ENV100H1 Lecture Notes - Lecture 19: Keystone Species, Wrasse, Climax Community

• School: UTSG
• Department: School of Environment
• Course: ENV100H1
• Professor: Barbara Murck

Document Summary

Keystone species may increase the biodiversity of a community. Sea stars: when they are present, they are diverse, when they are not, they are filled with blue mussels. One of the first experiments on keystone species. Predators maintain the biodiversity because they keep the most dominant competitors in check. They keep the parasite load small for the other fish species. When they are removed, the number of species go down. When they are added, they go up. Resistance it remains stable in response to the disturbance: uncommon due to narrow preferences of species. Resilience changes, but can eventually return to original state. Communities naturally undergo a lot of change due to severe disturbances. One of the early focuses of ecology at a systematic science: succession. Succession predictable series of changes in a community following a disturbance: usually big disturbances. Primary succession disturbance eliminates vegetation; soil: ex. Secondary succession some organisms survive: ex. Glacier coming through, lake drying, volcanic lava.