Biodiversity and Conservation

Species diversity is the variety in the number and richness of the species of a region. The number or species per unit area is called as species richness. Number of individuals of different species represent species evenness or species equitability. Communities where species are represented by more or less equal number of individuals exhibit evenness. Where one or more species have more individuals than other show dominance or unevenness. 

Statement A is incorrect as species diversity decreases and not increases as we move away from the equator towards the poles temperature decreases and conditions becomes harsh, vegetation decreases and less resources available to support species. 

When there are no more individuals of a species (plant or animal) alive anywhere in the world, the species is said to be extinct. A decrease in the species diversity progresses to extinction if left uncontrolled. Extinction is also known as the process of dying out. The process is a completely natural part of evolution. But sometimes extinctions happen at a higher and a faster rate than usual. Factors such as large body size, small population, massive habitat loss and position at a higher trophic level favor extinction. As forests are the main habitat for the wild animals, their loss favors the extinction of the same.

When there are no more individuals of a species (plant or animal) alive anywhere in the world, the species is said to be extinct. Extinction is also known as the process of dying out. The process is a completely natural part of evolution. But sometimes extinctions happen at a higher and a faster rate than usual. Factors such as large body size, habitat loss, small population and position at a higher trophic level favor extinction. Since the species residing in the tropics have their major habitat in the form of forests, thus deforestation causes, extinction of such species.

An endangered species is the species whose population faces a sudden downfall. In the case of wild animals, their habitat is the forest and deforestation of the forests due to ecological disasters, or use of timber for the construction of buildings makes them insecure in their homestead. 

Forests occupy more than 30 percent of Earth's land surface and account for 50 percent of plant productivity. Therefore 45% of the carbon stored on land is tied up in forests. Further, these being the dominant terrestrial ecosystem, the forest account for 75% of the gross primary productivity of the Earth's biosphere and 80% of the plant biomass. Removing half the forest cover, will not only bring in an increase in the population of human beings and other living organisms but will also bring about increased pollution and a great ecological imbalance.

Ecological succession is often initiated by disturbances that destroy existing populations or communities, allowing new species to colonize the area.

Biodiversity hotspots are biogeographic regions that are both a significant reservoir of biodiversity and are threatened with destruction, characterized by high levels of endemism (species found nowhere else).

When we destroy a forest, we destroy an ecosystem. It is because ecosystem constitutes of both abiotic and biotic components. The biotic components constitute all the living organisms present in the ecosystem, i.e. plants and animals. Whereas, abiotic components constitute the environmental factors like air, soil, water etc. When a forest is destroyed, it results in the loss of food and habitat of wild animals, due to which the population of wildlife is threatened. The loss of forest also results in deforestation, which affects the environment by raising the temperature and causing a flood. So, the correct option is A.

Economic development refers to the process of using natural resources for the development of the economy. But in developed countries the resources are exploited in a very large quantity that leads to the depletion of these stock of natural resources. The negative effects of economic development are increased air pollution, global warming and loss of biodiversity. 

If species are geographically isolated and separated for long period of time, they may lose ability to interbreed and produce fertile offsprings. Thus leading to formation of new species

• All plants and animals on earth engage in a process called respiration.
• Respiration combines oxygen and the food created during photosynthesis to produce usable energy. 
• One of the byproducts of respiration is CO2,  if plants stop to take up CO2 and stop releasing O2, then plants will stop to convert sunlight into carbohydrates, and die.
•  The death of autotrophs would lead to a chain reaction to the death of all higher-order organisms. Hence, Animals will die from the lack of oxygen if plants stop releasing oxygen into the atmosphere.

Pollution is the addition of contaminants into the natural environment that can cause undesirable change. It may be the chemical and physical change. Pollutants are the contaminants that cause pollution.

Wildlife represents the uncultivated or undomesticated species. They have a wide gene pool. The cultivated plants and domesticated animals have a narrow gene pool because these organisms have been selected by man over a period of thousands of year. Further, the cultivated plants and domesticated animals grow in protected environments. The uncultivated plants and nondomesticated animals, on the other hand, grow in natural surroundings in conjunction with disease-causing organisms and depend on the naturally evolved defense mechanisms. These organisms have evolved disease resistance, mechanisms and are a rich source of disease resistance germplasm.

Poaching is the process of illegal hunting, killing or capturing of wild animals for various purposes. The Sariska Tiger Reserve which was known for a good number of tigers has been reported for depleting tiger population because of the practice of poaching.