The size of savannah Africa: a lion's (Panthera leo) view
The size of savannah Africa: a lion's (Panthera leo) view
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DOI：
10.1007/s10531-012-0381-4
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发表时间：
2013-01-01
影响因子：
3.4
通讯作者：
Pimm, Stuart
中科院分区：
文献类型：
--
作者：
Riggio, Jason;Jacobson, Andrew;Pimm, Stuart
我们将非洲大草原定义为年降雨量在300至1 500毫米之间的地区。这一宽泛的定义涵盖了各种生境。因此，稀树草原包括1350万公里（2），包括非洲狮（Panthera leo）目前的大部分活动范围。密集的人口和广泛的土地转换为人类使用排除了狮子的使用。使用高分辨率卫星图像和人口密度数据，我们定义了狮子区，可能有狮子种群的地方。1960年，在1190万平方公里的热带稀树草原上，每平方公里的人口不到25人。到2000年，可比面积缩小到970万平方公里。在过去的50年里，非洲大萨凡纳地区的人口已经大幅减少，人口预测表明，在未来40年里，这些地区可能会大幅减少。目前自由放养的狮子种群的范围是340万公里（2）或约25%的萨凡纳面积。这一地区的狮群是分散的;所有可用的数据表明，在67个狮子区生活着32，000到35，000头自由放养的狮子。虽然这些数字与以前的估计数相似，但它们在地理上更全面。有大量证据表明大范围的下降和局部的减少。根据我们概述的标准，十个狮子区有资格成为狮子据点：东非四个，南部非洲六个。大约有24,000头狮子在据点里，另外还有4,000头在潜在的据点里。然而，超过6,000头狮子的长期生存能力令人怀疑。西非和中非的狮子种群受到严重威胁，最近，即使在名义上的保护区，也有许多当地的保护措施。
We define African savannahs as being those areas that receive between 300 and 1,500 mm of rain annually. This broad definition encompasses a variety of habitats. Thus defined, savannahs comprise 13.5 million km(2) and encompass most of the present range of the African lion (Panthera leo). Dense human populations and extensive conversion of land to human use preclude use by lions. Using high-resolution satellite imagery and human population density data we define lion areas, places that likely have resident lion populations. In 1960, 11.9 million km(2) of these savannahs had fewer than 25 people per km(2). The comparable area shrank to 9.7 million km(2) by 2000. Areas of savannah Africa with few people have shrunk considerably in the last 50 years and human population projections suggest they will likely shrink significantly in the next 40. The current extent of free-ranging lion populations is 3.4 million km(2) or about 25 % of savannah area. Habitats across this area are fragmented; all available data indicate that between 32,000 and 35,000 free-ranging lions live in 67 lion areas. Although these numbers are similar to previous estimates, they are geographically more comprehensive. There is abundant evidence of widespread declines and local extinctions. Under the criteria we outline, ten lion areas qualify as lion strongholds: four in East Africa and six in Southern Africa. Approximately 24,000 lions are in strongholds, with an additional 4,000 in potential ones. However, over 6,000 lions are in populations of doubtful long-term viability. Lion populations in West and Central Africa are acutely threatened with many recent, local extinctions even in nominally protected areas.