ECOLOGY TERMINOLOGY

•Ecosystem: all the abiotic and biotic factors in an area/environment surrounding a species

•Community: all the organisms present in an area/habitat/ecosystem

•Population: all the individuals of one species in an area

•Environment: sum of all conditions in the ecosystem outside the organism

ECOLOGY TERMINOLOGY

•Habitat: place within an environment in which specific organisms live

•Niche: species function in its habitat, the way the organism uses the abiotic and biotic resources of the environment of the organism to make the most of those opportunities

•Ecological niche – opportunities provided by the habitat and the adaptations

ECOLOGY TERMINOLOGY

•Two species occupy different niches when they DO NOT compete for resources

e.g. Feeding at different times on different organisms

e.g. Notch and window caterpillars feed on different parts of the flax

ECOLOGY TERMINOLOGY

•Two species NO LONGER occupy the same niche when: •one species displaces the other species (better adapted)•one species survives or none survive due to: - competition for abiotic and biotic resources

• Gause’s Principle - no two species with identical ecological niches can co-exist for long in the same place

Abiotic factors – the physical factors in the environment that can act as the stimuli for the organisms’ responses.

Prefixes:

•Light (photo-) - intensity, colour, direction, duration

•Gravity (geo-, gravi- in some texts) - up, down, orientation in space

The Environment

•Temperature (thermo-) - average and range

•Water (hydro-) - humidity, salinity, depth, average rainfall, turbidity, speed of current

•Current (rheo-) - align with current

The Environment

•Chemical (chemo-) - CO2, O2, salinity, pH, pheromones, toxins, inorganic nutrients, Macro/micronutrients

•Touch (thigmo-) - response to solid objects

•Sound – pitch, loudness, range

•Pressure – ocean depths, atmosphere, weather pattern formation

•Wind – velocity, gustiness, direction

•Substrate – composition

•Fire - recycling nutrients, seed germination

Adaptations

Adaptations are features that help an organism to make the most of the opportunities provided by the environment.

Organisms with adaptations more suited to the environment are more likely, through the process of natural selection, to pass on their genes to the next generation.

-Structural – morphological, e.g. colour, appendages

-Physiological – biochemical/metabolic e.g. hormones

-Behavioural – responses to the environment e.g. diurnal, aggression, courtship

-Life History – reproductive strategies for survival

Tolerance

Narrow range of physical factors that makes up the optimal range of tolerance for most organisms. If a factor is to extreme in either direction the organism suffers from physiological stress.

If a factor becomes too extreme (too high/too low) the environmental condition leads to death.

Many animal and plant behaviours are to ensure the organism maintains an optimal condition for survival and ultimately reproduction

Animals must detect and be able to respond to key physical factor changes in their environment

Biotic Factors – all relationships between members of the same species (intraspecific) and with members of other species (interspecific)

Intraspecific relationships:

Competition – for same resources; food, space, light, water, nesting sites, territory, nutrients etc

Reproduction – availability of mates, competition between males, courtship, pair-bond formation, parental care

Aggressive interactions - territories, hierarchies

Co-operative interactions – group formation for defence (prevent predation/grazing), aid survival (hunt in packs)

Biotic Factors –

Interspecific relationships:

Competition – for same resources; food, space, light, water, nesting sites, territory, nutrients etc

Predator / prey relationships

Plant / Animal – grazers, browsers

Succession – replacement of one species by another over time, each species modifying the environment to allow the new species to be established

Stratification – vertical relationships in space with other organisms

Zonation – bands of organisms that form in relation to a gradient in a major environmental factor

Animal / Animal

Plant / Plant

Symbiosis – variety of interactions involving close species contact.

Involves a host and a symbiot.

Mutualism (cooperation) - both species benefit

Commensalism - one species benefits, the other is unaffected

Parasitism (exploitation) - one species benefits, the other is harmed

Competition - neither species benefits

Neutralism - both species are unaffected

Note: endoparasites – live in the host ectoparasites – live on the host