New Publications Online From The USFS Southern Research Station

Geographic variation in prey preference in bark beetle predators

Mon, 23 Nov 2009 11:49:29 -0500

1. Bark beetles and their predators are useful systems for addressing questions concerning diet breadth and prey preference in arthropod natural enemies. These predators use bark beetle pheromones to locate their prey, and the response to
different pheromones is a measure of prey preference. 2. Trapping experiments were conducted to examine geographic variation in the response to prey pheromones by two bark beetle predators, Thanasimus dubius and Temnochila virescens. The experiments used pheromones for several Dendroctonus and Ips prey species (frontalin, ipsdienol, and ipsenol) and manipulated visual cues involved in prey location (black vs. white traps). The study sites included regions where the frontalin-emitter Dendroctonus frontalis was in outbreak vs. endemic or absent. 3. There was significant geographic variation in pheromone preference for T. dubius. This predator strongly preferred a pheromone (frontalin) associated with D. frontalis at outbreak sites, while preference was more even at endemic and absent sites. No geographic variation was found in the response by T. virescens. White traps caught fewer insects than black traps for both predators, suggesting that visual cues are also important in prey location. 4. The overall pattern for T. dubius is consistent with switching or optimal foraging theory, assuming D. frontalis is a higher quality prey than Ips. The two predator species partition the prey pheromones in areas where D. frontalis is abundant, possibly to minimise competition and intraguild predation.

Systemically Applied Insecticides for Treatment of Erythrina Gall Wasp, Quadrastichus erythrinae Kim (Hymenoptera: Eulophidae) Arboriculture & Urban Forestry Vol

Mon, 23 Nov 2009 11:36:16 -0500

The erythrina gall wasp (EGW), believed native to Africa, is a recently described species and now serious invasive pest of Erythrina (coral trees) in tropical and subtropical locales. Erythrina are favored ornamental and landscape trees, as well as native members of threatened ecosystems. The EGW is a tiny, highly mobile, highly invasive wasp that deforms (galls) host trees causing severe defoliation and tree death. The first detection of EGW in the United States was in O´ahu, Hawai´i in April 2005. It quickly spread through the Hawai`ian island chain (U.S.) killing ornamental and native Erythrina in as little as two years. At risk are endemic populations of Erythrina as well as ornamental landscape species in the same genus, the latter of which have already been killed and removed from O´ahu at a cost of more than USD $1 million. Because EGW are so small and spread so quickly, host injury is usually detected before adult wasps are observed, making prophylactic treatments less likely than therapeutic ones. This study evaluates two stem-injected insecticides, imidacloprid (IMA-jet®) and emamectin benzoate, delivered through Arborjet Tree I.V.® equipment, for their ability to affect E. sandwicensis (wiliwili) canopy demise under severe EGW exposure. IMA-jet, applied at a rate of 0.16 g AI/cm basal diameter (0.4 g AI/in. dia.), was the only effective treatment for maintaining canopy condition of wiliwili trees. Emamectin benzoate, applied at a rate of ~0.1 g AI/cm basal diameter (~0.25 g AI/in. dia.), was not effective in this application, although it was intermediate in effect between IMA-jet and untreated trees. The relatively high concentrations of imidacloprid in leaves, and its durability for at least 13 months in native wiliwili growing on a natural, dryland site, suggest that treatment applications against EGW can impact canopy recovery even under suboptimal site and tree conditions.

USDA-FS Termiticide report termiticide efficacy results for 2008

Wagner, Terry; Mulrooney, Joe; Shelton, Thomas; Peterson, Chris — Mon, 23 Nov 2009 11:23:20 -0500

The United States Department of Agriculture Forest Service (USDA-FS) evaluates candidate termiticides for federal and state registration. In 2008, the USDA-FS administered 33 agreements with product manufacturers as part of its ongoing Termiticide Testing Program. Two termiticides were installed at the four national test sites in Florida (February), Arizona (April), Mississippi (June), and South Carolina (September). A third termiticide was installed in Mississippi and South Carolina.

Tunneling and activity of Reticulitermes flavipes (Isoptera: Rhinotermitidae) exposed to low concentrations of nonrepellent termiticides

Mon, 23 Nov 2009 11:08:59 -0500

The use of slow-acting termiticides for the protection of structures against termite attack has received much attention since the development of the newer nonrepellent termiticides. The concept of delayed toxicity initially began with the evaluation of baiting systems for termite control because a slow-acting toxicant was needed to allow foragers contacting the toxicant in the bait to travel back to the colony to transfer it to nestmates before dying (Esenther & Beal 1978, Beal & Esenther 1980). Myles (1996) developed a treat and release method in which a resinous formulation of sulfluramide, a slow-acting stomach poison, was applied to termites captured in monitoring stations. After treatment, the termites were released back into traps to transfer the toxicant to nestmates. He observed 95% mortality in lab tests when 5 or
10% of termites were treated with this coating and >60% suppression of field populations of R. flavipes in the first year after treatment.

Symbioses: a key driver of insect physiological process, ecological interactions, evolutionary diversification, and impacts on humans

Klepzig, K.D.; Adams, A.S.; Handelsman, J.; Raffa, K.F. — Mon, 23 Nov 2009 11:09:06 -0500

Effects of light regime and season of clipping on the growth of cherrybark oak, white oak, persimmon, and sweetgum sprouts

Ficklin, Robert L.; Shelton, Michael G. — Fri, 20 Nov 2009 10:46:18 -0500

A mixture of cherrybark oak (Quercus pagoda Raf.), white oak (Q. alba L.), persimmon (Diospyros virginiana L.), and sweetgum (Liquidambar styraciflua L.) seedlings was grown in shadehouses to simulate light conditions beneath a canopy. After the first growing season, two release treatments were implemented (released and not released), and treatments were conducted during two seasons (winter and spring). All seedlings were clipped at 2.5 cm from the groundline in height when treatments were imposed. Survival of persimmon and sweetgum was 100% following clipping. There appeared to be a weak seasonal effect on oak survival, especially for white oak; survival was 100% for winter clipping and 93% for spring clipping. The oaks were considerably smaller in height, diameter, and above-ground biomass than their competitors, and the competitors also produced more stems per rootstock than the oaks. Cherrybark oak was more productive than white oak espeically in the released treatment. The oaks tended to have a higher percentage of their total biomass in foliage when compared with their competitors. Stem wood density of the oaks was considerably greater than that of their competitors. Leaf characteristics of all species were very responsive to the treatments; specific leaf area was consistently greater for the no-release treatment for all species. Results of this study suggest that for oak sprouts to grow faster than their competitors they must begin with an initial size advantage.

Linking stakeholder research needs and the federal data quality act: a case study of an endangered forest shrub in the southeastern Unitd States

Fri, 20 Nov 2009 09:30:35 -0500

The need for knowledge, ranging from development of new products or processes to the effects of specific actions on the environment, is greater now than at any point in the past. The greater need for research has generated stakeholder involvement in the research process. As a result, all facets of research, from planning through publication of results, are often scrutinized by stakeholders. While the basic nature of scientific inquiry has not changed, now more than ever the credibility of scientific results is based on thorough planning, peer reviews of experimental designs and analytical approaches, and assurance that data are of the highest quality. Public interest in the quality and accuracy of federal research rose to a level that resulted in the Data Quality Act of 2001. The Act required the establishment of guidelines for Federal research organizations and cooperators. We present a case study of the U. S. Forest Service's policies for research quality assurance and quality control, including developing quality assurance statements and plans, as applied to comprehensive research on the federally-listed, endangered forest shrub pondberry (Lindera melissifolia (Walt.) Blume).

Interpreting historical streamflow data from a third-order Coastal Plain watershed: runoff response to storm events.

La Torre Torres, Ileana B.; Amatya, Devendra M.; Callahan, Timothy J. — Wed, 23 Sep 2009 11:27:57 -0400

Hydrological studies in the Southeastern U.S. have primarily focused on runoff generation processes in Piedmont and mountainous areas; much less is known about the relevant processes in Coastal Plain watersheds. Hydrologic processes between these two areas may differ considerably due to climate, topography and soil composition. Because of the population growth and subsequent development in the last few decades in the Lower Coastal Plain (LCP) of South Carolina (SC), it is important to understand natural hydrologic processes in the LCP for predicting hydrologic impacts of land management activities and designing Best Management Practices (BMPs). Past and current research and monitoring efforts by the US Forest Service and collaborators on protected lands within the Francis Marion National Forest (FMNF) in the LCP, 53 km northeast of Charleston, SC provide excellent opportunities to interpret hydrological processes such as rainfall-generated runoff under well-studied and controlled conditions.
This study describes relationships between seasonal rainfall patterns and stream flow for a third order watershed, Turkey Creek, using ten years of historical rainfall and stream flow data (1964 1973). Storm event runoff-rainfall ratios were used to describe baseline runoff as a function of season and rainfall amount. It was hypothesized that runoff-rainfall ratios are smaller during the summer season and greater in the winter due to generally reduced flows as a result of increased evapotranspiration (ET) from the forests during summer-fall, and saturated soils with sustained flows in winter-spring. Alternatively, runoff-rainfall ratios may be directly proportional to the antecedent soil moisture condition (as estimated by rainfall amount during the 5 and 30 days preceding the storm event). Results showed statistically significantly (p = 0.01) higher runoff rainfall ratios for storms occurring during wet antecedent conditions than for dry antecedent conditions.

Partial disturbance of resources foraged by Reticulitermes flavipes

Shelton, Thomas G.; Gerard, Patrick D.; Wagner, Terence L. — Tue, 17 Nov 2009 09:56:33 -0500

The introduction of termiticidal baits over 10 years ago has increased interest in the basic foraging behavior of pest termite species. Due to the amount of interference with foraged cellulose material (bait matrices, both treated and untreated) in bait stations as part of some control programs, the following study was initiated to examine the response of termites to very short term (1 wk) partial disturbances of a foraged resource.

Host Specificity of Argopistes tsekooni (Coleoptera: Chrysomelidae), a Potential Biological Control Agent of Chinese Privet

Zhang, Yan Zhuo; Hanula, James; Sun, Jiang Hua — Thu, 12 Nov 2009 12:20:25 -0500

Chinese privet, Ligustrum sinense Lour., is a perennial semi-evergreen shrub that is a

serious invasive weed in the United States. Classical biological control offers the best hope for

controlling it in an economic, effective, and persistent way. Host speciÞcity of one of the most

promising biological control agents of Chinese privet, a ßea beetle, Argopistes tsekooni Chen (Coleoptera:

Chrysomelidae), was evaluated in China by using laboratory no-choice and choice tests on

13 species of Oleaceae and eight species in other families that have important economic value. In adult

no-choice survival and oviposition tests, the ßea beetle fed and survived for 30 d on Syringa oblata

Lindl., Jasminum nudiflorum Lindl., and three species in the genus Ligustrum. Females also oviposited

on these species, but only larvae from eggs laid on S. oblata and Ligustrum spp. developed successfully.

In addition, the beetles did not feed or oviposit on the species of economic importance. In choice tests,

adults preferred L. sinense for feeding and oviposition. These results show that A. tsekooni is relatively

host speciÞc and warrants further testing as a biocontrol agent of Chinese privet in the United States.

History, distribution, damage, and life cycle of a pine shoot gali sawfly, Xyela gallicaulis (Hymenoptera: Xyelidae). J. Entomol. Sci. 44(3):276-283

Yates, Harry O.; Smith, David R. — Thu, 24 Sep 2009 17:13:55 -0400

Larvae of Xyela gallicaulis Smith cause shoot stem galls in young pines. Loblolly pine, Pinus taeda L., is the most seriously damaged, but galls have been observed on slash pine, P. elliottii var. elliottii Engelm., and shortleaf pine, P. echinata Mill. Studies in Virginia and Georgia confirm a 2-year life cycle. Larval development takes 4 - 6 wks. After feeding, larvae bore out of the galls and drop to the ground where they form a papery cocoon in the soil to pupate, and where they remain for 22 - 25 months. Adults emerge from cells constructed in the soil from early-December to mid-January of the second year. Eggs are inserted into the vegetative buds during odd-numbered years. Insect associates found feeding in or on gall tissues are the Nantucket pine tip moth, Rhyacionia frustrana (Comstock) (Tortricidae), and the weevil Conotrachelus carolinensis Schoof (Curculionidae).

Site conditions, fire, and root disease: Leptographium sp. and Heterobasidion annosum paradigms. pp. 122-127. M. Garbelotto & P. Gontheir (Editors). Proceedings 12th International Conference on Root and Butt Rots of Forest Trees.

Otrosina, W. J.; Kliejunas, J. T.; Sung, S-J. S.; Maloney, P.; Spaine, P. C. — Wed, 23 Sep 2009 13:27:43 -0400

Forest tree species have evolved under climatic, geological, and biological forces over eons of time. Root disease fungi, particularly root rotting Basidiomycetes are key drivers of coniferous forest ecosystems. They have coevolved with their hosts under the pressure of these forces, and as such, are ideally in some state of equilibrium with them. Nonetheless, there are Significant departures from the notion that native root disease fungi function in the same manner under many present forest conditions as they did prior to anthropogenic influences upon the forest landscape. These cases are often unpredictable and bring about significant ecological consequences. For example, fire reintroduction in fire suppressed conifer stands has unplanned pathological consequences. Issues such ~s decades of fire exclusion and fire reintroduction also have implications vis-a-vis Heterobasidion annosum root disease in Sequoia giganteum ecosystems. With respect to other root infecting fungi, our research showed an association of delayed mortality in longleaf pine with presence of Leptographium terebrantis, L procerum, and other Ophiostomatoid pathogens, even after relatively cool bums. These fungal species are not considered virulent and longleaf pine is generally considered resistant to many diseases. These examples of unintended pathological consequences of management actions are a small number of -many.

Evaluation of HDPE water sample bottles and PVC sampler tubing used in herbicide dissipation studies.

Fischer, J. B.; Michael, J. L.; Gibbs, H. L. — Wed, 23 Sep 2009 13:00:23 -0400

The recovery of six herbicides (triclopyr, triclopyr ester, sulfometuron methyl, metsulfuron methyl, imazapyr, and hexazinone) was evaluated in two stream water samples, one from Weogufka Creek in the Alabama Piedmont and one from a stagnant stream in the Escambia Experimental Forest near Florida. Simulated field study conditions were used to evaluate collection, ambient (pre-retrieval) field storage, and freezer storage phases of stream water sampling. Method detection levels were developed for each herbicide in each water matrix. None -of the herbicides degraded significantly in either stream water after 24 days at 22 0 C to 25 0 C or after 12 months of freezer storage below _15 0 C. None of the herbicides tested appeared to leach from the automatic sampler tubing into subsequently collected samples. However, slight carryover of about 0.8% of the spiking level was observed in the first post-spike blanks collected for all herbicides. This appeared to be the result of physical adhesion of water droplets on tubing walls; no detectable carryover was observed in subsequent blanks. These results support the use of HDPE sample containers and flexible PVC automatic sampler tubing in environmental fate studies of herbicides.

Studies on black stain root disease in ponderosa pine. pp. 236-240. M. Garbelotto & P. Gonthier (Editors). Proceedings 12th International Conference on Root and Butt Rots of Forest Trees.

Otrosina, W. J.; Kliejunas, J. T.; Sung, S. S.; Smith, S.; Cluck, D. R. — Wed, 23 Sep 2009 13:34:07 -0400

Black stain root disease of ponderosa pine, caused by Lepfographium wageneri var. ponderosum (Harrington & Cobb) Harrington & Cobb, is increasing on many eastside pine stands in northeastern California. The disease is spread from tree to tree via root contacts and grafts but new infections are likely vectored by root feeding bark beetles (Coleoptera:Scolytidae). Soil and site relations along with disturbance are factors in the etiology of the disease. Thinning and prescribed burning are important silvicultural tools in maintaining forest health in eastside pine stands. Because soil compaction is a concern in many sites, skid trails are treated by subsoiling equipment to alleviate compaction where this might be an issue. However, little is known of the effects of these silvicultural treatments on incidence of black stain root disease on sites with high disease risk. These studies were initiated to address these concerns.

Cram, Michelle M.; Fraedrich, Stephen W. 2009. Stunt nematode (Tylenchorhynchus claytoni) impact on southern pine seedlings and response to a field test of cover crops.

Cram, Michelle; Fraedrich, Stephen — Wed, 23 Sep 2009 09:56:22 -0400

The stunt nematode, Tylenchorhynchus claytoni, was found to cause a reduction in root volume (cm3) of loblolly pine at population densities equivalent of 125 nematodes/100 cm3 (6 in3) soil and greater. The results of a host range test conducted in containers under controlled conditions determined that buckwheat cultivar (Fagopryum esculentum 'Mancan'), velvetbean (Mucuna pruriens), Kobe lespedeza (Lespedeza striata 'Kobe'), bicolor lespedeza (Lespedeza bicolor'), and purple nutsedge (Cyperus rotundus) are suitable hosts for the stunt nematode. Previous container studies concluded that pearl millet (Pennisetum glaucum) hybrid 'ET-300' was a nonhost for the stunt nematode. A 2-year field test of sorghum-sudangrass hybrid 'Sugar Graze,' pearl millet hybrid 'lifleaf 3,' and fallow found that the use of pearl millet as a cover crop greatly restricts population development of the stunt nematode in infested fields, and its use would be a good alternative to fallow.

The reporting revoluation—the southern endeavor

Brown, Mark — Fri, 02 Oct 2009 11:41:08 -0400

The need for expeditious portrayal of statewide inventory findings is paramount. Demand is intensifying. Yet, to date, relaying data results and analysis through traditional publications has been extremely time consuming. To address this issue, southern forest inventory and analysis (FIA) reporting is in transition. This article discusses the evolution of authorship, reporting formats, and incorporating nontraditional topics and presents examples of new instruments, such as "Factsheets" and "Congressional Corner" Web sites, and the advantages to address timely ouptut. This article summarizes ventures into wildland-urban interface analysis, National Woodland Owner Survey categorization, invasive/exotic species identification, National Forest System reporting, and nontimber-product use arenas beyond regular reporting. Finally, differences in key issues and other considerations identified that impede standardized format goals are discussed. Beyond the hurdle of transitioning from periodic to annual reporting, the future appears brighter; however, currently mandated timeframes and unresolved format consensus are leading to more succinct methods of output under present organizational staffing.

Soil organic carbon quality in forested mineral wetlands at different mean annual temperature.

Fissore, Cinzia; Giardina, Christian P.; Kolka, Randall K.; Trettin, Carl C. — Tue, 22 Sep 2009 16:35:35 -0400

Forested mineral soil wetlands (FMSW) store large stocks of soil organic carbon (SOC), but little is known on: (i) whether the quality of SOC stored in these soils (proportion of active versus more resistant SOC compounds) differs from SOC in upland soils; (ii) how the quality of SOC in FMSW varies with mean annual temperature (MAT); and (iii) whether SOC decomposition rates in these environments respond to warming and drying more strongly than those observed in upland soils. To address this substantial knowledge gap, we identified nine FMSW and fifteen paired upland forest sites across three bioregions in North America (sub-alpine in Colorado; north-temperate in Minnesota; and south-temperate in South Carolina) to test the following three hypotheses. First, FMSW store a higher proportion of active SOC compared with upland systems because long anaerobic periods favor the accumulation of labile substrates. Second, in FMSW, SOC quality decreases from cold to warm bioregions because high quality detritus accumulates preferentially at cool sites where decomposition is slow. Finally, decomposition of SOC in FMSW will respond more strongly to warming under aerobic conditions than SOC from upland forest soils because of higher accumulation of active SOC in FMSW. To test these hypotheses, we incubated FMSW and upland forest soils at two constant temperatures (10 and 30 °C) for 525-d under aerobic conditions and constant moisture. In contrast to our first hypothesis, we observed similarly rapid depletion of active SOC compounds at initial stages of incubation across FMSW and upland sites, and across the 525-d incubations we observed overall lower SOC decomposition rates in our FMSW soils. In line with our second hypothesis, and across FMWS and upland soils, we found greater SOC loss in the sub-alpine bioregion than both temperate regions. In contrast to our last hypothesis, we found no difference in the temperature sensitivity (Q₁₀) of SOC decomposition in FMSW and upland forest soils. Critically, total SOC loss (g SOC per g soil) was larger in FMSW because of the large amount of SOC stored in these ecosystems, indicating that despite a lack of difference between FMSW and upland responses, the total release of C from FMSW that could result from global warming may be large.

Quantifying the decline in transpiration of Tsuga Canadensis and predicting water budget implications of succession in southern Appalachian forests.

Davis, Joseph B. — Wed, 30 Sep 2009 12:23:42 -0400

Eastern hemlock (Tsuga canadensis (L.) Carr.) is declining throughout the eastern United States as a result of infestation of the hemlock woolly adelgid (HWA). As a principal species in riparian cove habitats in the southern Appalachians, its loss will have impact on the hydrologic budget in these systems. To estimate the impact on the hydrologic budget, we quantified transpiration over five years for T. canadensis, and over two years for co-occurring species Acer rubrum, Betula lenta, and Rhododendron maximum. Further, to understand the impacts of climate on transpiration, we compared transpiration to photosynthetically active radiation (PAR) and to vapor pressure deficit (VPD). Given the loss of T. canadensis from the ecosystem, we modeled implications on transpiration from two resulting succession scenarios, one in which R. maximum dominates, and one in which A. rubrum and B. lenta dominate. Transpiration was shown to decline since 2004 for T. canadensis, and no such decline was observed for the other species from 2006. The decline in transpiration was not shown to be a result of a changing climate conditions from the same study period. Using data from other studies, we modeled the succession of R. maximum following the loss of T. canadensis leaf area from the canopy. Also, we modeled the succession of A. rubrum and B. lenta resulting from a shift in sapwood area from T. canadensis to these species. Under both post-mortality scenarios, the transpiration component of the hydrologic budget increased. Although actual post-mortality scenarios are difficult to predict, the loss of T. canadensis will result in changes in the function of this ecosystem.

The forest inventory and analysis program: what's in it for landowners?

Harper, Richard — Fri, 02 Oct 2009 12:03:15 -0400

In 1597, Sir Francis Bacon coined the phrase, "Knowledge is power." KnOwledge today often means knowing where to find reliable information from branded research sources. One such source that benefits forest landowners and the forest community is the Forest Inventory and Analysis (FIA) program.

Decadal changes in potassium, calcium, and magnesium in a deciduous forest soil.

Johnson, D.W.; Todd, D.E.; Trettin, Carl C.; Mulholland, P.J. — Tue, 22 Sep 2009 16:47:24 -0400

Decadal changes in soil exchangeable K+, Ca2+, and Mg2+ concentrations and contents from 1972 to 2004 in eight intensively monitored plots on Walker Branch Watershed were compared with estimates of increments or decrements in vegetation and detritus. The results from these eight plots compared favorably with those from a more extensive set from 24 soil sampling plots sampled in 1972 and 2004. Increases in exchangeable K+ were noted between 1972 and 1982, but few changes were noted between 1982 and 2004 despite significant increments in vegetation and detritus and significant potential losses by leaching. Total K contents of soils in the 0- to 60-cm sampling depth were very large and a slight amount of weathering could have replenished the K+ lost from exchanges sites. With one notable exception, exchangeable Ca2+ and Mg2+ concentrations and contents decreased continuously during the sampling period. Decreases in exchangeable Ca2+ could be attributed mostly to increments in biomass and detritus, whereas decreases in exchangeable Mg2+ could not and were attributed to leaching. The major exception to these patterns was in the case of exchangeable Ca2+, where significant increases were noted in one plot and attributed to Ca release from the decomposition of Ca-rich coarse woody debris from oak (Quercus spp.) mortality. With minor exceptions, soils and changes in soils among the eight intensively sampled core plots were similar to those in a more extensive set of plots distributed across the watershed. This study shows that averaging among plots can mask significant and important spatial patterns in soil change that must be taken into account in assessing long-term trends.

Mapping land cover and estimating forest structure using satellite imagery and coarse resolution lidar in the Virgin Islands

Wed, 30 Sep 2009 18:01:53 -0400

Current information on land cover, forest type and forest structure for the Virgin Islands is critical to land managers and researachers for accurate forest inverntory and ecological monitoring. In this study, we use cloud free image mosaics of panchromatic sharpened Landsat ETM+ images and decision tree classification software to map land cover and forest type for the Virgin Islands, illustrating a low cost, repeatable mapping approach. Also, we test if coarse-resolution discrete lidar data that are often collected in conjunction with digital orthophotos are useful for mapping forest structural attributes. This approach addresses the factors that affect vegetation distsribution and structure by testing if environmental variables can improve regression models of forest height and biomass derived from lidar data. The overall accuracy of the 29 forest and nonforest classes is 72%, while most the forest types are classified with greater than 70% accuracy. Due to the larage point spacing of this lidar dataset, it is most appropriate for height measurements of dominant and co-dominant trees (R2 = 70%) due to its inability to accurately represent forest understory. Above ground biomass per hectare is estimated by its direct relationship with plot canopy height (R2 = 0.72%).

Assessment of forest fuel loadings in Puerto Rico and the U.S. Virgin Islands

Brandeis, Thomas; Woodall, Christopher — Thu, 01 Oct 2009 16:43:36 -0400

Quantification of the downed woody materials that comprise forest fuels has gained importance in Caribbean forest ecosystems due to the increasing incidence and severity of wildfires on island ecosystems. Because large-scale assessments of forest fuels have rarely been conducted for these ecosystems, forest fuels were assessed at 121 U.S. Department of Agriculture, Forest Service inventory plots on Puerto Rico, Vieques, and the U.S. Virgin Islands. Results indicated that fuel loadings averaged 24.05 Mg ha�"1 in 2004�"2006. Forest litter decreased from wetter to drier forest life zones. These island forests showed a paucity of coarse wood fuels (CWD) (2.91 Mg ha�"1) and relatively greater quantities of smaller-sized fine woody fuels (FWD) (10.18 mg ha-1 for FWD and 1082. mg ha�"1 for duff/litter) when compared to continental tropical forests. Between 2001 and 2006, DWD fuel loads decreased, while fine fuels and litter increased, such that total fuel loads remained constant on a subset of plots on Puerto Rico. This trend indicates that continued decomposition of CWD deposited by the last severe hurricane is balanced by increasing inputs of FWD from recovering and maturing secondary forests. Forest disturbance cycles and successional developments must be taken into account by agencies charged with fire protection and risk assessment.

Preliminary report on the segregation of resistance in chestnuts to infestation by oriental chestnut gall wasp

Anagnostakis, S; Clark, Stacy; Mcnab, Henry — Thu, 12 Nov 2009 16:26:01 -0500

In 1995, hybrid chestnuts were planted in North Carolina, (southern U.S.A.),

where the introduced insect Oriental Chestnut Gall Wasp (Dryocosmus kuriphilus) is

present. Of the 93 trees planted, 53 survived 12 years and were evaluated for the

presence of Oriental Chestnut Gall Wasp infestation. Among the survivors, 11 had

no wasp galls and 25 had few galls. Because the female parents were all susceptible,

the genes controlling resistance to infestation cannot be cytoplasmic. Numbers of

trees with little or no infestation suggest that genetic control may be a single,

dominant nuclear gene. If this 'is true, resistance can easily be transferred into

timber chestnuts and orchard chestnut cultivars.

Species diversity and composition in old growth and second growth rich coves of the southern Appalachian Mountains

Thu, 12 Nov 2009 14:51:59 -0500

Because of ongoing debate over the long term impacts of logging, we conducted

a study to assess if second growth (70 6 10 years) rich coves differ from old growth rich coves

(. 125 years) in species diversity or composition. We sampled twenty-six 0.1 ha plots,

representing these two age classes. We distributed the plots amongst three randomly selected

mountain ranges in the southern Appalachians of North Carolina, and sampled each

mountain range in separate years. We used nested subplots of 0.01 m2, 0.1 m2, 1 m2, 10 m2,

100 m2, and 1000 m2 to establish species-area relationships (SARs) for each age class. We

found no significant differences between the SARs for the two age classes, nor did we find

significant differences between age classes using the Simpson, Shannon-Wiener, or Sorensen

indices of species diversity. However, we found that total cover of all plant species was greater

in old growth rich coves, and that 10% of the tested species had lower abundance in second

growth. No species were present in old growth and absent in second growth, but species with

lower second growth abundance may warrant future study.

Effects of alternative silviculture on stump sprouting in the southern Appalachians

Atwood, Chad ; Fox, Thomas ; Loftis, David L. — Thu, 12 Nov 2009 15:03:49 -0500

Stump sprouts are an important form of regeneration for a number of species in the southern

Appalachians, especially the oaks (Quercus spp.). Alternative regeneration systems to clearcutting such

as shelterwood and leave-tree systems are being implemented in many hardwood stands in the

Appalachians. However, the effects of these alternative silvicultural systems on stump sprouts are not

known. Therefore, we evaluated the impact of three silvicultural systems: a clearcut, leave-tree, and

shelterwood on stump sprouting. These treatments were implemented in seven stands in Virginia and

West Virginia in the Appalachian Plateau (AP) and Ridge and Valley (RV) physiographic provinces. The

stands were even-aged oak dominated Appalachian hardwood stands with ages ranging from 62 to 100

years. Species were placed into six groups: (1) red oak (Quercus spp.), (2) chestnut oak (Q. prinus L.), (3) white

oak (Q. alba L.) and hickory (Carya spp.), (4) red maple (Acer rubrum L.), (5) mixed mesic, and (6)midstory

groups. Partial harvesting also reduced the number of sprouts per stump for the red oak group and red

maple. Sprouting probabilities were generally less in the Appalachian Plateau than the Ridge and Valley,

particularly for the oaks (Quercus spp.). Partial harvesting systems decreased sprouting in both

physiographic provinces. However, the sprouting in specific species groups varied between the two

physiographic provinces. In the Ridge and Valley, the highest sprouting rates were in the clearcut for the

red oak (60%), chestnut oak (77%), white oak�"hickory (26%), and midstory (33%) species groups. Red

maple sprouting was highest in the leave-tree (67%) in the Ridge and Valley. The mixed mesic and

midstory groups were only reduced in the Ridge and Valley. Sprouting was negatively correlated with

residual basal area for the red oak group, chestnut oak, and red maple. For the all oak species except

white oak, sprouting was reduced by about 2% for every 1m2/ha increase in residual basal area.