Option : Ecology Flashcards
Define limiting factor.
A factor that affects the distribution of a species.
Define characteristics of a species.
A range of factors tolerated by a species.
Define mutualism.
An relationship between organisms of 2 different species in which each member benefits.
Define parasitism.
A symbiotic relationship where the parasite gains an advantage to the detriment of the host which may be killed.
Define commensalism.
A relationship where one organism benefits and the other is neither harmed nor helped.
Explain the niche concept.
Each species plays a unique role within a community because of the unique combination of its spatial habitat and interactions with other species.
Define a niche.
The specialised habitat of an organism. Includes territory, nutrition & feeding habits, reproductive habits, interactions with other organisms, role in habitat.
Define intra-specific competition.
Competition between members of the same species.
Define inter-specific competition.
Competition between 2 different species who rely on the same resources.
Define keystone species.
A species which has a disproportionate effect on the structure of an ecological community.
Define feed conversion ratios.
The quantity of dietary input in grams required to produce a certain amount of body mass in livestock or fish.
Define gross production.
The total amount of organic matter produced per unit area per unit time by a trophic level in an ecosystem.
Define net production.
The amount of gross production remaining after subtraction of the amount used for respiration by the trophic level.
What do diameter of sink and thickness of arrow show in Gersmehl diagrams?
Diameter of sink is proportional to mass of nutrient stored in sink.
Thickness of arrow is proportional to rate of nutrient flow.
Define biome.
A geographical area that has a particular climate and sustains a specific community of plants and animals.
Define biosphere.
The total of all areas where living things are found.
Define ecological succession.
The predictable and orderly changes in composition of an ecosystem over time.
Define primary succession.
The emergence of a new community from a new ecosystem.
Define secondary succession.
The replacement of one ecosystem by another following environmental change.
Define closed ecosystems.
Ecosystems where energy but not matter is exchanged with surroundings.
Define open ecosystems.
Ecosystems where matter and energy are exchanged with surroundings.
Define alien species.
A species which arrives in a non-native habitat, usually as the intentional or accidental result of human activity.
Define endemic species.
Species native to an area.
Define bioaccumulation.
When an individual eats contaminated food or filters contaminated water, it builds up these chemical substances. This occurs within ONE trophic level.
Define biomagnification.
A process by which chemical substances become more concentrated at each trophic level.
Define indicator species.
An organism that occurs only when specific environmental conditions are present.
Define biotic index.
Index that compares the relative frequency of an indicator species.
Define in situ conservation.
A type of conservation that requires active management of nature reserves or national parks.
Define ex situ conservation.
The preservation of species outside their natural habitat.
Define competitive exclusion principle.
2 species that occupy a similar niche in the same location cannot coexist.
