Treitler Julia Tabea, Drissen Tim, Stadtmann Robin, Zerbe Stefan, Mantilla-Contreras Jasmin
RG Ecology and Environmental Education, Institute of Biology and Chemistry, University of Hildesheim, Universitätsplatz 1, 31141, Hildesheim, Germany.
Institute of Geography, University of Hildesheim, Universitätsplatz 1, 31141, Hildesheim, Germany.
BMC Ecol. 2017 Dec 19;17(1):42. doi: 10.1186/s12898-017-0148-6.
Endozoochory is, in grazing systems, a substantial vector for seed dispersal. It can play an important role in vegetation dynamics, especially in colonization processes through seed input on the vegetation and on the soil seed bank. We investigated the endozoochorous seed input of donkeys and goats on a semi-natural island ecosystem in the Mediterranean. Through germination experiments, we assessed the viable seed content of the dung of these grazing animals to estimate their suitability and efficiency for seed dispersal of the vegetation types of the island.
We show different dispersal patterns of donkeys and goats. Goats disperse a high number of diaspores from shrubs while donkeys disperse more diaspores of grasses. In addition, goats disperse plants of greater growth height and donkeys plants of shorter height. These dispersal patterns are in accordance with the vegetation types of which donkeys and goats disperse indicator species. Both, donkeys and goats, feed on and disperse species of the vegetation types, open grassland and temporarily wet grassland. In addition, goats feed on and disperse diagnostic species of the semi-open maquis and preforest formations.
Overall, our results show that donkeys and goats are complementing each other in their endozoochorous seed dispersal potential. This emphasizes the importance of both grazing animals for the vegetation dynamics of the semi-natural island ecosystem. Therefore, the adaption of the goat management to a traditional land management based on directed transhumance might maintain and enrich vegetation types.
在放牧系统中，内寄生动物传播是种子传播的一个重要途径。它在植被动态中可以发挥重要作用，特别是在通过向植被和土壤种子库输入种子的定居过程中。我们在地中海的一个半自然岛屿生态系统中研究了驴和山羊的内寄生动物传播种子输入情况。通过发芽实验，我们评估了这些放牧动物粪便中的有活力种子含量，以估计它们对该岛屿植被类型种子传播的适宜性和效率。
我们展示了驴和山羊不同的传播模式。山羊传播大量来自灌木的传播体，而驴传播更多的草本植物传播体。此外，山羊传播的植物生长高度更高，驴传播的植物高度更矮。这些传播模式与驴和山羊传播指示物种的植被类型一致。驴和山羊都取食并传播开阔草地和临时湿润草地等植被类型的物种。此外，山羊还取食并传播半开阔马基群落和森林前形成的诊断物种。
总体而言，我们的结果表明，驴和山羊在内寄生动物传播种子的潜力方面相互补充。这强调了这两种放牧动物对该半自然岛屿生态系统植被动态的重要性。因此，将山羊管理方式调整为基于定向游牧的传统土地管理方式可能会维持和丰富植被类型。
