Treesearch

Key message TRACC is an open-source software for standardizing the cleaning, conversion, and calibration of sap flux density data from thermal dissipation probes, which addresses issues of nighttime transpiration and water storage. Abstract Thermal dissipation probes (TDPs) have become a widely used method of monitoring plant water use in recent years. The use of TDPs requires calibration to a theoretical zero-flow value (DT0); usually based upon the assumption that at least some nighttime measurements represent zero-flow conditions. Fully automating the processing of data from TDPs is...

Laurel wilt is an extraordinarily destructive exotic tree disease in the southeastern United States that involves new-encounter hosts in the Lauraceae, an introduced vector (Xyleborus glabratus) and pathogen symbiont (Raffaelea lauricola). USDA Forest Service Forest Inventory and Analysis data were used to estimate that over 300 million trees of redbay (Persea borbonia sensu lato) have succumbed to the disease since the early 2000s (ca 1/3 of the pre-invasion population). In addition, numerous native shrub and tree species in the family are susceptible and threatened in the Western...

Hemlock woolly adelgid (Adelges tsugae Annand) (HWA) is an invasive forest insect sweeping across the native range of eastern (Tsuga canadensis [L.] Carr.) and Carolina (Tsuga caroliniana Engelm.) hemlocks, threatening to severely reduce eastern hemlock extent and to push Carolina hemlock to extirpation. HWA poses a significant threat to these eastern US natives, now infesting hemlocks across 19 states and more than 400 counties. For the long-term preservation of the species, ex situ genetic resource conservation efforts such as seed collection, storage, and adelgid-resistant hemlock...

The mechanisms governing the ability of water-soluble polymers (WSP) to alter the rheological properties of lignocellulosic biomass to achieve processing advantages are investigated. Lignocellulosic fiber surface chemistry is found to be an important factor in the efficacy of WSPs as rheological modifiers, and a strong correlation between the amount of adsorbed polymer at fiber surfaces and the yield stress of the fiber suspension indicate that adsorption of polymer is important for rheological modification. Three fiber suspensions of varying physical chemistry were produced from Aspen...

Hydraulic geometry offers robust scaling of channels across many orders of magnitude in natural rivers, irrigation canals, and laboratory channels (Ferguson 1986). Although the authors’ analysis focuses on fluvial deposits, it is worth noting that hydraulic geometry relations can be developed for a variety of fluids, which may have relevance for some Martian channels given that differences in gravity and atmospheric conditions (pressure, temperature, and, thus, viscosity) may cause channel hydraulics and flow rheology (Froude and Reynolds numbers) to differ from those on Earth. Data from...

Utah lotus (Lotus utahensis Ottley) is a North American leguminous forb that may hold promise for rangeland revegetation in the western United States for diversifying planting mixtures, attracting pollinators, providing high-quality forage, and expanding habitats for insects needed by sage-grouse chicks. Fourteen wildland seed collections of Utah lotus originating from Nevada and Utah were assessed for genetic variation of a wide range of phenotypic traits and genetic relationships. Population structure estimates defined by 552 amplified fragment length polymorphism (AFLP) markers identifie...

Human‐caused climate change is predicted to affect the frequency of hazard linked extremes. Unusually large wildfires, individually or expressed as area burned over time, are a type of extreme event that is constrained by climate and can be a hazard to society but also an important ecological disturbance. Here we project changes in the frequency of extreme monthly area burned by wildfires for the end of the 21st century for a wildfire‐prone region in the southeast United States. Predicting changes in area burned is complicated by the large and varied uncertainties in how the climate will...

Wildfires, harvesting, and beetle outbreaks all have different effects on forest dynamics and biogeochemical responses. Responses to beetle outbreaks vary with forest species composition, understory conditions, tree size and age, and other factors. Larger trees are more susceptible to mountain pine beetle attack. Mixed-age stands at the Fraser Experimental Forest had lower overall tree mortality and greater recovery potential. These findings provide support for maintaining age, species, and structural diversity within headwater forests.

Forest management that creates a diversity of prey habitats in ponderosa pine and mixed-conifer forests is beneficial to gos-hawks. The desired habitat diversity includes all tree age classes with a focus on older trees in fine-scale mosaics composed of groups of trees, scattered individual trees, large snags and logs and small openings with species-diverse and productive herbaceous-shrub communities.