Ecosystems & their living communities

allelochemicals

substances produced by plants that prevent or limit damage by herbivores

allelopathy

a form of competition involving the release of a chemical by one plant species that inhibits the growth of other species

cladodes

fine green branches that carry out photosynthesis in plant species where leaves are very reduced

commensalism

association between two different species in a community in which one benefits and the second apparently neither gains nor is harmed

decomposers

organisms, such as fungi, that can break down and absorb organic matter of dead organisms or their products

desiccation

dying out

detritivores

organisms that eat particles of organic mater found in soil or water

diversity

measure of "species richness" or the number of different species in a community

ecology

study of communities in their habitats and the interactions between them and their environment

haustoria

thin strand of tissue through which a plant parasite makes connection with its host

host

organism on or in which a specific parasite lives

mimicry

a situation in which one species has an appearance similar to that of a different but distasteful species where that similarity apparently gives protection against predators

parasite

organism that lives on or in another organism and feeds from it usually without killing it

parasitoids

adult females of some wasp and fly species that are like parasites but parasitoids slowly kill off their hosts

symbiosis

prolonged association between different species in a community in which at least one partner benefits; includes parasitism, mutualism and commensalism