Treesearch

Hardwood understories can contribute significantly to total ecosystem biomass and fuel loads, but few models are available to directly quantify this component. In part, this is due to the small size of the hardwoods. Many understory trees simply do not reach the height required to determine diameter at breast height (d.b.h.), so conventional models (e.g., the National Biomass Estimators [NBE]) that rely on this predictor are unavailable. Further, understory hardwoods can be present in such numbers or have inconvenient growth forms such that biomass estimates based on diameters are impractic...

Little is known about the performance of plantations relative to natural forests of the same climate zone and age. China has more plantations than any other country as a consequence of massive afforestation efforts.We use data from China to comparatively examine tree biomass and productivity of planted and natural stands in relation to climate zone, latitude, elevation, age and species diversity (richness).

To date, it is not clear which are the factors that most influence tropical forest recovery from hurricanes.Increased canopy openness and increased detritus (debris) deposition are two of the most likely factors,but due to their simultaneous occurrence during a hurricane, their relative effects cannot be separated without a manipulative experiment. Hence, in the Luquillo Experimental Forest (LEF) of Puerto Rico, the Luquillo Long-Term Ecological Research Program (LTER) has undertaken experimental manipulations in replicated 30 _ 30 m plots to simulate the major effects of hurricane...

Successful oak regeneration depends on the relative status of advanced oak reproduction and associated competing woody vegetation present when harvests or other stand-replacing disturbances occur. This study was installed to quantify the effect of microsite light availability and deer browsing on the development of advanced northern red oak (Quercus rubra) seedlings and competing vegetation in 80-year-old, mixed mesophytic Appalachian hardwood stands dominated by northern red oak. Advanced oak seedlings and competing woody species were monitored in forty-eight 0.4-acre permanent plots for...

Changes in disturbance frequencies, habitat fragmentation, and other biotic pressures are allowing sugar maple (Acer saccharum) to displace oak (Quercus spp.) in the upland forest understory. The displacement of oaks by sugar maples represents a major management concern throughout the region. We collected seedling microhabitat data from five upland oak forest sites in central Illinois, each differing in age class or silvicultural treatment to determine whether oaks and maples differed in their microhabitat responses to environmental changes. Maples were overall more prevalent in mesic...

Renewable energy has been at the forefront of the United States' energy policies. Cellulosic feedstocks have received considerable interest in the Appalachian region because of their abundance and availability, but cost competition from other energy sectors has limited their use in the region. Some other bioenergy feedstocks, such as corn and soybeans, are not a viable alternative for most of the region. Though not considered suitable for traditional agricultural crops, a large portion of disturbed mine land in West Virginia, Pennsylvania, and eastern Ohio has been reclaimed and planted...

Bottomland hardwood forests were damaged by Hurricane Katrina in 2005 when it made landfall along the Gulf Coast. Regenerating these areas, which can be difficult without planning and artificial regeneration, has often been problematic when using 1-0 bare-root seedlings because of inconsistencies with the seedling quality. Some growers have begun producing containerized and large-container potted seedlings to provide a more consistent seedling. This study evaluated the first-year height and ground line diameter (GLD) growth of three different planting stocks (1-0 bare-root, conventional...

From 2000 to 2008 hardwood regeneration

The William B. Bankhead National Forest is using active management to shift mixed Quercus-Pinus forests towards forests more dominated by upland hardwoods. We studied the use of three levels of thinning (none, light thin, and heavy thin) and three levels of prescribed fire (none, one burn, and two burns) and all combinations in a factorial experimental design to assess the level of juvenile sprouting in the hardwood reproduction cohort. Stands were either unthinned, thinned to 75 square feet of residual basal area (light thin), or thinned to 50 square feet residual basal area (heavy thin)....

Many studies on oak-dominated forests of the Central Hardwood region (CHR) have reported increasing abundance of fire-sensitive species and poor recruitment of oak (Quercus spp.) in the absence of frequent fire. However, most of these studies were conducted in the eastern and central CHR, and the assumption that similar dynamics occur in the western CHR has not been fully substantiated. We investigated forest dynamics in relatively undisturbed, mature oak-hickory forests of the Missouri Ozarks during a 15-year period (1995-2010). Data for this study were from untreated sites (controls) of...