11.8 methods of maintaining biodiversity

conservation

the preservation and careful management of the environment and natural resourcing. By conserving the natural habitat in an area, an organsis’s chances of survival are maintained, allow them to reproduce and species and genetic diversity can be safeguarded

extinct

no organisms of the species exist anywhere in the wild

extinct in the wild

organisms of the species exist only in captivity

endangered

a species that is in danger of extinction

vulnerable

a species that is considered likely to become extinct in the near future

sustainable development

economic development that meets the needs of people today, without limiting the ability of future generations to meet their needs

in situ conservation

• takes place inside an organisms natural habitat

• maintains genetic diversity of species

• allows evolutionary adaptions to take place meaning a species can adapt to changing environmental conditions

• by allowing the endangered species to interact with other species, it also preserves the interdependent relationships present in a habitat

• generally cheaper

examples of active management techniques of wildlife reserves

• controlled grazing

• restricting human access

• controlling poaching

• feeding animals

• feeding animals

• reintroduction of species

• calling or removal of invasive species

• halting succession

controlled grazing

only allowing livestock to graze a particular area of land for a certain period of time to allow species time to recover, or keep a controlled number of animals in a habitat to maintain it

restricting human access

eg. not allowing people to visit a beach during seal reproductive season, or by providing paths which prevent plants from being trampled

controlled poaching

this includes creating defences to prevent access, issuing fines or more drastic steps such as the removal of rhino horns

feeding animals

this technique can help to ensure more organisms survive to reproductive age

reintroduction of species

adding species to areas that have become locally extinct, or whose numbers have decreased significantly

culling or removal of invasive species

an invasive species is a species which is not native to an area and has negative impacts on the economy, environment or health. These organisms compete with native species for resources

halting succession

• succession is a natural process in which early colonising species are replaced over time until a stable, mature population is achieved

• for example, as a result of succession in the UK, any piece of land left for long enough will develop into woodland

• the only way to protect some habitats such as moorland is through controlled grazing

marine conservation zones

• preserve species rich areas such as coral which are devastated by non-sustainable fishing methods

• the purpose of the marine reserve is not to prevent fisherman from visiting the area but to create areas of refuge within which populations can build up and repopulate adjacent areas

• large areas of sea are often required for marine reserves

ex situ conservation

involves the removal of organisms from their natural habitat

botanic gardens

• species are actively managed to provide the best resources such as soil nutrients, sufficient watering, and the removal or prevention of pests

• there are roughly around 1500 botanic gardens worldwide holding 35000 plant species

• many relatives of selectively bred crops are under represented and these wild species are a source of genes giving resistance to disease or pests

seed bank

• seeds are carefully stores so that new plants may be grown in the future

• they are dried and stored at temperatures of -20 degrees to maintain their viability, by slowing down the rate at which they loose their ability to germinate

• almost all the temperature seeds and most tropical ones can be stored in this way

• helps to prevent the extinction of plant species as the seeds can be introduced in the future or used for genetic engineering

• they are predicted to remain viable for centuries

• doesn’t work for all plants - some plants die when frozen

captive breeding programs

• controlled breeding programs produce offspring in a human-controlled environment

• these are often run and managed by zoos and aquatic centres

• scientists working on captive breeding programs aim to create a stable, healthy population of a species and the n gradually reintroduce the species back into its natural habitat

• captive breeding program provide the animals with shelter, nutritious food, shelter, absence of predators

• suitable breeding partners can imported from other zoos

• maintaining genetic diversity within a captive breeding population can be difficult - mating can be arranged to ensure maximum genetic diversity and techniques such as artificial insemination and long term cryogenic storage of embryos can be used to allow new genetics lines to be introduced

reasons animals born in captivity may not be introduced back into the wild

diseases - there may be a loss of resistance to local diseases in captive-bred populations. Also, new disease might exist in the wild, to which captive animals have yet to develop resistance

behaviour - much behaviour is learn through copying or experience. In some cases, animals have starved because they have no concept of knowing how to search for feed

genetic races - the genetic make up of captive animals can be so different from the original population that the two populations cannot interbreed

habitat - in many cases the natural habitat must first be restores to allow captive populations to be reintroduced. If only a small suitable habitat exists it is likley that that habitat holds as many individuals as the habitat can support

international union for the conservation of nature

• at least once a year the IUNC publishes the red list detailing the current conservation status of threatened animals. Countries can then work together to conserve these species

• the IUNC was only involved in the establishment of the convention of international trade in endangered species

• this treaty recognises the international trade of wild plant an animal specimens and their products

• as the trade in wild animals and plants crosses boarders between countries, the effort to regulate it requires international cooperation to safeguard certain species from over-exploitation

the Rio convention

• the convention of biological diversity requires countries to develop national strategies for sustainable development

• the united nations framework convention on climate change is an agreement between nations to take steps to stabilise greenhouse gas concentrations within the atmosphere

• the united nations convention to combat desertification aims to prevent the transformation of fertile land into desert and reduce the effects of drought through programmes of international cooperation

countryside stewardship scheme

• sustaining the beauty and diversity of the landscape

• improving, extending and creating wildlife habitats

• restoring neglected land and conserving archaeological and historical features

• improving opportunities for countryside enjoyment