Climate Change in the Champlain Basin - The Nature Conservancy

More documents

Recommendations

Info

Climate Change in the Champlain BasinII. IntroductionDespite the pervasiveness, importance andlong-lasting nature of modern climate change,most natural resource management plans forthe Champlain Basin do not yet take full account of it.Many of these blueprints were developed before therewas widespread scientific consensus that human-drivenclimatic changes will present serious challenges to localecosystems and communities for the foreseeable future.However, climate change is already having both subtleand readily visible effects on the basin, and more impactsare likely to come in the decades ahead. Anticipatingthese impacts and acting far enough in advance ofthem to mitigate or adapt to them effectively will requiredeliberate, well-informed and proactive management.The goal of this study is to assess the patterns and ecologicalconsequences of recent and future climate change in theChamplain Basin and to help stimulate research and managementpractices that can most effectively support diversespecies assemblages and habitats in a warming future.Physical settingLake Champlain is 120 miles (193 km) long from north tosouth, and up to 12 miles (19 km) wide (interrupted bya breakwater; the greatest open-water width is 8 miles),with a surface area of 435 square miles (1127 sq. km). Itsmaximum depth is 400 feet (122 m) and average depthis 64 feet (19.5 m) [LCBP, 2004; J.E. Marsden, personalcommunication]. Lake Champlain drains to the north via theRichelieu River into the St. Lawrence River; the ChamblyCanal, opened in 1843, bypasses rapids on the Richelieu toallow navigation. The lake has also been connected since1823 to the Hudson River via the Champlain Canal.come primarily (95%) from nonpoint sources, with 46% ofthat from developed land and a little more than a third fromagricultural land (LCBP, 2008; Smeltzer et al., 2009). Thewatershed:lake area ratio is 18:1, and 78% of the basin iscomposed of natural cover, which includes forests, wetlandsand open water.As shown in a later section of this report, inter-annual fluctuationsin lake levels are strongly influenced by changes inregional precipitation, which today averages more than 40–45inches (100–115 cm) per year in the mountains and 30–35inches (75–90 cm) at low elevations. Lake levels typicallyvary on the order of 3–6 feet (ca. 1–2 m) over the course ofa year, with a mean elevation of 95.5 feet (ca. 29 m) abovesea level. Observational records from Burlington, VT, showseasonal maximum levels occurring in April–May and minimumlevels occurring in September–October (NOAA, 2006).Precipitation tends to be most abundant in summer and autumn,so the April–May lake level highs reflect snowmelt andrunoff from frozen or water-saturated soils more than directdeposition in spring, and the autumn lows may largely reflectreduced soil moisture and greater evaporative and transpirationlosses during the warmer months. The historical range oflake levels spans a record high of 101.9 feet above mean sealevel, measured in April 1993, and a low of 92.6 feet, measuredin December 1908 (USGS, 2006).Map 1. The Lake Champlain watershed encompasses8,234 square miles: 56% is located in Vermont, 37%in New York and 7% in Quebec. Including forests, wetlandsand open water, 78% of the watershed is naturalcover. Agricultural land accounts for 16% of the watershed.Six percent is developed land.Data Source: Land Use / Land Cover for the Lake ChamplainBasin, circa 2001, University of Vermont, Spatial Analysis Lab.Map by D. Farrell, The Nature Conservancy, Vermont ChapterLake Champlain’s multi-state and bi-national watershedencompasses 8,234 square miles (21,326 sq. km), 56% ofwhich lies in Vermont, 37% in New York and 7% in Quebec(Map 1). A little more than a half million people livewithin its boundaries. Dozens of rivers and streams, in eightmajor drainages, flow into Lake Champlain, carrying 90%of the water that enters the lake (LCBP, 2008). Excessivephosphorus loads causing “cultural eutrophication” (undesirablegrowth of aquatic plants and/or phytoplankton)4
What natural resource managers can expect and doLake ChamplainLake Champlain Basin...............................................Land Cover and Land UseLand Cover Classesn Urbann AgricultureChamplain Canaln Brushn Forestn Watern Wetlandn Barrenn Urban-Open5
Page 2 and 3: Climate Change in the Champlain Bas
Page 4: Climate Change in the Champlain Bas
Page 9 and 10: What natural resource managers can

Climate Change in the Champlain Basin - The Nature Conservancy

Create successful ePaper yourself

Delete template?

Save as template?