Seed dispersal kernel of the largest surviving megaherbivore-the African savanna elephant
Seed dispersal kernel of the largest surviving megaherbivore-the African savanna elephant
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DOI：
10.1111/btp.12423
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发表时间：
2017-05-01
期刊：
影响因子：
2.1
通讯作者：
Henley, Michelle
中科院分区：
文献类型：
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作者：
Bunney, Katherine;Bond, William J.;Henley, Michelle
由于更新世晚期的灭绝，欧洲、澳大利亚和美洲的巨型动物消失了，它们提供的巨型动物果实也随之消失了。非洲大草原象是现存最大的巨型食草动物，它为史前时代灭绝的巨型动物提供了宝贵的种子传播服务。大象种子传播的研究主要集中在非洲和亚洲的森林象上。非洲草原象在形态上与森林象不同。像森林象一样，它们从大量的树种中摄取大量的果实。尽管如此，人们对依赖大象传播的热带草原树木或这些种子传播的空间规模知之甚少。我们将在APNR/Kruger国家公园对四头公园大象进行的喂养试验的信息与在APNR/Kruger国家公园8年期间收集的38头戴项圈大象的现场遥测数据相结合，以评估稀树草原大象提供的种子传播服务。这项研究首次详细描述了非洲大草原象传播种子的空间尺度。我们的机制模型预测，50%的种子被携带超过2.5公里，在最大的肠道传播时间内，最远可以达到65公里。这些发现表明，热带草原象是迄今为止研究过的距离最远的陆生脊椎动物。保持它们作为种子传播者的生态作用可能是保护大草原内大型果树多样性的重要因素。这些结果表明，灭绝的巨型动物为巨型动物的果实提供了一种功能独特的传播服务。
Owing to the late Pleistocene extinctions, the megafauna of Europe, Australia and the Americas disappeared, and with them the dispersal service they offered megafaunal fruit. The African savanna elephant, the largest remaining megaherbivore, offers valuable insights into the seed dispersal services provided by extinct megafauna in prehistoric times. Elephant seed dispersal studies have for the most part concentrated on African and Asian forest elephants. African savanna elephants are morphologically distinct from their forest counterparts. Like the forest elephants they consume large quantities of fruit from a large number of tree species. Despite this little is known of the savanna trees that rely on elephants for their dispersal or the spatial scale at which these seeds are dispersed. We combined information from feeding trials conducted on four park elephants with field telemetry data from 38 collared elephants collected over an 8-year period in APNR/Kruger National Park to assess the seed dispersal service provided by savanna elephants. This study provides the first detailed account of the spatial scale at which African savanna elephants disperse seeds. Our mechanistic model predicts that 50 percent of seeds are carried over 2.5km, and distances up to 65km are achievable in maximum gut passage time. These findings suggest the savanna elephant as the longest distance terrestrial vertebrate disperser yet investigated. Maintaining their ecological role as a seed disperser may prove a significant factor in the conservation of large-fruited tree diversity within the savannas. These results suggest that extinct megafauna offered a functionally unique dispersal service to megafaunal fruit.