L21 island biogeography

L21 island biogeography - BILD 3 July 23, 2010 Woodruff:...

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Unformatted text preview: BILD 3 July 23, 2010 Woodruff: island biogeography 1 LE 52-5 Kangaroos/km 2 > 20 1020 510 15 0.11 < 0.1 Limits of distribution Tasmania DISTRIBUTION AND ABUNDANCE INTRINSIC AND ECOLOGICAL LIMITS TO A SPECIES RANGE AND DISTRIBUTION [see Campbell 52.2] Dispersal limits: physical barriers & time Habitat selection & behavior Biotic factors: competition, predatorprey & other interspecific interactions Abiotic factors: temperature, water, sunlight, wind, rocks & soil. Natural range expansions show the influence of dispersal on distribution SPECIES RANGES & THEIR EVOLUTIONARY DEVELOPMENT ADAPTATION, DISPERSAL & GENE FLOW, HISTORY Central populations vs Peripheral populations Hypothesis: adaptation at species border swamped by gene flow from central pops. Metapopulation models LE 50-7 New areas occupied Year 1996 1989 1974 Spread of great-tailed grackle over 22 years 20-50% OF AREA OCCUPIED BY A PARTICULAR BIOME TODAY WILL NO LONGER BE SUITABLE IMPACT OF CO 2 x 2 (2030-2060) ON THE BIOSPHERE TEMPERATURE: Up 2-4 o C; 3x more in polar regions PRECIPITATION: +10% but declines in some regions California: +/- 20% SNOWLINE: up 100m per degree C. SEA LEVELS: up 0.8 - 3.0 m (3-4 feet is best 50 yr guess) 10 ft is predicted in many models submergence of coast. Loss of wetlands/estuaries STORMS: +50% FIRES: increase Growing season changes Pests, weeds, emergent diseases all increase BILD 3 July 23, 2010 Woodruff: island biogeography 2 EFFECTS OF GLOBAL WARMING ON HUMANS Rise in sea level will submerge coastal wetlands and urban developments, some countries Flooding, beach erosion Salt water will impact aquifers Sacramento/San Joaquin delta: 60% cal H 2 O supply Agriculture: only 3% jobs but >20% economy Pests, weeds, diseases Growing season +20d in Kansas, +30d in Canada...
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This note was uploaded on 07/28/2010 for the course BIOLOGY BILD 3 taught by Professor Davidwoodruff during the Summer '10 term at San Diego.

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L21 island biogeography - BILD 3 July 23, 2010 Woodruff:...

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