干旱区生态环境知识资源中心

The role of below-ground herbivory in structuring natural and seminatural communities is becoming increasingly apparent. Many groups of invertebrates feed on subterranean plant parts, but insects and nematodes are the most important below-ground herbivores. Studies of interactions between below-ground herbivores have shown both competition and facilitation. Competition may be minimized through niche differentiation or by temporal or spatial avoidance. Studies have shown low levels of niche occupancy and no clear evidence for exclusive guilds or species packing. Facilitation may occur through substrate modification or the increased attractiveness of damaged roots to other herbivores. Specialist herbivores cause changes in plant community composition through their effects on specific host plants primarily as a result of the alteration of competitive interactions between coexisting plant species. Generalist herbivores can similarly affect plant community composition as a result of differences in their preference for plant species or differences in host plant susceptibility. Experimental studies have demonstrated the impact of below-ground herbivory on the rate and direction of vegetation succession, with belowground herbivores acting as keystone species in certain ecosystems. As a result of the focus of research on pest species or potential biological control agents, research has tended to focus on particular herbivore species and the effects on their host plant. This review shows that the role of below-ground herbivory in structuring plant communities and the interactions between such herbivores and other components of the biotic and physical environment of the soil remain important and fruitful areas for ecological research.