Information about the scale, frequency, and legacy of disturbance regimes and their relation to the distribution of forest species is sparse in Ozark ecosystems. Knowledge of these relationships is valuable for understanding present-day forest ecosystem species composition and structure and for predicting how Missouri's forests will respond to management. Here, we generate a correlation matrix of diverse variables to evaluate the hypothesis that plant and animal species abundances at MOFEP are closely linked to historic disturbance regimes induced by long-term interactions between humans and topographic roughness. Abrupt ring-width reductions in shortleaf pine, fire frequency, and historical data were used to determine the frequency of disturbance. Disturbance variables are correlated with topographic roughness, forest bird territory density, lizard and skink captures, blueberry fruit abundance, Armillaria spp. abundance, and three indices of forest succession derived from overstory tree species, oak overstory species, and tree species ground flora. Disturbance history, species distributions, and tree species diversity at the MOFEP sites support the argument that long-term disturbance regimes and successional sequences are major factors affecting species and structure in Ozarks forests.
Oak regeneration research in the United States has been ongoing in earnest since the late 1950s. Most research has focused on specific silvicultural practices, regeneration processes, site characteristics, and local limiting factors such as deer browsing or interfering species. Research has evaluated the effects of thinning on regeneration development, methods for oak planting, post-harvest treatments to control competing vegetation, and many other aspects of oak silviculture. All of these have provided solutions to individual problems in oak regeneration for local to regional areas. However, with all this research we still have difficulty regenerating oak forests.
Pin oak (Quercus palustris Muenchh.) and pecan (Carya illinoensis (Wangenh.) K. Koch) trees were planted on reforestation plots at Four Rivers Conservation Area in west-central Missouri. The study was conducted to determine survival and growth rates of the two species under different production methods and environmental variables. Production methods included direct seeding, bare root seedlings, and RPM® planting stock. Combinations of planting stock and species were implemented on two elevations (mounded or unmounded soils).
Variability in historic fire regimes in eastern North America resulted in an array of oak savannas, woodlands and forests that were dominant vegetation types throughout the region. In the past century, once abundant woodlands have become scarce due to conversion to agriculture, or development of forest structure in the absence of fire. Restoration of oak woodlands is a primary goal for land management agencies and conservation organizations. Although oak woodlands can be restored with a long-term regimen of prescribed burning, a combination of prescribed burning, timber harvesting and forest thinning produces the desired structure and composition more efficiently. Sustaining oak woodlands requires an occasional longer fire-free period to allow for replacement of the overstory by recruitment of trees from the reserve of oak sprouts that have accumulated in the understory. Prescribed fire is useful for sustaining oak woodlands, but it must be used judiciously to minimize timber damage and decreases in value. Integrating fire in a silvicultural prescription that uses the shelterwood regeneration method to promote competitive oak reproduction has been successfully applied in the eastern US to sustain oak forests. Restoration of oak ecosystems is possible but requires innovative combinations of traditional practices, including prescribed burning.
Variability in historic fire regimes in eastern North America resulted in an array of oak savannahs, woodlands and forests that were dominant vegetation types throughout the region. In the past century, once abundant savannahs and woodlands have become scarce due to conversion to agriculture, or development of forest structure in the absence of fire. In addition, the future dominance of oak forests is uncertain due to chronic low regeneration potential of oak across the region and insufficient overstory recruitment. Restoration of oak savannahs and woodlands, and sustaining oak forests are primary goals for land management agencies and conservation organizations. Insights learned from fire history research can be used to guide silviculture prescriptions to achieve these goals. Restoration of oak savannahs and woodlands requires a long-term regimen of prescribed burning, but it takes a combination of prescribed fire, timber harvesting and forest thinning to efficiently produce desired structure and composition. Sustaining oak savannahs and woodlands requires an occasional longer fire-free period to allow for replacement of the overstory by recruitment of trees from the reserve of oak sprouts that have accumulated in the understory. Prescribed fire is useful for sustaining oak forests, but it must be used judiciously to minimize timber damage and decreases in value. Integrating fire in a silvicultural prescription that uses the shelterwood regeneration method to promote competitive oak reproduction has been successfully applied in the eastern US to sustain oak forests. Restoration of oak ecosystems is possible but requires innovative combinations of traditional practices, including prescribed burning.
The 2019 National Silviculture Workshop brought together nearly 300 forestry practitioners and researchers from across the United States and Canada. The theme of this yearâs biennial Workshop was Forest Management-Research Partnerships.
Abstract Cradle‐knoll microtopography has been shown to influence soil and vegetation. However, the scale of commonly used topographic maps is too coarse for representation of microtopography. The objectives of this study were to investigate the influence of cradle‐knoll microtopography on the distribution of trees, to develop a method to quantify the spatial patterns and characteristics of cradle‐knolls, and to test for pattern similarity of cradle‐knolls within and among drumlins in the Nicolet National Forest, Wisconsin. Six drumlins were selected for study. Tree species, tree diameter, and microsite location (e.g., cradle, knoll, or neither) within which each tree was found were inventoried in three, 10‐m‐radius plots across each drumlin. The spatial location, length, width, relief, and orientation of 220 cradle‐knolls were inventoried along 200‐m transects using a T‐square sampling technique on summit and backslope positions of each drumlin. Sixty percent of the trees inventoried were growing on knolls and only 2% were growing in cradles. The same number of knolls and cradles occurred among drumlins and among backslopes and summits within drumlins. Cradle‐knoll relief differed among drumlins, and knoll relief is greater on backslopes than on summits within drumlins. Cradle‐knoll orientation differed among slope positions. These findings suggest that treethrow rates and the size of the uprooted trees are roughly the same among and within drumlins. Differences in relief among drumlins are probably an indication of how recently treethrow has occurred. Greater relief of knolls among backslopes and summits is probably because of slope‐mediated differences in cradle‐knoll formation. Slope position also affects cradle‐knoll orientation in these landscapes.
