Deforestation and Land Degradation

Deforestation leads to the increased percentage of carbon dioxide components of the environment because trees provide oxygen by taking up carbon dioxide when their number reduces the carbon dioxide was unable to be converted into oxygen. That's why its components increases.

• Deforestation is when humans remove or clear large areas of forest lands and related ecosystems for non-forest use. These include clearing for farming purposes, ranching, and urban use. In these cases, trees are never re-planted.
• Plants absorb large amounts of carbon dioxide from the atmosphere. When deforestation takes place it results in an increase in carbon dioxide concentration in the atmosphere which results in global warming.
• Without trees, rain runs off soil into rivers and streams, raising the water level which leads to floods. Hence deforestation results in the flood.
  
• Deforestation also results in the extinction of flora and fauna(plants and animals).
• Hence The consequences of deforestation are  Global warming, Flood and Extinction of flora and fauna.
• So, the correct answer is 'All the above'.

Trees release water vapor through transpiration, which contributes to cloud formation and local rainfall. Removing trees reduces this process, leading to drier conditions.

Grasslands provide forage to cattle and support wildlife based on grazing food chain. Grasslands have been put to two types of pressure : overgrazing and conversion. At one time, in the history of human civilization, cattle were reared in large number. The number continues to be high. For example : In arid and semi arid areas of India, the number of grazing animals is 2 to 10 times higher than the grasslands can support. This decreases productivity and quality of grasslands and causes Negative pollution ie reduction in soil productivity due to overuse. Positive soil pollution is reduction in soil productivity  due to addition of undesirable  substances e.g : Agrochemicals, industrial wastes, air pollutants washed down by rain, faulty sanitation etc.

Soil pollution is caused by the addition of substances and factors which decrease its productivity. When the chemicals from the wastes are released into the soil, there is contamination of the soil. This results in degradation of the soil because there is a loss of fertility of the soil and the nutrient value is reduced. 

Abiotic factors are non-living chemical and physical parts of the environment. Deforestation leads to loss of cover, and soil erosion is the physical removal of topsoil; both are abiotic processes that contribute to soil degradation.

Explanation: Overgrazing, over cropping and or deforestation can lead to desertification the spread of desert like lands due to these human activities accelerating natural erosion of soil.

1. Mining activity is the main cause of environmental degradation.
2. Both legal and illegal mining activities has resulted in soil contamination, groundwater contamination, surface water contamination and loss of bio-diversity.
3. It also led to destruction of habitat and soil erosion.

Soil erosion is a phenomenon in which soil of an area eroded due to deforestation, over-grazing, unplanned irrigation, etc., decrease the fertility of soil.

Afforestation is the process of planting trees, or sowing seeds, in a barren land devoid of any trees to create a forest. The benefits of this practice, which is called agroforestry, are:

1. It provides a supply of timber, fruit, and fodder for cattle apart from crop production
2. It prevents soil erosion and thus conserves soil.
3. It enables better retention of water
4. It shields crops from excessive wind and sun damage

In terms of the environmental benefits, planting trees is always beneficial whether it takes place in a barren land or is used as a method to regenerate a depleted forest. Trees help check atmospheric carbon dioxide; large scale afforestation can curb the problems caused due to burning of fossil fuels, industrialization and so forth.

Afforestation is the establishment of a forest or stand of trees in an area where there was no previous tree cover.
Reforestation is the reestablishment of forest cover, either naturally (by natural seeding, coppice, or root suckers) or artificially (by direct seeding or planting).

Deforestation is a major cause which leads to the change in soil properties. It affects the nutrient content (which cannot be replenished in the soil), texture and fertility of soil (due to erosion).

Soil erosion occurs when the weathered soil particles are dislodged and carried away by wind or water. Deforestation, agricultural development, temperature extremes, precipitation including acid rain, and human activities contribute to this erosion. Humans speed up this process by construction, mining, cutting of timber, over cropping and overgrazing. It results in floods and cause soil erosion.

Deforestation, clearance or clearing is the removal of a forest or stand of trees where the land is thereafter converted to a non-forest use. The less the soil is covered with vegetation, mulches, crop residues, etc., the more the soil is exposed to the impact of raindrops. When a raindrop hits bare soil, the energy of the velocity detaches individual soil particles from soil clods. Thus Deforestation would decrease the water holding capacity of the soil, so statement is false and Option B is correct.