conservation 3
habitat conservation 2
-intentional habitat creation:
-in situ conservation is only successful when there are suitable habitats
-these may already exist or need altering a suit biotic and abiotic needs
-any species colonized if it becomes suitable, some need introducing
-eg, wetlands, woodlands, artificial coral reefs
1) habitat shape:
-the perimeter of a habitat will have a strip where it merges with another
-some benefit from there others rely on the core conditions
2) habitat areas:
-depends on the species you're protecting
-larger animals need more space to make a viable population
-too small of an area can cause species death when resources are unavailable, which will then have a knock-on effect to other species in the community
3) biological areas:
-linking isolated areas allows dispersal of young if there is a local breeding surplus that can result in inbreeding
-if a species dies out in one area recolonization from another area can be possible
-allows organisms to avoid hazards when moving between habitats
4) habitat diversity:
-natural habitats are really uniform and have local variations in the conditions producing a greater range of possible niches thus increasing biodiversity
5) light levels:
-shading effects of tree cover inhibit the growth of plants on woodland floor
-higher light levels promote growth of plants in the habitat
6) water depth:
-your habitat will need some form of water body
-aquatic habitats are colonised differently based on water depth
-deeper water only leaves the tallest plants to photosynthesise
7) vegetation age structure:
-some habitats are dominated by plant species that can live long such as woodland
-dense woodland can reduce the biodiversity of an area by reducing light levels
-these conditions can be replicated by creating clearings for younger plants and leaving deadwood for plants that exploit dead trees
control of biotic features
-food:
-the survival of a species may increase if suitable conditions are provided for its food species
-control of predation:
-increase the survival of predators
-eg, creating nest sites out of reach of terrestrial predators for birds
-introduction of mammal predators to Islands with none will have drastic impacts
-control of competitors:
-if a competitor is controlled it may increase species survival allowing them to successfully occupy a niche
-eg, removal of rhododendron to allow wild flowers to grow as they are out computed for light
-pollination:
-many flowering plants need insects for pollination and food production
-they attract pollinators with bright flowers and sugar rich nectar
-may be necessary to have a variety that flower at different points in time so pollinators always have food
- seed dispersal:
-some species are important to plants for seed dispersal
-pathogen control:
-disease is is density-dependent, for health of the money can be helped by removing the weak
-however introduced diseases can wipe out natives with ressistance
-species reintroduction:
-some habitats have been changed by human activity but still have original features
-it may be possible to restore the habitats by recreating more natural conditions
-particularly important to reintroduce keystone species
-habitats may develop a much higher biodiversity if a variety of species are introduced such as planting mixed species woodland
-reintroduction examples:
-Yellowstone National Park: grey wolf top Predators until extermination in 1926 reintroduced in 1995:
-deer population decline so less saplings killed
-more trees so beaver population increase
-more dams so more wetland
-more wetlands so more wetland species
-Scotland:
-pine, oak and birch used to fuel and replaced with grazing moorland
-removal of grazers and reforestation so recovery of animals such as beavers
-activities that continue to maintain plagioclimax environments:
-grazing: prevents establishment of taller plants and maintains grassland
-mowing: removes thorny, stinging or bad tasting plants
-burning: remove vegetation not eaten by herbivores
-coppicing: trees cut to ground level
-pollarding: branches cut to above the height of grazers
control of biotic features 2
-control of ecological succession / plagioclimax maintenance:
-successful conservation of wildlife habitats do not just include establishing a suitable habitat area then protecting it from external influences
-natural changes occur due to ecological succession may reduce it's value for species present
-plagioclimax community: the climax stage of a community, influenced by humans or other outside factors
-eg, grazed farmland and heathland
-the traditional human activities that produce plagioclimaxes may change moving the conditions outside the range of tolerance for those that live there
-conservation programmes that aim to protect these Communities involve continuing farming practices necessary