Plant aboveground biomass ;Species diversity ;Functional diversity ;Functional traits ;Loess Plateau ;

Présentation (CNKI)