BIS 2B Lecture Notes - Lecture 21: Propagule, Pioneer Species, Species Pool

• School: UC-Davis
• Department: Biological Sciences
• Course: BIS 2B
• Professor: Mark Schwartz; Sharon Strauss

Document Summary

Lecture 21: succession and food webs communities - collections of species in same place. > who arrives at the location and interacts. > composition of community composition can vary over time. Determined by balance of new species invasion ability and established species resistance ability composition can reset by disturbance, the removal of organisms by physical or biological processes. Succession - predictable change in species composition thru time. Poor competitors susceptible to herbivores tolerant of harsh conditions. Late-successional species (k-selected) fewer propagules shorter dispersal. Good competitors slow establishment slow maturity resist herbivores less tolerant of harsh conditions. Ulva-gigartina model facilitation - ulva could modify environ to make it suitable for gigartina inhibition - ulva may exclude gigartina tolerance - gigartina grows slowly, takes longer to dominate community. But factors can naturally cause selective mortality of early success species competition. At intermediate frequencies of disturbance, there is highest species diversity. Not allowing competitive dominant species to completely dominate.