【作者】 夏茂林；

【导师】 王佺珍；

【作者基本信息】 西北农林科技大学 ， 草业科学， 2011， 硕士

【摘要】 鼠害是西藏高原广大农牧区的三大自然灾害之一。由于对天然草原长期的不合理利用,特别是超载过牧,使牧草生长发育受阻,繁殖能力衰退,优良牧草逐渐从草群中消失,适口性差的杂草以及毒草入侵群落,草地持续退化。退化草地为害鼠的生存、繁衍提供了有利条件,成为它们栖居和繁衍种群的适宜生境。近年来西藏高寒草地鼠害活动更加猖獗,因此西藏已被列入国家控害减灾和生态环境治理的重点区域之一。本论文以西藏高寒草原鼠害为研究对象,于2007、2008和2009年连续3年采用“堵洞、盗洞”调查法,对西藏那曲、拉萨、日喀则、山南、林芝、昌都等六个地区的高寒草原鼠害和地上生物量进行了定点动态调查。除拉萨以外其他各地区总洞数呈逐年增加的趋势,害鼠有效洞口密度2008年相对较高;结合各地区的气候变化以及植被环境分析,地上生物量连年下降,均与总洞数呈极显著负相关(P<0.01)。据调查结果分析,结论如下:1日喀则、那曲、山南、昌都以及林芝等五个地区鼠洞调查表明,连续3年总洞数差异不显著(P>0.05),呈现缓慢增长趋势;地上生物量连续3年呈下降趋势,说明草地连续退化。日喀则、那曲以及昌都,地上生物量变化差异显著(P<0.05)。2拉萨调查区由于采取了控制措施,鼠害状况得到缓解,总洞口数、有效洞口数、有效洞口率均呈现下降趋势,但是差异不显著。地上生物量连续3年呈缓慢增长趋势,显示草地退化得到有效遏制。3各地区地上生物量变化均与总洞数呈现极显著负相关(P<0.01),说明总洞口数能一定程度反应草地退化状况。4各地区不同年份的总洞数与有效洞口、有效洞口率均无显著相关,说明总洞数与有效洞口数之间没有必然的联系,有效洞口率不能反应害鼠的种群密度,依据有效洞口系数理论,有效洞口密度更能反应调查地当时的害鼠种群数量。5在地上生物量回归分析中,有效洞口率系数在模型中绝对值最大,其对地上生物量影响最大,结合模型的显著性,有效洞口率在一定程度上较好的反应鼠害程度,可作为草地退化的一个间接指标。6回归分析模型可以用来通过害鼠洞口数变化,间接估测西藏草地地上生物量。更多还原

【Abstract】 The plague of rats is one of three principal catastrophes in alpine grasslands of Tibet. Due to the unreasonable using the natural grasslands, especially over-grazing, the eminent pasturage has gradually disappeared from the grass group which not only made the fecundity of grass decline but also hinder the growing of grass and unpalatable, poisonous weeds have begun to invade the grassland which made the grassland gradually become worse and worse. By providing a favorable condition for surviving and propagating, the degenerative grasslands have developed suitable environment for rats’ habitation and propagating. Because the exacerbation of rats plague in Tibet alpine grassland, Tibet has been figured into the one of the most important area where our nation will put great efforts to reduce calamities and intense to protect the ecology and improve the environment. Referring the plague in Tibet alpine grassland as subject investigated, this thesis investigated rats plague in alpine and conducted dynamic research of above-ground biomass of fixed location in six places including Naqu, Lhasa, Shigatse, Lhoka, Linzhi and Changdu by the method of caulking and hole for robbing in successive three years of 2007 to 2009. The number of holes show increasing trend each year except Lhasa and the density of efficient holes of rats plague is relatively higher. By analyzing the climates of every place and the environment of plants, the research shows that the above-ground biomass is gradually reducing which appears the obviously negative correlation (p<0.01). After the investigating and analyzing, the conclusion comes out:1. The investigation of mouse-holes in Naqu, Shigatse, Lhoka, Linzhi and Changdu shows that the number of mouse-holes is still slightly increasing for the third year in succession even though the discrepancy is not obvious (p>0.05). The decline tread of above-ground biomass illustrates that the grasslands are undergoing degeneration especially the Naqu, Shigatse,Changdu (P<0.05).2. Thanks to the efficient regulatory measures in Lhasa, the plague has been alleviated and the total number of holes, the number of efficient holes, the rate of efficient holes show the descending trend in spite of unapparent disparity. In the successive three years, the gradual increasing of above-biomass indicates the degeneration of grasslands have been efficiently controlled.3. The variation of above-biomass has a negative relationship with total number of holes (p<0.01) indicates that total holes, in some extent, can response the condition of grasslands’ deterioration.4. There is no significant relationship between each area’s total number of holes and the number of efficient holes, efficient holes rate. It can not only indicate that there is no inevitable connection between total amount of holes and efficient holes but also the rat of efficient holes can’t reflect the population density of rates’ plague. On the contrary, the densities of efficient holes have better ability to reflect the population quantity of rodent in the investigated area according to theoretical analysis of efficient holes.5. In the analyses of above biomass’ returning, the coefficient of efficient holes’ rates is biggest in the mole of absolute value and it also have the biggest affection to the biomass. As a backstair index for the degeneration of grassland, the rates of efficient holes, in some extent, can preferably indicate the degree of plague .6. Regression model can estimate the amount of above biomass in grasslands of Tibet through the variation of rodent’s holes.更多还原