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

BIOME Temperate deciduous forest

Biomes Regions of the earth that are similar in organism type although the particular species differ Regions of the earth that are similar in organism type although the particular species differ Driven largely by climate – temp., water, seasonality Driven largely by climate – temp., water, seasonality Other factors – soil, topography Other factors – soil, topography Fig – Biomes of North America

The Major Biomes Tundra Tundra Taiga – the boreal forest Taiga – the boreal forest Temperate forest, including deciduous and conifers Temperate forest, including deciduous and conifers Savanna Savanna Rain forest – temperate and tropical Rain forest – temperate and tropical Grasslands Grasslands Deserts Deserts

22.5 °C 5 °C 40 °C

Bioclimatic tolerances The survival, growth, & reproduction of organisms is determined, in part, by maximum & minimum tolerance limits for physical conditions such as temperature (bioclimatic tolerances).

Temperature Temperature is partly determined by the amount of solar radiation hitting an area Temperature is partly determined by the amount of solar radiation hitting an area Depends on latitude, angle of incidence Depends on latitude, angle of incidence Fig

World biomes Fig

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 ” 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 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 Vegetation Extremely short growing seasons keep woody vegetation short and scattered, with ground cover is comprised mostly of mosses and lichens.

October

current climate modeled future climate possible vegetation shifts under global warming in North America

Vertical 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 dispersal Species may not inhabit an area because of biogeographical boundaries. Transplantation studies can give us information about potential ranges. Fig. 50.6

12/1/0634 Arctic vegetation-climate feedbacks Chapin et al Describe this diagram in words