Interspecific relationships Flashcards
Mutualism
When both species benefit from a relationship
++
Commensalism
When one species benefits and the other is not affected
+o
Antibiosis
When one species has a harmful effect on another species, but itself is not affected
o-
Exploitation
When one species benefits and the other is harmed
+-
Grazing/herbivory
Plants are affected by being eaten by organisms
(exploitation)
Predation
Predators eating other animals (exploitation)
Parasitism
Parasite causes harm to the host (exploitation)
Allelopathy
Plants secreting poisonous substances into the soil to kill other plants or stopping other plants growth (exploitation)
Competition
When both species are harmed
- -
Reasons for competition
Food, water, space and breeding sites
How is competition reduced
By more differences between their ecological niches
Mutualism example
Bees pollinating apple tree flowers
Commensalism example
Rata vine growing up a beech tree
Antibiosis example
Humans polluting water with sewage, which cows drink
Grazing/herbivory example
Caterpillar eating lettuce leaves
Predation example
Lions + gazelles
Parasitism example
Mosquitoes transmitting chemicals, causing malaria in humans
Allelopathy example
Walnut leaves inhibiting plants growing under tree
Competition example
Godwits and stilts competing for food on estuary
Gause’s principle of Competitive Exclusion
When two species have exactly the same ecological niche, they will not be able to co-exist
Ecological succession
- observed process over a change in the species structure over time
- driven by competition
Zonation
The natural layering of ecosystems that occur at different environmental gradients
