Ecology is a multi-scale science; ecologists have been hard-pressed to come up with a single definition which encompasses the entire field of ecology. Given this difficulty, it may be more useful to consider the subdisciplines which make up ecology. Major subdisciples are based on varying levels of complexity. Ecophysiology and behavior ecology study interactions between organisms and their environment. Population ecology (or autecology) focuses on populations of individual species. Community ecology (or synecology) looks at the interactions between different species within a defined area (an ecological community). Ecosystem ecology studies the flow of matter and energy through defined areas known as ecosystems.
There are other important divisions within the field of ecology. One of the oldest splits is between plant ecology and animal ecology. Other important splits include questions of scale, or the dichotomy between holism and reductionism and the debate between "top down" and "bottom up" control in ecological communities.
Ecophysiology or physiological ecology studies the response of individuals to their environment. Responses to temperature, moisture, light and nutrients fall within the scope of this field. Plant ecophysiology addresses such things as the response of photosynthesis and growth to environmental factors, while animal ecophysiology relates things like thermoregulation and energy consumption to the environment.
- Smith, Robert L., and Thomas M. Smith. 2001. Ecology & Field Biology. Benjamin Cummings