Broad-scale environmental influences on the abundance of saltwater crocodiles (Crocodylus porosus) in Australia
Broad-scale environmental influences on the abundance of saltwater crocodiles (Crocodylus porosus) in Australia
复制标题
DOI：
10.1071/wr06110
复制
发表时间：
2007-01-01
影响因子：
1.9
通讯作者：
Boggs, Guy
中科院分区：
文献类型：
--
作者：
Fukuda, Yusuke;Whitehead, Peter;Boggs, Guy
自从咸水鳄（Crocodylus porosus）免受狩猎保护以来的 30 年里，该物种在澳大利亚北部的数量大幅恢复。然而，监测研究显示，北领地、昆士兰州和西澳大利亚州的丰度存在巨大的地理差异。北领地的人口密度相当高，引发了人们对其他州恢复受到限制的质疑。我们通过对澳大利亚北部的物种与环境关系进行建模，研究了大范围的环境对人口丰度的影响。基于假设的模型强烈支持以下联系：（1）有利湿地植被类型（白千层、草和莎草）的总面积与总流域面积的比率，（2）降雨季节性的衡量标准，即最冷季度的总降水量与一年中最温暖季度的总降水量的比率，以及（3）一年中最冷季度的平均温度。另一方面，我们无法表明与 景观改变，如流域内高影响土地利用的程度或人口密度所表明的。我们的结论是，鳄鱼密度的地理差异主要归因于栖息地质量的差异，而不是各个管辖区采用的管理制度。
Saltwater crocodile ( Crocodylus porosus) populations have recovered strongly across northern Australia over the 30 years since the species was protected from hunting. However, monitoring studies show large geographical variations in abundance across the Northern Territory, Queensland and Western Australia. The Northern Territory has considerably higher densities, raising questions about constraints on recovery in the other states. We examined broad- scale environmental influences on population abundance by modelling the species - environment relationships across northern Australia. The hypothesis- based models showed strong support for the linkage to ( 1) the ratio of total area of favourable wetland vegetation types ( Melaleuca, grass and sedge to total catchment area, ( 2) a measure of rainfall seasonality, namely the ratio of total precipitation in the coldest quarter to total precipitation in the warmest quarter of a year, and ( 3) the mean temperature in the coldest quarter of a year. On the other hand, we were unable to show any clear negative association with landscape modification, as indicated by the extent of high- impact land uses or human population density in catchments. We conclude that geographical variations in crocodile density are mostly attributable to differences in habitat quality rather than the management regimes adopted in the respective jurisdictions.