David H. Van Lear

Using shelterwood harvests and prescribed fire to regenerate oak stands on productive upland sites

Regenerating oak stands on productive upland sites in the Piedmont region is a major problem because of intense competition from yellow-poplar. As a potential solution to this problem, we tested the hypothesis that a shelterwood harvest of an oak-dominated stand, followed several years later by a prescribed fire, would adequately regenerate the stand. Three oak-dominated stands, in which shelterwood harvests had been conducted several years earlier, were each divided into spring burn, summer burn, winter burn, and control treatments. Three years after the prescribed fires, oak had higher density and stocking in burned as compared to unburned areas while yellow-poplar had its highest density and stocking in the controls. Season-of-burn interacted with fire intensity to create several probable outcomes of stand development. Areas treated with high-intensity fire during the spring will develop into oak-dominated stands after just one burn. Controls and areas treated with low-intensity fire will become dominated by yellow-poplar. Other combinations of fire intensity and season-of-burn will produce mixed hardwood stands with varying proportions of oak. Combining shelterwood harvesting with prescribed fire appears to be a viable method for regenerating oak stands on productive upland sites in the Piedmont region and may be applicable elsewhere.

Effects of forest management on soil carbon: results of some long-term resampling studies.

The effects of harvest intensity (sawlog, SAW; whole tree, WTH; and complete tree, CTH) on biomass and soil C were studied in four forested sites in the southeastern US (mixed deciduous forests at Oak Ridge, TN and Coweeta, NC; Pinus taeda at Clemson, SC: and P. eliottii at Bradford, FL). In general, harvesting had no lasting effects on soil C. However, intensive temporal sampling at the NC and SC sites revealed short-term changes in soil C during the first few years after harvesting, and large, long-term increases in soil C were noted at the TN site in all treatments. Thus, changes in soil C were found even though lasting effects of harvest treatment were not. There were substantial differences in growth and biomass C responses to harvest treatments among sites. At the TN site, there were no differences in biomass at 15 years after harvest. At the SC site, greater biomass was found in the SAW than in the WTH treatment 16 years after harvest, and this effect is attributed to be due to both the N left on site in foliar residues and to the enhancement of soil physical and chemical properties by residues. At the FL site, greater biomass was found in the CTH than in the WTH treatment 15 years after harvest, and this effect is attributed to be due to differences in understory competition. Biomass data were not reported for NC. The effects of harvest treatment on ecosystem C are expected to magnify over time at the SC and FL sites as live biomass increases, whereas the current differences in ecosystem C at the TN site (which are due to the presence of undecomposed residues) are expected to lessen with time.

Hurricane-fire interactions in coastal forests of the south: a review and hypothesis

The extent to which periodic wildfires, burning in increased forest fuels following severe hurricanes, influenced coastal plain forest ecosystems prior to European settlement is unknown. A review of the literature suggests that, in many forests, conditions after exceptionally strong hurricanes promote the occurrence of fires of higher than normal intensity. While post-hurricane fires have not been prevalent or widespread in recent times in the southern US, a credible line of reasoning plus observations from outside the US supports the hypothesis of a hurricane-fire interaction, particularly in the era before organized fire suppression. The drastic effects caused by strong hurricanes and subsequent fire is likely to have been a significant part of the long-term disturbance regime of many ecosystems. Due to their infrequent occurrence and the difficulties involved in their study, these effects have been overlooked, minimized, or ignored. The hypothesis is presented that a hurricane-fire interaction influenced vegetation in specific ways in the presettlement South. Further, the present-day absence of this process may in part account for the continuing decline of certain plant communities. Opportunities for large-scale restoration of declining communities and ecosystems exist in areas where extensive vegetation change has already come in the form of drastic natural disturbance, such as that caused by severe hurricanes. Land managers may be able to facilitate the long-term process of restoring diverse, fire-maintained ecosystems by using a regime of frequent prescribed fires in areas impacted by strong hurricanes.

Diel Movement of Brown Trout in a Southern Appalachian River

Abstract Radio telemetry was used to monitor the diel movement of 22 brown trout Salmo trutta (268–446 mm in total length, TL) in the Chattooga River watershed. Forty-seven diel tracks, locating individuals once per hour for 24 consecutive hours, were collected for four consecutive seasons. High variability in movement both within and among individual brown trout resulted in similar seasonal means in total distance moved, diel range, and displacement. The majority of fish moved a total distance of less than 80 m within a diel range of less than 80 m and had a displacement of less than 10 m. Brown trout were more likely to occur in pool habitat independent of season or period of the day. Hourly movement patterns differed among seasons. During the winter and fall, trout moved only around sunrise; during the spring, they moved around sunrise, sunset, and intermittently throughout the night. Large brown trout (>375 mm, TL) were found to move greater total distances and establish wider diel ranges than small b...

Seasonal movement of brown trout in a southern Appalachian river

Abstract Radio telemetry was used to evaluate the seasonal movement, activity level, and home range size of adult brown trout Salmo trutta in the Chattooga River watershed, one of the southernmost coldwater stream systems in the United States. In all, 27 adult brown trout (262–452 mm total length) were successfully monitored from 16 November 1995 to 15 December 1996. During the day, adult brown trout were consistently found in small, well-established home ranges of less than 270 m in stream length. However, 8 of a possible 18 study fish made spawning migrations during a 2-week period in November 1996. The daytime locations of individual fish were restricted to a single pool or riffle−pool combination, and fish were routinely found in the same location over multiple sampling periods. Maximum upstream movement during spawning was 7.65 km, indicating that brown trout in the Chattooga River have the ability to move long distances. Spawning brown trout returned to their prespawning locations within a few days ...

Oak regeneration using the shelterwood-burn technique: management options and implications for songbird conservation in the southeastern United States

Shelterwood silviculture is commonly used to regenerate oaks in upland stands. However, competition from other species such as tulip-poplar (Liriodendron tulipifera) may deter oak regeneration when these traditional shelterwood techniques are used. The shelterwood-burn technique is a relatively new tool for regenerating oak-dominated stands on some upland sites while simultaneously minimizing undesirable hardwood intrusion with prescribed fire. Once successful oak regeneration has been achieved, three options are available which will result in different vegetative structure and composition within a stand and subsequently different habitats for songbirds. These options are: complete or partial canopy retention, post-harvest prescribed burning and complete canopy removal. Canopy retention, burning and removal treatments will create, respectively, two-age stands that are likely to harbor a diverse mixture of mature forest and early successional species; park-like woodlands with open woodland species; or early-successional habitats with shrubland species. We suggest that shelterwood-burn systems and the management options associated with them offer viable alternatives for managing both songbird and timber resources where oak-dominated stands are the desired goal in upland southeastern sites.