Community Ecology

Species distribution

helps protect food supply, etc

Range

geophraphical limits of a species

Ecosystem services

goods and services that humans derive rom the natural environment

Plants Role

the provide

• oxygen

• drinking water

• soils (humus - holds nutrients and prevents soil from becoming too pores or compact and good for soil health)

• carbon sequestration

• health

niche

range of abiotic/biotic conditions that a species lives in…

• envionrmental tolerance

fundamental niche

the locations where its physically POSSIBLE for a particular species to live

realized niche

the part/range of conditions a species ACTUALLY occupies… bc/ no species occupies its entire fundamental niche…

• because biotic interactions restrict it

  • predation, parasitism, competition, etc

‘fast’ life history

individuals allocate most energy to early reproduction, rapid growth, and have short lifespans

• and spend less energy on defending themselves against getting eaten and stuff

slow life history

slow growth, late reporduction, longer life spans, more energy spent on growing

Why organisms are where they are

dispersal limitations, abiotic limitations (weather/climate)

Generalists

able to use a wide variety of resources and tolerate a wider range of environments

Specialists

adapted to specific conditions w smaller restricted distributions

Established soils

detrivores (like fungi) break down dead organisms and return C, N, P to the soil, and worms convert organic matter into humus

• and nitrogen-fixing bacteria in the soil

New soils

• nitrogen and phosphorus brought by seabirds

• plant growth stats to SLOWLY provide carbon for soil formation

Bioaccumulation

toxins accumulating in the body without being cleared

biomagnification

increase in amount of accumulation toxin as one moves up the trophic chain

how do interactions BETWEEN species affect coexistence and distributions?

Positive interactions between species

these increase fundamental niche by exchanging survival and reproduction (commensalism, mutualism), and can facilitate successful colonization

Negative interactions

these LIMIT the REALIZED niche (competition, predation, disease)

Community assembly

3 types of species (interspecific) interactions

Competition, exploitation, facilitation

competition

negative-negative interaction —- individuals both use a resource that limits the survival and reproduction of the other

• both species = harmed by each other so survival and reproduction for both decrease

competitive exclusion

2 species w the same identical resources canNOT coexist, so eventually one will disappear, and one will fill the niche