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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。
The “harmful” or “harmless” rodents are closely related to their habitats. In this paper, the control plots of Haloxylon ammodendron and non-demonstration areas in southern Gurbantunggut desert were selected as the survey sites for comparative analysis The characteristics of rodent pests in Haloxylon ammodendron were studied in two habitats. Then, the ecological thresholds of Haloxylon ammodendron in desert area were discussed. The findings are as follows: (1) The Haloxylon ammodendron in southern Gurbantunggut desert is relatively light. Haloxylon ammodendron mortality caused by mice was 4.29% on average in non-demonstration areas and 2.12% on average in demonstration areas. (2) The growth of Haloxylon ammodendron is a factor that attracts mice to feed. The base diameter, height and crown width of Haloxylon ammodendron had a significant linear positive correlation with the number of effective rat holes and the total number of rat holes, and the difference of their growth status determined the degree of harm to rats. (3) Rodents fed on the basal part of Haloxylon ammodendron slightly, while the feeding on the collateral of all levels of Haloxylon ammodendron was not only selective, but also affected by the number of habitats and their own populations. The mild hazard ratio of Haloxylon ammodendron was greater than that of moderate and severe hazard, while the degree of harm of Haloxylon ammodendron, primary and secondary branches was significantly correlated with the total number of rat holes. The number of effective rat holes was only related to Haloxylon ammodendron Level of collateral damage was significantly correlated. (4) The degree of damage of the whole plant Haloxylon ammodendron had an exponential function relationship with the number of its subtropical mouse holes. When the total number of rat holes was more than 5 per plant, Haloxylon ammodendron harms began to aggravate. Therefore, The ecological threshold for prevention and treatment is 5 per rat hole.