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Accueil du site → Doctorat → Chine → 2020 → Response of Main Populations Interspecific Relationships to Grazing in Stipa Breviflora Desert Steppe

Inner Mongolia Agricultural Universit (2020)

Response of Main Populations Interspecific Relationships to Grazing in Stipa Breviflora Desert Steppe

张爽;

Titre : Response of Main Populations Interspecific Relationships to Grazing in Stipa Breviflora Desert Steppe

Auteur : 张爽;

Grade : Doctoral Dissertation 2020

Université : Inner Mongolia Agricultural Universit

Résumé partiel
Stipa breviflora desert steppe has special species composition and community type,fragile ecological environment and sensitive response to grazing.The influence of different grazing intensity on population is different,which leads to the change of the relationship between plant populations.In order to study the relationship between the main plant populations of Stipa breviflora Desert Steppe under different grazing intensities,the main plant populations of Stipa breviflora Desert Steppe in Inner Mongolia(Stipa breviflora,Allium polyrhizum and Cleistogenes songorica)were selected as the research objects,and three grazing treatments(no grazing,medium grazing and heavy grazing)were adopted in the randomized block experiment design.From 2015 to 2019,the data of population density and aboveground biomass of main plants were obtained by random sampling method,and the spatial data of main plant population were obtained by mechanical sampling method,and the soil nutrient data were measured.Combining with variance analysis,grey correlation analysis,canonical principal component analysis and geostatistical analysis,the response of the main plant population function and population interrelation to grazing disturbance in Stipa breviflora desert steppe was analyzed from the aspects of main plant population and community dynamics,niche,soil resource distribution pattern and population spatial distribution pattern,and the following conclusions were obtained.(1)With the increase of grazing time and intensity,the population density,important value and aboveground biomass of Stipa breviflora decreased gradually.The density of main plant population and the ratio of aboveground biomass to community in the dry year are relatively large.With the increase of grazing time,the proportion of main population decreased.The interannual climate has a great impact on the population and community dynamics of the main plants,and grazing interference will reduce the impact.(2)When the population is in the same density,its interspecific affinity takes the form of symmetry.In the middle density of main plant population,the species compatibility is the strongest,and in the high density,the species compatibility is the weakest.

Mots clés : Desert steppe; Grazing intensity; Population dynamics; Interspecific relationship; Spatial distribution pattern;

Présentation (CNKI)

Page publiée le 5 juin 2021