Surveying in Architecture (ARCG112)

Quiz Lecture 9 - Introduction to Vegetation

Dr. Joao Pinelo Silva, Assistant Professor

Question 1

Why is it important to distinguish deciduous trees from evergreen trees?

  1. Because of their color
  2. Because one type drops their leaves seasonally, which affects its role as visual or wind barrier, and the capacity to 'absorb' noise
  3. Because deciduous trees grow taller than evergreen ones
  4. Because the roots of evergreen trees run deeper into the soil
  • What is the difference between deciduous and evergreen trees?
  • What qualities of trees are affected by the loss of leaves?

Since deciduous trees lose their leaves during the winter, during this period their capacity to act as noise dampeners, wind deflectors, and shading devices is compromised.
Nonetheless, the seasonal variation of the performance of trees might be appropriate in some circumstances. For example, deciduous trees are suitable to shade areas or buildings which need shading during the summer, but not during the winter.

Question 2

How many rows of trees are necessary to create an efficient wind barrier?

  1. One row of evergreen or three rows of deciduous
  2. Three rows of evergreen or six rows of deciduous
  3. Six rows of evergreen or three rows of deciduous
  4. Three rows of evergreen or three rows of deciduous
  • Changes on the performance of the tree as wind barrier are related to its density
  • What trees are denser throughout the year? Deciduous or evergreen?

The density of evergreen trees does not change noticeably throughout the year, as they keep their leaves. Deciduous trees, on the other hand, are much less dense during the winter when they have no leaves. Therefore, to create an effective (non-seasonal) wind barrier with trees, studies show that at least three rows of evergreen trees or six rows of deciduous are necessary.

Question 3

When creating an acoustic barrier with vegetation, what is more efficient?

  1. To place the barrier as close to the source of sound as possible
  2. To place the barrier as far to the source of sound as possible
  3. The placement of the barrier does not matter as long as it is put between the source of sound and the user
  4. Vegetation has no influence on the propagation of sound
  • It is more efficient and easier to curb the propagation of sound close to a source because there one can take directionality into account, and avoid its spread in the first place.

Studies show that acoustic barriers are more efficient when placed closer to the source of sound as it prevents the sound from propagating.