Life processes in the biosphere

The range of a factor in which a species can survive

Light Water Nutrients pH Habitat provision

Food supply Disease Pollination seed dispersal Competition Predation

A group of closely related organisms that can inter-breed to produce fertile offspring

The science of grouping organisms based on their characteristics. Any taxonomic group is a taxon

The role an individual has in its habitat

All the individuals of a single species in a certain area.

All the members of all the species that live in an area

The combination of abiotic and biotic factors, including the community of species, their inter-relations with each other and the environment

A large geographical region with particular climatic features, in which a community of unique species live.

Pioneer species

The sequence of stages in ecological succession

Seed dispersal brings seeds to a body of water. The lake edges become colonised by plants so provides habitats for animals. As plants grow and die the body of water will fill with DOM and soil, this makes the water shallower so rooted plants can survive in the open water. As the body of water fills with soil aquatic organisms die out, much bigger plants colonise the waterlogged soils. More water is removed by transpiration, more trees like oak colonise they form a canopy which changes the abiotic factors. Climax community is reached

Development on bare rock. Algae first colonise then mosses, a thin layer of soil builds up. As soil builds up bigger plants colonise, abiotic factors become less extreme. Flowering plants colonise when insects become established. Eventually trees colonise, a climax community is reached

Starts on sand. Drainage is rapid, low in nutrients so plants find it hard to establish themselves. Eventually they will succeed, their roots stabilise the sand, nutrients build and more plants colonise. Eventually a climax community will be reached

A climax community which is prevented from reaching its natural state due to human intervention

Mowing

Grazing of animals and mowing

Succession on land that has previously been colonised but damaged by floods, fires, earthquakes etc

Burning of heather is used to prevent oak woodlands establishing themselves. The older heather is also less nutritious, burning allows younger heather to grow which is food for grouse.

Factors that do not change their impact based on the density of a population, e.g. flood, drought

Factors that change their impact based on the density of a population, e.g. disease, competition, predation, food supply

When the prey population rises there is alot of food for predators, so their population rises. The prey population then decreases, there is now less food for predators so their population declines. The prey populations recover and it happens again.

Breeding rate of endangered species is low so CBR programme is used. A non-indigenous species introduced is a pathogen, predator or competitor. An indigenous predator being removed so its prey species becomes over populated and is causing ecological damage