Elementary Studies On Monitoring Harmful Rodents Based On 3S Technological System

The materials on grassland mice condition and the effects on grassland vegetation were obtained in Xiahe county though outside investigating method from March of 2002 to April of 2003. Statistical method was used to analysis grassland mice zone constitute, community structure, community demarcation, unstable mice density change, the damaging condition and level of mice, vegetation characteristics, vegetation community structure and developing characteristics under different damaging levels and vegetation community structure. The damaging degree corresponding vegetation characteristics, in other words, vegetation succession that is caused by mice damage was uncovered. It is advantageous to supervise mice damage with 3S technology system, and it would provide scientific bases for this technique.There are 29 kinds of rodents in Xiahe county. And it concludes 19 genuses and 6 families (including 3 subfamilies). Myospalax and Ochotona are predominant. According to mice zone composing characteristics, especially the distribution of predominant species and sub-predominant species and roosting place characteristics, seven communities may be demarcated in the investigating area. I .M. fontanieri+ M. aspalax+ O. curzoniae communityII. M. aspalax + M.fontanieri + Microtus oeconomus +Allactaga sibirica communityIII.O. curzoniae+ M. oeconomus + Citallus dauricus communityIV. O. thomasi+ O. thibetana+ Pitymys ierne communityV. O. cansus+Cricetulus longicaudatus communityVI. M.smithi + Citallus dauricus + O. daurica community VII. M. oeconomus+M. fuscus communityFrom April to October, for Myospalax, the mean soil stack is 607.7 per square hectares, and the mean mice density is 40.1 per square hectares; for Ochotona, the mean available hole density is 110 per square hectares, and the mean mice density is 52.4 per square hectares.The damage degree of Myospalax and Ochotona could be demarcated four classes: lenient damage, middle damage, hard damage, over-damage. The damaging degree is significantly different among the number of mice, soil stack (or available holes), secondary bare area, the up-ground vegetation amass and the vegetation covering degree, so these could be criterion for demarcating damage degree. These are also the maincharacteristics of the damage degree.Vegetation investigating plot that is corresponded with four damage degrees were analyzed with clustering analysis. Four damage degrees have different vegetation community and developing degree. It manifests mice pest could cause the direction of vegetation community succession. In different confidence level, vegetation succession direction is:In different confidence level, this community's succession direction is:The same,then...