Treesearch

Although alternative control strategies using biocontrol agents have reduced populations of many pest insects, biocontrol of termites has met with limited success. Termite living conditions—crowded colonies in moist soil—are seemingly ripe for epizootic outbreaks, yet, termite colonies rarely succumb to disease. The source of their immunity comes from a multi-tiered defense system involving cellular, physiological, and behavioral mechanisms, the combination of which protects termites at individual and colony levels. Defeating termite immunity, however, may be possible by chemically...

The Sturgeon chub (Macrhybopsis gelida) is a cyprinid fish native to the Missouri and Mississippi River basins of the U.S. Suspected long-term declines in the size of its distribution have prompted a review of its conservation status by the U.S. Fish and Wildlife Service, a process which depends on reliable methods to delineate the distribution and status of extant populations. To facilitate monitoring of Sturgeon chub populations, we developed a quantitative PCR assay to detect Sturgeon chub DNA in environmental samples. The assay consistently detected Sturgeon chub DNA in concentrations...

Although protist species composition in the hindgut of subterranean termites is known to vary among termite species, less is known about the effects of biocides on protist population dynamics within a single species. The goal of this study was to observe the potential effect of chitosan, an environmentally friendly antimicrobial compound, on protist communities harbored in hindguts of Reticulitermes virginicus. Workers of two termite colonies collected from different locations were exposed to treated wood with different concentrations of chitosan (0.5%, 1% and 2%) and two sets of control-tr...

Riparian areas, wetlands, and groundwater-dependent ecosystems, which are found at all elevations throughout the Blue Mountains, comprise a small portion of the landscape but have high conservation value because they provide habitat for diverse flora and fauna. The effects of climate change on these special habitats may be especially profound, due to altered snowpack and hydrologic regimes predicted to occur in the near future. The functionality of many riparian areas is currently compromised by water diversions and livestock grazing, which reduces their resilience to additional stresses...

Aim: Abiotic conditions are key components that determine the distribution of species. However, co-occurring species can respond differently to the same factors, and determining which climate components are most predictive of geographic distributions is important for understanding community response to climate change. Here, we estimate and compare climate niches of ten subdominant, herbaceous forb species common in sagebrush steppe systems, asking how niches differ among co-occurring species and whether more closely related species exhibit higher niche overlap. Location: Western United...

Bark beetle outbreaks are increasing in frequency and intensity, generating massive inventories of dead trees globally. During attacks, trees are pre-inoculated with ophiostomatoid fungi via bark beetles, which has been shown to increase termite presence and feeding. These events may, in turn, alter biogeochemical cycles during decomposition. We examined these relationships by experimentally inoculating dead wood with bluestain fungi in a temperate pine forest. Across ten replicate plots, eight 0.5 m-long logs were inoculated with Ophiostoma minus and eight with distilled water. Half of...

Concern about excessive woody debris removals during biomass harvests has led to the development of biomass harvesting guidelines (BHGs) for retaining woody debris for habitat and nutrient cycling. However, the efficacy of BHGs has not been experimentally examined. Two BHG treatments applied during clearcutting and thinning operations were examined in a replicated complete-block experiment. The first BHG treatment included the retention of one-third of tops of trees ≥8 in. dbh and one-third of trees <8-in. dbh. The second included the retention of all tops of trees ≥8-in. dbh and no...

The problems associated with air pollution and higher air temperatures in cities have been known for over a century, but so have the impacts of trees and forests on improving air quality and regulating air temperatures. Science has advanced our understanding on the various ways that trees affect air quality and temperatures. Trees affect air quality and consequently human health in both positive and negative ways by regulating air temperatures, altering the local microclimates, altering building energy use, removing air pollutants and emitting various chemicals. While the overall effect of...

Current design standards incorporate the use of preservative treated and naturally durable wood where conditions are suitable for deterioration, but treatment options for mass timber products, particularly, cross laminated timber (CLT) remain to be addressed. Termiticide treatment is a necessity for CLT structures, especially in southeastern climates. Wood species currently used to fabricate CLT are non-durable, and current design standards do not properly address incorporation of preservative treatments into these systems. In this study, 12” x 14” x 4” Douglas-fir CLT pieces were installed...

Field data examining the long-term effects of chemical wood preservatives on refractory wood species with abundant heartwood is limited. This study was initiated to determine, by ground contact exposure, the effectiveness of preservativetreated heartwood material comprised of refractory Douglas-fir, Engelmann spruce, or southern pine. The study compared incised and non-incised lumber treated at three retentions with either ammoniacal copper arsenate (ACA) or chromated copper arsenate (CCA) and placed in ground contact at Mississippi and Wisconsin field test sites in 1975 and 1976, respectiv...