Vegetation and its effect to the temperature in the environment

BuHaynayan 02 |April 2024

30 April 2024 | Grade 8, Science Subject Area

In your Science class and/or any printed or online sources, you might have known that the environment is cooler if there are trees. You might have felt and noticed it if you go to the provinces with lots of trees. In Manila city, the Arroceros Forest Park was recorded to be at 36 °C heat index on 23 April 2024, while the rest of the city has a heat index of 41 °C. This is 5 °C.It is known as the last lung of Manila since it is the only forested area in the city.

How do trees or any vegetation cool down a certain environment?

Carbon dioxide is a greenhouse gas in the atmosphere. It traps in heat released from the ground. Trees would take in the CO₂ and release oxygen through the process of photosynthesis.

But trees do not just give us oxygen and take in carbon dioxide. The area below the tree canopy or tree cover in forest ecosystems is cooler compared to an open area during daytime. These provide shade to organisms below the trees. 

These trees have low albedo or reflectivity of light energy. This allows trees to absorb more heat, cooling the environment. As there is more energy absorbed by trees, they transpire more or give off water vapor to the atmosphere through their leaves and stems. This leads to high humidity and higher chances of rainfall. The opposite happens in pasture vegetation like plots of land with minimal vegetation or plants.

Looking around the Ateneo de Manila Junior High School campus, which area would be the hottest, especially during the afternoon when the sun is at the highest point in the sky? Give one (1) reason to defend your answer.

References:

[1] Chapin, S., Matson, P. A., & Mooney, H. A. (2014). Principles of Terrestrial Ecosystem Ecology. Springer Science, Business Media.

[2] Uson, M. (24 April 2024). Arroceros Forest Park records 5 degrees cooler temperature than Manila's heat index. Philippine Star Life. https://philstarlife.com/news-and-views/712293-arroceros-forest-park-cooler-manila-heat-index 

[3] Smith, R. L., & Smith, T. M. (2015). Elements of Ecology, Global Edition. Pearson Education Canada.

[4] Taiz, L., & Zeiger, E. (2014). Plant Physiology and Development (6th ed). Sinauer Associates Inc., U.S.