As we continue our exploration of the requirements for developing and implementing a sustainable site plan, we now shift our focus to the use of the site's existing vegetation.
This portion of our discussion can be considered as one of the main factors as to why Landscape Architects must take a more prominent role in the development and implementation of sustainable and equitable site plans. So without further adieu, let us set the stage for today's discussion;
...the proposed project ensures that air will be able to flow through the site in an unobstructed manner and that as much existing vegetation is preserved as possible in order to reduce air pollution...
Of the four requirements for a sustainable site plan, we find that in the development and implementation of site plans, far too little importance is placed on the preservation of existing vegetation as well as the introduction of new vegetation.
A closer examination of this requirement reveals that there are a few more reasons for preserving the site's existing vegetation than simply reducing air pollution. Considering the fact that everything is connected to everything else, we discover that a site's existing vegetation contributes to the goals of some of the other factors we have discussed as well as making significant contributions to additional environmental and ecological issues that are not mentioned in the four requirements.
Existing vegetation on a site;
- Helps reduce wind speeds on a site;
- Helps provide mature and effective visual buffers;
- Helps reduce soil erosion caused by wind on a site;
- Helps reduce erosion caused by rainfall on a site;
- Helps clean rainwater falling on a site;
- Helps distribute rainwater to the soil on a site;
- Helps the site's soil remain healthy and functional;
- Helps control the site's temperature;
- Helps create livable, functional, enjoyable and aesthetically pleasing spaces on a site;
- Helps foster a more sustainable ecological community by providing habitats for native animal species;
- Helps protects the overall ecological community from exotic species of plants, animals and diseases.
Phew, that list would make this requirement run about three pages as opposed to the simplified three lines that it now occupies. I would tend to agree with that statement, however what this list demonstrates is how underutilized existing vegetation truly is in the development and implementation of a majority of site plans.
On the other hand, the "simplified" sustainable site plan requirement helps illustrate one of the most underutilized ecological and environmental attributes of plants; the reduction of air pollution.
There are very few cities in this world which utilize trees as a major air pollution abatement device. One cannot dispute the scientific evidence that clearly shows the process in which airborne contaminants are removed from the atmosphere by trees. Everyone who has had an elementary school education should be familiar with the process called photosynthesis.
For those who don't recall the entire process, the only thing you need to concern yourself with is that trees absorb carbon dioxide and other dangerous gases and through photosynthesis, convert those gases into oxygen and release that oxygen back into the atmosphere.
At this point you may be saying to yourself; if preserving the existing vegetation on one site helps reduce air pollution, imagine how clean the air in my community would be if ten, twenty or thirty sites preserved as much existing vegetation as they could!!
Aha!! Remember, everything is connected to everything else!!!
Not only would the air be cleaner, but let us not forget that the soils would be functioning properly; vast areas of paved parking would be much cooler in the summer months from the shade provided; the visual impacts of such crowning architectural achievements as Lowe's, WalMart and any other "big-box" buildings would be greatly reduced; soil erosion resulting from gusting winds would be reduced; rainwater would be cleaner when it finally reached the ground; and our society and culture would be vastly improved through the creation of enjoyable, functional spaces.
Let us not forget who is best equipped to deal with these factors during the development and implementation of sustainable site plans; the Landscape Architect.
Hyper-Capitalists need not worry about the impact of retaining existing vegetation on a site, and here's why. If you plan properly, the site can be planned to avoid having to remove vegetation, redistribute the disturbed soil and then replace or "mitigate" the impact of the removed trees! All of this means less construction costs resulting from informed site planning!!
(Note: many municipalities require that developments either replace existing vegetation that has been removed through either planting new vegetation or contributing a formulated monetary payment to what is generally referred to as a "community beautification fund"; once again offering developers the opportunity to use money to offset their negative environmental impacts!!)
You may be asking yourself; Why don't we try to preserve as much as we can if there are so many positive attributes associated with existing vegetation?
Therein lies the issue; we need to move towards a more sustainable and equitable society and culture. This need goes beyond rewarding the few people who make buildings more efficient through LEEDs certification; beyond those extremists who chain themselves to old-growth trees in the Pacific-Northwest; beyond those who opt for a "green" home.
As a society and culture, we need to realize one thing: everything is connected to everything else.
When we finally accept and embrace this notion, only then will we be able to move towards a more equitable and sustainable society.
Study nature, love nature, stay close to nature. It will never fail you. -Frank Lloyd Wright
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