Department of Scientific Services, Beira, Sofala Province, Mozambique.
ARC-Animal Production Institute, Rangeland Ecology Group, Nelspruit, South Africa.
PLoS One. 2019 Mar 13;14(3):e0212864. doi: 10.1371/journal.pone.0212864. eCollection 2019.
How do large-mammal communities reassemble after being pushed to the brink of extinction? Few data are available to answer this question, as it is rarely possible to document both the decline and recovery of wildlife populations. Here we present the first in-depth quantitative account of war-induced collapse and postwar recovery in a diverse assemblage of large herbivores. In Mozambique's Gorongosa National Park, we assembled data from 15 aerial wildlife counts conducted before (1968-1972) and after (1994-2018) the Mozambican Civil War (1977-1992). Pre-war total biomass density exceeded 9,000 kg km-2, but populations declined by >90% during the war. Since 1994, total biomass has substantially recovered, but species composition has shifted dramatically. Formerly dominant large herbivores-including elephant (Loxodonta africana), hippo (Hippopotamus amphibius), buffalo (Syncerus caffer), zebra (Equus quagga), and wildebeest (Connochaetes taurinus)-are now outnumbered by waterbuck (Kobus ellipsiprymnus) and other small to mid-sized antelopes. Waterbuck abundance has increased by an order of magnitude, with >55,000 individuals accounting for >74% of large-herbivore biomass in 2018. By contrast, elephant, hippo, and buffalo, which totaled 89% of pre-war biomass, now comprise just 23%. These trends mostly reflect natural population growth following the resumption of protection under the Gorongosa Restoration Project; reintroductions (465 animals of 7 species) accounted for a comparatively small fraction of the total numerical increase. Waterbuck are growing logistically, apparently as-yet unchecked by interspecific competition or predation (apex-carnivore abundance has been low throughout the post-war interval), suggesting a community still in flux. Most other herbivore populations have increased post-war, albeit at differing rates. Armed conflict remains a poorly understood driver of ecological change; our results demonstrate the potential for rapid post-war recovery of large-herbivore biomass, given sound protected-area management, but also suggest that restoration of community structure takes longer and may require active intervention.
大型哺乳动物社区在濒临灭绝的边缘后是如何重新组合的？由于很少有数据能够同时记录野生动物种群的减少和恢复情况，因此几乎无法回答这个问题。在这里，我们首次深入定量地描述了在一个多样化的大型食草动物群体中，由战争引起的崩溃和战后恢复的情况。在莫桑比克的戈龙戈萨国家公园，我们收集了 1968-1972 年（战前）和 1994-2018 年（战后）期间进行的 15 次空中野生动物普查的数据。战前的总生物量密度超过 9000 公斤/平方公里，但在战争期间，种群数量下降了超过 90%。自 1994 年以来，总生物量已大幅恢复，但物种组成发生了巨大变化。以前占主导地位的大型食草动物，包括大象（Loxodonta africana）、河马（Hippopotamus amphibius）、水牛（Syncerus caffer）、斑马（Equus quagga）和角马（Connochaetes taurinus），现在被水羚（Kobus ellipsiprymnus）和其他中小体型的羚羊所超过。水羚的数量增加了一个数量级，2018 年有超过 55000 只水羚，占大型食草动物生物量的 74%。相比之下，战前生物量占 89%的大象、河马和水牛，现在仅占 23%。这些趋势主要反映了在戈龙戈萨恢复项目恢复保护后，自然种群增长的情况；重新引入（7 个物种的 465 只动物）在总数量增长中仅占比较小的一部分。水羚的数量在增加，显然还没有受到种间竞争或捕食（整个战后期间，顶级食肉动物的数量一直很低）的限制，这表明该群落仍在变化之中。大多数其他食草动物的数量在战后都有所增加，尽管增长速度不同。武装冲突仍然是生态变化的一个了解甚少的驱动因素；我们的结果表明，在合理的保护区管理下，大型食草动物生物量有迅速恢复的潜力，但也表明群落结构的恢复需要更长的时间，并且可能需要积极的干预。
