霍城县温性荒漠化草原蝗虫种群空间格局及抽样模型的建立

Spatial Pattern of Grasshopper Population and Sampling Model in Desert Grassland of Huocheng County

本研究以样方法调查霍城县温性荒漠化草原蝗虫种群密度,利用聚集度指标、Iwao m^(*)/m回归模型研究分析草原蝗虫种群在上坡、中坡、下坡、坡脚平地的空间分布型,并确定理论抽样数。结果表明,蝗虫分布型主要以聚集分布为主,有些种类表现出均匀分布和随机分布特点,如蓝斑翅蝗(Oedipoda caerulescens)、绿纹蝗(Aiolopus thalassinus)、荒地剑角蝗(Acrida oxycephala)等3种蝗虫分布于下坡及坡脚平地,均为均匀分布,其余种类随着坡地及植被群落结构不同表现出不同的分布型。建立的最适理论抽样数模型为(1/D)2(1.0602/m+0.1515);最佳序贯抽样模型为T′0,T″0(n)=0.5000n±0.7537 n,基于回归模型抽样技术明确了蝗虫在置信概率t=1,D=0.1、0.2、0.3时,当m=0.5头/m^(2),最大理论抽样数分别为227、57、25头;当m=1.0头/m^(2)时,最大理论抽样数分别为121、30、13头;当m=1.5头/m^(2)时,最大理论抽样数分别为86、21、10头;当m=2.0头/m^(2)时,最大理论抽样数分别为68、17、8头。

Taking desert steppe locusts in Huocheng County as the research object,the population density of locusts in desert steppe in Huocheng County was investigated by standard site sampling method,and the spatial distribution patterns of desert steppe locusts in uphill,middle slope,downhill slope and bottom slope flat land were studied.The spatial distribution patterns were determined by using aggregation index and Iwao m*/m regression model,and the theoretical sampling number was determined.The results showed that the locust distribution pattern in this area was mainly clustered,with uniform distribution and random distribution.Some species showed both uniform and random distribution characteristics,such as the following three locusts:Oedipoda caerulescens,Aiolopus thalassinus,and Acrida oxycephala,distributed uniformly on the downhill slope and the flat ground at the foot of the slope,while the other species showed different distribution patterns with different slope and vegetation community structure.The optimal established theoretical sampling number model was(1/D)2(1.0602/m+0.1515).The optimal sequential sampling model was T′0,T″0(n)=0.5000n±0.7537 n as follows:Based on the regression model sampling technique,it was clear that when the confidence probabilities of locusts were t=1,D=0.1,0.2 and 0.3,and m=0.5 locust/m^(2),the maximum theoretical sampling numbers were 227,57 and 25 locusts respectively.When m=1.0 head/m^(2),the maximum theoretical sampling numbers were 121,30 and 13 heads,respectively.When m=1.5 head/m^(2),the maximum theoretical sampling numbers were 86,21 and 10 heads,respectively.When m=2.0 heads/m^(2),the maximum theoretical sampling numbers were 68,17 and 8 heads,respectively.