Oak mortality associated with crown dieback and oak borer attack in the Ozark Highlands was studied. Oaks as a major component of the upland oak-hickory forests represented 70 percent of stand basal ...area. Episodic oak decline/crown dieback had resulted in high mortality, particularly for black and scarlet oaks. Most of the oaks had healthy crowns and only about 10 percent of the black and scarlet oaks and 6 percent of the white oaks exhibited moderate crown dieback. Most of the oaks showed evidence of attack by oak borers. It was observed that oaks exhibiting borer exit wounds were not especially prone to moderate or severe crown dieback or accelerated mortality.
We examined the spatial pattern of forests in Indiana to (1) determine the extent, connectivity and percent edge of all forests; (2) examine the change in connectivity among these forests if all ...riparian zones were replanted to forest or other native vegetation; (3) determine the location, spatial dispersion, and percent edge of current oldgrowth forest remnants; (4) predict future changes in area and spatial distribution of oldgrowth forests based on current land management plans of public agencies; and (5) discuss biological implications of different edge widths, patch sizes, and spatial configurations of forests in Indiana. To achieve this, we produced a map of forested riparian zones using a Geographic Information System (GIS) buffering function and developed GIS models to predict locations of potential old-growth forests on lands designated in public agency management plans as preserves or unmanaged forests. A proximity index (PX) was used as a quantitative measure of effective connectivity of forest patches. PX values ranged from 0 to nearly 3,000, where a value of 0 is effectively isolated and a value of 3,000 is very well connected. For the 9,508 patches and 2,026,716 ha of all forests in both Indiana and the surrounding area, the average PX was 19.49. Adding a 200-m forest buffer to both sides of all nonforested riparian areas resulted in a decreased number of fragments to 3,634 and an increase of 1,724,664 ha of forest (the buffer). A 20-m buffer would add 172,466 ha of forest. The PX was not used to analyze riparian areas because it was not appropriate for the dendritic pattern formed when riparian areas were revegetated. Total area of old-growth forests ≥ 4 ha held in public trust in Indiana is 362 ha divided among 19 forests. An additional 8 sites ≥4 ha in private ownership contain 215 ha. Most old-growth forests are isolated within an agricultural matrix. The percentage of old-growth forest areas located within 40 m, 200 m, 400 m, and 600 m of a nonforest edge were 23%, 75%, 89% and 93% respectively. PX values for all 19 old-growth sites were 0, implying that they are very isolated sites. If current public forest management plans are followed, the area and number of old-growth forests will increase and their relative isolation will decrease. Potential future old-growth forests consisted of 137 patches and 82,520 ha with an average PX of 1.8. Of this amount 27,297 ha were within Hoosier National Forest purchase boundaries but are currently in private ownership.
Four mature northern red oak (Quercus rubra L.)-white oak (Quercus alba L.) stands in the Boston Mountains of northern Arkansas were studied to describe the vegetation dynamics of forests heavily ...impacted by oak decline. Northern red oak was the species most susceptible to decline. Across the four stands, 51-75% of red oak density (trees/ha) was dead or dying, as was 40-70% of the red oak basal area. Red oak damage occurred across a range of tree sizes. Healthy red oak had low populations of red oak borer (Enaphalodes rufulus Haldeman), and dead/dying red oak supported large numbers of borers. Impacts on white oak were less severe and generally limited to smaller trees. Decline had changed what once were red oak-dominated stands to more mixed forests of white oak, hickory (Carya spp.), red oak, blackgum (Nyssa sylvatica Marsh.), and red maple (Acer rubrum L.). Understory trees and seedlings were predominantly blackgum, red maple, hickory, black cherry (Prunus serotina Ehrh), flowering dogwood (Cornus florida L.), and sassafras (Sassafras albidum Nutt. Nees). However, well-developed red and white oak advance regeneration was present in all stands. It is unclear if the death of overstory trees will favor the regeneration of nonoaks, or whether oak regeneration will successfully recruit within canopy gaps created by this disturbance.
We examine the relationship between disturbance regime and plot size for woody biomass estimation in a midwestern old-growth deciduous forest from 1926 to 1992. Analysis was done on the core 19.6 ac ...of a 50.1 ac forest in which every tree 4 in. dbh and greater has been tagged and mapped since 1926. Five windows of time are compared-1926, 1976, 1981, 1986 and 1992. The most efficient plot sizes requiring measurement of the feast total area range from 0.02 to 1.6 ac. A small plot size was recommended after grazing disturbance, and a large size was recommended when mortality was high and acceptable error was low.
Applied Ecology Section Potter, Deborah Ulinski; Spetich, Martin A.
Bulletin of the Ecological Society of America,
10/2005, Letnik:
86, Številka:
4
Journal Article
Fire helped shape the structure and species composition of hardwood forests of the eastern United States over the past 14,000 years. Periodic fires were common in much of this area prior to European ...settlement, and fire-resilient species proliferated. Early European settlers commonly adopted Native American techniques of applying fire to the landscape. As the demand for wood products increased, large cutover areas were burned, sometimes leading to catastrophic fires and subsequent early successional habitats. By the early 1900s, these catastrophic fires resulted in political pressure leading to policies that severely restricted the use of fire. Fire suppression continued through the twentieth century due to an emphasis on commodity production and under-appreciation of the ecological role of fire. Without fire, fire-sensitive species were able to successfully outcompete fire-adapted species such as oak and pine while early successional habitats matured into older and more homogeneous forests. In the late twentieth century, land managers began reintroducing fire for ecosystem restoration, wildlife habitat improvement, hazardous fuel reduction, and forest regeneration. Responsible expanded use of prescribed fire and other management tools in the region could help mitigate past actions by increasing the amount and distribution of early successional habitats, plant and animal diversity, and landscape heterogeneity.
Oak seedling outplanting performance Spetich, Martin A; Dey, Daniel C
Tenth Workshop on Seedling Physiology and Growth Problems in Oak Plantings : October 16-17, 2007 / edited by Brian Roy and Emile S. Gardner and Daniel C. Dey,
2008
Publication
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