IB Bio B4.2 Ecological Niches

(Ecological) Niche

The role of the species in an ecosystem

- Includes what it eats, when it is active, its habitat

- Includes ALL biotic & abiotic factors

Fundamental Niche

Potential niche of a species based on adaptations & tolerance limits

Realized Niche

The actual niche of a species when in competition with other species

Example of Chthalamus vs. Semibalanus

1. The presence of Semibalanus affects the Chthalamus population

2. The presence of Chthalamus does NOT affect the Semibalanus population

Competitive Exclusion

One species will always go extinct if two species' niches are the same

Niche Partitioning

There are a diversity of species on Earth, so each species occupy a slightly different niche; these small differences allow for coexistence

Obligate Aerobe

Need/have to be in an area with atmospheric levels of oxygen

Obligate Anaerobes

Have to be in an environment in an area with lower than atmospheric levels of oxygen

Facultative Anaerobes

Can live in either areas with oxygen or without

Autotroph(s)

Produce carbon compounds from inorganic compounds using light or inorganic chemical energy; uses external energy source

- Some prokaryotes

- Algae: Huge group of organisms ranging from seaweed to single-celled algae (not a true clade)

- Plants

- Some archaeans

Photoautotroph

A type of autotroph that uses light to create organic compounds

Chemoautotroph

A type of autotroph that uses inorganic chemical energy to make carbon compounds (organic energy)

Photosynthesis

Conversion of light energy from the sun into chemical energy

- Used by not just plants, but also photosynthetic organisms

Chemosynthesis

Process by which ATP is synthesized by using chemicals as an energy source instead of light

- Used by things such as iron-oxidizing bacteria

Light Energy

Energy in the form of moving waves of light

Chemical Energy

Energy stored in chemical bonds

Holozoic Nutrition

A type of heterotrophic nutrition that involves the intake of complex organic matter, either as solids or liquids

- Food is ingested, digested internally, absorbed & assimilated (stored)

- Consumers

Mixotrophs

Can be both autotrophs & heterotrophs

- Some choose to do both; some have to do both

- Often protists (singled-celled eukaryotes)

- Euglena

- Ocean Plankton (Phytoplankton or zooplankton)

Saprotrophs (Decomposers)

Heterotrophs but not consumers

- Secrete enzymes to external environment & digest food externally

- Pull in digested nutrients only

Archaeans

Extremophiles

- Photoautotroph (use light)

- Chemoautotroph (oxidation of inorganic chemicals such as sulfur)

- Heterotroph (oxidation of carbon compounds)

Tall trees

Growth tall (canopy or emergent trees)

Lianas

Root in the ground & then wrap around trees to get higher

Epiphytes

Grow on other trees

Strangler epiphytes

Start on tree & then grow down into the ground, take nutrients from others

Shade-tolerant shrubs

Can absorb far red light that can reach the ground through the trees

Hominidae Teeth

Teeth differences reflect difference in diets

Homo-sapiens

Us, omnivores

Paranthropus robustus

Nutcrackers; people who eat nuts

Homo-floresiensis

Really small mouth, missing pre-molars

Herbivores vs. Plants

Herbivores evolve adaptations to feed on plants and plants evolve adaptations to resist herbivory

Predators vs. Prey

Predators evolve adaptations for finding, catching, & killing prey and prey animals evolve adaptations for resisting predation