TAYLOR GRAZING ACT OF 1934. 1. halt deterioration. 2

1
RANGELANDS

• GRASSLANDS, DESERT SHRUBLAND, AND SHRUB WOODLAND
   
• Precipitation 10-30 inches/yr  
• 29 of US is rangeland  

2
TAYLOR GRAZING ACT OF 1934

• 1. halt deterioration
• 2. improve range quality
• 3. stabilize rangeland economy  

3
IMPORTANT WILDLIFE OF THE GRASSLANDS

• Waterfowl (prairie potholes and marshes)
• Large ungulates (deer, elk, pronghorn)
• Smaller mammals and birds

4
(No Transcript)
5
(No Transcript)
6
GRAZING PERMIT CONTROVERSY

• Nearly 5 million cattle and sheep graze on 80 of
  public rangelands annually  
• Permits cost one-fifth that charged by private
  landowners
• Federal subsidy 100 million/yr over the water
  subsidy they get
• In 45 National Parks, 150 National Wildlife
  Refuges, and BLM lands
• http//www.sagebrushsea.org/pdf/factsheet_Grazing_
  Economic_Contributions.pdf

7
GRAZING PERMIT CONTROVERSY, continued

• Current fee doesn't even pay for administration
  of program
• Ecosystem is being damaged by overgrazing and
  miss-management wildlife suffer
• Ranchers benefit, but land belongs to everyone
• The paradox persists. Why?

8
RANGELANDS

• Grasslands
• Desert Shrubland
• Shrub Woodland  
• Tropical - Savanna, campos, llanos
• Temperate - prairie, steppes, pampas, veld
• Arctic - Tundra (mostly wetland too)

9
ECOLOGY OF RANGELANDS  

• Metabolic reserve lower half of grass plant  
• Decreasers - plants favored by grazing animals
  subject to decline when grazed
• Increasers - avoided by grazers abundance
  increases upon grazing
• Invaders - dominate overgrazed areas

10
ECOLOGY, continued

• Overgrazing
• Too many animals for too long
• grasses replaced by woody plants and forbs
• reduces water and nutrients
• reduces litter, exposes soil
• more wind erosion  
• Undergrazing  
• brown leaf and stem left to age (poor food
  quality)
• kills off (chokes) grasses and favors woody
  vegetation
• reduces water and nutrients
• reduced root mass leads to soil erosion

11
MANAGEMENT OF RANGELANDS

• Control amount of grazing
• periods of grazing and rest (deferred rotation)
• continuous grazing
• holistic grazing (6 paddock rotation)  
• Control vegetation
• fire
• herbicides

12
MANAGEMENT OF RANGELANDS, continued 

• Control rodents and predators  
• Rodent control
• Controls don't last (temporary relief
• Ecology gives long-term solution
• Predator control
• controls don't work (temporary relief)
• Ecology gives long-term solution  
• Coyotes eat Rodents!!!

13
COYOTE PROBLEMS 

• The federal government kills coyotes!
• '1080' in collars
• cyanide in "coyote getter"
• costs about 1,000 per coyote!
• ineffective in reducing coyotes
• Other methods to deal with coyotes
• fencing
• guard dogs
• good animal husbandry practices
• Kansas model program only costs 5 of nearby
  states' programs

14
NORTH AMERICAN GRASSLANDS

• tall-grass prairie southeastern edge
• mid-grass (mixed-grass) prairie north and west
  of tallgrass prairie
• short-grass prairie western plains
• Palouse prairie great basin country
• Valley grasslands California's Central Valley
• Desert grasslands Arizona and New Mexico and
  Mexico

15
MORE ECOLOGY

• Most grasslands are subject to great variability
  in temperature, precipitation, grazing, and fire,
  leading to "multiple stable states" rather than
  one climax community type  
• Global warming and grasslands
• may increase decomposition rate and thus increase
  CO2 release (positive feedback)  
• Grassland restoration is in progress  
•  

16
TEMPERATE AND TROPICAL DESERTS  

• Characteristics
• Hot vs. Cool deserts
• temperatures below freezing may be rare or common
• What creates the desert environment?
• Rain shadow - mountains
• Cold upwelling - oceans  

17
SPECIAL FEATURES OF DESERT ECOSYSTEMS

• caliche - cement-like subsoil of calcium
  carbonates  
• desert pavement - hard, protective surface layer
   
• cryptobiotic crust - algae, fungi, and lichens
  form a fine organic tissue
• may take 200 years to reform if disturbed

18
DESERTS, ecological problems

• Desertification- drying of arid ecosystems is a
  global concern
• Other Problems
• Overgrazing by livestock
• Competition with feral ungulates
• ORV's
• compact soil, disrupt surface
• first pass does most of damage  
• Reptiles, mammals, and birds are all reduced in
  number of species and number of individuals per
  species under heavy and very heavy ORV use  
• Even moderate use cuts species to lt11

19
Effects of ORVs on desert fauna(Density per 2
ha plot)
Even moderate use cuts species to lt11
20
Problems, continued

• Invasion of exotic plants  
• Annual grasses of genus Bromus that choke out
  native plants after a rain, die, and carry fire
  (native species evolved w/o fire)  
• Salt cedar - shrub replacing willow and
  cottonwood in riparian areas
• Deep-rooted, high transpiration dries soil
• Carries fire resprouts vigorously after fire,
  outcompeting native species  
• Beaver and deer do not feed on it

21
Problems, continued

• Global warming will increase desertification  
• Desert soils are a source of carbon in the
  atmosphere more desert surface and weaker
  cryptobiotic crusts will add to the greenhouse
  effect!  

22
Management of arid/desert systems

• Need to limit use of ORV's
• California Desert Protection Act
• 1994 - upgraded several deserts to National
  Parks, enlarged areas of protection, and
  designated more "wilderness"