The number of different species present in an environment and the relative abundance of each species are the two components that make up species diversity. The region considered could be a biome, a habitat, or the entire biosphere. The diversity of living organisms can't be accurately measured in tropical rainforests, but it is still high even in places with low species diversity, such as the glaciers of Antarctica. For example, species diversity denotes a woody forest that may have four or five different tree species, while a particular reef may contain 100 different types of fish, crabs, and coral. This article will explain to you about Species Diversity which will be helpful in preparing the Environment Syllabus for the UPSC Civil Service exam.

What is Species Diversity?

• The number of different species found in a given area is referred to as the species diversity.
• In nature, species do not interbreed because they differ genetically from one another. However, closely related species share a lot of their inherited traits.
• For example, 98.4% of the genes in humans and chimps are similar. It is the proportion of a species' total population to all the species' combined total number of organisms in a given biome.
• "One" denotes the presence of just one species, while "zero" would indicate infinite diversity.

Components of Species Diversity

• When all of the species present are equally abundant in the area, diversity is greatest. Species diversity is made up of two components:
  • Species richness: It refers to the number of different species found in an ecosystem. Tropical areas have a higher species richness because the environment supports a large number of species.
  • Species evenness: The relative abundance of individuals within each species. If the number of individuals within a species remains relatively constant across communities, the species is said to have high evenness; if the number of individuals varies from species to species, the species is said to have low evenness. Greater specific diversity results from high evenness.
• In an ecosystem, it is possible to have a high species richness but a low species evenness. For example:
  • There may be a large number of different species (high species richness) in a forest, but only a few members of each species (low species evenness).
  • A forest may have only a few plant species (low species richness), but many of each species (high species evenness).
• The diversity of species varies by geographical location, with the tropics having the highest diversity and decreasing as we move towards the poles.
• Tropical rainforests, coral reefs, and the ocean bottom zone have the most species.
• The richness of species increases as the explored area expands.

Ecosystems with High Species Diversity

Tropical Rainforests

• They are home to 50% of all species. There are 5–10 million different types of insects.
• The tropical regions are home to 40% of the 2,75,000 species of flowering plants that exist worldwide. Tropical woods are home to 30% of all bird species.
• Tropical forests' abundance of species is mostly a result of their relatively stable environmental circumstances.

*To know more about the topic, click this link Tropical Rainforests

Coral Reefs

• The vast coral reef ecosystem is composed of colonies of small coral organisms.
• The high amount of photosynthesis in the algae present inside the coral is due to the transparency of the water in coral reef systems, which allows sunlight to penetrate deeply.
• Richness in species is a result of niche specialization and adaptation to varied shocks.

*To know more about the topic, click this link Coral Reefs

Species Diversity - Importance

• Maintains Balance: A diverse and balanced number of species are present in a healthy ecosystem to maintain the ecosystem's balance.
• More Fruitful: Ecosystems with greater species diversity are typically more fruitful. For instance, an ecosystem with many different producer species will produce a lot of biomass to support more different consumer species.
• More Stable And Sustainable: An ecosystem is more sustainable and stable when it has a greater diversity of species and production.
• Endurance to Environmental Pressures: The ability to endure environmental pressures like drought or invasive infestations increases with species diversity.
• Ability to Respond: An ecosystem's ability to respond to any disaster depends on its species diversity.
• Numerous advantages of healthy biodiversity include the storage and recycling of nutrients, the creation of soil and prevention of erosion, the absorption of toxic gases, and the stability of the climate.
• Nature provides us with a wide range of goods, including fruits, cereals, meat, timber, fiber, raisins, dyes, medications, antibiotics, etc.
• According to estimates, the Amazon forest contributes 20% of the world's total oxygen to the atmosphere.
• Each species plays a specific, irreplaceable role that is necessary for pollinators, symbiotic partnerships, and decomposers.
• Vast-scale interactions between organisms, like those in the food web, are facilitated by diversity in large numbers.
• The link between bacteria, plants, and the nitrogen cycle is vital, and earthworms improve soil fertility.
• In addition to this, there are additional advantages including leisure and tourism, education, and research.

Species Diversity - Threats

• Because of human activity, the pace of species extinction in the world is accelerating.
• "The Evil Quartet" is a term used to describe the four main reasons for diversity loss.
  • Habitat Loss and Fragmentation: They are key contributors to the loss of species diversity and the extinction of plants and animals.
    • These factors include pollution, urbanization, and a variety of other human activities.
    • For instance, the Amazon rainforest (the planet's lungs), which is home to millions of species, is being cut down and removed for a variety of reasons.
    • Tropical rainforest, which once spanned 14% of the landmass, now only makes up about 6% of it.
  • Overexploitation: Excessive use of natural resources causes many species to go extinct.
    • For instance, the passenger pigeon, Steller's sea cow, and several marine fish are overfished.
  • Alien Species Invasions: Some alien species that are purposely or accidentally introduced can become invasive and wipe out native species.
    • For instance, the extinction of cichlid fish in Lake Victoria because the Nile perch was introduced
    • The indigenous catfish in rivers are in danger due to the illegal introduction of African catfish.
  • Co-extinctions: Co-extinctions occur when two species that are related to one another go extinct at the same time. For instance, a parasite may become extinct along with its host fish.
    • When one species goes extinct, it also causes the extinction of other species, just like a plant pollinator.

Threats to Species Diversity

Species Diversity - Conservation

• Every species contributes significantly to an environment. Diversity needs to be preserved because if it goes extinct, it is irreplaceable. The biodiversity can be preserved in a variety of ways.
• In-situ Conservation: In-situ conservation refers to the protection of biodiversity-rich areas like biosphere reserves, national parks, and sanctuaries; preserving the Sunderbans for numerous threatened species, including the olive ridley sea turtle, mangrove species, and the royal Bengal tiger.
• Hotspots for biodiversity have been found that are rich in species. Globally, 34 hotspots have been identified.
• India has a history of preserving the environment. In many civilizations, wildlife and trees are given complete protection, such as in sacred groves.
• Ex-situ Conservation: Ex-situ conversations take place when endangered and threatened species are located, removed, and preserved in designated areas like botanical gardens, wildlife safaris, etc. with full protection.
• Cryopreservation procedures are used to preserve the gametes of endangered species.
• The seed bank houses the seeds of plants with significant economic value.

Conclusion

A diverse and balanced number of species exists in a healthy ecosystem to maintain an ecosystem's balance. In an ecosystem, all species rely on one another, either directly or indirectly. It is therefore critical to maintain high species diversity in order to create a more efficient, productive, and sustainable ecosystem.