succession

• what is meant by ecosystems being dynamic


  they are subject to change
• what causes ecosystems to change over time


  the interactions between organisms and their environments
• what is meant by succession


  this is the change in structure and species composition of a community over time
• what is meant by primary succession


  this is the introduction of plants and animals into areas that have not previously supported a community
• what is meant by secondary succession


  this is the reintroduction of organisms into a bare habitat previously occupied by plants and animals that may have been damages by fire or natural disasters
• what is meant by a sere


  these are the stages during succession when particular communities dominate
• what is meant by a pioneer species


  A species that can colonoise an inhospitable environment
• what leads to the formation of primitive soil


  the accumulation of dead and decomposing organic material
• what is meant by a climax community


  this is a long living community
• what are the three factors that affects succession


  migration , competition and facilitation
• what is meant by migration and how does it effect succession


  the migration of non-native species may spread themselves widely altering communities
• what is vital for succession to progress ,In terms of migration

  the arrival of spores seeds and animals
• what is meant for competition in succession


  inter specific competition
• what is meant by facilitation in succession


  the positive interactions between species that become increasingly significant as succession progresses
• what is meant by mutualism


  When both species benefit from the relationship
• what is the two types of facilitation


  mutualism and commensalism
• what is meant by commensalism


  this is the loose interaction between organisms in which one benefits and the other is unaffected
• what factors assist in the colonisation of a habitat


  the seeds previously dispersed by flowering plants and spores from fungi may remain in the soil and begin to germinate
• how can migrating animals help colonise a habitat


  they will produce droppings which will improve the nitrates levels in the soil
• what are the six ways in which human interference


  grazing , moorland management , farming , deforestation , industry and urban development
• what is meant by grazing


  this is when livestock such as sheep eat the grasses and other plants
• what is meant by moorland management


  this is when heather colonisation is controlled by burning
• what is meant by farming and how does it effect the colonisation of a habitat


  ploughing and growth of crops by mono culture stops trees and crops from becoming established
• what is meant by deforestation and how does it effect the colonisation of a habitat


  this is when trees are cut down and this can cause erosion of soil
• what are examples of industry's that effect colonisation

  coal mining and quarrying of stone
• how does urban development effect the colonisation of a habitat


  building of new roads and buildings