Study On The Diversity And Spatial Distribution Pattern Of Three Common Poisonous Plants In Meadow Grassland Of Dumont County

Toxic grasses are the main biological disaster,affecting the productivity improvement of grassland.It has the effect of “reducing production and reducing quality” for grass collecting,harvesting,grazing and ecological vegetation construction.The breeding of toxic grasses have unpredictable damage economic growth of grassland,which is not conducive to the high quality and efficient development of animal husbandry.Thus,it can provide a good working basis for ecological improvement,production improvement and beautiful life in the grassland areas by investigating the main toxic grasses from species diversity index,interspecific association and spatial distribution pattern.The paper was divided into three research contents,Dumont county meadow grassland as the research object.The first was recorded the “four degrees and one volume” quantitative characteristics of grassland plants by the sample collection method to analyze the spatial distribution of the diversity index of the main toxic grasses populations.The second was recorded the presence or absence of species where randomly set 50 50 cm × 50 cm squares in the mowing and no mowing areas,to analyze the plant interspecific association.The third was selected three representative plots in the mowing and no mowing areas by the adjacent grid-like method to analyze the distribution pattern of poisonous plant populations.The main results were as follows:(1)In the Dumont county meadow steppe research area,the Patrick richness index,Shannon–Wiener diversity index,Pielou evenness index of poisonous plant communities were ranged from-22.32 to 33.11,-1.39 to 5.73,-1.44 to 2.12,respectively.The spatial distribution of three indices was higher in the central part than north and south.(2)The seven species pairs(Stellera chamaejasme with Leymus chinensis,Potentilla flagellaris,Anemarrhena asphodeloides,Saussurea japonica,Euphorbia fischeriana,Lilium pumilum,Clematis hexapetala,respectively)were positive association,and the association index of Stellera chamaejasme with Euphorbia fischeriana was increased.The four species pairs(Stellera chamaejasme with Stipa baicalensis,Artemisia carvifolia,Phragmites communis,Lespedeza davurica,respectively)were negative association,and the association index was decreased.The two species pairs(Stellera chamaejasme with Artemisia argyi,Scutellaria baicalensis,respectively)were transformed from negative association to positive association after mowing treatment,and the association index of Stellera chamaejasme with Scutellaria baicalensis was higher than no mowing treatment.The species pair(Stellera chamaejasme with Lespedeza hedysaroides)was transformed from positive association to negative association after mowing treatment,and the association index was decreased.(3)The five species pairs(Euphorbia fischeriana with Potentilla flagellaris,Artemisia argyi,Stellera chamaejasme,Lespedeza hedysaroides,Clematis hexapetala,respectively)were positive association,and the association index was decreased.The two species pairs(Euphorbia fischeriana with Artemisia carvifolia,Lespedeza davurica,respectively)were negative association,and the association index was decreased.The five species pairs(Euphorbia fischeriana with Leymus chinensis,Stipa baicalensis,Scutellaria baicalensis,Phragmites communis,Lilium pumilum,respectively)were transformed from negative association to positive association after mowing treatment.The two species pairs(Euphorbia fischeriana with Anemarrhena asphodeloides,Saussurea japonica,respectively)were transformed from positive association to negative association after mowing treatment,and the association index was decreased.(4)The five species pairs(Clematis hexapetala with Artemisia carvifolia,Stellera chamaejasme,Anemarrhena asphodeloides,Euphorbia fischeriana,Lespedeza davurica,respectively)were positive association,and the association index of Clematis hexapetala with Euphorbia fischeriana was decreased.The three species pairs(Clematis hexapetala with Leymus chinensis,Stipa baicalensis,Saussurea japonica,respectively)were negative association,and the association index was increased.The four species pairs(Clematis hexapetala with Potentilla flagellaris,Scutellaria baicalensis,Lespedeza hedysaroides,Lilium pumilum,respectively)were transformed from negative association to positive association after mowing treatment,and the association index was increased.The two species pairs(Clematis hexapetala with Artemisia argyi,Phragmites communis,respectively)were transformed from positive association to negative association after mowing treatment,and the association index was decreased.(5)In the no mowing treatment,I-class cluster and overall of Stellera chamaejasme population were showed aggregate distribution,II-class,III-class cluster of Stellera chamaejasme,Euphorbia fischeriana,Clematis hexapetala population were showed random distribution.In the mowing treatment,I-class cluster and overall of Stellera chamaejasme,Euphorbia fischeriana,Clematis hexapetala population were showed aggregate distribution.