BIO MOD 4: Ecological Relationships

Interspecific interactions

Interactions between species

Feeding interactions

Interactions involving feeding relationships

Non-feeding interactions

Interactions that do not involve feeding

Predation

Involves one animal species killing and feeding on another animal

Intraspecific interactions

Interactions within species

Competition

Struggle between organisms for the same supply of environmental resource that is in limited supply

Competitive exclusion

One species is better at obtaining resources, excluding the other from the available resources and sometimes driving them to extinction

Resource partitioning

Species changing their behaviour and resource use, allowing both species to access resources in the same environment

Symbiosis

Relationship where two quite different organisms live in and function together in close association, to the benefit of at least one of them

Mutualism

Both species benefit from the relationship

Commensalism

Only one species benefits but the other is unaffected

Parasitism

One species benefits, the other is harmed

Ectoparasites

Parasites that live outside the host

Endoparasites

Parasites that live inside the host

Vector

Host that transfers a parasite to another

Amensalism

One is inhibited or killed and the other is unaffected

Examples of symbiotic relationships

mutualism, commensalism, amensalism, parasitism

Obligate mutualism

Both species are completely dependent on each other for survival and reproduction

Facultative mutualism

Both species benefit from interacting but do not rely on each other for survival

Feeding interdependencies

Make species in a food web vulnerable to changes in their ecosystem

Ecological niche

Role an organism occupies in its environment, including how it uses resources and interacts with other species

Competitive exclusion principle

States how two species cannot have the same niche in an ecosystem

Carrying capacity

Maximum population that can be supported by an ecosystem due to limited resources

Consequences of predation

Predators affect the distribution and abundance of their prey

Factors affecting number of prey and predators

Includes number of predators, availability of prey food, reproduction rate, and death rate

Consequences of competition

Affects reproduction and survival rates, leading to population fluctuations

Consequences of symbiosis

Profound consequences for all life on Earth, including increased biodiversity

Disease

Any process that adversely affects the normal functioning of tissues in a living organism

Selection pressure

Population changes due to various factors affecting birth rates

Environmental resistance

Factors that limit the growth of populations due to reduction in health, reproduction rate, and survival

Tolerance range

Physical conditions that an organism can tolerate and survive

Population explosion

Exponential population growth when not limited by resources, predators, or disease

Quadrats

A square frame randomly placed on the ground for studying stationary populations

Transects

Straight line cut across a landscape for measuring distribution

Mark Recapture

Involves capturing, marking, releasing and then recapturing animals to estimate population