[Biodiversity] Meaning and Types of Species+ Mock Questions for CSATDevendra Vishwakarma
- What is biodiversity?
- Keystone species
- Sentinel species: frogs
- Blue whales
- Non-native species
- Vultures and diclofenac
- What is biodiversity hotspot?
- Plant biodiversity and Green Revolution
- Cites: convention on international trade
What is Biodiversity?
Biodiversity = biological diversity. It means number and variety of plants and animals. Consider following example:
- Jungle a has 10 tigers and 100 deers.
- Jungle b has 20 tigers in 200 deers.
- Jungle c has 10 lions and 10 tigers, 100 deers and 100 wild buffalos.
Here jungle c has the most biodiversity. [jungle b also has 220 animals but ‘variety’ is less.] Which of the following statement is true?
- Biodiversity is high in isolated islands
- Biodiversity is low in tropical forests and coral reefs.
- Biodiversity is higher in europe compared to south asia.
Well, All statements are incorrect.
- Isolated islands have limited number of variety in plants and animals compared to tropical rainforest or coral reefs. Because number of competitors and predators are limited.
- In the subtropical and polar regions of Northern Hemisphere, the climate is very cold, the region had gone through ice-ages = less population =less competition =less predators =less evolution= less biodiversity of plants and animals (compared to African or Brazilian jungle)
- In general, you will find less variety in plant and animal species in some European country (Ukraine) compared to a tropical country like Vietnam.
- So, As you move from equator towards the poles, biodiversity decreases. (latitudes)
Talking about Europe, almost all plans eaten today in Europe have originated in the developing countries around the equator.
- Coffee: Ethiopia
- Rice: India
- Wheat: turkey and Afghanistan
- Soya, cucumber, orange: china
Q. Consider the following statements (UPSC CSAT-2011)
1. Biodiversity is normally greater in the lower latitudes as compared to the higher latitudes.
2. Along the mountain gradients, biodiversity is normally greater in the lower altitudes as compared to the higher altitudes.
Which of the statements given above is/are correct?
(a.) 1 only
(b.) 2 only
(c.) Both 1 and 2
(d.) Neither 1 nor 2
ans. 1st statement is true. (europe vs africa).
Second statement is true. Higher you go= colder atmosphere = less biodiversity.
- These species determine the ability of a large number of other species to survive.
- When the keystone species becomes extinct. It has snowballing (=cascading) effect on extinction of other species (just like increase in petrol price on inflation)
- Examples of keystone species
- Bees : pollination of fruits and flowers. Albert Einstein once said, “if the honeybee goes extinct, we have four more years on earth”.
- Plankton : food of many fishes
Sentinel species: frogs
- They are sensitive indicators of environmental problem.
- For example, frogs, toads, salamander. They are amphibians (can live in both land and water).
- Frogs breath through their moist skin, which is very sensitive to pollutants in environment.
- In amphibians, fertilization is typically external, meaning that the sperm and egg join outside of the female’s body.
- They lay unprotected eggs (without shell like chicken egg) in water or moist damp places, so their eggs are also very vulnerable to pollution, temperature, humidity change etc.
- Thus, a rapid decline in the population of frogs thus would indicate a looming environmental problem.
- (Homework) difference between coldblooded and warm blooded animals.
- Largest mammals on Earth. Elephents are the largest mammals on land only.
- International whaling commission (IWC) was set up in 1946 to fix anyone hunting quotas for the countries. Since 1980s IWC called for a halt on whale poaching
- But Japan, Norway and Ireland are major countries that still continue to indulge in whale hunting, they are unhappy with IWC and cites restrictions.
Q. Which of the following Statements are true?
- 1.Construction of large dam will increase the biodiversity in the area.
- 2.Fish and Amphibians are cold-blooded animals.
- 3.Whale is a cold-blooded fish.
- 4.Whale dives out of water to regulate its body temperature
- 5.Polar bear is a cold blooded animal because it goes in hibernation.
- For example, in the 18th century, rabbits introduced in Australia for sport shooting.
- Since they were a non-native species in Australia, it meant they had no predators or competitors to control their population. They destroyed a vast range of plants and reduced the forest area.
- Rats of several species were unintended stowaways* on oceanic voyages, and thus spread around the world.
- Infected humans took the human immunodeficiency virus (HIV), which caused aids from Africa to the rest of the world.
- Stowaways= a person who hides aboard a ship or plane in the hope of getting free passage
Bird : Another Sentinel Species
- Birds are very important for seed dispersal, insect and rodent control, scavenging (vultures), and pollination.
- Many birds are also sentinel species e.g.Vultures
- Colombia has more than 1800 species of birds = most bird-diverse country
- India’s got about 1250 =we rank in top-10 in terms of bird diversity.
Vultures and Diclofenac
- Diclofenac is a painkiller medicine used mostly for arthritis in humans
- Veternary Diclofenac is used on cattle, as painkiller, stopping inflammation and fever.
- When Animals are treated with Diclofenac, this drug keeps accumulating in their body. When these animals die, Vultures eat them = kidney failure =death of vulture.
- Hence Government of India banned Veternary Diclofenac. Now farmers have to use other expensive drugs instead of Diclofenac.
- Bigger Why should we care? Let the vultures die! What difference does it make to us or to the environment ?
- Well, Less vultures= more dead animals for dogs to eat = dog population increases = more problem of rabies.
- Secondly, vulture’s digestive system can destroy many parasites, but dog’s digestive system cannot. Hence dogs who eat dead animals are more disease carriers than vultures.
What is biodiversity hotspot?
- It is an area unusually rich in biodiversity of birds and animals, but they are under constant threat of overexploitation. Such an area is called a biodiversity hotspot
- Example of biodiversity hotspots in India : eastern Himalayas, western Ghats. (more in separate articles)
Plant biodiversity and Green Revolution
- But under the green revolution program, the government introduced HYV (high yielding variety) seeds. So, instead of 30,000 indigenous varieties of rice, now Indian farmers plant only 12 HYV rice varieties.= reduced biodiversity of rice.
Cites: convention on international trade in endangered animals and plant species.
- The illegal smuggling of rare species, exotic pets (orangutan), ornamental plants (orchid, cactus) is estimated to be $8 billion per year, which is second only to the illegal weapons smuggling.
- Cites convention restricts the trade of endangered plants and animals and also the trade of clothing, food, medicine, and souvenirs, produced out of these species.
- Cites is a step by world’s oldest global environmental organization IUCN = international union for conservation of nature and natural resources (iucn), hq: Switzerland.
- The same ICUN maintains the red list of threatened species.
Q. Which of the following statements are true?
- 1.Introduction of high yielding verity of seeds increases biodiversity.
- 2.“Green Revolution” has increased biodiversity in India.
- 3.CITES convention regulates the whale poaching.
- 4.CITES is a convention made by UNESCO.
- 5.Western Himalaya and Eastern Ghats are examples of biodiversity hotspots.