BIOL 122 Lecture Notes - Lecture 28: Santa Barbara City College, Right Fielder, Left Fielder
Document Summary
Two species co-exist in different areas of the intertidal zone. Larvae are free swimming, can settle anywhere in the water column. Never find the other species in the other respective zone. When b. was excluded from the lower zone, c. grew well in the lower zone. B grows quickly, prys off the c. C limited by competition with b (biotic) When c was excluded from the upper zone, b did not expand to the upper zone. B is limited by abiotic factors (desiccation) B did not expand down to the lowest regions of the intertidal region. Limited by predatory starfish only found in the lower regions. Abiotic factors in competition include access to water and periodic disturbances like fire. Predation and herbivory can also complicate competition. Goldenrod herbivory by beetles allows less successful competitors to flourish. Adaptation to desiccation determines the distribution of barnacles. The presence of predators oblates spadefoot toad"s competitive advantage. Left field unsprayed beetles reigned supreme.
