Canyon de Chelly National Monument is a complex of canyons along Chinle Wash in the Navajo Reservation in northeastern Arizona.  Dramatic changes occurred to the canyon during the 20th century.  Tamarisk and Russian olive were introduced to stabilize the channel and banks, and likely invaded by natural processes as well.  The top left photo by Ansel Adams in 1942 shows Canyon de Chelly prior to invasion.  The top right photo shows the canyon in 2006 during the height of the invasion.  And just below the photo shows the canyon after our exotic plant removal project.  During the invasion process the stream channel incised deeply into their sandy beds, and the former floodplains dried up.  The National Park Service was concerned that the dominance of exotic shrubs had changed the canyon complexes by reducing historical view, natural vegetation, triggered erosion, and by lowering the water table reduced forage for Navajo livestock.  We worked with the NPS to design and implement a factorial experiment to test two woody plant removal techniques on a landscape scale.  The ecological portion of this work became the dissertation for Lindsay Reynolds, pictured above.  The geomorphic portion of this work became the dissertation for Kris Yaeger.  A historical air photo analysis was used for the MS thesis of Dan Cadol.  Papers from Lindsay and Dan’s work are attached.

CadolRathburnCooper2011
Reynolds&Cooper.JVS.OnlineMS.2010
Reynolds&Cooper2011PlantEcology
ReynoldsCooperHobbs