Question

Write only the name of classification of the plants on the basis of temperature.

Answer 1

Ecological temperature is very much essential for the physiological functioning of the plant. The world’s vegetation has been divided into four types depending on the temperature condition- Megatherms, mesotherms, microtherms, hekistotherms.

Complete Answer:
The main source of temperature is the sun. The temperature of a place varies due to altitude, air humidity, change in seasons, day and night, and distance from the water bodies.

The plants are classified into four types depending on the temperature variations-
1. Megatherms- The plants which grow in tropical areas are called megatherms. They require high temperature throughout the day for proper growth.
Example- Tropical rainforest.
2. Mesotherms- These plants require high temperature in the summer season and low temperature in the winter season.
Example Sub- tropical regions.
3. Microtherms- The plants which mostly grow in the alpine region are called microtherms. They require low temperatures for growth.
Example alpine region.
4. Hekisotherms- These plants grow in very cold regions. Example Mixed coniferous forests.
The plants exhibit various mechanisms which help in maintenance of temperature balance. For example- enhanced evaporation can aid in cooling the plants in the hot region and maximising the sunlight absorption can help in raising the temperature in cold areas.

Note: The very high and very low temperature has an adverse effect on the metabolism in the plants. In low temperatures, water gets frozen into ice crystals in the intercellular spaces. It causes cold injuries. Whereas at high temperature, various vital bio-physiological processes like respiration, transpiration, protein metabolism get affected. This can cause death of the plant. It is referred to as heat injury.