03797nas a2200193   4500008004100000020001400041245014200055210006900197260001100266300001200277490000800289520304800297653002703345100002703372700002003399700002503419700002403444856013503468       2012                        eng d  a0378-112700aRestoration of shortleaf pine (Pinus echinata)-hardwood ecosystems severely impacted by the southern pine beetle (Dendroctonus frontalis)0 aRestoration of shortleaf pine Pinus echinatahardwood ecosystems   cJun 15  a181-2000 v2743 aIn the Southern Appalachian Mountains of eastern USA, pine-hardwood ecosystems have been severely impacted by the interactions of past land use, fire exclusion, drought, and southern pine beetle (SPB, Dendroctonus frontalis). We examined the effects of restoration treatments: burn only (BURN); cut + burn on dry sites (DC + B); cut + burn on sub-mesic sites (MC + B); and reference sites (REF; no cutting or burning) on shortleaf pine-hardwood forests. We also evaluated the effectiveness of seeding native bluestem grasses. Structural (down wood, live and dead standing trees, shrubs, herbaceous layer) and functional (forest floor mass, C, and N; soil C, N, P. and cations; and soil solution N and P) attributes were measured before and the first and second growing seasons after treatment. We used path analysis to test our conceptual model that restoration treatments will have direct and indirect effects on these ecosystems. Total aboveground mass loss ranged from 24.33 Mg ha-1 on the BURN to 74.44 Mg ha-1 on the DC + B treatment; whereas, REF gained 13.68 Mg ha-1 between pre-burn and post-burn. Only DC + B sites had increased soil NO3-N, NH4-N Ca, Mg, and PO4-P and soil solution NO3-N, NH4-N, O-PO4 for several months. We found a significant increase in the density of oak species (Quercus alba, Q. coccinea, Q. montana, Q. rubra, and Q. velutina) on all burn treatments. However, oaks accounted for a smaller proportion of the total stem density than red maple, other tree species, and shrubs. The high densities of woody species other than oaks, coupled with the fast growth rates of some of these species, suggests that oaks will continue to be at a competitive disadvantage in these pine-hardwood communities through time, without further intervention. Pine regeneration was not improved on any of our burned sites with little to no recruitment of pines into the understory after two years and the pine saplings that were present before the burns were killed by fire on all sites. We found an increase in herbaceous layer cover and richness on all fire treatments. DC + B had higher bluestem grass cover than the other treatments, and it was the only treatment with increased bluestem grass cover between the first (2.96%, SE = 0.29) and second (6.88%, SE = 0.70) growing seasons. Our path model showed that fire severity explained a large proportion of the variation in overstory response; and fire severity and overstory response partially explained soil NO3-N. These variables, directly and indirectly, explained 64% of the variation in soil solution NO3-N at 30 cm soil depth (within the rooting zone for most plants). We found a good-fit path model for herbaceous layer response in the second growing season, where fire severity had direct effects on overstory and herbaceous layer responses and indirect effects on herbaceous layer response mediated through overstory response. Our path model explained 46% and 42% of the variation in herbaceous layer cover and species richness, respectively. Published by Elsevier B.V.10aDendroctonus frontalis1 aElliott, Katherine, J.1 aVose, James, M.1 aKnoepp, Jennifer, D.1 aClinton, Barton, D.  uhttps://weevil.myspecies.info/restoration-shortleaf-pine-pinus-echinata-hardwood-ecosystems-severely-impacted-southern-pine-beetle02264nas a2200169   4500008004100000020001400041245020400055210006900259260000800328300000800336490000700344520154300351653002701894100001801921700002001939856013501959       2012                        eng d  a1049-964400aThe effect of larval predators Thanasimus dubius (Coleoptera: Cleridae), produced by an improved system of rearing, against the southern pine beetle Dendroctonus frontalis (Coleoptera: Curculionidae)0 aeffect of larval predators Thanasimus dubius Coleoptera Cleridae  cJan  a1-60 v603 aThe southern pine beetle, Dendroctonus frontalis (Coleoptera: Curculionidae) (SPB), is known to be a major bark beetle pest of pines throughout the southeastern United States. A common predator of bark beetles, Thanasimus dubius (Coleoptera: Cleridae), has been suggested to play a prevalent role on SPB dynamics. Evaluations of T. dubius have been limited by rearing methods; an artificial diet for larval T. dubius exists, and preservatives such as sorbic acid could help to maximize diet shelf-life and enhance the efficiency of the rearing system. The effects of sorbic acid at different concentrations (0%, 0.1% and 0.2%) in the larval diet for T. dubius were measured, and the effects of increased feeding time intervals (2-3 vs. 5 days) on predator performance evaluated. In addition, an experimental bioassay was conducted where newly hatched T. dubius larvae were released at four densities (0, 50, 100, and 200 per log) on pine logs infested by SPB. Sorbic acid in the diet reduced female fecundity (by 20-40%), but did not affect adult T. dubius size or longevity. However, using this preservative may not be necessary because it had no effect on the overall efficiency of the rearing system, while refreshing the larval diet every 5 days (compared with 2-3 days) did improve its efficiency, even without sorbic acid. The release of larval T. dubius resulted in a highly significant effect on the SPB ratio of increase (RI). This experiment was facilitated by the improvements in our rearing methods. Published by Elsevier Inc.10aDendroctonus frontalis1 aCosta, Arnaud1 aReeve, John, D.  uhttps://weevil.myspecies.info/effect-larval-predators-thanasimus-dubius-coleoptera-cleridae-produced-improved-system-rearing-again