Presentation on theme: "Grazing Grazing is another form of predation – a grazer is simply a predator that moves from ‘victim’ to victim consuming part of it but not killing it."— Presentation transcript:
1 GrazingGrazing is another form of predation – a grazer is simply a predator that moves from ‘victim’ to victim consuming part of it but not killing it outright!
2 Grazing - definition grazer feeds on part of the prey allows the prey to recover(the term grazing applies to plants as theirstructure allows this)does not eat the prey outright(the energy expended in catching animal preymeans that it makes economic sense to eat thewhole individual)
3 Effect of Grazing on Species Diversity The effect of grazing on a plant depends on the type of plant and the intensity of the grazing.Consider these 2 plants:What would be the effect of grazing on each of them?
4 Basal MeristemsGrasses have growing points (or meristems) that are close to the ground. They are called basal meristems.How well a plant with a basal meristem responds to grazing depends up on the intensity of the grazing and the competition from other plants!
5 Competition From higher you learned that: Competition occurs when there is a resource that is in short supply (eg. Food, space, water).Intraspecific competition occurs between organisms of the same species.Interspecific competition occurs between organisms of different species.
6 Interference and Exploitation Competition Interference Competition – when 2 or more species fight over resourcesExploitation Competition – when 2 species use the same resources and in doing so each reduces the survival chances of the other species.Use your scholar notes to identify an example of each.
7 NichesNiche – the sum of the characters that determine the position of an organism in its ecosystem. It consists of all the biotic and abiotic factors required for the survival of that species and which limit its distribution and growth. It may also refer more simply to the feeding relationship of an organism in an ecosystem.Simply put the NICHE of an organism is like its JOB in the ecosystem.
8 Fundamental Niche Realised Niche When a species is living in an ecosystem without any competition for resources. This is usually a theoretical or artificial situation.Realised NicheThe resources that a species can actually make use of in its ecosystem.
9 HomeworkAn investigation into species diversity in mowed and unmowed lawns. (Pg 47/48) Complete the online Scholar activity and check your answers.Fundamental and Realised Niche (Pg 51)Complete the reading of Topic 3. Go over learning outcomes and make notes.Try the online end of topic test when you feel you are ready.