荒漠草原蝗虫时空生态位的研究

STUDIES ON TIME AND SPATIAL NICHE OF GRASHOPPERS ON THE DESERT STEPPE IN NINGXIA

在宁夏贺兰山东侧天然草地5类不同植被类型的草场，对9种蝗虫种群生物量进行调查，以15天为时间步长，构成种群发生数量的多维矩阵数据，以多元统计分析，建立各蝗虫的时间、空间、以及时间×空间的多维生态位；并根据时间维的变化，进行了生态位胀缩和中心转移分析。结果表明：（1）共存的蝗虫种类在“资源”利用上存在着明显的分化；空间生态位重叠较高的种类，在时间生态上则明显分化。（2）各蝗虫的空间生态位都沿着时间维的变化进行胀缩与中心转移；其胀缩速率因蝗虫种类而不同，并受气候因素的明显影响。（3）黄胫小车蝗Oedaleusinfernalis、大胫利蝗Cumpabrhipisdavidiano、红翅皱膝蝗Anagraorisrhodopa是宁夏荒漠草原蝗虫群落中暴发潜能最大的种类。

A study was conducted in the desert steppe area on the eastern side of HelanMountain,to determine resource utilization in time and space by 9 species of grasshopper.The pattern of use for these resource was analyzed from population biomasses simpled on thefive types of grassland being divided bassd on the characters of vegetational structure andtopographic and geological features,once every 15 days from June to Septamber in 1994 - 1995.The constituted data matrices were used in multi-statistical analysis to form themultidimationl time space niches of these. In consideration of the time -dimension, the expanse andcontraction,centres shifting of these niches were analysed. The results showed that: 1)Therewere sufficient differences between species for overall overlap associated with resource use toexplain coexistence in the assemblagest resource segregation,species grouping are differenton variant grasslamds and there are obvious partions of utilization in time among the specieswhich nave hight of niche overlap in spece; 2)The centres and areas of each time and spatialniche of 9 species of grasshopper change with time. The shifting distance are different foreach species. The shifting speeds are influenced by the weather; 3) 3 species, oedaleusinfernalis,compabrhipis davidlano and Angaraoris rhodops, are the species that havepotantial outbreak of population.