Post on 10-Feb-2016
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Life: levels of organization
– organism (individuals): any form of life– population: a group of interacting individuals of
same species– community: populations of different species in given
area– ecosystem: community + non–living environment
(e.g. nutrients)– biome: an ecosystem that covers a large geographic
area where plants of certain types live due to the specific climate in the area
BIOMETemperate deciduous forest
BiomesBiomes• Regions of the earth Regions of the earth
that are similar in that are similar in organism type organism type although the although the particular species particular species differdiffer
• Driven largely by Driven largely by climate – temp., climate – temp., water, seasonalitywater, seasonality
• Other factors – soil, Other factors – soil, topography topography
Fig. 50.10 – Biomes of North America
The Major BiomesThe Major Biomes
• TundraTundra• Taiga – the boreal forestTaiga – the boreal forest• Temperate forest, including deciduous and Temperate forest, including deciduous and
conifersconifers• SavannaSavanna• Rain forest – temperate and tropicalRain forest – temperate and tropical• GrasslandsGrasslands• DesertsDeserts
22.5 °C
5 °C40 °C
Bioclimatic tolerancesBioclimatic tolerancesThe survival, growth, & reproduction of organisms is determined, in part, by maximum & minimum tolerance limits for physical conditions such as temperature (bioclimatic tolerances).
TemperatureTemperature• Temperature is Temperature is
partly determined partly determined by the amount of by the amount of solar radiation solar radiation hitting an areahitting an area
• Depends on Depends on latitude, angle of latitude, angle of incidenceincidence
Fig. 50.11
World biomes
Fig. 50.24
Tropical Rain Forest
• Most diverse biome• Characterized by tall
trees, a dense canopy and vines
• Exploited and endangered - half of this biome has been destroyed for cash crops despite poor soil
• 90-100” rain/year
Desert
• Deserts cover 1/3 of the earth’s surface and are spreading because of overgrazing
• Vegetation includes cacti and thorny bushes
• <10” rain/year
Grassland
• Most has been converted to farmland due to rich soils
• Good for crops and grazing animals
• 10-30” rain/year
Temperate Deciduous Forest
• Most exploited biome• Only about .1% of
original forest remain• This is our biome• 30-80” rain/year
Coniferous Forest (Taiga)
• Logging has stripped many parts of this biome
• Vegetation primarily evergreen trees
• 15-40”rain/year
Taiga Forests & Boreal ClimateTaiga Forests & Boreal Climate
Coniferous forests occur where winter temperatures are low and precipitation is abundant..
Tundra
• Vegetation limited, mostly lichens, moss and grasses
• Not enough precipitation for trees
• “permafrost” frozen soil
• <10”rain/year
Tundra VegetationTundra Vegetation
Extremely short growing seasons keep woody vegetation short and scattered, with ground cover is comprised mostly of mosses and lichens.
October 2006 27
current climate
modeled future climate
possible vegetation shifts under global warming in North America
Vertical Climate ChangeVertical Climate Change
Ascending a mountain brings changes in temperature and precipitation, and so to will bring changes in vegetation types and micro-climates, as illustrated in this sketch that moves from grassland to tundra and icecap across a short distance of 180 km, and up a steep elevation of 4 km.
Species dispersalSpecies may not inhabit Species may not inhabit an area because of an area because of biogeographical biogeographical boundaries.boundaries.
Transplantation Transplantation studies can give us studies can give us information about information about potential ranges.potential ranges.
Fig. 50.6
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Arctic vegetation-climate feedbacks
Chapin et al. 2005
Describe this diagram in words