Natural Vegetation Flashcards
Explain the term natural vegetation
It refers to the plant cover that has grown on their own without any interference by humans and has not been disturbed over a long period of time so to allow its individual species to adjust them fully to the climate and soil condition.
What are the significances of forests in maintaining the ecological balance?
- Helps in regulating or moderating the climate.
- Helps in controlling soil erosion by binding the soil with their roots.
- Helps in recharging underground water by avoiding surface run-off hence also reduces chances of flood. - Helps in increasing the fertility of the soil by adding humus.
- Purifies the air by absorbing carbon dioxide hence controls atmospheric pollution.
- Provides protected and natural habitat for wild animals.
- Helps in providing rainfall through transpiration.
What is Van Mahotsav?
This movement was launched in 1950 to make people aware of the importance of planting trees. Every year free saplings are distributed during the monsoon season in the first week of July. These saplings are planted in schools, colleges, alongside of roads and areas affected by soil erosion.
Explain with reference to climate why tropical evergreen forests are evergreen
This region experiences high temperature accompanied with high rainfall. As well as there is high humidity almost 77% throughout the year.
Why are tropical evergreen forests not of great commercial importance?
The trees grow in mixed stands with thick undergrowth and the trees are difficult to cut as the timber is very hard.
How do tropical evergreen forests affect the climate of the region?
Forests help in regulating or moderating the climate. It also helps in providing rainfall through transpiration.
What are the characteristic features of trees in tropical evergreen forests?
- The trees are tall with a height more than 45m. - The trees do not have fixed time to shed their leaves hence appear evergreen throughout the year. - The trees have less economical value as they are difficult to cut as the timber is hard. - The trees are broadleaved that forms a canopy which does not allow the sunlight to reach the ground.
Why do trees in tropical deciduous forests shed their leaves?
Trees shed their leaves together almost for six to eight weeks during spring and early summers to conserve the water during the dry season.
Why are tropical deciduous forests commercially the most exploited?
Trees are found in pure stands, the forest is less dense, and they provide good quality timber.
Why does vegetation change with altitude in mountain forests?
Vegetation in mountainous regions varies according to the elevations since temperature and rainfall also change.
Why are mountain forests absent in the Western Ghats?
Mountain forests are absent in the Western Ghats because the height of these mountains rarely exceeds 1500m.
Why are trees absent above a certain height in mountain forests?
Trees cannot grow beyond the snow line as this region is permanently snow-covered and the frozen sub-soil does not support tree growth.
How are mangrove forests ecologically important?
- The tangled roots also provide excellent conditions for nesting and breeding of a variety of marine fishes, birds, and aquatic animals. - The trees along the coast act as a buffer to reduce the impact of sea waves or tsunamis, hence preventing soil erosion.
Why do mangrove forests need breathing roots?
Mangrove forests need breathing roots because they have specialized breathing roots known as Pneumatophores that contain small pores which enable the tree to respire during high tide.
Name two important species of trees found in mangrove forests.
Keora, Amur, Sundari, Rhizophora
