Ecological Interactions

Role of a species in a community Environmental factors that determine the species distribution

Species that occur only in one area or one environment

The total environment which can be exploited without biotic constraints

Resources actually utilized due to environmental constraints or other species (aka limiting factors)

Environmental conditions that limit growth, distribution, and abundance of a population determine optimal survival conditions when in deficiency or in excess

• physiological stress due to inappropriate levels of a critical environmental factor • competition with other species • predation, including parasitism and disease

organisms whose sensitivities can tell about the environmental conditions in an area

No two species can occupy the same niche indefinitely more efficient species in resource use will exclude the other excluded species will disappear or develop a new niche and use resources differently aka resource partitioning

• Mutualism ++ • Commensalism +0 • Parasitism +- • Predation +- • Competiton +-/+-

Plays a critical role in a biological community that is out of proportion to its abundance effect ripples across multiple trophic levels ecosystem heavily depends on them

supports a network of species e.g. pollinators, nutrient circulators

abundant in ecotone boundaries Ecotone: area where two major communities meet or blend together