Landscape disturbance variables and woylie capture rate over time

Data from: Temporal patterns in the abundance of a critically endangered marsupial relates to disturbance by roads and agriculture

Sheet one contains the capture rate of woylies at each site between 1994 and 2012. Blank cells indicate no sample collected during that year. Sheet two contains the measured road network density, proximity to agriculture and timber harvesting history of each of the 22 grid and 5 transect locations.

The aim of this study was to investigate how landscape disturbance associated with roads, agriculture and forestry influenced temporal patterns in woylie (Bettongia penicillata) abundance before, during and after periods of rapid population change. Data were collected from an area of approximately 140,000 ha of forest within the Upper Warren region in south-western Australia. Woylie abundance was measured using cage trapping at 22 grid and five transect locations with varying degrees of landscape disturbance between 1994 and 2012. We found evidence that the distribution and abundance of woylies over time appears to be related to the degree of fragmentation by roads and proximity to agriculture. Sites furthest from agriculture supported a greater abundance of woylies and had slower rates of population decline. Sites with fewer roads had a greater abundance of woylies generally and a greater rate of increase in abundance after the implementation of invasive predator control. The results of this study suggest that landscape disturbance is less important at peak population densities, but during times of environmental and population change, sites less dissected by roads and agriculture better support woylie populations. This may be due to the role these factors play in increasing the vulnerability of woylies to introduced predators, population fragmentation, weed species invasion, mortality from road collisions or a reduction in available habitat. Strategies that reduce the impact of disturbance on woylie populations could include the rationalisation of forest tracks and consolidation of contiguous habitat through the acquisition of private property. Reducing the impact of disturbance in the Upper Warren region could improve the resilience of this critically important woylie population during future environmental change.

数据来源：极度濒危有袋类动物种群丰度的时间格局与道路及农业干扰的关联

本数据集相关信息如下：第一张工作表收录了1994年至2012年间各监测点位的沃利袋鼠（woylie，Bettongia penicillata）捕获率，空白单元格代表当年未采集到有效样本；第二张工作表涵盖22个样方与5条样带点位的实测道路网络密度、农业用地邻近度及木材采伐历史数据。

本研究旨在探究道路、农业与林业相关的景观干扰，在种群快速变动阶段的前、中、后期，如何影响沃利袋鼠丰度的时间动态格局。研究数据采集自澳大利亚西南部上沃伦（Upper Warren）地区约14万公顷的森林区域。1994年至2012年间，研究团队采用笼捕法，在22个样方与5条样带点位开展调查，这些点位的景观干扰程度各不相同，以此测算沃利袋鼠的种群丰度。

研究结果显示，沃利袋鼠的时空分布与丰度似乎与道路造成的生境割裂程度及农业用地邻近度密切相关。距离农业用地最远的监测点，沃利袋鼠种群丰度更高，种群下降速率更慢；道路密度较低的点位，沃利袋鼠整体丰度更高，且在实施外来捕食者防控措施后，种群丰度的增长速率更快。

本研究结果表明，景观干扰在种群密度峰值期的影响相对较弱，但在环境与种群发生变化的阶段，受道路与农业割裂程度更低的点位能更好地维持沃利袋鼠种群。这一现象可能源于以下机制：上述干扰因素会提升沃利袋鼠对外来捕食者的易感性、加剧种群碎片化、引发杂草入侵、导致道路碰撞致死，或是缩减可用生境面积。

降低干扰对沃利袋鼠种群影响的保护策略可包括：对林道进行合理化整合，以及通过收购私有土地来连通并整合连续生境。在上沃伦地区降低干扰影响，可提升这一极度重要的沃利袋鼠种群在未来环境变化中的恢复力。