Causes of Spatial and Temporal Patterns in Rocky Intertidal Communities of Central and Northern California. Volume 1 of 2. Executive Summary

摘要

Literature relevant to understanding the causes of variation in distribution, abundance, and species composition of rocky intertidal plants and animals along the coastline of central and northern California is reviewed. The effects of natural disturbances including effects investigated by experimentation in the field, are contrasted with the effects of pollution. In the absence of pollution and major storms, populations are generally more variable in space than in time. At any one site and time, disturbances caused by grazing, predation, and wave action are of special significance. Community succession following disturbance is a complex phenomenon that varies with the mode, degree, and history of disturbance, the life history characteristics of the organisms disturbed, dispersal, recruitment, and a variety of possible interactions among species. The importance of dispersal and recruitment to recovery from disturbance and the predictability of rate and outcome of recovery are still largely unknown. Impacts resulting from point sources of pollution may cause gradients of stress, succession is broadly predictable. In the absence of biological disturbance (e.g. of grazers and predators), opportunistic ephemeral species may persist. In the presence of intermittent stress or catastrophic perturbations, succession is less predictable.