|Title||Insect population dynamics meets ecosystem ecology: effects of herbivory on soil nutrient dynamics.|
|Publication Type||Journal Article|
|Year of Publication||2001|
|Journal||Agricultural and Forest Entomology|
In reality, the idea that insect herbivores may regulate nutrient availability and primary production has no fundamental link with theories of mutualism or plant fitness. Plant productivity is measured in different units (carbon per m2 per year) and at a different level of organization (the community) than is fitness (proportional representation in the next generation measured at the level of individual plants). Theories of herbivore-mediated changes in nutrient cycling need not be found guilty by association with controversial views of herbivores as mutualists. Given the recent interest in the role of species in ecosystems (Jones & Lawton, 1995) and publications by Schowalter (2000) and Belovsky & Slade (2000), it is worth re-examining potential effects of insect herbivores on ecosystem function. The discussion that follows is limited to the effects of foliar-feeding herbivores on soil nutrient dynamics and subsequent productivity. Effects of wood-boring insects on nutrient dynamics are well documented (e.g. Dale et al., 1990) and, although root feeding insects can influence nutrients in soils (Maron & Connors, 1996; Maron & Jefferies, 1999; Hunter 2001), the effects of below-ground fauna on nutrient dynamics are a whole other can of worms, so to speak. In addition, although the focus of this article will be insect folivores, I beg your indulgence if a few four-legged and eight-legged herbivores make brief appearances to illustrate an occasional ecological principle.