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Landscape connectivity in ecology is, broadly, "''the degree to which the landscape facilitates or impedes movement among resource patches''".〔Taylor, P.D., Fahrig, L., Henein, K. and Merriam, G. 1993. Connectivity is a vital element of landscape structure. Oikos 68:571–573.〕 Alternatively, connectivity may be a continuous property of the landscape and independent of patches and paths.〔Fischer, J., Lindenmayer, D.B. and I. Fazey. 2004. Appreciating ecological complexity: habitat contours as a conceptual landscape model. Conservation Biology, 18: 1245–1253.〕〔Fischer, J. and D.B. Lindenmayer. 2006. Beyond fragmentation: the continuum model for fauna research and conservation in human-modified landscapes. Oikos, 112: 473–480.〕 Connectivity includes both structural connectivity (the physical arrangements of disturbance and/or patches) and functional connectivity (the movement of individuals across contours of disturbance and/or among patches).〔Brooks, C. P. 2003. A scalar analysis of landscape connectivity. Oikos 102:433-439.〕〔Baguette, M., S. Blanchet, D. Legrand, V. M. Stevens, and C. Turlure. 2013. Individual dispersal, landscape connectivity and ecological networks. Biological Reviews Of The Cambridge Philosophical Society 88:310–326.〕 The degree to which a landscape is connected determines the amount of dispersal there is among patches, which influences gene flow, local adaptation, extinction risk, colonization probability, and the potential for organisms to move as they cope with climate change.〔Hodgson, J.A., C.D. Thomas, B.A. Wintle, and A. Moilanen. 2009. Climate change, connectivity and conservation decision-making: back to basics. Journal of Applied Ecology, 46: 964-969.〕〔McRae, B. H., Hall, S. A., Beier, P., Theobald, D. M. 2012. Where to Restore Ecological Connectivity? Detecting Barriers and Quantifying Restoration Benefits. PLoS ONE 7:e52604.〕 ==Connectivity metrics== Although connectivity is an intuitive concept, there is no single consistently-used metric of connectivity. Theories of connectivity include consideration of both binary representations of connectivity through "corridors" and "linkages" and continuous representations of connectivity, which include the binary condition as a sub-set 〔Fischer, J., Lindenmayer, D.B. and I. Fazey. 2004. Appreciating ecological complexity: habitat contours as a conceptual landscape model. Conservation Biology, 18: 1245–1253.〕〔Fischer, J. and D.B. Lindenmayer. 2006. Beyond fragmentation: the continuum model for fauna research and conservation in human-modified landscapes. Oikos, 112: 473–480.〕 Generally, connectivity metrics fall into three categories:〔Calabrese, J. M., and W. F. Fagan. 2004. A comparison-shopper's guide to connectivity metrics. Frontiers in Ecology and the Environment 2:529-536.〕 # Structural connectivity metrics are based on the physical properties of landscapes, which includes the idea of patches (size, number of patches, average distance to each other) and relative disturbance (human structures such as roads, parcelization, urban/agricultural land-use, human population). # Potential connectivity metrics are based on the landscape structure as well as some basic information about the study organism's dispersal ability such as average dispersal distance, or dispersal kernel. # Actual (also called realized, or functional) connectivity metrics are measured based on the actual movements of individuals along and across contours of connectivity, including among patches (where these exist). This takes into account the actual number of individuals born at different sites, their reproduction rates, and mortality during dispersal.〔Watson, J. R., S. Mitarai, D. A. Siegel, J. E. Caselle, C. Dong, and J. C. McWilliams. 2010. Realized and potential larval connectivity in the Southern California Bight. Marine Ecology Progress Series 401:31-48.〕 Some authors make a further distinction based on the number of individuals that not only disperse between sites, but that also survive to reproduce.〔Pineda, J., J. A. Hare, and S. Sponaungle. 2007. Larval transport and dispersal in the coastal ocean and consequences for population connectivity. Oceanography 20:22-39.〕 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Landscape connectivity」の詳細全文を読む スポンサード リンク
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