鼠害治理下有效洞与废弃洞的动态

Dynamic patterns of available and abandoned holes under rodent pest control

害鼠给经济、生态等带来很大损失,但作为生态系统的一员,鼠类的存在对有些生物是有益的,它们的洞穴可以作为鸟类等生物的栖息场所,鼠洞的多少反映了这些生物的生存条件。在鼠害治理中,不能将害鼠彻底消灭,否则将危害到得益于它们的生物。本文通过数学模型研究了害鼠治理下废弃洞、有效洞以及废弃洞数量/有效洞数量的动态规律,分析了治理措施、治理强度对鼠洞数量的影响。其中有效洞代表害鼠的数量,废弃洞(有时要加上有效洞)代表得益于害鼠的生物的生存条件。在任何治理措施下,有效洞数量都减少,但废弃洞数量可能增加也可能减少,受控制强度及种群参数的影响。废弃洞数量/有效洞数量在综合治理时不变,在不育控制时减少,在其他情况下增加。

Rodent pests often cause large damage to economy and ecology. However, as a mem ber of many ecosystems, rodents are beneficial to other species. Some birds live in the rodents abandoned holes, and thus, the quantity of abandoned holes reflects the dynamics of these bird populations. In rodent pest control, rodents should not be exterminated thoroughly, because it would damage the species that benefit from rodents. In this paper, mathematical models were used to study the dynamic patterns of the quantities of the abandoned and available holes and their ratios, with the effects of rodent pest control measures and intensities on the changes of the rodent available and abandoned holes quantities analyzed. The quantity of available holes repre sented the population density of rodent pests, while the quantity of abandoned holes （ sometimes both the available and the abandoned holes） represented the life conditions of the species that benefit from rodent pests. It was shown that under any control measures, the quantity of available holes was decreased, while that of abandoned holes was increased or decreased, depending on the control intensity and the population parameters of rodent species. The ratio of the abandoned holes to the available holes was unchanged under comprehensive control, decreased under contra ception control, and increased under other control measures.