Climate of Rangelands

J. Schmidt (www.nps.gov)J. Peterson Jim Peaco (www.nps.gov)

Climate plays primary role Climate:

Long-term patterns of temperature & precip

Weather = short-term variation in temp., precip. wind, humidity, etc.

Biome: Largest terrestrial ecosystem that is

easily recognizable. Prairies, shrublands, woodlands, forests,

etc. Ecosystems:

Community of organisms & abiotic environment

How does climate affect global vegetation patterns? Affects plant biomass (amount of

vegetation) Drives photosynthesis Determines growing periods (frost-free

period) Affects types of plants that will grow:

Trees need more water than shrubs, forbs & grasses.

Some plants like it hot & some like it cold. Depends on plant physiology.

Influences soils texture & structure.

Climate Affects Vegetation Rangelands

evolved where precip was insufficient for forests, but too much for barren deserts. Robert Whittaker’s classification of biomes, based on annual precipitation, temperature

These are RANGELANDS

Variation in Annual Precipitation Across U.S.

Variation in PrecipL.A. Sharp Experimental Area –Malta Idaho

Min Precip = (1989) 6.6 inches Max Precip = (1982) 23.6 inches Average = 14.9 inches

Effective precip = when precipitation is usable

Geographic Climate Regions

Mediterranean

Pacific Northwest

Great Basin

Southwest Deserts

Great Plains

Mountains

Mountains

Figure by K. Launchbaugh

Grassland &

Savannas

Mediterranean

Deserts & Semidese

rts

Deserts & Semidese

rts

Topographic Effects Mountains can create Orographic

Barriers with Rain Shadows on the leeward side

From http://web.mst.edu/~rogersda/umrcourses/ge301/

Hadley Cell EffectAtmospheric circulation patterns between circulation between the equator and 30 latitude.

http://people.eku.edu/davisb/Africa/Hadleycell.jpg

Hadley Cell EffectCreates bands of moist or dry zones around the globe.

http://serc.carleton.edu/images/eslabs/weather/hadley_cells_semi_permanent.jpg

Equator 30

http://www.whymap.org/

Continental Land Effects Lands around large bodies of water

tend to have climates with: Mild temperatures Abundant precipitation (moist or mesic)

Centers of continents are often: Extreme temperature variation

(summer to winter) Dry

Continental Patterns

Watch Global Circulation video at: www.youtube.com/watch?v=qh011eAYjAA

http://earthobservatory.nasa.gov/Features/BlueMarble/Images/land_shallow_topo_2048.jpg

Rangelands of the World

Summary of Climate Patterns of precip. & temp drive

patterns of vegetation. Geographic effect

Orographic barriers & rain shadows Altitude and latitude are important

Hadley cells Continental effects