Home General Knowledge GK SPECIAL TOPIC : EX-SITU METHODS OF CONSERVATION OF BIODIVERSITY
GK SPECIAL TOPIC : EX-SITU METHODS OF CONSERVATION OF BIODIVERSITY
Tuesday, 22 April 2014 09:50

 

GK SPECIAL TOPIC

 

EX-SITU METHODS OF CONSERVATION OF BIODIVERSITY

Ex-situ conservation is the preservation of components of biological diversity outside their natural habitats.  This involves conservation of genetic resources, as well as wild and cultivated or species, and draws on a diverse body of techniques and facilities.  Some of these include:


a) Botanic Gardens

Botanic gardens can be defined as "public gardens which maintain collections of live plants mainly for study, scientific research, conservation and education.


Botanic gardens are able

• to rehabilitate indigenous and threatened species and restore them to  protected portions of their former habitats;

• to exploit commercially those species which are plentiful; and

• to promote wildlife education to a broad range of target groups such as politicians, school and college students, and communities living in and around wildlife areas.


b) Translocations

Sometimes conservation of faunal species involves or necessitates translocation of animals. This means the movement of individuals from its natural habitat, or from captivity, to another habitat. Translocations are carried out in connection with introductions or reintroductions, and should be handled with extreme caution.

They are generally justified when:

Land development will definitely destroy wildlife habitat and translocation is the only way of preserving the animals in the area.

Boosting the numbers of a threatened wild population to ensure its survival by adding other individuals of the same species.

Splitting an existing population that is at risk, to prevent loosing the entire population.


These operations are carried out often with support from international captive breeding programs and receive the cooperation of zoos, aquaria, etc. Such programmes have to be carefully planned and carried out to ensure success. The success rates of the establishment of translocated species vary. Overall, the translocation of game species (species used for hunting) appears to have been more successful than efforts connected with threatened or rare species. The success rates of establishment for translocated amphibians and reptiles are particularly low at 19% and 25% respectively.


c) Artificial Insemination:

Artificial insemination, or AI, is the process by which sperm is placed into the reproductive tract of a female for the purpose of impregnating the female by using means other than sexual intercourse or natural insemination.


Artificial insemination is widely used for livestock breeding, especially for dairy cattle and pigs. Techniques developed for livestock have been adapted for use in humans.


Artificial insemination of farm animals is very common in today's agriculture industry in the developed world, especially for breeding dairy cattle. (75% of all inseminations).Swine is also bred using this method (up to 85% of all inseminations). It provides an economical means for a livestock breeder to improve their herds utilizing males having very desirable traits.


d) Somatic Cell Cloning

Somatic Cell Cloning holds some promise for propagating from one or a few survivors of an almost extinct species. The nucleus of a somatic cell is removed and kept, and the host's egg cell is kept and nucleus removed and discarded. The lone nucleus is then fused with the 'deprogrammed' egg cell. After being inserted into the egg, the lone (somatic-cell) nucleus is reprogrammed by the host egg cell. The egg, now containing the somatic cell's nucleus, is stimulated with a shock and will begin to divide. After many mitotic divisions, this single cell forms a blastocyst (an early stage embryo with about 100 cells) with almost identical DNA to the original organism. The technique of transferring a nucleus from a somatic cell into an egg that produced Dolly was an extension of experiments that had been ongoing for over 40 years. In the simplest terms, the technique used to produce Dolly the sheep – somatic-cell nuclear transplantation cloning – involves removing the nucleus of an egg and replacing it with the diploid nucleus of a somatic cell.


e) Seed bank

The preservation of plant germplasm in seedbanks, (or genebanks), is one of the techniques of ex-suit conservation of plant species. Seeds have a natural dormancy feature, which allows for their suspended preservation for long periods of time with little damage, provided the conditions are favourable. Banking dormant seeds enables to keep genetically representative samples of rare and endangered plant species as a kind of “genetic insurance”.


Storing germplasm in seedbanks is both inexpensive and space efficient. It allows preservation of large populations with little genetic erosion. Seedbanks also offer good sources of plant material for biological research, and avoid disturbance or damage of natural populations. Two types of seeds may be considered.

The orthodox seed those that can be dried at low humidity and stored at low temperatures. These orthodox seeds can remain viable for many years and are rather easily stored in seedbanks.


The recalcitrant seeds do not tolerate low humidity and temperature, and thus are not good material for seedbanking conservation.


Preparation for storage is different for each species and has to be assessed before any conservation planning. Roughly, the different processes imply first collection of the seeds, then drying to a moisture content of less than 6%. The seeds are then stored at low temperature (below -18 degree C). As seeds tend to lose germinative power over time monitoring of viability and regeneration processes must be done frequently.

 


Last Updated on Wednesday, 23 April 2014 07:10