Effects of mammalian herbivore declines on plant communities: observations and experiments in an African savanna

摘要: Summary 1. Herbivores influence the structure and composition of terrestrial plant communities. However, responses communities to herbivory are variable depend on environmental conditions, herbivore identity abundance. As anthropogenic impacts continue drive large declines in wild herbivores, understanding context dependence becomes increasingly important. 2. Exclosure experiments frequently used assess how ecosystems reorganize face defaunation. Yet many landscapes, wildlife often accompanied by other activities, especially land conversion livestock production. In such cases, exclosure may not reflect typical outcomes human-driven extirpations herbivores. 3. Here, we examine community changes abundance herbivores interact with abiotic factors (rainfall soil properties). We also explore effects differ between large-scale exclosures landscape sites where activity has caused declines, increases. 4. Abiotic modulated stronger effect sizes lower-productivity environments. Also, shifts structure, species richness following differed considerably which had declined were replaced livestock. Plant low distinct both physical from control experiments. The power (soil rainfall) gradients influencing response was greatly dampened or absent sites. One likely explanation for these observed differences is compensatory associated depression extirpation wildlife. 5. Synthesis. Our results emphasize importance heterogeneity modulating mammalian covariation declines. They suggest caution when extrapolating predict consequences defaunation as it proceeds Anthropocene.