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Projected distributions of novel and disappering climates by 2100 AD. Williamsm J.W., Jackson S.T., Kutzbach J.E., 2007, PNAS. Introduction. “Climate is primary control of distribution of species and ecosystem processes.” Analysis of A2 and B1 scenario;
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Projected distributions of novel and disappering climates by 2100 AD Williamsm J.W., Jackson S.T., Kutzbach J.E., 2007, PNAS
Introduction “Climate is primary control of distribution of species and ecosystem processes.” Analysis of A2 and B1 scenario; GOAL: identification of region that will experience: • High magnitude of local climate change • Novel climates • Disappearance of extant climates Introduction – Methods – Results - Discussion
Niche Theory Disappearing climate:extant climate disappears. Novel climate:a climate not yet present on earth Climatic Shift:locally changed, but still existing on earth. Introduction – Methods – Results - Discussion
Niche Theory Species 1-3: several ecological responses Community sp.1 & sp.3 disappears Community sp. 1 & sp. 2 forming Species 4: Extinction Introduction – Methods – Results - Discussion
Methods and Results • Simulation of mean June-Aug and Dec-Feb air temperature and precipitation using IPCC A2 and B1 emission scenarios for the end-20th- and end-21st-century. • Interpolate simulations to a 2.8° by 2.8°grid. • Calculation of Standard Euclidean Distance (SED) for the degree of dissimilarities between 20th and 21st century climate in each grid point. Introduction – Methods – Results - Discussion
Methods • Local change: High SED indicates large local climate change and integrated changes in temperature and precipitation • Novel climates: Climatic distance (SED) between the end 21st century simulations for each grid point and its closest analog from the global pool of 20st century climates • Disappearing climates: Climatic distance (SED) between the 20th century realization for each grid point and its closest 21st century climatic analog from the global pool 21st-century 20th-century Introduction – Methods – Results - Discussion
Local climate change • Large changes everywhere in the A2 scenario • Larges changes in tropical and subtropical regions Introduction – Methods– Results - Discussion
Novel future climates A2 B1 • Clustering in tropical and subtropical regions scarcity in higher latitudes • Highest dissimilarities over the Amazon and Indonesian Rainforest Projected poleward shift of thermal zones is a key determinant. Introduction – Methods– Results - Discussion
Disappearance of extant climates A2 B1 • Concentration in tropical mountains and poleward side of continents Introduction – Methods– Results - Discussion
Consideration of dispersal limitation: pool of potential analogs is restricted to grid points within 500 km of each target grid point Increased risk for species to experience the loss of extant or the occurrence of novel climate Introduction – Methods– Results - Discussion
Risk of change in relation to global mean annual warming. • Risk of novel and disappearing climates is linear to the magnitude of mean global warming No obvious threshold for “dangerous” climate change Introduction – Methods– Results - Discussion
Biodiversity Hotspots http://www.nature.com/scitable/nated/content/5895/10.1038_403853a0-f1_large_2.jpg Introduction – Methods– Results - Discussion
Biodiversity Hotspots Areas of disappearing climates closely overly hotspots Disappearing Climates B1 Introduction – Methods– Results - Discussion
Niche theory http://ecuador.indymedia.org/images/2007/10/21985.jpg
Discussion A2 B1 Models predict: increased risk of fire and loss of forest cover in amazonia. Introduction – Methods– Results - Discussion
Discussion • Tropical species are very sensitive. - temperatures vary little - small climatic range size
Discussion Forecasting species-level response is a challenge: Can they adapt? Can they migrate? What about interspecific differences in response time? Conservation: dynamic networks of connected reserves? Introduction – Methods– Results - Discussion
Take home message “Many current species and associations will be disrupted or disappear entirely.”