An edge effect is the effect of the juxtaposition of contrasting environments on an ecosystem. This term is commonly used in conjunction with the boundary between natural habitats, especially forests, and disturbed or developed land. Edge effects are especially pronounced in small habitat fragments where they may extend throughout the patch. Juxtaposition (noun) is an act or instance of placing two things close together or side by side. ... In ecology, an ecosystem is a combination of all the living and non-living elements of an area. ... Habitat (from the Latin for it inhabits) is the place where a particular species lives and grows. ... Habitat fragmentation is a process of environmental change important in evolution and conservation biology. ...

When an edge is created to any natural ecosystem, and the area outside the boundary is a disturbed or unnatural system, the natural ecosystem is seriously affected for some distance in from the edge. In the case of a forest where the adjacent land has been cut, creating an openland/forest boundary, sunlight and wind penetrate to a much greater extent, drying out the interior of the forest close to the edge and encouraging rampant growth of opportunistic species at the edge. Air temperature, vapour pressure deficit, soil moisture, light intensity and levels of photosynthetically active radiation (PAR) all change at edges. Natural is defined as of or relating to nature; this applies to both definitions of nature: essence (ones true nature) and the untouched world (force of nature). Natural is often used meaning good, healthy, or belonging to human nature. This use can be questioned, as many freely growing plants... Prism splitting light Sunlight in the broad sense is the total spectrum of electromagnetic radiation given off by the Sun. ... Wind is the roughly horizontal movement of air (as opposed to an air current) caused by uneven heating of the Earths surface. ... A forest is an area with a high density of trees (or, historically, a wooded function as carbon dioxide sinks, animal habitats, hydrologic flow modulators, and soil conservers, constituting one of the most important aspects of the Earths biosphere. ... In biology, a species is the basic unit of biodiversity. ... PAR is the range of light, 400-700nm that can be photosynthesized by plants. ...

In a 1994 paper Skole and Tucker estimated that the amount of Amazonian area modified by edge effects exceeded the area that had been cleared. Forest fires are more common close to edges as a consequence of increased desiccation at edges and increased understory growth present due to increased light availablity. Increased understory biomass provides fuel that allows pasture fires to spread into the forests. Increased fire frequency since the 1990s are among the edge effects which are slowly transforming Amazonian forests. The amount of forest edge is also orders of magnitude greater now in the United States than when the Europeans first began settling North America. Some species have benefitted from this fact, for example the Brown-headed Cowbird, which is a brood parasite that lays its eggs in the nests of songbirds nesting in forest near the forest boundary. Thus, the more edge in relation to the forest interior, the more cowbirds and the fewer songbirds as a result. Another example of a species benefiting from the proliferation of forest edge is the Poison-ivy. 1994 (MCMXCIV) was a common year starting on Saturday of the Gregorian calendar, and was designated like the International Year of the Family and the International Year of the Sport and the Olympic Ideal. // Events January Bill Clinton January 1 : North American Free Trade Agreement (NAFTA) goes into effect. ... The Amazon Basin is the part of South America drained by the Amazon River and its tributaries. ... Understory (or understorey) is the term for the area of a forest which grows in the shade of the overstory or canopy. ... To meet Wikipedias quality standards, this article or section may require cleanup. ... This article is about the continent. ... World map showing North America A satellite composite image of North America. ... Binomial name Molothrus ater Boddaert, 1783 The Brown-headed Cowbird, Molothrus ater, is a small icterid. ... Brood parasite is a term specifically applied to birds or insects that leave their eggs in the nests of other birds or insects to be raised. ... An average Whooping Crane egg is 102 mm long, and weighs 208 grams In some animals, an egg (Latin ovum) is the zygote, resulting from fertilization of the ovum. ... A basket style nest A nest is place of refuge built to hold an animals eggs and/or provide a place to raise their offspring. ... A songbird is a bird belonging to the suborder Oscines of Passeriformes (ca. ... Binomial name Toxicodendron radicans (L.) Kuntze Poisonivy (Toxicodendron radicans or Rhus toxicodendron), in the family Anacardiaceae, is a woody vine that is well-known for its ability to produce urushiol, a skin irritant which for most people will cause an agonizing, itching rash. ...

In the case of developed lands juxtaposed to wild lands, problems with invasive exotics often result. Species such as Kudzu, Japanese Honeysuckle, and Multiflora Rose have done terrible damage to natural ecosystems. Purple flowers of the highly invasive Pattersons Curse infest the Warrumbungle National Park in New South Wales, Australia. ... Binomial name Pueraria lobata (Willd. ... Binomial name Lonicera japonica Thunb. ... Species Rosa multiflora Thunb. ...

See also

• Habitat fragmentation
• Landscape ecology

Habitat fragmentation is a process of environmental change important in evolution and conservation biology. ... Landscape ecology is a subdiscipline of ecology and geography that is the study of spatial variation in interested in the of elements in the landscape (such as fields, hedgerows, woodlots, rivers or towns) and how their distribution affects the distribution and flow of energy and individuals in the environment (which...

References

• Skole, D.L. and C. Tucker. 1994. Tropical deforestation and habitat loss fragmentation in the Amazon: satellite data from 1978-1988 (Science) 260:1905-1910