Limitation and stress - always or never ?

摘要

Few terms are as abundant and as confusing in the ecological literature as 'limitation' and 'stress'. Limitation is the more general term, and stress is a specific (extreme) part of it. Limitation has its roots in economy and in agriculture; stress has its roots in physics, and was later adopted by psychologists, physiologists and in medicine before it made its way to ecology. 'Limitation' is considered the alpha and omega of ecology -the science of limiting resources and nature' s house-keeping (Malthus 1798, cited in Grubb 1989). Most often, 'limitation' is used as if there were general agreement on what the target of its action is, and on how the action arises. However, depending on what is considered 'limited', plants may be either never, or almost always limited, so the term is obscure.