Impacts of grazing by different large herbivores in grassland depend on plant species diversity
Impacts of grazing by different large herbivores in grassland depend on plant species diversity
复制标题
草原上不同大型食草动物放牧的影响取决于植物物种多样性
DOI：
10.1111/1365-2664.12456
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发表时间：
2015-08-01
影响因子：
5.7
通讯作者：
Zhong, Zhiwei
中科院分区：
文献类型：
--
作者：
Liu, Jun;Feng, Chao;Zhong, Zhiwei
大型食草动物对草原生态系统中的植物群落有显著的影响，其影响的程度和过程在很大程度上取决于植物和食草动物的特性。以前的研究强调了植物生产力在预测草食动物对草原的影响方面的重要性。然而，很少有人考虑不同的草食动物如何影响植物群落，而植物群落反过来又会产生不同的植物多样性。在为期两年的放牧实验中，我们测试了在欧亚草原东部植物多样性水平高和低的情况下，大型食草动物(牛或羊，或两者兼有)对植物群落的影响。研究发现，对于植物多样性较高的草地，牛羊混牧显著提高了植物多样性，但牛羊单独放牧对草地植物多样性没有影响。在高多样性草地上，牛羊单独放牧或牛羊混合放牧对植物生物量无显著影响。然而，对于植物多样性较低的草地，单独放牧和牛羊混牧显著增加了植物多样性，但显著降低了植物生物量。绵羊放牧对植物多样性和生物量均无显著影响。我们的结论是，放牧对草原的影响强烈地依赖于草食动物组合和放牧前的植物多样性。与低植物多样性相比，在植物多样性较高的情况下，食草动物放牧对草地结构和生态系统功能的维持可能有更大的贡献。此外，我们的数据表明，在植物多样性较高的草地系统中，多物种混合放牧制度可能是放牧管理的最佳方案。这项研究强调了维持植物和草食动物多样性对优化生态系统功能的重要性。我们得出结论，草原放牧的效果强烈地依赖于草食动物组合和放牧前的植物多样性。与低植物多样性相比，在植物多样性较高的情况下，食草动物放牧对草地结构和生态系统功能的维持可能有更大的贡献。此外，我们的数据表明，在植物多样性较高的草地系统中，多物种混合放牧制度可能是放牧管理的最佳方案。这项研究强调了维持植物和草食动物多样性以优化生态系统功能的重要性。
It is well documented that large herbivores have pronounced effects on plant communities in grassland ecosystems, and the extent and course of their effects can largely depend on both plant and herbivore characteristics. Previous studies highlighted the importance of plant productivity in predicting the impact of herbivores on grasslands. Yet, there has been little consideration of how different herbivores affect plant communities that, in turn, differ in plant diversity. In a 2-year grazing experiment, we tested the effects of large herbivores (cattle or sheep, or both together) on plant communities under high and low plant diversity levels in eastern Eurasian steppe. We found that, for high plant diversity grassland, mixed grazing by cattle and sheep significantly increases plant diversity, but we found no effect of grazing by cattle or sheep alone. Grazing by cattle or sheep alone or mixed grazing by cattle and sheep did not significantly affect plant biomass in the high diversity grassland. However, for low plant diversity grassland, grazing by cattle alone and mixed grazing by cattle and sheep significantly increased plant diversity, but significantly decreased plant biomass. There was no significant impact on both plant diversity and biomass from sheep grazing.Synthesis and applications. We conclude that the effects of grazing in grassland strongly depend on herbivore assemblages and pre-grazing plant diversity. Herbivore grazing might contribute more to the maintenance of grassland structure and ecosystem functioning under high plant diversity compared with low plant diversity. Furthermore, our data suggest that multiple-species mixed grazing regimes in grassland systems with high plant diversity could represent the optimal protocol for grazing management. This study emphasizes the importance of maintaining both plant and herbivore diversity to optimize ecosystem functioning.We conclude that the effects of grazing in grassland strongly depend on herbivore assemblages and pre-grazing plant diversity. Herbivore grazing might contribute more to the maintenance of grassland structure and ecosystem functioning under high plant diversity compared with low plant diversity. Furthermore, our data suggest that multiple-species mixed grazing regimes in grassland systems with high plant diversity could represent the optimal protocol for grazing management. This study emphasizes the importance of maintaining both plant and herbivore diversity to optimize ecosystem functioning.