PARENT SESSION
Contributed Oral Session 49: Climate and Vegetation Dynamics
Tuesday, August 9, 8:00 AM - 11:30 AM, Meeting Room 520 C, Level 5, Palais des congrès de Montréal
Climate change vegetation shifts across global ecoregions.
Gonzalez, Patrick*,1, Neilson, Ronald2, Drapek, Raymond2, 1 The Nature Conservancy, Arlington, VA, USA2 USDA Forest Service, Corvallis, OR, USA
ABSTRACT- Spatial analyses of global vegetation identify the ecoregions where climate change could cause the most extensive shifts in terrestrial vegetation. Because climate change alters the spatial and temporal patterns of temperature and precipitation, climate change will cause geographical shifts in the ranges of individual species and vegetation zones. Climate change has already combined with other factors to shift vegetation zones in West Africa, the Southwestern United States, and Spain. Previous analyses used the MAPSS global vegetation equilibrium model to represent potential current vegetation distributions based on 1961-1990 climatology and to model potential future vegetation distributions based on the HADCM2SUL general circulation model of a doubling of 1990 atmospheric CO2 by 2100 AD. The authors have re-examined those results using the ecoregion as the unit of analysis. The authors re-projected the MAPSS current and future global vegetation distributions to Lambert Azimuthal Equal Area projection for each continent at 50 km resolution and classified vegetation into one of nine biomes: arid land, boreal forest and taiga, grassland, savanna and woodlands, shrub steppe, temperate evergreen forest, temperate mixed forest, tropical broadleaf, tundra. For the 567 of 867 WWF ecoregions of area ≥ 25 000 km2, the authors calculated the fraction of ecoregion area where the biome would change. Results indicate potential vegetation changes on 34% of global non-ice areas in the period 1990-2100 AD. Changes vary from an average of 24% of non-ice area in Africa to 46% in Europe. Thirty-four ecoregions representing 4% of global terrestrial area showed a 1990-2100 potential vegetation change ≥ 0.75. The five ecoregions projected to experience the highest fractional change were: Flint Hills tall grasslands (North America), Western Siberian hemiboreal forests (Asia), Yukon Interior dry forests (North America), Carnarvon xeric shrublands (Australia), Altai alpine meadow and tundra (Asia).
Key words: climate change, vegetation shifts, ecoregions