Wolf Christopher, Ripple William J
Global Trophic Cascades Program, Department of Forest Ecosystems and Society, Oregon State University, Corvallis, OR 97331, USA.
R Soc Open Sci. 2017 Jul 12;4(7):170052. doi: 10.1098/rsos.170052. eCollection 2017 Jul.
The majority of the world's terrestrial large carnivores have undergone substantial range contractions and many of these species are currently threatened with extinction. However, there has been little effort to fully quantify the extent of large carnivore range contractions, which hinders our ability to understand the roles and relative drivers of such trends. Here we present and analyse a newly constructed and comprehensive set of large carnivore range contraction maps. We reveal the extent to which ranges have contracted since historical times and identify regions and biomes where range contractions have been particularly large. In summary, large carnivores that have experienced the greatest range contractions include the red wolf () (greater than 99%), Ethiopian wolf () (99%), tiger () (95%) and lion () (94%). In general, the greatest range contractions occurred in Southeastern Asia and Africa. Motivated by the ecological importance of intact large carnivore guilds, we also examined the spatial extent of intact large carnivore guilds both for the entire world and regionally. We found that intact carnivore guilds occupy just 34% of the world's land area. This compares to 96% in historic times. Spatial modelling of range contractions showed that contractions were significantly more likely in regions with high rural human population density, cattle density or cropland. Our results offer new insights into how best to prevent further range contractions for the world's largest carnivores, which will assist efforts to conserve these species and their important ecological effects.
世界上大多数陆生大型食肉动物的分布范围都大幅收缩,其中许多物种目前面临灭绝威胁。然而,人们几乎没有做出努力来全面量化大型食肉动物分布范围收缩的程度,这阻碍了我们理解此类趋势的作用和相关驱动因素的能力。在此,我们展示并分析了一组新构建的、全面的大型食肉动物分布范围收缩地图。我们揭示了自历史时期以来分布范围收缩的程度,并确定了分布范围收缩尤为严重的地区和生物群落。总之,经历了最大分布范围收缩的大型食肉动物包括红狼(超过99%)、埃塞俄比亚狼(99%)、老虎(95%)和狮子(94%)。一般来说,最大的分布范围收缩发生在东南亚和非洲。鉴于完整的大型食肉动物群落具有重要的生态意义,我们还研究了全球及区域范围内完整的大型食肉动物群落的空间范围。我们发现,完整的食肉动物群落仅占世界陆地面积的34%。相比之下,历史时期这一比例为96%。分布范围收缩的空间模型显示,在农村人口密度高、牛密度高或耕地多的地区,收缩的可能性显著更大。我们的研究结果为如何最好地防止世界上最大型食肉动物的分布范围进一步收缩提供了新的见解,这将有助于保护这些物种及其重要的生态效应。