Where annual rainfall is greater than ________, there are tropical evergreen forests.
200 cm
Understanding Tropical Evergreen Forests and Rainfall
Tropical evergreen forests are a type of forest found in areas with high rainfall and consistent temperatures throughout the year. These forests are known for their dense vegetation and trees that retain their leaves year-round, giving them an "evergreen" appearance.
Rainfall Requirement for Tropical Evergreen Forests
One of the key factors determining the presence of tropical evergreen forests is the amount of annual rainfall. These forests thrive in regions that receive a significant amount of precipitation.
- The rainfall is typically heavy and well-distributed throughout the year.
- This constant availability of water supports the lush, dense growth characteristic of these forests.
Different forest types are associated with different rainfall levels. Tropical evergreen forests require very high rainfall compared to other types like tropical deciduous forests or thorny bushes.
Based on ecological studies and geographical data, tropical evergreen forests are commonly found in areas where the annual rainfall is significantly high. Specifically, an annual rainfall greater than 200 cm is generally considered the minimum requirement for the formation and sustenance of tropical evergreen forests.
Let's look at the given options in the context of this requirement:
- 150 cm: This level of rainfall is typically associated with tropical deciduous forests, which shed their leaves in the dry season.
- 100 cm: This rainfall level is even lower and supports drier deciduous forests or grasslands.
- 300 cm: This is well above the minimum requirement and certainly supports tropical evergreen forests.
- 200 cm: This is the threshold commonly cited for tropical evergreen forests. Areas receiving rainfall greater than 200 cm per year are suitable for these forests.
Therefore, where annual rainfall is greater than 200 cm, tropical evergreen forests are typically found.
| Forest Type | Approximate Annual Rainfall Requirement |
|---|---|
| Tropical Evergreen Forests | > 200 cm |
| Tropical Deciduous Forests | 100 cm to 200 cm |
| Tropical Thorn Forests and Scrubs | < 70 cm |
Conclusion
The presence of tropical evergreen forests is strongly linked to high annual precipitation. An annual rainfall exceeding 200 cm provides the necessary moisture for the continuous growth of vegetation characteristic of these dense forests.
Revision Table: Tropical Forests & Rainfall
| Forest Type | Key Feature | Rainfall |
|---|---|---|
| Tropical Evergreen | Remain green all year | High (> 200 cm) |
| Tropical Deciduous | Shed leaves in dry season | Moderate (100-200 cm) |
Additional Information: Characteristics of Tropical Evergreen Forests
- Location: Found in areas near the equator.
- Biodiversity: Extremely rich in plant and animal life.
- Vegetation Structure: Multi-layered forest structure with a dense canopy.
- Trees: Trees reach great heights (often over 60 meters).
- Examples: Amazon rainforest, Congo rainforest, Western Ghats of India, parts of Southeast Asia.
Important Questions from Biogeography
In the soil-forming regime, which one of the following occurs in a region where evapotranspiration exceeds precipitation significantly?
Which one of the following is not a soil forming factor ?
Which one of the following is the natural vegetation of South east China?
Consider the following statements regarding soils :
1. Soils having a very high content of sodium and calcium and pH of more than 7.0 are alkaline soils.
2. Black cotton soil had developed on the Deccan basaltic lava under hot and humid conditions.
3. Laterite soils are characterised by a deep weathered layer from which silica has been leached.
Which of the statements given above is/are correct?
The following 6(Six) items consist of two statements, Statement I and Statement II. Examine these two statements carefully and select the correct answer using the code given below.
Statement I: The Laterite soils develop in areas with high temperature and high rainfall.
Statement II: Laterite soils are the result of an intense leaching process.
