Editing Edge effects (section)

==Examples==
When edges divide any [[nature|natural]] ecosystem and the area outside the boundary is a disturbed or unnatural system, the natural ecosystem can be seriously affected for some distance in from the edge. In 1971, Odum wrote, 'The tendency for increased variety and diversity at community junctions is known as the ''edge effect''... It is common knowledge that the density of songbirds is greater on estates, campuses and similar settings...as compared with tracts of uniform forest.'. In a forest where the adjacent land has been cut, creating an open/forest boundary, [[sunlight]] and [[wind]] penetrate to a much greater extent, drying out the interior of the [[forest]] close to the edge and encouraging growth of opportunistic [[species]] there.  Air temperature, [[vapor pressure deficit]], [[water content|soil moisture]], light intensity and levels of [[photosynthetically active radiation]] (PAR) all change at edges.

===Amazon rainforest===
One study estimated that the amount of [[Amazon Basin]] area modified by edge effects exceeded the area that had been cleared.<ref>{{cite journal
  | last = Skole
  | first = D. L.
  |author2=C. Tucker
  | title = Tropical deforestation and habitat loss fragmentation in the Amazon: satellite data from 1978-1988
  | journal = [[Science (journal)|Science]]
  | volume = 260
  | issue =5116
  | pages = 1905–1910
  | year = 1994
  | doi =10.1126/science.260.5116.1905
  | pmid = 17836720  | hdl = 10535/3304
 | s2cid = 12853752
 | hdl-access = free
  }}</ref> "In studies of Amazon forest fragments, micro-climate effects were evident up to 100m (330ft.) into the forest interior."<ref name = "Corlett2011">{{cite book|last=Corlett|first=Richard, T|title=Tropical Rain Forests an Ecological and Biogeographical Comparison|year=2011|publisher=Wiley-Blackwell|location=John Wiley & Sons Ltd, The atrium, Southern Fate, Chichester, West Sussex, PO19 8SQ|isbn=978-1-4443-3254-4|pages=266–267|edition=Second|author2=Richard B. Primack}}</ref> The smaller the fragment, the more susceptible it is to fires spreading from nearby cultivated fields. Forest fires are more common close to edges due to  increased light availability that leads to increased desiccation and increased [[understory]] growth. Increased understory [[biomass]] provides fuel that allows pasture fires to spread into the forests. Increased fire frequency since the 1990s is among the edge effects that are slowly transforming Amazonian forests. The changes in temperature, humidity and light levels promote invasion of non-forest species, including [[invasive species]]. The overall effect of these fragment processes is that all forest fragments tend to lose native [[biodiversity]] depending on fragment size and shape, isolation from other forest areas, and the forest matrix.<ref name = "Corlett2011"/>

===North America===
The amount of [[forest edge]] is orders of magnitude greater now in the [[United States]] than when the [[European ethnic groups|European]]s first began settling [[North America]]. Some species have benefited from this fact, for example, the [[brown-headed cowbird]], which is a [[brood parasite]] that lays its [[egg (biology)|eggs]] in the [[bird nest|nest]]s of [[songbird]]s nesting in forest near the forest boundary.<ref>{{Cite journal |last1=Howell |first1=Christine A. |last2=Dijak |first2=William D. |last3=Thompson |first3=Frank R. |date=2007-02-01 |title=Landscape context and selection for forest edge by breeding Brown-headed Cowbirds |url=https://doi.org/10.1007/s10980-006-9022-1 |journal=Landscape Ecology |language=en |volume=22 |issue=2 |pages=273–284 |doi=10.1007/s10980-006-9022-1 |s2cid=2775157 |issn=1572-9761 |access-date=2023-02-14 |archive-date=2023-07-31 |archive-url=https://web.archive.org/web/20230731180239/https://link.springer.com/article/10.1007/s10980-006-9022-1 |url-status=live }}</ref> Another example of a species benefiting from the proliferation of forest edge is [[Poison ivy (plant)|poison ivy]]. <ref>{{Cite journal|last=Fraver|first=Shawn|date=1994|title=Vegetation Responses along Edge-to-Interior Gradients in the Mixed Hardwood Forests of the Roanoke River Basin, North Carolina|url=https://conbio.onlinelibrary.wiley.com/doi/abs/10.1046/j.1523-1739.1994.08030822.x|journal=Conservation Biology|language=en|volume=8|issue=3|pages=822–832|doi=10.1046/j.1523-1739.1994.08030822.x|issn=1523-1739|access-date=2021-01-27|archive-date=2021-01-31|archive-url=https://web.archive.org/web/20210131222233/https://conbio.onlinelibrary.wiley.com/doi/abs/10.1046/j.1523-1739.1994.08030822.x|url-status=dead}}</ref>

Conversely, [[Dragonfly|Dragonflies]] eat [[mosquito]]es, but have more trouble than mosquitoes surviving around the edges of human habitation.  Thus, trails and hiking areas near human settlements often have more mosquitoes than do deep forest habitats.  [[Grass]]es, [[huckleberry|huckleberries]], [[Ribes sanguineum|flowering currant]]s and [[shade-tolerant and -intolerant species|shade-intolerant]] trees such as the [[Douglas-fir]] all thrive in edge habitats.

In the case of developed lands juxtaposed to wild lands, problems with [[invasive exotic]]s often result. Species such as [[kudzu]], [[Japanese honeysuckle]] and [[multiflora rose]] have damaged natural ecosystems. Beneficially, the open spots and edges provide places for species<!-- which? native or invasive, ruderal/pioneer? --> that thrive where there is more light and vegetation that is close to the ground. Deer and elk benefit particularly{{Citation needed|date=November 2009}} as their principal diet is that of grass and shrubs which are found only on the edges of forested areas.