EXH2176034578

http'J/_w.nato.edu/ol_nbooW0309051347/htmVR1 .html, copyright 1995, 2000 The National Academy of Sciences, all rights reserved CHARACTERISTICS AND BOUNDARIES Committee on Characterization of Wetlands Water Science and Technology Board Board on Environmenud Studies and Toxicology Commission on Geosciences, Environment, and Resources National Research Council NATIONAL ACADEMY PRESS Washington, D.C. 1995 AR 034578 Exhibit-2176 Wetlands:Characteristicsand Boundaries(1995) http://_vww.nap.eclu/openbooW030gO51347/html/149.html,copyrightlg95, 2000 The NationalAcademy of Sciences,all rightsreserved Especially Controversial Wetlands INTRODUCTION The wetlands and associated landscape features discussed in this chapter have been the subject of pacticular controversy because of their location, their unusual characteristics, or their regulatory status. They include _st wet- lands, riparian ecosystems, isolated and headwater wetlands, especially shallow wetlands, agricultural wedands, nonagricdttLral altered sites, and transitional zones. These areas are the source of many problems related to wetland regulation and delineation; their classification is pazticularly sensitive to changes in do]inca- don procedures. PERMAFROST WETLANDS Permafrost is soil that has a temperature continuously below 320F (0*C) for years or more. This definition distinguishes permafrost from seasonal frost. The distribution of permafrost in the United States is restricted to Alaska and a few high alpine areas in the conterminous states. Except at latitudes and eleva- tions so high that there is no summer thaw, permafrost is overlain by a zone of seasonal thaw called the active layer, which typically is 14-79 in. (25-200 cm) thick. Maximum depths of thaw are found where the climate is warmest and the soils are driest; minimum depths of thaw are found in the eoldost and wettest environments. North of the…

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Call to order – Roll Call – Quorum Established – Land Acknowledgement We would like to acknowledge that our Agency operates in four present-day counties, which are the traditional lands of the Coast Salish people, past and present. This acknowledgement does not take the place of authentic relationships with indigenous communities in our jurisdiction and [...]