Treesearch

Twentieth century land use and management practices have increased the vertical and horizontal continuity of fuels over expansive landscapes. Thus the likelihood of large, severe wildfires has increased, especially in forest types that previously experienced more frequent, less severe fire (Allen and others 2002). Disturbances such as fire may promote nonnative plant invasions by increasing available light and nutrients, as well as by decreasing competition from native plants for these resources (Fox 1979; Melgoza and others 1990). Once established, nonnative species may further alter fuel...

This chapter explains how various fire suppression and postfire management activities can increase or decrease the potential for plant invasions following fire. A conceptual model is used to summarize the basic processes associated with plant invasions and show how specific fire management activities can be designed to minimize the potential for invasion. The recommendations provided are focused specifically on invasive plant management, although other considerations can take precedence under certain situations. Every fire presents a unique combination of site history and management goals,...

Monitoring, as defined by Elzinga and others (1998), is "the collection and analysis of repeated observations or measurements to evaluate changes in condition and progress towards meeting a management objective." Analyses of monitoring data may indicate that a project is meeting land management goals, or it may indicate that goals are not being met and management methods need to be adapted to reach them. Monitoring is an essential step in adaptive management (Chong and others 2006). For many federal agencies, monitoring is required by Agency or Congressional mandates (Elzinga and others 1998).

This volume synthesizes scientific information about interactions between fire and nonnative invasive plants in wildlands of the United States. If the subject were clear and simple, this volume would be short; obviously, it is not.

Fire is a process integral to the functioning of most temperate wildland ecosystems. Lightning-caused and anthropogenic fires have influenced the vegetation of North America profoundly for millennia (Brown and Smith 2000; Pyne 1982b). In some cases, fire has been used to manipulate the species composition and structure of ecosystems to meet management objectives, including control of nonnative invasive plant species (DiTomaso and others 2006a; Grace and others 2001; Keeley 2001; Myers and others 2001; Pyke and others, in review). However, fire can also threaten human life, property, and...

Considerable experimental and theoretical work has been done on general concepts regarding nonnative species and disturbance, but experimental research on the effects of fire on nonnative invasive species is sparse. We begin this chapter by connecting fundamental concepts from the literature of invasion ecology to fire. Then we examine fire behavior characteristics, immediate fire effects, and fire regime attributes in relation to invasion potential. These concepts form the basis for examining the literature that supports or refutes several common generalizations regarding fire effects on...

The alteration of fire regimes is one of the most significant ways that plant invasions can affect ecosystems (Brooks and others 2004; D'Antonio 2000; D'Antonio and Vitousek 1992; Vitousek 1990). The suites of changes that can accompany an invasion include both direct effects of invaders on native plants through competitive interference, and indirect effects on all taxa through changes in habitat characteristics, biogeochemical cycles, and disturbance regimes. Effects can be far-reaching as they cascade up to higher trophic levels within an ecosystem (Brooks and others 2004; Mack and...

It may be impossible to overstate the complexity of relationships among wildland ecosystems, fires, and nonnative invasives. Strategies for managing these relationships are similarly complex; they require information on local plant phenology, ability to produce various levels of fire severity within burns, willingness to combine fire with other management techniques, and systematic monitoring to improve effectiveness. Oversimplification and short-sightedness in planning can lead to unintended degradation of the ecosystem; lack of monitoring may leave such consequences unnoticed and...

The Northeast bioregion extends from Maine to Maryland and northern Virginia, south along the northwest slope of the Appalachians to Tennessee, and west to the ecotone between prairie and woodland from Minnesota to northeastern Oklahoma. It is composed of a wide variety of landforms and vegetation types. Elevation ranges from sea level along the Atlantic coast, to 243 to 600 feet (74 to 183 m) at the Great Lakes, to over 6,000 feet (1,800 m) in the northern Appalachian Mountains.

This chapter identifies major concerns about fire and nonnative invasive plants in the Southeast bioregion. The geographic area covered by this chapter includes the entire States of Louisiana, Mississippi, and Florida; all except the northernmost portions of Delaware and Maryland; the foothill and coastal ecosystems of Virginia, North Carolina, South Carolina, Georgia, and Alabama; and the lower elevation plant communities of Arkansas, southeastern Missouri, southeastern Oklahoma, southwestern Tennessee, and eastern Texas.