Treesearch

Some of the changes to U.S. forests will be directly caused by the effects of an altered climate, such as increases in atmospheric carbon dioxide (CO2) temperature (T), and nitrogen (N) deposition on tree growth, mortality, and regeneration. Other changes will be indirectly caused by climate-induced changes in disturbances, such as droughts, fire, insect outbreaks, pathogens, and storms (see Chap. 4). In this chapter, we document current knowledge of the potential direct of climate change on biogeochemical cycling (i.e., carbon [C], nutrients, and water) and forest tree distributions.

Short- and medium-term evaluation of how fuel treatments are working is the only way to know if the hundreds of activities on the ground are adding up to the goals of more resilient landscapes and increased safety of people and property. Monitoring is a critical resource for decision makers who design fuels management programs, however it is an often neglected part of the fuel management cycle.

Implementing fuel treatments in every place where it could be beneficial to do so is impractical and not cost effective under any plausible specification of objectives. Only some of the many possible kinds of treatments will be effective in any particular stand and there are some stands that seem to defy effective treatment. In many more, effective treatment costs far more than the value of treatment benefits. Understanding the scope of the fuel management challenges in these forests is the first step towards identifying fuel treatment approaches that are likely to be both effective and...

Background and aims. A soil fertility gradient, ranging from infertile to highly fertile soils, may define whether or not a plant will establish and spread at a site. We evaluated whether or not such a fertility gradient exists for Rosa multiflora Thunb., a nonnative invasive shrub, and Kalmia latifolia L., a native problem shrub, in closed-canopy forests of the eastern U.S. Methods. We sampled soil and vegetation at the regional scale, along four randomly located 1-km transects in 70+ year-old undisturbed forests in each of three national forests in Ohio, Pennsylvania and West Virginia....

Autumn is a season of dynamic change in forest streams of the northeastern United States due to effects of leaf fall on both hydrology and biogeochemistry. Few studies have explored how interactions of biogeochemical transformations, various nitrogen sources, and catchment flow paths affect stream nitrogen variation during autumn. To provide more information on this critical period, we studied (1) the timing, duration, and magnitude of changes to stream nitrate, dissolved organic nitrogen (DON), and ammonium concentrations; (2) changes in nitrate sources and cycling; and (3) source areas...

The USDA-FS Termiticde Testing Program has been evaluating termiticide performance since the 1930s. The program has provided baseline performance data for all termiticdes currently registered in the U.S. Through this report and individual product reports, registered termiticide performance data has been provided to pesticide manufacturers, regulators, the pest management industry, and the American public for decades. As new products are tested, the USDA-FS will continue to provide updated information.

Several mechanical approaches to managing vegetation fuels hold promise when applied to the dry mixed conifer forests in the western United States. These are most useful to treat surface, ladder, and crown fuels. There are a variety of techniques to remove or alter all kinds of plant biomass (live, dead, or decomposed) that affect forest resilience. It is important for managers to understand when (e.g., relative to stage of succession or time of year) and where (e.g., with respect to forest type or proximity to values at risk) each technique will best accomplish management objectives. This...

Fire has had a profound historical role in shaping dry mixed conifer forests in the western United States. However, the uncertainty and complexity of prescribed fires raises the question “Is fire always the best option for treating fuels?” The decision to use prescribed fire is dependent upon several factors.

Wood is a durable engineering material when used in an appropriate manner, but it is susceptible to biological decay when a log, sawn product, or final product is not stored, handled, or designed properly. Even before the biological decay of wood becomes visually apparent, the decay can cause the wood to become structurally unsound. The progression of decay to that critical state depends heavily on temperature and moisture conditions. As a preventative measure, wood preservatives are chemical treatments applied to wood to protect less-durable wood species from decay. To ensure that these...

This study applied dilute acid (DA) and sulfite pretreatment to overcome the recalcitrance of lignocelluloses (SPORL) to deconstruct earlywood and latewood cell walls of Douglas fir for fermentable sugars production through subsequent enzymatic hydrolysis. DA pretreatment removed almost all the hemicelluloses, while SPORL at initial pH=4.5 (SP-B) removed significant amount of lignin between 20 and 25 %. But both are not sufficient for effective enzymatic saccharification. SPORL at low initial pH=2 (SP-AB) combines the advantage of both DA and SPORL-B to achieve approximately 90 % hemicellul...