L20 Biomes & Climate Flashcards
define weather
atmospheric conditions over short time periods within small geographic areas
define climate
atmosphere conditions over long time periods within large geographic areas
list the influences of earth’s climate
sun, atmosphere, oceans, topography
explain the influence of solar radiation on earth’s climate
- prevents darkness and freezing
- main control is the angle hits earth
- seasonality
- temperature variation leads to species distribution
explain the influence of the atmosphere on earth’s climate
- provides insulation
- maintains moderate temperature
- air currents (prevailing winds)
explain the influence of oceans on earth’s climate
- stores and transports heat and moisture (especially to higher latitudes)
- carries more than air
- cycling of water determines regional climates
explain the influence of topography on earth’s climate
- physical land surface differences affect local climate
- temperature drops with increase in variation
what are biomes
Broad geographic areas with similar climates have similar communities of species
what are the types of biomes, how many are in each type?
terrestrial (10 major) and aquatic (2 minor)
how does climate affect terrestrial biomes
determines vegetation distribution
what is a terrestrial biome
Involve assemblages of similar communities, distinguished by the dominant plant type and vegetation structure
Climate is described by
(1) mean annual _____________
(2) mean annual _____________
precipitation; temperature
what is an aquatic biome
living and non-living entities of water bodies, and are defined by salinity levels
describe freshwater (lakes, rivers) in aquatic biomes
- salt concentration of less than 1%
- linked to terrestrial biomes through which they pass
describe saltwater (oceans, estuaries) in aquatic biomes
- salt concentration ~3%
- cover about 75% of Earth’s surface
- have an enormous impact on the biosphere
what are the other abiotic factors defining aquatic biomes
light penetration, nutrient levels, oxygen
availability and climate
define productivity
rate of generation in biomass for ecosystems (units of mass per unit surface (or volume) per unit time)
define primary productivity
refers to the rate of generation of biomass by photoautotrophs (through photosynthesis)
what can limit primary productivity
light (aquatic) and water (terrestrial) availability
what factor can limit productivity in all ecosystems
nutrient availability
define nutrient
elements and compounds that are required for survival consumed by organisms
define macronutrients
nutrients required in relative large amounts (carbon, nitrogen, phosphorus)
define micronutrients
nutrients needed in smaller amounts
what does Liebig’s Law of the Minimum state
For every population there will be one limiting resource which determines the carrying capacity of the ecosystem
why are the rates of primary productivity high near continents
runoff of nitrogen and phosphorus from the continents supplies abundant nutrients to the ocean
what is the latitudinal diversity gradient
species diversity peaking near the equator and declining towards the poles
what global patterns are defined by biomes
species diversity/distribution, generation of biomass, resource availability, temperature, humidity
