Spatial Distribution Of Micro-plaques In The Grassland Of Xilamuren Desert Steppe In Different Management Methods

Xilamuren grassland is located in the ecotone between agriculture and animal husbandry.It belongs to desert grassland and its ecology is fragile.In recent years,grassland has been degraded to varying degrees due to climate change and human disturbance.In this paper,the patch characteristics of grassland communities under three typical management methods:fully enclosed,semi-enclosed(seasonal enclosure)and free grazing are studied.Based on the characteristics of soil habitat,the above-ground plant communities under typical grazing disturbances in desert grasslands are analyzed.Response characteristics,the conclusions are as follows:(1)There are 13 types of grassland micro-plaques in the enclosed area,with a total number of 156.The plant community on the top of the slope is Stipa Kryloviipatches,and the bottom of the slope is mainly Leymus chinensis-Stipa patches,with degraded indicator vegetation.Artemisia frigida plaques andConvolvulus ammannil plaques;there are 16 types of grassland micro-plaques in the semi-enclosed area,and three types of background plaques,namely Leymus chinensis plaque,Leymus chinensis-Stipa plaque,and Stipa chinensis-Cleistogenes squarrosa patch,a class 1 indicator grassland microplaque,is a silver gray spiral patch;free grazing areas are dominated by Artemisia frigida.(2)The enclosed area has the highest IJI of 38.14,and various types of patches are highly intertwined,followed by the free grazing area 30.70,and the semi-enclosed area 23.46 is the weakest.The edge area of the grassland micro-plaques in the semi-enclosed area is smaller than the plaque-level indexes such as PARA,average plaque area CA,plaque shape index SHAPE,and fractal dimension index FRAC.The shape of the overall vegetation patch is the smallest,and the semi-enclosed area has the smallest complexity,and the enclosed area has the most complex performance.Combined with the index of landscape condensation,such as COHESION,the grassland micro-plaque structure in the semi-enclosed area is more stable.(3)Where the staggered edge of the patch has the greatest impact,the grassland is significantly degraded.In addition to the large number of adjacent patches on the background,the spread of the degradative indicator micro-plaques and the IJI value of the parallel index are large.In the enclosed area,the plaque shape index LSI and the spread and juxtaposition index IJI values are relatively high,the plaque shape is complex,the adjacent plaques are diverse,and the micro-plaque stability is low.(4)The distribution of plant communities showed a certain regularity with the microenvironment of the slope.From the top of the slope to the bottom of the slope,soil moisture increased,fine particles increased,background plant diversity increased.