CHAPTER 9: STRATEGIES FOR PROTECTING BIODIVERSITY (Translocating plants…
CHAPTER 9: STRATEGIES FOR PROTECTING BIODIVERSITY
Connecting Remnant Vegetation
Clearing vegetation threatens biodiversity. It results in fragmentation, where small patches of
remain among the clear area - these are important for the conservation of some animal populations. However, these remnant vegetation are often small and isolated from one another - have significant conservation value but is expensive to manage
is made up of all the local populations in each of the patches. The local population interact with one another through individuals moving between the populations.
Local pop can undergo large fluctuation when confronted with different environmental variations, but overall metapopulation will not vary much.
To improve the conservation potential of these fragments/patches is to improve the connection between them in the form of a network of
of remnant vegetation. Advantages of Corridors:
expensive to establish and maintain, at the expense of other conservation methods that may be more effective
help spread of fire
suppress genetic variation if genetic diversity of a subpopulation is swamped by the genetic diversity of the immigrants
Aid the spread of diseases, pests and weeds
Allow exchange of genes between subpopulations to reduce the impact of genetic drift and inbreeding
Provide avenues for possible recolonisation
Provide habitat for plants and animals
Allows movement of animals between patches
Corridors are usually in rural areas, but they are also found in urban environment.
Urban environments contain patches of remnant vegetation, and some local governments have initiated replanting programs.
Habitat restoration and regeneration programs
- aid in restoring pathways (and habitat) for a range of animals to increase resilience among population and species.
Urban creeks can be useful corridors, as they form an existing network throughout the urban area.
Protection in Conservation Reserves
Conservation reserves are protected areas of land managed for nature conservation. Include many categories.
: Reserves that are intended to protect natural and scenic areas of national or international significance for scientific, educational and recreational use.
Other types of reserves do not provide as high a level of protection for for flaura and fauna. Eg multiple-use management.
Reserves should be located in areas that will protect a region's biodiversity, taking into account the need to protect biodiversity at various levels - individual species, communities, ecosystems or landscapes.
some ecosystems are represented in many reserves, and some are not represented at all.
The land available for reserves has tended to be land of little economic value. Land of high economic value, (e.g areas with soil suitable for agriculture and forests valuable for timber protection) is underrepresented in reserves.
These area have not been well protected from threatening processes. Procedures are being developed to ensure that a representative system of reserves are established, at least for forested areas.
Habitat Edge Effects
The size and shape of an area of remnant vegetation (e.g patches of native trees, shrubs and grasses remaining after habitat fragmentation) affect a size's conservation value and overall biodiversity.
The narrow linear shape is most prone to impacts from surrounding areas; the circular shape provides the best protection.
The edges are most susceptible to impacts from the surrounding areas often due to human activity. These edge effects are different from Chapter 7.
Translocating plants and Animals
- When a plant or animal is returned to an area from which they have been eliminated or where their numbers are low
To make sure the translocated individuals will survive in their new environment, their genetic make-up should be similar to that of the area's original population. - May not be possible if original pop is extinct, so trial reintroductions may be necessary
- When plants or animal are translocated to an area that used to be part of their range, but where none of that species remains.
Reintroduced organisms can be collected from the wild or often done for rare species, plants grown in a nursery or animals bred in a captive breeding program.
Help overcome a reduction in numbers of a threatened species. Careful planning and research needed to be undertaken before these programs occur.
Provide future generations with a more complete and accurate record of now-threatened species (e.g black rhinos, giant pandas and tigers)
most of the DNA banks for endangered animals have a conservation purpose. - Useful for the genetic material stored in these banks increases the genetic diversity of species at risk of becoming extinct.
material from gene banks can infuse small populations with new genetic material, increasing their chances of survival.