Treesearch

Springs are the point of origin for most headwater streams and are important regulators of their chemical composition. We analysed solute concentrations of water emerging from 57 springs within the 3 km2 Fool Creek catchment at the Fraser Experimental Forest and considered sources of spatial variation among them and their influence on the chemical composition of downstream water. On average, calcium and acid neutralizing capacity (bicarbonate-ANC) comprised 50 and 90% of the cation and anion charge respectively, in both spring and stream water. Variation in inorganic chemical composition...

Pile burning is the most common method of logging residue disposal in Rocky Mountain forests. Though the high temperatures reached during burning affect numerous soil properties in the short term, the longer-term effects of the practice are less clear. We previously identified a 50-year time series of burn scars created after clear cut harvesting in lodgepole pine stands where we reported sparse tree colonization across the entire chronosequence. Here we analyzed soil nutrients and chemistry and conducted in situ and greenhouse seedling bioassays to determine whether edaphic factors or...

Background: Snags (standing dead trees) are important biological legacies in forest systems, providing numerous resources as well as a record of recent tree mortality. From 1997 to 2017, we monitored snag populations in drought-influenced mixed-conifer and ponderosa pine (Pinus ponderosa) forests in northern Arizona. Results: Snag density increased significantly in both forest types. This increase was driven largely by a pulse in snag recruitment that occurred between 2002 and 2007, following an extreme drought year in 2002, with snag recruitment returning to pre-pulse levels in subsequent...

Changing climatic conditions prompt concerns about vegetation response to disturbance under future compared to past conditions. In this long-term study, we examined soil climate and vegetation differences at lower, mid, and upper elevations in two separate locations in the Great Basin, USA. We hypothesized that soil climate and vegetation associations across the elevational gradient could help predict responses under future warming and drying. We measured soil water availability, soil temperatures, and vegetation cover in relation to fire and perennial herb removal at each elevation for...

Wood finishes (paint, varnish, and stain, for example) give a desired appearance, protect wood surfaces, and provide a cleanable surface. Many people consider appearance most important when choosing finishes for wood products. However, from a technical aspect, protection—from water, sunlight, and weathering—is most important for wood used outdoors. For wood indoors, appearance and a cleanable surface are generally most important. When selecting a finish, one should consider appearance, protection, cleanability, how properties of wood affect finish application, and how long it will likely...

In North America, most housing and commercial structures built prior to the 20th century used wood as the major structural material. The abundant wood resource formed the basic structure for most houses, commercial buildings, bridges, and utility poles. Today, houses and many light commercial and industrial buildings are made using modern wood structural materials. Recently, there has been increased interest in using wood for various types of transportation structures, including highway bridges. In this chapter, the features of various types of building systems are described. Emphasis is...

Fire safety is an important concern in all types of construction. The high level of national concern for fire safety is reflected in limitations and design requirements in building codes. These code requirements and related fire performance data are discussed in the context of fire safety design and evaluation in the initial section of this chapter. Because basic data on fire behavior of wood products are used to evaluate fire safety for wood construction, the second major section of this chapter provides additional information on fire behavior and fire performance characteristics of wood...

Many specialty treatments can be applied to wood to improve its performance. Treatments addressed in this chapter are those that make permanent changes in the shape of a wood product or improve properties, such as hardness, toughness, moisture resistance, dimensional stability, decay resistance, and mechanical or machining properties, through combinations with nonwood resources such as resins, polyethylene glycol (PEG), and acrylates.

Insects and other pests can travel between countries in pallets and other wood packaging materials through international trade. Because these pests can cause significant ecological damage, their invasion into non-native countries is undesirable. Heat sterilization is currently the most practical and environmentally friendly treatment to kill pests in solid wood materials and prevent their transfer between continents and regions. Consequently, regulations requiring heat sterilization are becoming more common. Two important questions should be considered in heat sterilizing solid wood...

Biosecurity and decontamination procedures for herpetofaunal conservation fall into several broad categories . This corresponds to the multifaceted decontamination approach tied to the stages of pathogen emergence (pre-arrival, invasion front, epidemic and establishment), and the intertwining contexts of natural resource management activities, the human dimension of transmission of novel pathogens, and integrated biodiversity conservation practices. Standard field-hygiene protocols generally aim to reduce the likelihood of human-mediated spread of disease-causing pathogens or invasive...