What is Biodiversity?
Biodiversity definition: ‘Bio’ means life, and ‘diversity’ means differentiation or variation in distribution. It refers to the differentiation of lives involving flora and fauna in a particular locality. In another sense presence of different kinds of organisms in a particular habitat is called biodiversity. Biodiversity is the totality of genus, species, and ecosystem in a region or the world.
Plant diversification:
It is the distribution and adaptation of different plants in different regions of the world. There are many factors upon which plant diversification depends, namely:
- Climatic factors: temperature, wind, shade, water, fog, dew.
- Edaphic factor: soil texture, structure, water content, quality, height.
- Topographic factor: latitude, altitude, slop.
- Biotic factor.
Types of Biodiversity
Based on the above factors, biodiversity may be classified as follows:
Ecological diversity: when ecological factors or climatic factors cause diversity, then it is called ecological diversity. Here temperature, heat requirement, moisture, light intensity is responsible for the diversification of plants. E.g.
- Xerophytic plants in a desert area
- Hydrophytic plants in a swamp or water-logged area
- Vegetative crops in a temperate region
Even in Bangladesh, tea grows only in Sylhet and Chattogram, mango in Rajshahi, litchi in Dinajpur, and coconut in coastal regions. This diversity of plants occur due to ecological diversity.
Genetic diversity: when the variation of genetic constituents causes diversity, then it is called genetic diversity; e.g. rice, wheat, jute, sugarcane are phenotypically different due to different chromosome no. Moreover, they do not grow in the same season and require different cultural practices, weather, and climatic conditions due to genetic constituents’ variation.
Species diversity: when the different species of plants cause diversity, it is called species diversity. If there are two individuals with the same genetic constituents but they may not be identical. For example, Aus, Aman, Boro, IR, and BR rice at species under the family of Gramineae but are distinct for growing season, habit, growth, development, and yielding attributes; This is due to the species diversity.
Taxonomic diversity: the distribution of species among different groupings. Taxonomic categories (groupings) include phylum, class, order, family, genus, and species. A place with high taxonomic diversity, for example, might include species from many different families.
Importance of biodiversity
There are many reasons biodiversity is essential. It affects all forms of life, even humans. Just as a diverse community means multiple resources for a black-capped chickadee, it also means multiple resources for us. Some of the resources that come to mind are the medicines used when ill, foods, the wood used for houses and furniture, and the paper we write and print on. Recreational resources include hunting, wildlife, viewing, camping, and other outdoor activities that we take pleasure in. not only does biodiversity provide resources that are important to life, it also provides the setting for ecological services such as nutrient cycling, erosion control, cleaning the air, filtering water and pollination.
Biodiversity is significant ecologically and economically. It also plays a vital role in our daily life because it is applicable in different fields for better development in the modern world. Some of the essential fields on which biodiversity is applicable are as follows:
- Importance in agriculture: in the agricultural field, biodiversity plays a vital role to produce a new variety of plants or crops by producing a change in their genetic traits, and it also helps in preventing the crops from disease such as coffee plants., rice. It is also called agricultural biodiversity.
- Importance in human life: biodiversity plays a significant role in our lives because they are beneficial for producing different valuable products such as food, water, and different types of pharmaceutical products, which help in recovery.
- The industrial importance of biodiversity: in the field of industry, it is also used to produce different kinds of materials, such as building materials derived from different kinds of biological resources and biodiversity. The industrial products produced as a result of biodiversity are fibres, dyes, oil, rubber.
Threats of biodiversity
Many of our biological resources are threatened with degradation. Some of the major threats to biodiversity are:
- Habitat loss: the area is converted from a natural state to a semi-natural or unnatural state.
- Habitat fragmentation: large areas are divided into smaller, often scattered units.
- Invasive species: many are aggressive and out-compete native species.
- Overuse and exploitation of resources: poor management can stress communities when resources are used faster than replenished.
- Pollution: can affect communities and species in numerous ways depending on the contaminant.
- Climate change: climate changes can stress natural communities to the point that species assemblages change.
Biodiversity threats can work in tandem and may escalate problems. For example, habitat loss often results in fragmented habitats scattered over an area. A fragmented habitat can be detrimental to biodiversity because more openings allow invasive and naturally aggressive species to enter and compete with native species. Smaller habitat patches may not be large enough for species requiring large areas, and they may disappear. Increased edges in fragmented habitats may also result in unnaturally high predation. Erosion and water contamination could increase from removing vegetation that acts as a soil anchor and water filter.
Causes of loss of biodiversity
Almost all of the terrestrial land is occupied by human beings. Therefore, the places for other lives are seriously hampered, and they have been started declining from the nature in our country. In the name of the development work all over Bangladesh causing severe environmental degradation that includes various types of indifferent activities of its inhabitants.
Forestry and biodiversity management have been losing ground for other forms of land uses without much consideration for land potential. Large-scale land-use changes have caused heavy destruction of forests, converting the area into barren lands. The salient causes for the degradation of biodiversity in both the terrestrial and ecosystems are as follows:
- Human interference for agriculture and settlement
- Unsustainable use of natural resources
- Hill cleaning, cutting and destruction
- Destruction of habitats of organisms
- Illegal hunting of animals
- Traditional management practice
- Encroachment
- Short-sighted development efforts
- Overexploitation
- Collection fare zoos studies and the researches
- Loss of indigenous species by the introduction of exotic species
- Control of pests and predators
- Pollution from various sources
- Deforestation
- Increased salinity due to the low flow of some river waters.
- Socio-economic and political causes
- Secondary influence of extinction, e.g. extinction of an animal due to extinction of another animal on which it depends
- Other factors:
- Distribution range
- Degree of specialization
- Position of the organisms in the food chain
- Reproduction rate
- The causes are the symptoms of poverty, landlessness, underdevelopment, lack of proper land use planning, the socially unbalanced land tenure system, socio-economic immobility, short-sighted urbanization policy.
Plant diversity conservation
What is Conservation?
It is an exercise for the proper maintenance, management, and utilization of natural resources and ecosystems for the long-time benefit of humanity.
Types of conservation
- In-situ conservation: it is the conservation of biodiversity within the dynamic evolution ecosystem of the original habitat in the natural environment. In general, in-situ conservation methods share these characteristics:
- Target species are maintained within some ecosystems.
- Land use of the site is limited.
- Regeneration of target spp occurs without human manipulation.
- Ex-situ conservation: keeping components of biodiversity alive outside of their original habitat of the natural environment is known as ex-situ conservation. This method includes many practices that conserve natural resources outside the natural distribution of the parent population. E.g. seed gene bank, base collection, active collection.
- In-vitro conservation: the conservation of biodiversity in the box; conservation of an organism in a medium under aseptic condition is known as in-vitro conservation. It must be free from any germ. For this purpose, decontamination should be done. In-vitro conservation further classified into two groups such as:
- Short term in-vitro conservation: in-vitro conservation means to conserve natural plants resources (seeds, pollen, apical meristem, tissue, cell suspension of plants) in tissue culture under ascetic conservation means to conserve. It is also known as a culture to culture conservation.
- Long term in-vitro conservation: it means to conserve plant natural resources for a long time. E.g. conservation of seeds, pollen, apical meristem, bud, tissue, cell suspension of plants at liquid nitrogen. Temperature (-196oC) without significant damage to the viability of the tissue. It is also known as cryopreservation (‘cryo’ means very low temperature) for more than six months. Conservation under very low temperatures is known as cryopreservation. It is done under -196oC temperature.
Advantages of in-situ conservation
- It is the best way of conservation because all growth factors are favourable for vegetation.
- The plant gets mycorrhizal or fungal support in its habitat.
- Conservation of viable population is very easy and less costly.
- The method is more suitable in those areas wherein dangerous species are not listed.
- Provide a favourable ecosystem for others.
- The role of support to others is more under this conservation.
- It is more suitable for new species emergence.
- It is highly suitable for recalcitrant seed conservation.
Advantages of ex-situ conservation
- Selective conservation is possible.
- Selectively economic and commercially suitable.
- Diversity should be maintained as we like.
- Commercially valuable.
Advantages of in-vitro conservation
- A diseased free plant could be conserved by this method.
- Economically not suitable for all plants but highly suitable for some specific species.
- It requires efficient workers and technology but yields high profit selectively.
- Dissemination of propagules is highly easy.
Conservation of biodiversity
The participation of people from all stages of life is indispensable for the management of a sustainable environment. All possibilities of conservation of biodiversity will go in vain without the participation of people from every level. Both the government and non-government organizations will have to work together with international agencies to have a solid breakthrough to fight out the serious unsuitability of our environment. To make this program effective, we must involve education, information dissemination, action programs, preventive measures, and some related policy executions.
The success of this program will depend on the highest level of policymaking that would lead to the recognization and reorientation of the management of different sectors of developmental works. The proper ecosystem must be preserved by creating wildlife sanctuaries, game reserves, and national parks. There should exist some protected areas to conserve the wildlife and for other forms of life. It is possible to preserve plants and animals in laboratories, zoos, and gardens in genes, tissue, or seeds.
Action plans proposed for biodiversity conservations
Action plans for the conservation of biodiversity must be directed to:
- The invention of biological resources in different parts of the country, including the island ecosystems.
- Conservation of biodiversity through a network of protected areas including national parks, sanctuaries, biosphere reserves, marine reserves, gene banks, wetlands, coral reefs.
- Rehabilitation of rural poor tribals displaced due to creation of protected areas.
- Conservation of microorganisms helps in the reclamation of wasteland and revival of the biological potential of the land.
- Protection and sustainable use of genetic resources germplasm through appropriate laws and practices.
- Control of overexploitation through the organization CITES and other agencies.
- Protection of domesticated plant and animal species in order to conserve indigenous genetic diversity.
- Maintenances of corridors between different nature reserves for the possible migration of species in response to climate or any other disturbing factor.
- Support for protecting traditional skills and knowledge for conservation.
- Multiplication and breeding of threatened species through modern techniques of tissue culture and biotechnology.
- Discouragement of monoculture introduction.
- Restriction in the introduction of exotic species without adequate investigations.