Food Web Structure and Its Controls II
The previous chapter highlighted the influence of consumers on their food resources, and defined some consequences of such top-down controls. Here, we discuss how resources might influence producers and consumers, effects that can cascade upwards through food webs. We first review selected cases of bottom-up control, then look at evidence of interaction of top-down and bottom-up controls. We end the chapter by examining how both top-down and bottom-up controls are increasingly subject to external forcing by climate-driven change and human activities.