BIO201H5 Lecture 16: 25
Document Summary
Herbivores eat plants: lizards do benefit plants. Lizards eat only few spiders, thus lizards + spiders act as one big predator that push down herbivore population. Thus plant can take a break and grow: community contains 2 components: fresh water ponds and terrestrial plant community that grows around pond, done by removal experiment with fish and without fish. Fish are predators on invertebrates, food is larval dragonfly. Dragonfly are predators on pollinators (bees) that pollinates flowers. Fish directly eat larvae, producing ve effect. Larvae directly metamorphose into dragonfly +ve effect. Fish have indirect ve effect on dragonfly this turns into the effect on pollinator. Thus have indirect effect by multiplying the direct effect: - fish have +ve indirect effect on pollinators and plant (since they reduce population of dragonfly) If fish present, population of larvae will decrease, thus decreasing population of adult dragonflies. If no fish present, population of larvae will grow, thus population of dragonfly also grow.
