Tree
From Envirowiki
A tree is a woody plant over a certain height. Trees form the basis of forests, but also exist in wetlands, bayous, savanahs and to a lesser extent, deserts.
Trees act as air purifying mechanisms, as well as temperature stabilisers (they can reduce the urban heat island effect by 6°C[1][2][3]).
Most trees reproduce via seeds, although some, such as beech trees, can spread via suckers - effectively cloning themselves.
Trees provide timber for buildings and furniture, and since the forests they grow in replenish relatively quickly (compared to other resources, such as fossil fuels), can continually be harvested as a sustainable level. Unfortunately, this isn't the case for most harvesting, especially old growth logging.
Some trees also provide food, usually in the fruit or seeds. Fruit is often a low energy-input way of growing food, since a tree lives for years, and fruits many times over it's lifetime - and you don't have to kill the tree to eat the fruit, unlike root vegetables or meat, or even cereals or leafy vegetables.
[edit] References
- ↑ was quoted on the chicago city greenroofs page, now unavailable
- ↑ "Trees and Vegetation". Retrieved on 2008-06-23.
- ↑ Wong, Nyuk Hien; Chen Yu (2005-09). "Study of green areas and urban heat island in a tropical city". Habitat International 29 (3): 547-558. DOI:10.1016/j.habitatint.2004.04.008. Retrieved on 2008-06-23.
