The biodiversity present on Earth today is made up of many millions of diverse biological species that have evolved over four billion years. Biodiversity refers to the diversity of life on Earth, which encompasses all creatures, species, and populations, as well as genetic variation among them and their complex assemblages of communities and ecosystems. It also refers to the interconnection of genes, organisms, and ecosystems, as well as their interactions with their surroundings.
As per United Nations Earth Summit (1992), the term “biodiversity is defined as ‘the variability among living organisms from all sources, including terrestrial, marine and other aquatic ecosystems and the ecological complexes of which they are a part; this includes diversity within species, between species and of ecosystems”.
The conservation and sustainable use of biodiversity are critical to environmentally sustainable development. Biodiversity is a component of our everyday lives and a source of resources for families, communities, nations, and future generations.
Different levels of Biodiversity
Biodiversity is categorized into three types
- Genetic biodiversity,
- Species biodiversity,
- Ecosystems biodiversity
- It is concerned with gene variation within a certain species.
- It can be helpful for the Species to adapt to the changing surroundings through genetic variety.
- This variety is intended to ensure that certain species survive extreme changes and, as a result, pass on favorable genes.
- The survival of individuals ensures the survival of the population
- It refers to several living species on the planet.
- Species differ significantly in their genetic makeup and do not interbreed in nature.
- Closely related species, on the other hand, share many inherited features. For example, humans and chimps share around 98.4 percent of their DNA.
- It is the ratio of one species’ population to the total number of organisms in the given biome.
- ‘Zero’ would indicate infinite diversity, whereas ‘one’ represents the presence of only one species.
Ecosystem/ Community Diversity
- This relates to the many habitat kinds. A habitat is the total of a region’s climate, vegetation, and terrain.
- Around the world, there are several types of habitats. Ecosystems include coral reefs, grasslands, wetlands, deserts, mangroves, and tropical rain forests.
- Changes in climatic circumstances are also followed by changes in vegetation. Each species adapts to a certain type of habitat.
- As the environment changes, the species that are most adapted to that habitat take precedence. Thus, the nature of the environment influences the variety or diversity of species in the ecosystem.
Method of Measuring Biodiversity
There are two main methods of measuring biodiversity on earth.
- Species richness
- Species evenness
Species richness; is the measure of the number of species found in a community. It is also divided into three types of measurements, i) alpha, ii) beta and iii) gamma diversity
- Alpha diversity; refers to the diversity within a certain region or ecosystem, and is generally stated in terms of the number of species (i.e., species richness) in that ecosystem.
- Beta diversity; is a comparison of ecological diversity, commonly assessed as the difference in the number of species between the ecosystems
- Gamma diversity; is a measure of the overall diversity of the different ecosystems within a region.
Species evenness; measures the proportion of species at a given site, e.g. low evenness indicates that a few species dominate the site.
Different Services provided by Biodiversity
Biodiversity provides various types of services, here in this part of the discussion we are going to focus on the services of ecosystem, biological and social services provided by biodiversity
- Ecosystem Services
- Protection of water resources
- Soils formation and protection
- Nutrient storage and recycling
- Pollution breakdown and absorption
- Contribution to climate stability
- Maintenance of ecosystems
- Recovery from unpredictable events
- Biological services
- Medicinal resources and pharmaceutical drugs
- Wood products
- Ornamental plants
- Breeding stocks
- Diversity in genes, species, and ecosystems
- Social services
- Research, education, and monitoring
- Recreation and tourism
- Cultural values
Major Causes behind the Loss of Biodiversity
Loss of biodiversity happens when a specific species goes extinct or the environment necessary for its life is degraded. The latter is more prevalent since habitat damage is an inevitable consequence of development.
Species go extinct when they are exploited for commercial benefit or killed for sport or sustenance. For example, Thousands of sharks are killed each year for sport and food. Shark skins are utilized for the production of leather goods. Shark livers were used as a vitamin A supplement until the 1950s. Many countries consume shark fin soup and shark steaks. Extinction of species may also occur as a result of environmental factors such as ecological substitutions, biological factors, and pathological causes caused by either nature or man.
The natural causes of biodiversity losses are floods, earthquakes, landslides, rivalry among species, lack of pollination, and diseases.
On the other hand, the man-made reasons behind the loss of biodiversity are Habitat destruction Uncontrolled commercial exploitation, Hunting & poaching, Conversion of rich bio-diversity sites for human settlement, and industrial development, Extension of agriculture, Pollution, Filling up of wetlands, Destruction of coastal areas.
Methods of Conservation of Biodiversity
Conservation of biodiversity is very important because it provides different types of services for our daily life as discussed above. There are two ways or modes of conservation of biodiversity, a) Ex-situ and b) In-situ conservation.
- Ex-situ conservation is the preservation of biodiversity outside of the locations where it naturally occurs.
- Animals are raised or plants are cultivated here, similar to zoological parks or botanical gardens.
- Another type of ex situ conservation is the reintroduction of an extinct animal or plant into its natural environment.
- For example, the extinct Gangetic gharial (India) has been reintroduced into rivers in Uttar Pradesh, Madhya Pradesh, and Rajasthan.
- Seed banks, botanical, horticultural, and recreational gardens are important centers for ex-situ conservation.
- In-situ conservation refers to the preservation of animals and plants in their natural environments. The following natural habitats have been established:
- National parks
- Biosphere reserves and
- Reserved forests
- Protected forests