Treesearch

Grasslands are areas dominated by grasses and herbs with few or no trees. Grasslands receive too much rain for a desert environment and too little for a forest. Temperate North American grasslands, especially, have undergone changes on a continental level. Their high productivity and fertility, added to their level topography and lack of trees, make them ideal sites for farming and ranching. The transformation and loss of grasslands is causing the loss of species that depend on them, including grasslands birds, prairie dogs, and the black-footed ferret, the most endangered mammal of North...

Numerous ecologists and conservationists believe that prairie dogs increase ecosystem diversity and preserve the function of grasslands (Whicker and Detling 1988, Miller et al. 1994, Jones et al. 1994, Power et al. 1996, Weltzin et al. 1997, Miller et al. 2000), yet this perspective is controversial (Stapp 1998). In contrast, many ranchers and land owners view prairie dog conservation and restoration as a threat to their livelihoods because they believe that prairie dog holes pose a threat to livestock and the prairie dogs consume forage. While numerous studies of prairie dogs have been...

Grasslands comprise a small part of the Chihuahuan Desert but are vital to the biological diversity of the ecoregion. Characteristic grasses of the Chihuahuan Desert are tobosa (Pleuraphis mutica) and black grama (Bouteloua eriopoda) but other common species include alakali sacaton (Sporobolus airoides), big alkali sacaton (S. wrightii), mesa dropseed (S. flexuosus), blue grama (B. gracilis), sideoats grama (B. curtipendula), hairy grama (B. hirsuta), slender grama (B. filiformis), chino grama (B. brevista), spruce top grama (B. chondrosioides), bush muhly (Muhlenbergia porteri), several...

When European explorers first observed the vast grasslands of the American continent, they viewed a series of interconnected, intact grassland ecosystems flourishing with an enormous diversity of flora and an abundance of wildlife. The term "sea of grass" appears frequently in descriptions of the vast prairie grasslands that extended from Canada to central Mexico. Many writers stated that the variety of wildlife species and their numbers "staggered the imagination." Relying on the thriving grasslands, the plains teemed with bison, pronghorn, deer, bighorn sheep, badgers, fox, prairie dogs,...

Grasslands of the Chihuahuan Desert region are ecologically and economically important. These grasslands are valued for their rangeland, wildlife, watershed, and recreation resources. Biological diversity also raises the value of grassland communities. The potential for multiple uses within the region increases as the diversity of the resource base increases. In order to sustainably manage for biological diversity, it is important to understand the factors that influence the ability of organisms to coexist within a given area. The following discussion focuses on the main factors that...

The semi-arid grasslands in the Mexico-United States border region are relatively intact and provide one of the best opportunities in North America to preserve and nurture an extensive series of grassland ecosystems. The conference was organized to increase appreciation for the importance of the remaining semi-arid grasslands and to create a platform for expanding the integration of natural and social sciences among individuals and organizations. The conference was attended by ranchers, environmentalists, academics, and agency personnel from both nations. Main topics include grassland...

The Landscape Fire and Resource Management Planning Tools Prototype Project, or LANDFIRE Prototype Project, was conceived, in part, to identify areas across the nation where existing landscape conditions are markedly different from historical conditions (Keane and Rollins, Ch. 3). This objective arose from the recognition that over 100 years of land use and wildland fire suppression have dramatically affected wildfire characteristics and associated landscape composition, structure, and function (Turner and others 2001). Metrics were needed to describe the extent and distribution of highly...

A critical component of the Landscape Fire and Resource Management Planning Tools Prototype Project, or LANDFIRE Prototype Project, was the development of a nationally consistent method for estimating historical reference conditions for vegetation composition and structure and wildland fire regimes. These estimates of past vegetation composition and condition are used as a baseline for evaluating current landscape conditions in terms of ecological departure from historical conditions (Landres and others 1999). Simulated historical fire regime characteristics provide managers with informatio...

This report traces the flow of timber harvested in the "Four Corners" States (Arizona, Colorado, New Mexico, and Utah) during calendar year 2002, describes the composition and operations of the region's primary forest products industry, and quantifies volumes and uses of wood fiber. Historical wood products industry changes are discussed, as well as trends in timber harvest, production, and sales of primary wood products.

Rangelands, which comprise more than 40 percent of China’s land surface area, are an important natural resource that provides a direct livelihood for at least 39 million people. Although the importance of rangelands has been recognized for millennia, during the latter part of the 20th Century China’s rangelands have been subject to over-use by a growing population that is dependent on this natural resource for their livelihood and land-use changes that have diminished productivity and promoted degradation. The first internationally funded agricultural project was initiated in the Inner...