B4.2 Ecological Niches

Outline the biotic and abiotic elements contributing to a species’ ecological niche (role in ecosystem)

• zones of tolerance determines habitat

• food obtained using light, co2, h2o OR by other organisms.

• Species specialize to compete for food

• Some species provide a service to others/the biome

what three categories of oxygen requirements are there

obligate aerobes, obligate anaerobes, facultative anaerobes.

Obligate aerobes

• require continuous o2 supply

• all animals and plants and some skin bacterium

Obligate anaerobes

• inhibited/killed by o2

• archea

facultative anaerobes

• use o2 if available

• yeast

• E coli

the three groups of photosynthesizers

• plants

• eukaryotic algae

• bacteria

assimilation

using digested foods to synthesise macromolecules

thus assimilating them into body (making part of body)

egestion

voiding undigested materials from gut

Saprotrophic nutrition

• Bacteria and Fungi are saprotrophic usually (the decomposers)

• secretes digestive enzymes into the dead organic matter to digest it

• Niche = releases elements back to ecosystem

The three domains of life

archea

bacteria

eukaryotes

What is known about archea?

• chemotrophs, autotrophs, or hetero

• adapted to extreme environments

• super small - need electron microscope

adaptations of herbivores for feeding on leaves

jaw-like mouthparts

tubular mouth parts

ability to produce enzymes that detox seeds and make self toxic for next in food chain

adaptations of plants to herbivory

• spines

• stinging

• secondary metabolites (ex. makes themselves toxic w glycocides)

what are secondary metabolites

organic compounds in plants not necessary for survival but for signaling and defense

adaptation plants have to harvest more light

• canopy trees - dominant shoots

• lianas - climb through other trees so less xylem needs to be produced

• Epiphytes - grow on trunks/branches

• Strangler Epiphytes - circles trunk to kill and grow on it

• Shade-tolerant shrubs - wide to absorb any light hitting floor

Fundamenal niche

Range of tolerance for abiotic factors

• pre-competitive

• ideal niche

realized niche

range of tolerance to biotic factors

• post-competative

• actual niche

• competitive exclusion

competitive exclusion

when mutiple species have overlapping niches, they will compete to exclude eachother from parts of its fundamental niche.