Mouse population eruptions in New Zealand forests: the role of population density and seedfall.
Mouse population eruptions in New Zealand forests: the role of population density and seedfall.
复制标题
新西兰森林中的老鼠数量激增：人口密度和种子掉落的作用。
DOI：
10.1111/j.1365-2656.2000.00462.x
复制
发表时间：
2000
影响因子：
4.8
通讯作者：
W. Ruscoe
中科院分区：
文献类型：
--
作者：
D. Choquenot;W. Ruscoe
总结
1.散发性爆发家鼠种群提供了一个机会，以测试内在和外在因素如何相互作用，以限制啮齿动物种群的想法。 新西兰的家鼠种群栖息在山毛榉森林和相关的马赛克爆发时，秋季山毛榉种子是高。我们分析了25年的数据，小鼠密度和山毛榉种子从山毛榉和罗汉果/硬木森林镶嵌在新西兰测试小鼠密度的影响，山毛榉种子和大鼠密度对小鼠丰度的变化率，估计为连续的季节转换（r）的密度指数的变化率。
2.对于秋季到冬季和冬季到春季的过渡，r与每个过渡开始时的秋季种子下降的幅度和鼠密度有关，无论是单独考虑还是一起考虑森林类型。 对于春季到夏季和夏季到秋季的过渡，r仅与小鼠密度有关。密度依赖性可能反映了内在社会因素、种内食物竞争或寄生虫、疾病或捕食者的影响。
3.我们修改了啮齿类动物繁殖努力变化的概念模型，以导出一个一般模型，说明对食物可获得性的密度无关性增加的数字响应如何被密度依赖性机制和人口增长的外在前兆所修改，从而驱动某些啮齿类动物种群密度的零星爆发。 对于新西兰的家鼠，对种子落下的数值反应被一些未识别的密度依赖性机制修改，以产生零星的爆发。人口增长的外在前体似乎是重要的其他爆发家鼠种群。
4.山毛榉林的家鼠密度波动性大于罗汉果阔叶林，前者的最大增减率均高于后者。 密度往往是较高的，在罗汉果/阔叶林时，整体密度低，和较高的山毛榉林时，整体密度高。这表明，在爆发之间，小鼠坚持在podocarp/硬木森林比在相邻的山毛榉林在更高的密度。
Summary
1. Sporadically eruptive house mouse populations provide an opportunity to test ideas about how intrinsic and extrinsic factors interact to limit rodent populations. New Zealand house mouse populations inhabiting beech forests and associated mosaics erupt when autumn beech seedfall is high. We analysed 25 years of data on mouse density and beech seedfall from a beech and podocarp/hardwood forest mosaic in New Zealand to test the effects of mouse density, beech seedfall and rat density on rates of change in mouse abundance, estimated as the rate of change in a density index for sequential seasonal transitions (r).
2. For autumn to winter and winter to spring transitions, r was related to the magnitude of autumn seedfall and mouse density at the start of each transition, regardless of whether forest types were considered separately or together. For spring to summer and summer to autumn transitions, r was related to mouse density alone. Density dependence could reflect the influence of intrinsic social factors, intraspecific competition for food, or the effects of parasites, diseases or predators.
3. We modified a conceptual model of variation in rodent reproductive effort to derive a general model of how numerical responses to density-independent increases in food availability, modified by density-dependent mechanisms and extrinsic precursors to population increase, drive sporadic eruptions in the density of some rodent populations. For house mice in New Zealand, the numerical response to seedfall was modified by some unidentified density-dependent mechanism(s) to generate sporadic eruptions. Extrinsic precursors to population increase appear to be important in other eruptive house mouse populations.
4. House mouse density in beech forest was more volatile than in podocarp/hardwood forest, maximum rates of increase and decrease being higher in the former. Density tended to be higher in podocarp/hardwood forest when overall density was low, and higher in beech forest when overall density was high. This suggests that between eruptions, mice persist in podocarp/hardwood forest at higher densities than in adjoining beech forest.