Case StudiesExpertsOrganizationsLiterature

Grassland

Approximately 40% the earth’s land cover, the grassland biome is characterized by wide-open, flat areas of wind-pollinated grasses that are constantly mowed by a variety of grazing mammals. The height of the grasses is most often correlated to the amount of rainfall. Fire, drought and grazing limit the establishment of shrubs/trees and play an important role in maintaining the biodiversity of the grasslands, perhaps more so in the tropical savannas.

Temperate grasslands, found in North America (praires), South America (pampas), South Africa (veldts) and Central Eurasia (steppes), undergo hot summers and cold winters with moderate rainfall. These interior grasslands are distinguished by deep-rooting, perennial tallgrasses, flowers and herbs with very few shrubs and trees. Due to their rich, fertile soils and favorable climate, many of these ecosystems have been converted to agricultural production or ranching. The steppe ecosystems are considerably more arid, dominated by shorter grasses.

Tropical grasslands (savannas) are close to the equator and remain warm year round with marked dry and wet seasons that discourage the creation of forests. Grasses and forbs, which tend to be dormant during the dry season, are the predominant vegetation along with scattered shrubs and trees. Savannas – found in Africa, India, Australia and South America – typically have well-drained soils with only a thin layer of humus, often located in the transitional region between rainforest and desert.

Most of the large fauna of the grasslands and savannas are now extinct or seriously endangered as a result of human activities. Agriculture and grazing are the major sources of degradation; as a result, huge portions of the grassland ecosystems are now being lost to salinization and desertification. Human-induced fires, water diversion and species loss, which have disturbed natural regeneration cycles, pose a substantial threat to the health of the grasslands.

WEBSITES

Center for Invasive Plant Management (CIPM)
The CIPM Restoration Resource Database can be searched to find resources on restoration, particularly relating to invasive species. A search provides a short description of the resource and contact information, web links, and/or journal references for obtaining the resource.

Environment Canada: Grassland Restoration
Restoration is defined as a process undertaken to bring back or rebuild to original condition (Oxford Concise Dictionary). Most of us view restoration efforts only in the context where an activity has destroyed not only the plant cover, but also the wildlife and the soil. We need to consider restoration in a broader context. Proper grazing techniques and prescribed burning, as discussed earlier, are restorative techniques. The following section illustrates some restoration techniques as well as possibilities for protection of grassland vegetation cover.

Grassland Biome
The climate for   grasslands is basically dry.  Precipitation usually does not exceed 100 cm per year, with a minimum near 20 cm per year.  Also, grasslands tend to be in temperate to subtropical areas, often with cold winters and hot summers.  As you can see in the diagram below, average annual temperatures range from below 0 degrees C to about 20° C.  The warmer end of this range would probably tend towards tropical savanna.  As moisture levels increase, grasslands usually give way to temperate forests or taiga, depending on the temperature.

Temperate Grasslands
Temperate grasslands are composed of a rich mix of grasses and forbs and underlain by some of the world’s most fertile soils. Since the development of the steel plow most have been converted to agricultural lands.

Tropical Savannas
Tropical savannas or grasslands are associated with the tropical wet and dry climate type, but they are not generally considered to be a climatic climax. Instead, savannas develop in regions where the climax community should be some form of seasonal forest or woodland, but edaphic conditions or disturbances prevent the establishment of those species of trees associated with the climax community.

University of California Museum of Paleontology: Grassland Biome
Grasslands are characterized as lands dominated by grasses rather than large shrubs or trees. In the Miocene and Pliocene Epochs, which spanned a period of about 25 million years, mountains rose in western North America and created a continental climate favorable to grasslands. Ancient forests declined and grasslands became widespread. Following the Pleistocene Ice Ages, grasslands expanded in range as hotter and drier climates prevailed worldwide.

US Fish & Wildlife Service
Grasslands are another type of habitat that is disappearing across New York. Grasslands provide habitat for many different species of wildlife. Most notably, recent studies have shown that grassland nesting birds are declining in numbers. One factor contributing to this decline is the loss of suitable habitat. Partners for Fish and Wildlife has been restoring grasslands across New York with great success. After grassland restoration projects are complete, many landowners have witnessed the return of species they have not seen for many years. The program works, and it will continue to work with the enrollment of private landowners into the program.

Wisconsin Department of Natural Resources
The restoration of native grasslands affects ecological diversity by increasing the abundance of native plants and creating the necessary habitats for native animals and insects. In addition, grasslands are stable systems and an established prairie absorbs more rainfall than many other vegetative covers reducing erosion and runoff, which can improve water quality.

World Wildlife Fund
Large expanses of land in the tropics do not receive enough rainfall to support extensive tree cover. The Tropical and Subtropical Grasslands, Savannas, and Shrublands are characterized by rainfall levels between 90-150 centimetres per year.

en espanol

Restoration Radio


Home | COMMUNITY RESTORATION NETWORK | Database | Restoration | Ecosystems | Degradation | Countries | Funding | Conferences | Education | Volunteer | Video/Audio | About the GRN

©2016 Society for Ecological Restoration | 1017 O Street NW | Washington D.C. 20001
tel (202) 299-9518 | fax (270) 626-5485