Understory (or understorey) is the term for the area of a
forestwhich grows in the shade of the emergent or forest canopy. Plants in the understory consist of a mixture of seedlings and saplings of canopy trees together with understory shrubs and herbs. Young canopy trees often persist as suppressed juveniles for decades while they wait for an opening in the forest overstory which will enable their growth into the canopy. On the other hand, understory shrubs are able to complete their life cycle in the shade of the forest canopy. Also some small trees such as dogwoodand hollyrarely grow tall and are generally understory trees.
Forest understories have lower light intensities. The
wavelengths of light that are available are only a subset of those that are available in full sunlight. Understory plants must therefore be shade tolerant—they must be able to photosynthesize successfully with the limited amount of light that is available. They are often able to use wavelengths not available to canopy trees. In temperate deciduous forests understory seedlings "leaf out" before the canopy trees do. This is important because it allows the understory plants a window in which to photosynthesize without the canopy present. This brief period (usually 1–2 weeks) is often a crucial period which allows the plant to maintain a net positive carbon balanceover the course of the year.
Forest understories also have higher humidity than exposed areas. The forest canopy reduces solar radiation, so the ground does not heat up as rapidly. Consequently, the understory dries out more slowly than does more exposed areas. The greater humidity allows
fungiand other decomposers to flourish. This drives nutrient cycling, and provides favorable microclimates for many animals and plants.
Wikimedia Foundation. 2010.
Look at other dictionaries:
understory — (n.) in reference to forest vegetation, also understorey, 1945, from UNDER (Cf. under) + STORY (Cf. story) … Etymology dictionary
understory — [un′dər stôr΄ē] n. [ UNDER + STORY2] the smaller trees, saplings, and, sometimes, shrubs that grow beneath the large trees in woods or forests … English World dictionary
understory — noun Date: 1902 1. an underlying layer of vegetation; specifically the vegetative layer and especially the trees and shrubs between the forest canopy and the ground cover 2. the plants that form the understory … New Collegiate Dictionary
understory — ˈ ̷ ̷ ̷ ̷ˌ ̷ ̷ ̷ ̷ noun Etymology: under (III) + story 1. : a foliage layer lying beneath and shaded by the main canopy of a forest 2. a. : the plants (as seedlings, shrubs … Useful english dictionary
understory — /un deuhr stawr ee, stohr ee/, n. the shrubs and plants growing beneath the main canopy of a forest. [1900 05; UNDER + STORY2] * * * … Universalium
understory — noun The layer of plants that grow in the shade of the canopy of a forest … Wiktionary
Old-growth forest — Old growth redirects here. For the Dead Meadow album, see Old Growth (album). See also: Ancient woodland Old growth European Beech forest in Biogradska Gora National Park, Montenegro … Wikipedia
Aspen parkland — refers to a transitional biome between prairie and boreal forest stretching from northeastern British Columbia through central and northwestern Alberta, central Saskatchewan to central and southern Manitoba. Aspen parkland consists of groves of… … Wikipedia
Kelp forest — Kelp forests are underwater areas with a high density of kelp. They are recognized as one of the most productive and dynamic ecosystems on Earth.Mann, K.H. 1973. Seaweeds: their productivity and strategy for growth. Science 182: 975 981.] Kelp… … Wikipedia
Ecology of the North Cascades — Main article: North Cascades The North Cascades are high and rugged with varied conifer species. The Ecology of the North Cascades is heavily influenced by the high elevation and rain shadow effects of the mountain range. The North Cascades is a… … Wikipedia