MANAGING AND SUSTAINING GRASSLANDS December 10-11, 2009

What are grasslands? Grassland biomes are… dominant vegetation are grasses rather than trees or shrubs also known as prairie, savanna, or steppe located mostly in the interior of continents. too moist for desertification – receive inches of annual rainfall prevented from succeeding to forest by seasonal drought, herbivore grazing, and fire include pasture – usually enclosed, managed grasslands planted with domesticated species

Grassland biomes are places where the dominant vegetation are grasses rather than trees or shrubs.

Grassland biomes include prairie,

Savanna

Steppe

Grasslands are located mostly in the interior of continents. Grassland biomes

Grasslands are too moist for desertification. They generally receive inches of seasonal annual rainfall.

Grasslands are prevented from succeeding to forest by seasonal drought, herbivore grazing, and fire.

Grasslands include pasture – usually enclosed, managed grasslands planted with domesticated species.

And also rangelands like this shortgrass prairie in Montana.

Ecological Importance of Grasslands Soil formation Erosion control Storage of atmospheric carbon Gene pools for crossbreeding grain crops Nutrient cycling Biodiversity Habitat Food

The moniker of amber waves of grain is no exaggeration.

According to Landscape Native, a Canadian “grassroots” organization, tallgrass prairies (TGPs) are extremely important for sequestering carbon from the air in their extensive root systems. Globally, the above and below ground storage of carbon in temperate grasslands is estimated at 335 billion tons, 97% of which is contained in the soil. This represents the amount of carbon released by 240 billion cars in one year(Amthor et al., 1998; U.S. Climate Technology Cooperation, 2007) TGPs are also great for biodiversity as they attract many insects, birds, and many other animals. Photo source:

An aerial view shows the J. Clark Salyer National Wildlife Refuge, ND. Wedged amid grain fields, it remains one of the most productive breeding grounds for migratory waterfowl in the United States.

Wisp grass seedpods sway in the wind in South Dakota's Badlands National Park. Fifty-six different grass species are found in Badlands.

Economic Importance of Grasslands Mostly used for agricultural purposes: domestic crops rangelands and pasture for livestock grazing

Lately, grasslands have become a source of biofuels such as this switchgrass plantation.

Threats to Grasslands Poor agricultural practices can strip rich grassland soils of nutrients. Continued global warming could turn marginal grasslands into deserts as rainfall patterns change. Land once incompatible with row-crop agriculture, but which provided a living to ranching families and habitat for prairie wildlife, is being converted to row crops. Development of urban areas is increasingly cutting into grassland habitat. Drought-hardy, cold-resistant, and herbicide-tolerant varieties of soybeans, wheat, and corn allow crops to expand into native grassland. Where only one crop is grown, pests and disease can spread easily, creating the need for potentially toxic pesticides.

The Konza Prairie, in the Flint Hills south of Manhattan, Kansas is the last remaining untouched tallgrass prairie in the United States.

Another Threat -- Overgrazing Overgrazing Overgrazing (left) occurs when too many animals graze for too long and exceed carrying capacity of a grassland area. Figure 10-21

Managing Grasslands Moderate grazing Moderate grazing levels are healthy Remove mature vegetation Stimulate plant growth Encourages diversityOvergrazing Reduces vegetative cover Increases erosion Compacts soil Makes area prone to invasion by undesirable species Undergrazing Undergrazing – absence of grazing for > 5years Overgrazed slope in East Timor

Sustainable Grassland Management Control the number of grazing animals Rotational grazing Provide multiple strategic accesses to water Supplemental feeding locations Suppress invader plant species Herbicide spraying Mechanical removal Controlled burning Controlled, short-term trampling Replanting and restoration with native seeds Rotational Grazing System, Washington County, VA

A Case for Rotational Grazing

Sustainable Grassland Management Example of restored area along the San Pedro River in Arizona after 10 years of banning grazing and off-road vehicles. Figure 10-22

Other Solutions Continue education efforts on how to protect the soil and prevent soil erosion. Protect and restore wetlands, which are an important part of grassland ecology. Rotate agricultural crops to prevent the sapping of nutrients. Plant trees as windbreaks. Conduct dry season burning to obtain fresh growth and to restore calcium to the soil that builds up in the dry grasses.

Case Study: Grazing, Land Management, and Urban Development in the American West Four government agencies – the Bureau of Land Management (BLM), U.S. Forest Service, U.S. Fish & Wildlife Service and the National Park Service -- administer over 383 million acres of public lands (17% of the total area of the United States). – Grazing allowed on 256 million of these acres (11%) As cattle ranching is supplanted by agribusiness, ranchers are selling their land to developers for housing developments, condos, and small “ranchettes.” Ranchers, ecologists, and environmentalists are joining together to preserve the grasslands on cattle ranches. – Paying ranchers conservation easements (barring future owners from development). – Pressuring government to zone the land to prevent development of ecologically sensitive areas. What is the best strategy for preserving western U.S. grasslands?

Further Reading Splendor of the Grass: The Prairie’s Grip by Verlyn Klinkenborg Splendor of the Grass: The Prairie’s Grip by Verlyn Klinkenborg Work Cited: Unless otherwise cited photographs are from: Miller Jr., G.T. Living in the Environment, 15 th ed. Brooks-Cole, Thomson Learning, National Geographic Society