In ecology , resistance is the ability of a population or community to avoid displacement from some state of development as a result of an environmental stress . Populations or communities with inherently high resistance are relatively stable when challenged by such conditions. If the stress is greater than the population threshold, though, change must occur.
In general, species that are larger in size, relatively competitive, longer-lived, with longer generation times and high investment in offspring are relatively resistant to intensified stresses. When these species or their communities are overcome by environmental change, however, they have little resilience and tend to recover slowly.
In contrast, species that are smaller in size, short-lived, highly fecund, and with shorter generation times have little ability to resist the effects of perturbation. However, these species and their communities are resilient, and have the ability to quickly recover from disturbance. This assumes, of course, that the environmental change has not been too excessive, and that the habitat still remains suitable for their regeneration and growth.
See also Biotic community; Ecosystem; Population biology