In this week’s edition of Earth Matters, we present Dr Tom Swetnam at The 9th annual Gila River Festival and his presentation of Wildfire and Climate Changes in the Southwest: Past, Present and Future. Dr Swetnam is Regents’ Professor and director of the laboratory of Tree-Ring Research at the University of AZ.
He discusses how multi-year droughts and extensive forest fires have occurred repeatedly during past centuries, but recent events are extraordinary in several ways. Wildfire problems in the western U.S. arise from the combined effects of a century of human-land uses, rising temperatures, reduced rainfall and snowpacks, invasive plants, and people building homes within highly burnable landscapes. Impacts of recent extreme events include reduced river flows, high severity wildfires that convert forests to grasslands and shrublands, soil erosion and degraded watersheds. Historical documents and tree-ring data from the Southwestern U.S., including from the upper Gila watershed, reveal the details of the causes and consequences of these changes. Despite a gloomy outlook regarding future climate changes, we still have opportunities to learn and apply lessons from both the distant past and from recent outcomes of successful and unsuccessful forest and watershed restoration strategies.
Dr. Swetnam studies changes in climate and forest disturbances using dendrochronology, the analysis of annual tree rings. He has worked extensively on wildfire history and ecology in pine and giant sequoia forests of the Western US, Mexico and South America. He is currently studying fire, climate and carbon dynamics in central Siberia.
Visit gilaconservation.org (http://gilaconservation NULL.org) for more information on how you can become involved in the efforts to Save The Gila.
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Earth Matters / Tom Swetnam at the Gila River Festival