01858nas a2200193   4500008004100000245009800041210006900139300000900208490000800217520128200225653001501507653001801522653001801540653000801558653001501566653001301581100001701594856005301611       2004                        eng d00aFocus on deforestation: zooming in on hot spots in highly fragmented ecosystems in Costa Rica0 aFocus on deforestation zooming in on hot spots in highly fragmen  a3-150 v1023 aMost estimates of deforestation are derived for areas that are not intrinsically related to the causes of deforestation, making it hard to link such estimates with strategies for improved land management. In this paper a method is presented to identify local areas of high rates of deforestation within larger areas, using remote sensing and geographic information systems (GIS). These deforestation hot spots are identified using a local analysis approach, considering for every location only land cover changes taking place in the immediate vicinity, and they thus reflect local deforestation. This method has potential application in improved land policy development, land management and it could supplement land use change modeling at the landscape level. Specifically, the method could be used to undertake a risk assessment of the effectiveness of ecological corridors. The method was applied to the province of Limón in Costa Rica, where commercial agriculture has caused large scale deforesta- tion. The deforestation hot spots in the period 1986–1997 that were identified with this method represent a large proportion of the total deforestation having taken place in the province, and for each of the hot spots specific drivers of deforestation could be identified.10aCosta Rica10adeforestation10afragmentation10agis10aland cover10aland use1 aVan Laake, P  uhttps://insectafgseag.myspecies.info/fr/node/50902944nas a2200313   4500008004100000245008000041210006900121300001200190490000700202520200400209653001802213653001702231653001602248653001802264653002402282653002202306653002502328100001702353700002102370700002302391700001702414700002902431700002302460700002802483700001702511700002602528700002302554856005302577       2005                        eng d00aEdge Influence on Forest Structure and Composition in Fragmented Landscapes0 aEdge Influence on Forest Structure and Composition in Fragmented  a768-7820 v193 aAlthough forest edges have been studied extensively as an important consequence of fragmenta- tion, a unifying theory of edge influence has yet to be developed. Our objective was to take steps toward the development of such a theory by (1) synthesizing the current knowledge of patterns of forest structure and composition at anthropogenically created forest edges, (2) developing hypotheses about the magnitude and distance of edge influence that consider the ecological processes influencing these patterns, and (3) identifying needs for future research. We compiled data from 44 published studies on edge influence on forest structure and composition in boreal, temperate, and tropical forests. Abiotic and biotic gradients near created forest edges generate a set of primary responses to edge creation. Indirect effects from these primary responses and the original edge gradient perpetuate edge influence, leading to secondary responses. Further changes in veg- etation affect the edge environment, resulting in ongoing edge dynamics. We suggest that the magnitude and distance of edge influence are a direct function of the contrast in structure and composition between adjacent communities on either side of the edge. Local factors such as climate, edge characteristics, stand attributes, and biotic factors affect patch contrast. Regional factors define the context within which to assess the ecological significance of edge influence (the degree to which the edge habitat differs from interior forest habitat). Our hypotheses will help predict edge influence on structure and composition in forested ecosystems, an important consideration for conservation. For future research on forest edges in fragmented landscapes,we encourage the testing of our hypotheses, the use of standardized methodology, complete descriptions of study sites, studies on other types of edges, synthesis of edge influence on different components of the ecosystem, and investigations of edges in a landscape context10acreated edges10aedge effects10aforest edge10afragmentation10alandscape processes10aplant communities10avegetation structure1 aHarper, K.A.1 aMacdonald, Ellen1 aBurton, Philip, J.1 aChen, Jiquan1 aBrosofske, Kimberley, D.1 aSaunders, Sari, C.1 aEuskirchen, Eugenie, S.1 aRoberts, Dar1 aJaiteh, Malanding, S.1 aEsseen, Per-Anders  uhttps://insectafgseag.myspecies.info/fr/node/333