Managing Rangelands

rangeland: landscape of grasses and/or scattered trees

- uncultivated & provides forage for large animals

- gradient in precipitation, soil structure, topography

Rangelands

- few inputs (contrast with cropland)

forage: standing plant material (grasses, forbs, shrubs) that is edible

Herbivory:

grazing: consuming grasses & forbs

browsing: consuming leaves/twigs of woody plants

* Manipulate grazing system of large herbivores for plant & animal production

* Maintain healthy rangeland by controlling # grazing livestock

* Rangeland Mgt & Wildlife

* Grazing on Public Lands & Endangered Species

* Sage Grouse – 40 to 80% population declines (overgrazing, invasion of cheat grass)

* Rangeland Mgt & Predators / Wildlife Damage / Predator Control

Rangelands:

1) are a renewable resources if managed properly (ecosystem mgt)

2) important site of energy flow / nutrient cycling

ruminants: herbivores with microbes in digestive system needed to digest cellulose (fiber) – transfer plant fiber to another energy source

Native vs. Domestic Grazing Systems

• Differences in selection & competition among species

Grass Forbs & Browse

Cacti

Horses 100%

Cattle 90% 10%

Sheep 40% 60%

Pronghorn 6% 83% 11%

117 pronghorns = 1 horse

105 pronghorns = 1 cow

7 pronghorns = 1 sheep

Selectivity among some N.American ungulates

Pronghorn

Sheep

Cattle

BisonLeast

Most

1) Grassland

2) Forest

3) Savanna

4) Chaparral / Desert Shrubland

5) Tundra

Types of Rangelands

* differences in climate (precipitation/ temperature), vegetation, fauna

Grassland (prairie, pampas, steppe, veld)

Types of Rangelands

- High productivity of forage

- Grasses (family Gramineae) & forbs (broad-leaved)

- Fibrous root, soil & water conservation, soil

Grazers: cattle, elk, bison, musk oxen,

Forest (shrub, temperate, tropical)

Types of Rangelands

- Compared to grassland: wetter conditions/lower fertility

- Browsing habitat, but little grazing benefit

- National Forest, Bureau of Land Mgt (BLM) lands

Browers: moose, pronghorn, goats, deer

Savanna (barrens)

Types of Rangelands

- Grasslands with scattered shrubs/trees

- Influence of fire / transitional area

Chaparral / Desert Shrubland

Types of Rangelands

- arid climate

- low-growing shrubs with deep-root systems

- sensitivity to domestic grazing & riparian zones

Tundra

Types of Rangelands

- Low-growing vegetation, “tree-less”

- permafrost

- highly sensitive / native herbivores & migration

Intermediate feeders: sheep, caribou, burros

Rangeland Ecology

* How does range management (grazing by domestic livestock impact the rangeland community in the long-term?

* Excessive grazing & retrogression

Rangeland Ecology

• Wet rangelands, such as southern pine forest or the tallgrass prairie = quicker recovery after retrogression (<5 years)

Rangeland Ecology• Drier rangelands, such as the

Chihuahuan desert, slower recovery after retrogression (20+ years)

Rangeland Ecology

• Those plants that collectively occupy a site in the absence of severe disturbances – such as excessive grazing, fire and cultivation – are collectively referred to as the climax.

Grazing & metabolic reserve

Decreasers = high nutritional value, palatable, decrease with moderate grazing

e.g., sideoats grama, little bluestem

Increasers= high nutritional value, less palatable, initial increase with heavy grazing pressure

e.g., blue grama, Nebraska sedge

Invaders = low nutritional value, less (or not) palatable (poisonous), increase with heavy grazing pressure

e.g., Canada thistle, ragweed

Grazing Systems

• Continuous Grazing: animals graze one area during growing season

• Pros = less labor, cheaper

• Cons = overgrazing possible, damage riparian areas

• Rotational Grazing: alternate grazing between multiple areas within or among growing season(s)

• Pros = better range condition, protect riparian areas

• Cons = more work, more planning

• Precision Grazing Systems

• similar to precision farming

• GPS technology….map grazing units

• Develop grazing system plan accordingly….

Protecting Riparian Zones