Species Interactions and Community

Niche

Encompasses the physical habitat and ecological roe of a species

Fundamental niche

Includes full range of abiotic and biotic factors that permit the species to live

Realized niche

The actual range of habitats occupied by a species

Phylogenetic niche conservatism

Closely related species tend to be more similar to each other in niches than are distantly related species

Antagonistic interactions

Where at least one participant loses more than it gains

• competition, predation, parasitism, and herbivore

Mutualistic interactions

Both species benefit

Each side acts in own best interest and bears costs that are weighed against benefits in terms of growth and reproduction

Commensalisms

One species benefits and no affect on the other

Competition

2 individuals of the same or different species use the same limited resource

Intraspecific competition

Between individuals of a single species

Interspecific competition

Between individuals of a different species

Competitive exclusion

When 2 species have overlapping niches, one will become extinct in that place or change its niche

Resource partitioning

Where species whose niches overlap diverge and become different subspecies or species

Parasites

Live in close association with another species, gaining nutrition by consuming the hosts tissues

Do not typically kill the host, but can reduce host fitness and population size

Herbivory

The consumption of plant parts, directly affects the products of photosynthesis, removing them from plant production

Community

The set of all populations found in a given place

Biodiversity

The variety of genetic sequences, cell types, metabolisms, species, life history’s, phylogenetic groups, communities, and ecosystems

Keystone species

A species that has a disproportionately large effect on its environment relative to its abundance, playing a critical role in maintaining the structure of an ecological community.

Ecosystem engineers

Keystone species that shape the physical environment, creating habitat for others

Succession

The predictable order of species colonization and replacement in a new or newly disturbed patch of habitat

Climax community

Final stage of succession forming a mature assembly

Theory of island biogeography

The number of species that can occupy a habitat island depends on two factors: the size of the island and its distance from the source of colonists