Treesearch

The use of prescribed fire to sustain oak forests has increased rapidly in the last decade as the threat of poor regeneration and increased dominance of shade tolerant or fire sensitive tree species grows. While prescribed fire can favor oak regeneration, it may also increase the invasion and expansion of nonnative invasive plant species (NNIS). Little is known about the effects of fire on invasives in eastern U.S. oak forests. The majority of knowledge regarding the response of NNIS is anecdotal as managers have reported the expansion of invasives such as tree-of-heaven (Ailanthus...

We know little about the response of birds to savanna and woodland restoration in the Ozarks or how important such habitats are to birds of conservation concern. Bird species such as red-headed woodpecker, prairie warbler, field sparrow, and blue-winged warbler are species of regional concern, and declines of these species may be due to historical declines in savannas and woodlands. Our objective was to compare abundance of focal bird species between sites managed to restore savanna or woodland conditions and forested sites with no restoration management in the Ozark Highlands of Missouri...

Fire is increasingly being used in oak forests to promote oak regeneration, improve wildlife habitat, and reduce hazardous fuel loads. Although recent research has begun to shed light on the relationships among fire, bats, and bat habitat, these interactions are not yet fully understood. Fire may affect bats directly through heat and smoke during the burning process or indirectly through modifications in habitat. Studies suggest fire generally has beneficial effects on bat habitat by creating snags, reducing understory and midstory clutter, creating more open forests, and possibly increasin...

Timber rattlesnakes (Crotalus horridus) are excellent model organisms for understanding the effects of large scale habitat manipulations because of their low-energy lifestyle, rapid response to changes in resource environment, uniform diet (small mammals), and simple behaviors. We present two case studies that illustrate interactions between timber rattlesnakes and fire in a single large population. Case 1 describes the decimation and subsequent 11 year recovery of a timber rattlesnake subpopulation associated with a fire during a particularly vulnerable time of year. In Case 2, four...

Recent warming at high-latitudes has accelerated permafrost thaw in northern peatlands, and thaw can have profound effects on local hydrology and ecosystem carbon balance. To assess the impact of permafrost thaw on soil organic carbon (OC) dynamics, we measured soil hydrologic and thermal dynamics and soil OC stocks across a collapse-scar bog chronosequence in interior Alaska. We observed dramatic changes in the distribution of soil water associated with thawing of ice-rich frozen peat. The impoundment of warm water in collapse-scar bogs initiated talik formation and the lateral expansion...

Because there are few long-term dendrochronological and lake sediment data for the southern Appalachians, little is known regarding the history of fire in this region's forests through the Holocene. Radio-carbon ages for 82 soil charcoal samples collected from local depositional sites along a topographic gradient from mixed hardwood (Liriodendron tulipifera and Quercus spp.) to oak-pine (Quercus prinus and Pinus rigida) forest provide a coarse-grained picture of changes in fire frequency within a 10-ha area during the Holocene. Fires were frequent over the past 4,000 years, and their...

Native Americans are often considered to have exploited available natural resources rather than modifying their environments to maximize yields. As simpler societies evolved into more complex ones, there is a consensus that intensification of habitat modifications also increased. However, landscape scale archeological inventories now show relatively intensive modifications of specific landscapes through most of human history, including so-called simpler societies. Records of these modifications are difficult to obtain. Archeological site distributions can be used to understand human...

Our understanding of long-term fire history in the eastern United States is derived from the interpretation of a variety of archives. While cultural records are available for some sites, biological archives are most frequently used to reconstruct long-term historical fire regimes. The three most commonly used biological archives in eastern oak forests include: the relative abundance of micro- and macroscopic charcoal found in lake and wetland sediment cores, charcoal macrofossils recovered from mineral soil, and dated fire scars on tree cross-sections. Quantitative data from these biologica...

The vegetation of the Cross Timbers forests was maintained for thousands of years by fire; the historic fire return interval was likely 1 to 10 years. Fire suppression over the past century led to a doubling of stand basal area, increased diversity of tree species, reduced dominance of oak, and increased mesic species intolerant of fire. Dendrochronological studies suggested tree mortality from severe droughts opened stands and accelerated recruitment of eastern redcedar (Juniperus virginiana L.) where fire was suppressed. Without reintroduction of fire, Cross Timbers forests will become...

We used a small plot study on Pushmataha Wildlife Management Area in southeast Oklahoma to determine the efficacy of fire frequency and thinning as management tools for restoration of oak savanna, oak woodlands, pine-bluestem woodlands, and pine savanna for application on a landscape scale. On selected experimental units, we initially reduced stand density to favor either oak canopy dominance or pine dominance to near presettlement stand density. Thinned stands were then subjected to 0-, 4-, 3-, 2-, and 1-year late dormant season (late February - early April) fire frequency regimes for 26...