古尔班通古特沙漠南部梭梭鼠害特征及防治生态阈值研究

鼠类的"有害"或"无害"与其生境密切相关,文中以位于古尔班通古特沙漠南部的梭梭鼠害防治示范区和非示范区为调查样地,对比分析了两种生境中梭梭林的鼠害特征,进而探讨了沙漠区梭梭鼠害防治的生态阈值。研究发现:(1)古尔班通古特沙漠南部梭梭鼠害整体较轻。由鼠类引起的梭梭死亡率,非示范区平均为4.29%,示范区平均为2.12%。(2)梭梭的生长状况是吸引鼠类前来取食的因素。梭梭的基径、高度、冠幅与其冠下有效鼠洞数和鼠洞总数都成极显著的线性正相关关系,其生长状况的差异性决定了鼠类危害的程度。(3)鼠类对梭梭基部的取食较轻,而对梭梭各级侧枝的取食不仅具有选择性,还受生境和自身种群数量的影响。梭梭基部的轻度危害比率大于中度危害和重度危害比率,而梭梭侧枝、一级侧枝、二级侧枝的危害程度与鼠洞总数呈显著相关关系,有效鼠洞数只与梭梭二级侧枝的危害程度呈显著相关关系。(4)单株梭梭整株危害程度与其冠下鼠洞总数呈指数函数关系,当鼠洞总数>5个/株时,梭梭整株危害程度开始加剧,故该研究认为梭梭鼠害防治的生态阈值为鼠洞总数为5个/株。

Study on the harm characteristics of rodents to Haloxylon ammodendrom and its control for ecological threshold value in the south of Gurbantonggut Desert

Choosing two natural forests and demonstration areas of Haloxylon ammodendrom in the south of Gurbantonggut Desert,we studied the harm characteristics of rodents to Haloxylon ammodendrom and its control ecological threshold value.The conclusions are as follows.(1) The total mortality of Haloxylon ammodendrom caused by mouse is lower and it is 4.29% in the natural forests,while in the demonstration areas is it 2.12%,showing that the excessive grazing of rodents is not the main reason for Haloxylon ammodendrom death.(2) The base diameter,the height and the crown diameter of Haloxylon ammodendrom have highly significant linear positive correlation with rodentholes under crown of Haloxylon ammodendrom,which indicats that the growth of Haloxylon ammodendrom is one of the factors attracting rodents for feeding.(3) The ratio of slight damage to Haloxylon ammodendrom is more than moderate hazard and severe damage,explaining that the harm of rodents to the base of Haloxylon ammodendrom is lighter and rodents don’t make it as main food sources.There exists larger difference among the hazard ratio of all levels of collaterals of Haloxylon ammodendrom.We discovered that there is significant correlation among the hazard degree of collateral,the first collateral,the second collateral,the third collateral and the total rodentholes,while there is significant correlation between the hazard degree of the second collateral and the effective rodentholes,illustrating that the feeding of rodents to all levels of collaterals of Haloxylon ammodendrom is not only possessing selective,but also is influenced by habitat and its population quantity.(4) There is exponential function relationship between the harm degree of whole Haloxylon ammodendrom and the total number of rodentholes under its crown.When the total number of rodentholes is 5 per plant,the harm degree of mouse to whole Haloxylon ammodendrom begins to be significant,so it needs to strengthen control on rodents at the same time,therefore,the control ecological threshold value we gained is 5 per plant in this study.