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

Titre : Desert Steppe Plant-Soil Responses to Fence Enclosure

Auteur : 余轩

Grade : Master 2022

Université : Ningxia University

Résumé
Grassland plays an important role in maintaining biodiversity.In recent years,under the background of ecological civilization construction,the state and local governments have generally implemented projects such as returning farmland to grassland,enclosing and banning grazing,and Ningxia has implemented a full 20 years of Grazing prohibition,its effect is very obvious,but at the same time,the prospect of grazing prohibition is full of controversy.The scientific basis for these disputes involves the evaluation of the effects of enclosure and grazing prohibition.Desert steppe plant-soil is the core factor that affects the ecosystem and is related to the productivity of the ecosystem.In this study,the plant communities in different states of enclosure and grazing in two soil habitats,lime zebra soil and aeolian sandy soil,were used as the research objects.Community functional traits,species diversity and functional diversity were studied,and then combined with integrated analysis to further verify on the whole China scale,to explore the adaptation mechanism of desert steppe plant communities.The main conclusions are as follows :（1）Plants in desert grassland mainly adopt trade-off rather than synergy in different soil habitats.Rapid growth strategy plants adapt to aeolian sandy soil habitat,and resource conservation strategy plants adapt to calcareous soil habitat.Grazing is more inclined to screen resource conservative species.Therefore,based on the principle of diversified restoration of functional traits,the focus of grassland ecosystem management in the future is to protect or artificially improve the proportion of resource conservative species,especially under the condition of aeolian sandy soil habitat.（2）The results showed that the effects of years of closure on plant diversity in different soil habitats were different:6 years of closure was beneficial to improve plant diversity in calcareous soil habitat,15 years of closure was beneficial to improve plant diversity in aeolian sandy soil habitat ;Grazing improves the functional diversity compared with enclosure.Therefore,based on the consideration of plant diversity,the calcareous soil habitat needs to be enclosed and moderately utilized,while the aeolian sand soil habitat needs to be enclosed for a long time.In addition,the analysis showed that there was a negative correlation between biomass and plant diversity.Calcareous soil habitat,enclosure to improve soil quality.（3）The functional diversity was affected by soil habitat.Compared with aeolian sandy soil habitat,calcareous soil improved the functional diversity ;Compared with 5 and 6 years,15 and 10 years of enclosure improved functional diversity ;Enclosure improves functional diversity compared to grazing.（4）Through integrated analysis,the effects of enclosure and different years of enclosure on plant,soil and species diversity in China’s desert steppe were further verified.Enclosure can improve the quantitative characteristics,biomass and soil quality of plant communities.This is consistent with the field test results.However,the improvement of diversity index is mainly reflected in the long-term enclosure treatment,which is different from the research results of calcareous soil habita

Mots clés : desert steppe ;species diversity ;functional traits ;soil habitat ;integrated analysis ;

Présentation (CNKI)