Treesearch

The Ozark Highlands of Missouri have experienced a complicated series of exploitive events (Flader 2004). The area was heavily cut over for timber at the turn of the last century and was overgrazed by privately owned livestock through the early 1900s. Decades of fire suppression since the 1940s further altered plant composition and structure. The current state of forest and woodland herbaceous communities may be quite unlike those seen historically.

Oak woodlands are characterized by open understories and dense ground flora composed of forbs, grasses, and sedges. They once were common in the western Central Hardwood Forest region and the prairie-forest transition zone where low-intensity fires occurred frequently. In the absence of fire, many of the woodland ecosystems throughout much of this region have succeeded to compositions and structures resembling those of mesophytic forests. Consequently, forest managers are increasingly interested in restoring the structure and composition of oak woodlands by thinning and prescribed burning....

The Northern Forest Futures Project aims to reveal how today's trends and choices are likely to change the future forest landscape in the northeastern and midwestern United States. The research is focused on the 20-state quadrant bounded by Maine, Maryland, Missouri, and Minnesota. This area, which encompasses most of the Central Hardwood Forest region, is the most heavily forested and most densely populated region in the Nation (Shifley et al. 2012). The Northern Forest Futures Project adds detail and context (e.g., Bowker and Askew 2013, Cordell et al. 2012, U.S. Forest Service 2014) to...

The North American hardwood dimension and components industry plays a critical role in the hardwood forest products industry as the industry is a user of high-value hardwood lumber. Customer expectations, global markets, and international competition, however, require hardwood dimension and components manufacturers to continuously improve their ability to manage their products and businesses. Accurate and timely product costing information is critically important for companies in planning the optimal utilization of company resources. While an overestimation of product costs can lead to...

The potential expansion of freeze-tolerant (FT) Eucalyptus plantations in the United States has raised concerns about the implications for water resources. Modeling was used to examine the potential effects of expanding the distribution of FT Eucalyptus plantations in US Department of Agriculture Plant Hardiness Zones 8b and greater on water yield (Q). Analyses focused on two scales: the stand scale and the regional scale at the 12-digit Hydrologic Unit Code (HUC) watershed. Results suggested that the stand-level implications of planting FT Eucalyptus on Q could vary by location, the land...

Dendroctonus frontalis Zimmermann is considered one of the most important economic and ecological forest pests in the United States, Mexico, and Central America. Recently, two apparent morphological variants of this species were discovered occurring syntopically in Central America and southern Mexico. Morphotype A beetles lack a series of Þne parallel ridges on the episternal area of the prothorax that are present on morphotype B. The goal of the present work was to clarify the taxonomic status of the morphotypes of the D. frontalis species complex. Geometric morphometric analyses of...

Bursaphelenchus xylophilus (Steiner & Buhrer) (Nematoda: Aphelenchoididae), the pinewood nematode and the causal agent of the pine wilt disease, is a globally important invasive pathogen of pine forests. It is phoretic in woodborer beetles of the genus Monochamus (Megerle) (Coleoptera, Cerambycidae) and has been able to exploit novel indigenous species of Monochamus (but only Monochamus) in newly-invaded areas. North America (NA) is the continent of origin for the B. xylophilus/Monochamus spp. phoretic system. NA also contains the largest number of Monochamus species known to act as...

Hemlock woolly adelgid (Adelges tsugae Annand, HWA) outbreaks are posing a major threat to eastern hemlock (Tsuga canadensis L. Carr.) and Carolina hemlock (Tsuga caroliniana Engelm.) forest landscapes in the eastern USA. As foundation species, hemlocks play a variety of functional roles in forest landscapes. These species usually occur as isolated canopies and mixed species in landscapes where variation in topography is extreme. Spatially explicit inventory information on HWA induced hemlock mortality at landscape scale does not exist. High resolution aerial imageries enable landscape...

A method for determining the sex of live adult Laricobius nigrinus Fender (Coleoptera:Derodontidae) is described. Beetles were briefly chilled and positioned ventral-side-up under a dissecting microscope. Two forceps with blunted ends were used to gently brace the beetle and press on the centre of the abdomen to extrude its terminal segments. Male beetles were distinguished by a sclerotised, reticulate ninth abdominal sternite. In females, the distinct ovipositor (tergite, valvifers (ninth sternite), and laterotergites of the ninth abdominal segment) was visible. The procedure was rapid...

Roptrocerus xylophagorum (Ratzeburg) (Hymenoptera: Pteromalidae) is a common Holarctic parasitoid of the larvae and pupae of bark beetles (Coleoptera: Curculionidae: Scotytinae). In no-choice laboratory bioassays, we found that male wasps derived either from northern California or southwestern Mississippi, United States of America more frequently displayed sexual behaviours (including mounting, wing fanning, and copulation attempts) to glass bulb decoys treated with hexane cuticular washes of females derived from the same parasitoid population rather than the distant population. This...