Temperature

Definition

Temperature is a measure of the average kinetic energy of the particles in a substance, influencing physical processes like evaporation and transpiration. It plays a crucial role in determining the rate at which water evaporates from surfaces and how plants lose water through transpiration, affecting overall evapotranspiration rates in an ecosystem. Variations in temperature can significantly impact these processes, as higher temperatures typically lead to increased evaporation and transpiration rates.

5 Must Know Facts For Your Next Test

1. Temperature directly affects the saturation vapor pressure, which determines how much moisture air can hold; warmer air can hold more moisture.
2. At higher temperatures, the rate of evaporation increases due to higher kinetic energy in water molecules, leading to faster water loss from surfaces.
3. Transpiration rates can also increase with temperature, as plants open their stomata to take in carbon dioxide for photosynthesis, allowing more water vapor to escape.
4. Temperature influences plant physiology; certain species may have optimal temperature ranges for transpiration, impacting their growth and survival.
5. During periods of extreme temperature changes, both evaporation and transpiration can be significantly altered, affecting water availability in ecosystems.

Review Questions

• How does temperature influence the rates of evaporation and transpiration in an ecosystem?
  • Temperature has a direct impact on both evaporation and transpiration rates. Higher temperatures increase the kinetic energy of water molecules, leading to faster evaporation from surfaces like soil and water bodies. Similarly, elevated temperatures cause plants to transpire more by opening their stomata wider to facilitate photosynthesis. This results in a higher rate of water loss from both the environment and plants, ultimately affecting overall evapotranspiration.
• Discuss the relationship between temperature and humidity in shaping evapotranspiration processes.
  • Temperature and humidity are interconnected factors that influence evapotranspiration. Higher temperatures increase the capacity of air to hold moisture, thereby affecting the saturation vapor pressure. If humidity levels are low, even slight increases in temperature can lead to significant evaporation rates. Conversely, high humidity can limit evaporation despite higher temperatures because the air is already saturated with moisture. Understanding this relationship is crucial for accurately estimating evapotranspiration in various environments.
• Evaluate how variations in temperature might affect plant species distribution based on their transpiration needs.
  • Variations in temperature can significantly influence plant species distribution by affecting their transpiration needs and capacities. Species adapted to warmer climates may thrive where higher temperatures lead to increased transpiration, facilitating nutrient uptake and growth. However, if temperatures exceed a certain threshold, it may stress these plants, reducing their ability to retain water and survive. Conversely, cooler temperatures may favor species that require lower transpiration rates for efficient water use. Thus, changes in temperature can alter ecological balances and shift plant distributions over time.

Related terms

Evapotranspiration:

The sum of evaporation from the land surface plus transpiration from plants, representing the total water loss from a specific area.

Humidity: The amount of moisture present in the air, which interacts with temperature to influence evaporation rates.

Photosynthesis: The process by which green plants convert light energy into chemical energy, affecting transpiration rates based on temperature conditions.