Ecological Relationships and Succession

Symbiosis describes close, long-term interactions between species. Mutualism benefits both partners: mycorrhizal fungi extend plant root networks in exchange for sugars, and clownfish protect anemones from parasites while gaining shelter from predators. Commensalism benefits one species without affecting the other: barnacles attach to whale skin for free transportation without harming the whale. Parasitism benefits one species at the expense of another: tapeworms absorb nutrients from a host's intestine. These relationships shape community structure—removing mycorrhizal fungi from a forest can reduce tree growth by 50%, demonstrating that invisible partnerships are as important as visible predator-prey interactions.