Why Trees / Plants Grows on Cliff (rock Surface)?

WHY TREES / PLANTS GROW ON CLIFF (ROCK SURFACE)?

Figure 1 - This photo was taken 7th March 2015 at Ha Long Bay[pic 1]

in Hanoi during my Discovering Year.

3 Hypotheses (guesses) about its function:

1. Act as shield to protect the cliff from erosion and weathering and also stabilizes the cliff (hold).
2. Provide food and shelter for animal that live on the cliff and nearby area (eg. Monkey).
3. Photosynthesis – provide oxygen to the surrounding area.

Act as shield to protect the cliff from erosion and weathering and also stabilizes the cliff.

• Due to less barrier around the area (just water and cliff), wind speed around the area are blowing at high speed and because of that, small debris or particles are being blown away and some deposited at the cliff surface. With the availability of the supporting factor that enable plant to grow (sunlight, right temperature, fresh water, oxygen, rock decomposition and others) small plants start to grow on the cliff.
• High-speed wind can cause erosion on the surface of the rock due to friction between the rock surface and the debris that the wind brings. This can be seen from the structure of the cliff surface.
• Algae formed around the cliff also one of the reason that enable trees and other plants to grow in the area.
• With the existence of the tree / plants, level of erosion is low because the trees / plant act as a barrier.
• Same goes to the weathering section, plants / trees reduce the percentage of weathering happening for example, leaf from the plant intercept the rain water (precipitation) before the water actually infiltrate into the cliff. In addition, plants also shield the cliff from direct sunlight that may cause physical weathering or exfoliation.
• Root from the plants/ trees help to hold the cliff together and stabilize the structure of the cliff.