Dawson Stuart J, Kreplins Tracey L, Kennedy Malcolm S, Renwick Juanita, Cowan Mark A, Fleming Patricia A
Terrestrial Ecosystem Science and Sustainability, Harry Butler Institute, Murdoch University, Murdoch, Australia.
Department of Primary Industries and Regional Development (present address), South Perth, Australia.
Integr Zool. 2023 Mar;18(2):299-315. doi: 10.1111/1749-4877.12683. Epub 2022 Oct 12.
Rangelands worldwide have been subject to broadscale modification, such as widespread predator control, introduction of permanent livestock water and altered vegetation to improve grazing. In Australia, these landscape changes have resulted in kangaroos (i.e. large macropods) populations increasing over the past 200 years. Kangaroos are a key contributor to total grazing pressure and in conjunction with livestock and feral herbivores have been linked to land degradation. We used 22 years of aerial survey data to investigate whether the density of 3 macropod species in the southern rangelands of Western Australia was associated with: (i) land use, including type of livestock, total livestock, density of feral goats, type of land tenure, and kangaroo commercial harvest effort; (ii) predator management, including permitted dingo control effort, estimated dingo abundance, and presence of the State Barrier Fence (a dingo exclusion fence); and (iii) environmental variables: ruggedness, rainfall, fractional cover, and total standing dry matter. Red kangaroos (Osphranter rufus) were most abundant in flat, open vegetation, on pastoral land, where area permitted for dingo control was high, and numbers were positively associated with antecedent rainfall with a 12-month delay. Western grey kangaroos (Macropus fuliginosus) were most abundant on flat, agricultural land, but less abundant in areas with high permitted dingo control. Euros (Osphranter robustus) were most abundant in rugged pastoral land with open vegetation, where permitted dingo control was high. While environmental variables are key drivers of landscape productivity and kangaroo populations, anthropogenic factors such as land use and permitted dingo control are strongly associated with kangaroo abundance.
世界各地的牧场都经历了大规模的改造，例如广泛的捕食者控制、引入永久性牲畜水源以及改变植被以改善放牧条件。在澳大利亚，这些景观变化导致袋鼠（即大型有袋类动物）数量在过去200年中不断增加。袋鼠是总放牧压力的关键因素，与牲畜和野生食草动物一起被认为与土地退化有关。我们利用22年的航空调查数据，研究了西澳大利亚南部牧场3种有袋类动物的密度是否与以下因素相关：（i）土地利用，包括牲畜类型、牲畜总数、野山羊密度、土地所有权类型以及袋鼠商业捕猎力度；（ii）捕食者管理，包括允许的澳洲野犬控制力度、估计的澳洲野犬数量以及州界围栏（一道澳洲野犬排除围栏）的存在；（iii）环境变量：地形崎岖度、降雨量、植被覆盖度和总立地干物质。红袋鼠（赤大袋鼠）在平坦、开阔植被的牧区最为丰富，那里允许控制澳洲野犬的区域面积很大，且数量与延迟12个月的前期降雨量呈正相关。西部灰袋鼠在平坦的农业用地上最为丰富，但在允许高度控制澳洲野犬的地区数量较少。尤金袋鼠（壮硕大袋鼠）在植被开阔的崎岖牧区最为丰富，那里允许控制澳洲野犬的力度很大。虽然环境变量是景观生产力和袋鼠数量的关键驱动因素，但土地利用和允许的澳洲野犬控制等人为因素与袋鼠数量密切相关。
