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Ocean/Envir 260 Lecture #19: Climate Change and Invasive Species in the Puget Sound Ecosystem 1 Ocean/ENVIR 260 Autumn 2010 Lecture 19 © 2010 University of Washington Climate Change “There are two major drivers of the future environmental quality in this region: the specific effects of global warming combined with the size and scale of the human footprint.” -- Foreword to “Uncertain Future,” report to Puget Sound Action Team from UW Climate Impacts Group 2 Ocean/ENVIR 260 Autumn 2010 Lecture 19 © 2010 University of Washington Climate Change and Invasive Species • Related issues • Warmer climate will: – Introduce new species – Change some existing species to “invasives” – Create disturbances, new vulnerabilities • New species may better suit new conditions The mountain pine beetle (left) is threatening British Columbia forests (brown trees above are dead), where it now can survive most winters 3 Ocean/ENVIR 260 Autumn 2010 Lecture 19 © 2010 University of Washington Invasive Species • No clear definition – Alien: originated elsewhere (can be challenge to know) – Weed: a species we don’t like • Can be native or not – Colonizer: thrives in disturbed habitats • Can be native or not Ocean/ENVIR 260 Autumn 2010 Lecture 19 Zebra mussels encrusting water current measuring device 4 © 2010 University of Washington Alien Species • Brown and Sax: – Generally increase local biodiversity, while decreasing global biodiversity • Common species spread, rare/endemic species are lost • Simberloff: – “Guilty until proven innocent” • Risk from invasives is too great • Sagoff: – Aesthetic, moral, spiritual choice, no scientific basis for preference 5 Ocean/ENVIR 260 Autumn 2010 Lecture 19 © 2010 University of Washington Invasive Species • Humans? – Escaped evolutionary setting – Highly adaptable generalists – Alter their environment dramatically Olduvai Gorge, Tanzania, where fossil of Homo habilis, dated 1.85 to 1.6 million years old, was discovered 6 Ocean/ENVIR 260 Autumn 2010 Lecture 19 © 2010 University of Washington Climate Change • Today’s focus: – What do we know confidently about climate change in the Puget Sound region? • Reduced snow pack • Oceans: higher, more acidic • New ecological communities – How can we adapt? Cover for report excerpted in Course Pack 7 Ocean/ENVIR 260 Autumn 2010 Lecture 19 © 2010 University of Washington “No-Analog” Communities • Species respond differently, unpredictably to climate change – – – – Move? Rapid evolution? Unchanged? Extinction/extirpation? • Result: new ecological communities Pacific Northwest oak communities, like others, are unlikely to stay the same 8 Ocean/ENVIR 260 Autumn 2010 Lecture 19 © 2010 University of Washington Reduced Snow Pack • Warmer temperatures cause: – More precipitation falls as rain – Earlier, more rapid melting • Mid-elevations most affected – Higher: snow pack remains – Lower: no snow pack now • Reduced water supply – Biggest human impact? Measuring snow pack 9 Ocean/ENVIR 260 Autumn 2010 Lecture 19 © 2010 University of Washington River Flows • More flooding – More runoff not stored in snow pack – More rain-on-snow • Causes worst floods • Human impacts • Ecological impacts – Salmon eggs lost – More, larger disturbances Flooded Snoqualmie River Valley, 2006 10 Ocean/ENVIR 260 Autumn 2010 Lecture 19 © 2010 University of Washington River Flows • Change flow regimes – Less snow, earlier melt – “Snow-dominated” become “transitional” – “Transitional” become “rain-dominated” • Ecological impacts – Challenges for outmigrating salmon Projected changes to average flows in Snohomish River—note 2040s and 2080s (Source: UW Climate Impacts Group) 11 Ocean/ENVIR 260 Autumn 2010 Lecture 19 © 2010 University of Washington River flows • Summer flows lower – Intensifies competition with human needs • Higher water temperatures – Higher air temp – Less water to absorb solar input – Cool sources (snow melt) reduced • Results: – More stress, new communities Dry stream bed 12 Ocean/ENVIR 260 Autumn 2010 Lecture 19 © 2010 University of Washington Puget Sound • Strong links to ocean: – Higher sea level • Three feet by 2100? • Worse in South Sound – Increased acidification • From CO2 uptake • Shelled zooplankton, larvae fare worst – Warm-water species enter system – Changes in coastal upwelling? • Affect nutrients, food web 13 Ocean/ENVIR 260 Autumn 2010 Lecture 19 © 2010 University of Washington Puget Sound • Water quality changes – Higher temperatures – Different freshwater inflows • Affects salinity, flushing – More biological productivity in surface waters – Lower DO in deep waters Ocean/ENVIR 260 Autumn 2010 Lecture 19 Hood Canal: even more serious challenges for “dead zones” with low dissolved oxygen 14 © 2010 University of Washington Puget Sound • Habitat changes – Shoreline at risk from rising sea level – Changed salinity further threatens salt marshes • Food web changes – Shoreline and plankton are both key – Unpredictable impacts Salt marsh on Indian Island, near Port Townsend 15 Ocean/ENVIR 260 Autumn 2010 Lecture 19 © 2010 University of Washington Terrestrial Habitats and Species • Species move north, higher elevations • More disturbances – Forest fires – Floods – Winds? • Invasive species • New ecological communities Snoqualmie wildlife corridor, fragmented by I-90 and “checkerboard” land ownership 16 Ocean/ENVIR 260 Autumn 2010 Lecture 19 © 2010 University of Washington Adaptive Strategies • Guiding principles: – Focus on processes, systems, connectedness – Many of best actions to address climate change are already top priorities for ecosystem – Adaptive management • Monitor, learn as go 17 Ocean/ENVIR 260 Autumn 2010 Lecture 19 © 2010 University of Washington Forest management • Ecosystem and carbon benefits: – Longer rotations – Reduce/stop clearcuts • Leave more live trees, snags, downed wood – Maintain forest cover • Less conversion to development – 1B metric tons, next 50-75 years? • Across western WA, OR 18 Ocean/ENVIR 260 Autumn 2010 Lecture 19 © 2010 University of Washington Adaptive Strategies • Multi-benefit actions: – Water conservation • Address reductions in supply • Enhance in-stream uses – Riparian restoration • • • • Habitat benefits Shade, microclimate Reduce flood hazards Increase resilience, connectedness Lake Whatcom, the source of water supply for the City of Bellingham. Many households served by the City have no water meters. 19 Ocean/ENVIR 260 Autumn 2010 Lecture 19 © 2010 University of Washington Adaptive Strategies • Floodplain management – Keep development out – Levees: remove, set back • Reduces flood risks • Improves habitat values • Low-impact development – Reduces stormwater impacts – Recharges groundwater • Cooler, higher summer flows FEMA floodplain map, portion of middle Skagit River; projected flows do not yet include climate change 20 Ocean/ENVIR 260 Autumn 2010 Lecture 19 © 2010 University of Washington Recap: climate change and invasive species • Climate change and increased human footprint are primary drivers of ecological change • In Puget Sound, water supply is biggest known human concern for climate impacts • Major changes coming to marine, freshwater, and terrestrial ecosystems • Many adaptive strategies for climate are top priority actions in their own right 21 Ocean/ENVIR 260 Autumn 2010 Lecture 19 © 2010 University of Washington