- Grades: PreK–K, 1–2, 3–5, 6–8
Any growth of vegetation
that casts shade upon growths beneath it is a form of vegetation canopy.
Such canopies form an integral part of the ecology of the area under consideration
and are studied for the role they play and their effects on the local
biological community as a whole. The most noted canopies
are those of the large rain forests of the world, which may rise to an
average height of about 50 m (165 ft) above the forest floor. These forests
are likely to have secondary and even tertiary canopies formed by more
shade-tolerant trees and smaller growths. Life forms, both animal and
vegetable, that dwell within such canopy layers tend to be well defined
for a given region, and each layer has its characteristic climate (or
microclimate) conditions. Systems of forest canopies play dynamic roles
in the global carbon cycle. Modeling of such processes as photosynthesis,
evapotranspiration, and energy transfer for a region must therefore take
canopy functions into major account. Some scientists estimate that the
Amazonian canopy alone may house half of the world's species, including
fully a third of the species of birds.
Bibliography: Lasky, Kathryn, The Most Beautiful Roof in the World (1997); Lowman, Margaret, and Nadkarni, Nalini, eds., Forest Canopies (1995); Moffett, Mark, The High Frontier: Exploring the Tropical Rainforest Canopy (1993).