Lecture 2 - Ecoregions and Intro to Biomes

habitat

natural environment in which an organism lives

ex: koalas live in coastal islands, tall eucalyptus trees, and low inland woodlands

we really mean macrohabitat

macrohabitat

large-scale enviroment category defined by certain plants and climate conditions

microhabitats

smaller

ex: cooler part of a tree canopy near the trunk - koalas hug to avoid overheating during heat waves

**same as microclimate

3 classification systems to divide world’s biodiveersity into named regions

(1) ecoregions

(2) ecological land units

(3) biomes

ecoregions

created by US EPA

defined based on plants, landforms, soils, climate, etc.

has 4 nested levels to define regions in finer detail - in continental US: 
level I - 15 

level II - 50

level III - 182

level iv - 1000

ecological land units

US geological survery (USGS) and ESRI (geographic mapping company) made this based on 250m grid from satelltie imagery

defined based on:

• climate specifically temp + precip = bioclimate

• landforms

• lithology

• land cover

almost 4000 worldwide, based on unique combos of 4 factors

bioclimate

water and temp conditions

water: fresh vs. salt for aquatic ; annual precipitation and seasonal precipitation extremes for terrestrial habitats

temp: annual temp and seasonal extremes

ex: very cold dry; cold very wet; warm dry; hot moist

landforms

flat/smooth/irregular plains

escarpments (long steep slopes)

low hills

hills

low mountaints / high mountains

surface water (lakes/reservoirs)

lithology

sedimentary rock

unconsolidated sediments

evaporites

metamorphic rock

volcanics

ice and glaciers

water - not considered lithology but important for ELUs

land cover

bare

urban areas

shrubland

grassland

cropland

forest, open

forest, closed

snow and ice

water

biome

large-scale classification of habitat

on land - usually defined along bioclimate axes (temp and precipitation)

in oceans - usually defined along axes of light/depth and distance to land

diff biomes

cold dry = tundra

hot dry = savanna, desert

cold wet = nowhere is both

hot wet = tropical rainforest

**there are a ton of inbetweens