Climate of Rangelands J Peterson Jim Peaco www

Climate of Rangelands J. Peterson Jim Peaco (www. nps. gov) J. Schmidt (www. nps. gov)

Climate plays primary role o Climate: n n o Biome: n n o Long-term patterns of temperature & precip Weather = short-term variation in temp. , precip. wind, humidity, etc. Largest terrestrial ecosystem that is easily recognizable. Prairies, shrublands, woodlands, forests, etc. Ecosystems: n Community of organisms & abiotic environment

How does climate affect global vegetation patterns? o Affects plant biomass (amount of vegetation) n n o Affects types of plants that will grow: n n o Drives photosynthesis Determines growing periods (frost-free period) 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 o Rangelands evolved where precip was insufficient forests, but too much for barren deserts. These a re RAN GELAN DS Robert Whittaker’s classification of biomes, based on annual precipitation, temperature

Variation in Annual Precipitation Across U. S.

Variation in Precip L. A. Sharp Experimental Area –Malta Idaho Effective precip = when precipitation is usable Min Precip = (1989) 6. 6 inches Max Precip = (1982) 23. 6 inches Average = 14. 9 inches

Geographic Climate Regions t. P ea Gr lai s ntain Sou thw est De Figure by K. Launchbaugh ser ts ns Great Basin Mou ins nean terra Medi Mounta Pacifi c North west

Grassland & Savannas Deserts & Semideserts Mediterranean Deserts & Semideserts

Topographic Effects o Mountains can create Orographic Barriers with Rain Shadows on the leeward side From http: //web. mst. edu/~rogersda/umrcourses/ge 301/

Hadley Cell Effect Atmospheric circulation patterns between circulation between the equator and 30 latitude. http: //people. eku. edu/davisb/Africa/Hadleycell. jpg

Hadley Cell Effect Creates 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 o Lands around large bodies of water tend to have climates with: n n o Mild temperatures Abundant precipitation (moist or mesic) Centers of continents are often: n n Extreme temperature variation (summer to winter) Dry

Continental Patterns http: //earthobservatory. nasa. gov/Features/Blue. Marble/Images/land_shallow_topo_2048. jpg Watch Global Circulation video at: www. youtube. com/watch? v=qh 011 e. AYj. AA

Rangelands of the World

Summary of Climate o o Patterns of precip. & temp drive patterns of vegetation. Geographic effect o o Altitude and latitude are important n o Orographic barriers & rain shadows Hadley cells Continental effects