Directed seed dispersal towards areas with low conspecific tree density by a scatter-hoarding rodent
Directed seed dispersal towards areas with low conspecific tree density by a scatter-hoarding rodent
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DOI：
10.1111/ele.12000
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发表时间：
2012-12-01
期刊：
影响因子：
8.8
通讯作者：
Jansen, Patrick A.
中科院分区：
文献类型：
--
作者：
Hirsch, Ben T.;Kays, Roland;Jansen, Patrick A.
分散囤积的动物分散储存的种子，以减少依赖密度的食物储备盗窃。这种行为可能导致定向扩散到同种树木密度较低的地区，那里的种子和幼苗存活率较高，并可能对植物群落的空间结构产生深远影响。我们在巴拿马科罗拉多岛的巴罗科罗拉多岛用中美洲黑木耳和木兰棕榈籽验证了这一假说。我们对种子被Agutis缓存和重新缓存的过程进行了无线电跟踪，计算了每个缓存周围的成年Astrocaryum树的密度，并测试了在随机分散下，种子缓存周围的观察到的树木数量是否比预期的下降得更多。成苗成活率与种子密度呈负相关，种子带向同种树密度较低的地点，有利于种子逃逸天敌。这种行为可能是一种广泛的机制，导致分散囤积动物进行高效的种子传播。
Scatter-hoarding animals spread out cached seeds to reduce density-dependent theft of their food reserves. This behaviour could lead to directed dispersal into areas with lower densities of conspecific trees, where seed and seedling survival are higher, and could profoundly affect the spatial structure of plant communities. We tested this hypothesis with Central American agoutis and Astrocaryum standleyanum palm seeds on Barro Colorado Island, Panama. We radio-tracked seeds as they were cached and re-cached by agoutis, calculated the density of adult Astrocaryum trees surrounding each cache, and tested whether the observed number of trees around seed caches declined more than expected under random dispersal. Seedling establishment success was negatively dependent on seed density, and agoutis carried seeds towards locations with lower conspecific tree densities, thus facilitating the escape of seeds from natural enemies. This behaviour may be a widespread mechanism leading to highly effective seed dispersal by scatter-hoarding animals.