Conserving Biodiversity
- As human activities continue to cause a decline in biodiversity, the need for solutions to this problem increases
- The problem is complex, and there is no one simple solution, so a mixture of different approaches is needed
- The complexities are often due to conflicts between the needs of the natural world and the needs of humans; these conflicts are not always easy to resolve
- Examples of different approaches to dealing with the biodiversity crisis include
- In situ conservation, e.g.
- Protected areas
- Rewilding
- Reclamation
- Ex situ conservation, e.g.
- Zoos
- Botanic gardens
- Seed banks
- Tissue banks
- In situ conservation, e.g.
In situ conservation
Protected areas
- A protected area is a defined geographical space, such as a national park or nature reserve, that is managed and protected for the purposes of conservation
- National parks are government-controlled areas within countries where the wildlife and environment are protected
- Nature reserves are smaller regions than national parks, and can be on privately or publicly owned land
- Restrictions inside protected areas could include
- Humans access is strictly controlled
- Industrial activities such as agriculture and building are tightly regulated
- Hunting is limited or completely prohibited
CC BY-SA 3.0 , via Wikimedia Commons
Kruger National park is the largest national park in South Africa
Rewilding
- This is the restoration of ecosystems to a point at which they can sustain themselves; such sustainable ecosystems are by their nature biodiverse habitats
- Rewilding can be allowed to occur on private or publicly owned land
- Rewilding can be active or passive
- Active rewilding involves human intervention, e.g. removing human features such as roads, and reintroducing locally extinct species
- Passive means leaving an area alone to allow ecological processes to gradually restore themselves, e.g. stopping the management of land to allow natural succession to occur
- Note that passive rewilding will not work for the restoration of some habitat types, e.g. grassland habitats often require grazing to prevent the dominance of tree species
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Longhorn cattle at the Knepp estate in the UK mimic the action of extinct ancient grazing species, creating a diverse grassland habitat
Reclamation
- Reclamation refers to the reclaiming and restoration of areas that have been damaged by human activities, e.g. abandoned quarries or areas where deforestation has taken place
- Such projects aim to restore previously existing ecosystems
Ex situ conservation
Zoos
- Captive breeding programmes in zoos can increase the number of individuals of a species
- This can be carried out by artificial insemination, allowing the flow of genes between individuals that may be living in different zoos
- This prevents problems that can arise from low genetic diversity
- This can avoid difficulties with captive breeding
- Captive breeding can lead to the release of individuals back into the wild
- This can be carried out by artificial insemination, allowing the flow of genes between individuals that may be living in different zoos
- Zoos are an invaluable resource for scientific research
- Scientists are able to closely study animal genetics, behaviours and habitat requirements
Botanic gardens
- Botanic gardens are the plant equivalent of zoos
- They use cuttings and seeds collected from the wild to establish a population of the endangered species in captivity
- Methods of tissue culturing and cloning can also be used to obtain large numbers of plants from a small sample size
- The captive population can be used in the future for reintroduction into habitats where they have become rare
- Research is a major role of botanic gardens
- Scientists can investigate reproduction and growth in different plant species so that they can be grown in captivity
- Habitat requirements can be assessed so that new habitats can be found if necessary
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Botanic gardens, such as this one in Rio de Janeiro, Brazil, can increase the populations of threatened plant species and carry out scientific research and education
Seed banks
- A seed bank is a facility that conserves plant diversity by drying and storing seeds in a temperature-controlled environment
- Cool, dry conditions generally increase the length of time for which seeds remain viable
- Seeds can only be stored for so long; after a certain period of time the stored seeds are grown into plants and fresh seeds for storage are taken from those plants
- If the plant species goes extinct then the seeds can be used to grow them again
- Usually, seeds of the same species are collected from different sites to maintain genetic diversity
- The Svalbard Global Seed Vault in Norway contains seeds from almost 1 million plant species
- It is located in the Arctic Circle with ideal environmental conditions
- Many organisations send seeds from crop plants to be stored there for safekeeping
CC BY-SA 4.0, via Wikimedia Commons
The Svalbard Global Seed Vault in Norway contains seeds from almost 1 million plant species
Tissue banks
- Tissue banks, or frozen zoos, store genetic material from animals at very low temperatures
- It is thought that properly frozen tissue samples can last indefinitely
- Ideally, samples are collected from different individuals of the same species to maintain genetic diversity
- Two different types of tissue can be stored in tissue banks
- Germplasm
- This includes reproductive tissue, such as sperm cells, egg cells, and embryos
- This material can be used by zoos in captive breeding programmes
- In theory, IVF could be carried out with a suitable surrogate species to bring back an extinct species from this tissue
- Somatic tissue
- This is non-reproductive tissue, or body cells
- This type of tissue contains the full genome of the species, and can be used for DNA research
- It is thought that such tissue could be used for cloning extinct species in the future
- Germplasm
