Grassland Management Explained through Images

Introduction

Core Ideas Identify ecosystem services provided by grasslands. Define rangelands and pastures and explain how overgrazing impacts these areas. Describe methods for managing rangelands that limit impacts of overgrazing and help preserve grassland habitat.

Grasslands How can you describe grasslands? Savanna, steppe, prairie and pampas are all grasslands. Tom Koerner, USFWS, Mountain-Prairie, Missouri Coteau #2, CC BY 2.0 Martie Swart, Zebra on Grasslands in South Africa, CC BY 2.0 USDA, Wildlife on the Thunder Basin National Grassland, CC BY 2.0 Grasslands go by many names. In the U.S. Midwest, they're known as prairies.  In South America, they're called pampas. Central Eurasian grasslands are referred to as steppes, while in Africa they're named savannas.  What they all have in common is grass as their naturally dominant vegetation. Grasslands are found where there is not enough regular rainfall to support the growth of a forest, but not so little as to form a desert. How can you describe grasslands?

Rangelands and Pastures Rangelands and pastures are part of grassland ecosystems. How do rangelands and pastures compare and contrast? David Stein, Where the Buffalo Roam, Yellowstone, 2016, CC BY 2.0 Roy Luck, Cattle at Pasture Near Salmon, ID, 1992, CC BY 2.0 Rangelands are unfenced grasslands in temperate and tropical climates that supply forage, or vegetation for grazing (grass-eating) and browsing (shrub-eating) animals. Pastures are managed grasslands or fenced meadows that are often planted with domesticated grasses or other forage crops such as alfalfa an dclover. Greg Shine, Bureau of Land Management, Cattle grazing on rangeland east of Steens Mountain, CC BY 2.0 Paul VanDerWerf, Grazing Cows, Brunswick, ME, CC BY 2.0

Fire and Grazing in Grasslands Gerald Vicker, USFWS, Fire. Public Domain USFWS, Mountain Prairie, Mom and Calf (4819440992), Public Domain In most grassland ecosystems, fire is the primary mode of decomposition, making it crucial in the recycling of nutrients.   Moderate levels of grazing are healthy for grasslands, because removal of mature vegetation stimulates rapid growth and encourages greater plant diversity. Blades of rangeland grass grow from the base, not the tip. As long as only the upper portion of the blade is eaten and the lower portion remains in the ground, rangeland grass is a renewable resource that can be grazed again and again. A combination of heavy livestock grazing and fire-suppression has drastically altered the structure, composition, and diversity of the shortgrass prairie ecosystem on the Great Plains, allowing woody species to dominate many areas and promoting fire-intolerant invasive species. In semi-arid ecosystems where the decomposition of woody material is slow, fire is crucial for returning nutrients to the soil and allowing the grasslands to maintain their high productivity. How would fire suppression affect grasslands?

Grasslands are Overgrazed

Railroad Valley, NV, overgrazed sagebrush steppe and salt desert Overgrazing Overgrazing occurs when too many animals graze an area for too long, damaging grasses and their roots and exceeding the area’s carrying capacity. How do you think overgrazing affects biodiversity? Satellite image of the border between Egypt (left) and Israel (right). The Egyptian side is overgrazed. Railroad Valley, NV, overgrazed sagebrush steppe and salt desert Carrizo Plain Ecological Reserve, overgrazed (left) and undergrazed (right) Cattle, sheep, and goats graze on about 42% of the world’s grasslands. Matt Lavin, Railroad Valley, NV: Overgrazed sagebrush steppe and salt desert, 2015, CC BY-SA 2.0 Eco-Intelligent, Land Degradation: Role of Overgrazing, October 21, 2016 at https://eco-intelligent.com/2016/10/21/land-degradation-overgrazing/ NASA Gateway to Astronaut Photography, Israel Egypt Border, 2010, Public Domain

Effects of Overgrazing Grassland Ecosystem Services Effects of Overgrazing Soil formation Erosion control Nutrient cycling Storage of atmospheric carbon dioxide Maintenance of biodiversity Reduced grass cover, exposing topsoil to erosion by water and wind Compacted soil, reducing its ability to hold water Promoted invasion of species such as sagebrush, mesquite, cactus, and cheatgrass, which cattle will not eat How does overgrazing impact soil health? How are the ecosystem services and economic services of the grassland at odds with one another?

Protection of Rangelands

We can manage rangelands more sustainably How can we protect rangelands? Control the number of grazing animals and the duration of their grazing in a given area so the carrying capacity of the area is not exceeded. Control timing of grazing: Avoid grazing an area at the same stage of plant growth year after year. Avoid grazing an area to frequently during the growing season. Limit numbers of animals, in order to avoid exceeding the area’s carrying capacity. Rotational grazing: confine cattle to one area via portable fencing for a short time (1–2 days) and then moved. Provide supplemental feed at selected sites and strategically locate water holes and tanks and salt blocks to reduce overgrazing. Suppress the growth of unwanted invader plants by use of herbicides, mechanical removal, or controlled burning or use controlled, short-term trampling by large numbers of livestock. Popular Science Monthly Volume 80, Land Damaged by Overgrazing, 1912, Public Domain Open Prairie Landscae in Chain O’ Lakes State Park, Illinois, via <a href="https://www.goodfreephotos.com/">Good Free Photos</a>, Public Domain