METAPOPULATION VIABILITY OF ARBOREAL MARSUPIALS IN FRAGMENTED OLD-GROWTH FORESTS: COMPARISON AMONG SPECIES'
METAPOPULATION VIABILITY OF ARBOREAL MARSUPIALS IN FRAGMENTED OLD-GROWTH FORESTS: COMPARISON AMONG SPECIES'
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支离破碎的古老森林中树栖有袋动物的群居活力：物种间比较
DOI：
10.2307/1942062
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发表时间：
1995
期刊：
影响因子：
--
通讯作者：
R. Lacy
中科院分区：
文献类型：
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作者：
D. Lindenmayer;R. Lacy
使用种群活力分析（PVA）通用软件包进行计算机模拟分析，用于检查山刷尾负鼠（Trichosurus caninus）和大滑翔机（Petauroides volans）的有限数量的复合种群结构的动态。这些树栖有袋动物栖息在澳大利亚东南部高大的桉树林中。正如对利德比特负鼠 Gymnobelideus Leadbeateri 的一项平行研究一样，结果表明，在某些混合种群结构中，栖息地斑块之间的移动增加可能会对种群稳定性产生不利影响，进而降低种群持久性。这些负面影响在由 4、10 或 20 只动物组成的非常小的亚群组成的模型集合种群中最为明显。随着斑块间移动的增加以及更多小亚群的增加，这些模式得到了加强。当来自已经不稳定和下降的亚种群的动物分散到无人居住的栖息地（充当种群下沉的一种类型）时，这些反直觉的发现似乎就会产生。在对 40 只动物的较大亚群进行建模的情况下，这些人口统计趋势发生了逆转。在这种情况下，运动和额外的栖息地斑块对亚种群和集合种群动态的影响是积极的。与各种人口统计参数的结果相反，增加的运动和增加的亚群对所检查的所有类型的集合种群结构之间的遗传变异性具有有益的影响。对这两个物种的结果进行了相互比较，并与对利德比特负鼠（Gymnobelideus Leadbeateri）的调查进行了比较。这些比较证实了总体趋势，但也揭示了 T. caninus、P. volans 和 G. Leadbeateri 集合种群行为的潜在数量差异。其中许多差异归因于出生率和死亡率等关键生活史参数的变化，但集合种群活力的趋势并不简单地与种群内在增长率相关。这三个物种在人口统计和遗传稳定性所需的集合种群的规模上有所不同，并且它们对人口统计和遗传随机性的敏感性的排序可能不一致。不同的物种，即使是同一行会的物种，对干扰和环境扰动的脆弱性也可能有所不同。我们的分析还强调，在制定景观和区域尺度野生动物保护战略时，需要了解集合种群的结构和组成。
Computer simulation analyses using a generic package for population via- bility analysis (PVA) were used to examine the dynamics of a limited number of meta- population structures of the mountain brushtail possum, Trichosurus caninus, and the greater glider, Petauroides volans. These arboreal marsupials inhabit tall eucalypt forests in south- eastern Australia. As in a parallel study of Leadbeater's possum, Gymnobelideus leadbeateri, the results indicated that there are some metapopulation structures in which increased movement between habitat patches may have a detrimental effect on demographic stability and, in turn, reduce population persistence. These negative impacts were most pronounced in model metapopulations composed of an ensemble of very small subpopulations of 4, 10, or 20 animals. The patterns were accentuated with increased inter-patch movement as well as the addition of further small subpopulations. These counter-intuitive findings appear to result when animals from already unstable and declining sub-populations disperse into unoccupied patches of habitat that act as a type of population sink. These trends in pop- ulation demography were reversed in scenarios in which larger subpopulations of 40 animals were modeled. In such cases the impacts of movement and additional habitat patches on subpopulation and metapopulation dynamics were positive. In contrast to the results for various demographic parameters, increased movement and added subpopulations had a beneficial effect on genetic variability among all the types of metapopulation structures that were examined. Results for the two species were compared to each other and also with investigations of Leadbeater's possum, Gymnobelideus leadbeateri. These comparisons confirmed general trends but also revealed potential quantitative differences in the behavior of metapopulations of T. caninus, P. volans, and G. leadbeateri. Many of these differences were attributed to variations in key life history parameters such as birth and death rates, but trends in metapop- ulation viability did not correlate simply with intrinsic rates of population growth. The three species differed in the size of metapopulations required for demographic and genetic stability, and the rank order of their susceptibility to demographic and genetic stochasticity may not be consistent. Different species, even those within the same guild, may vary in vulnerability to disturbance and environmental perturbation. Our analyses also emphasized the need to understand the structure and composition of metapopulations in the development of strategies for conservation of wildlife at the landscape and regional scales.