Treesearch

Fine and coarse woody debris (WD), or woody necromass, serves a multitude of functions in forests including: essential habitat for countless vertebrate, arthropod and microbial species; substrate for regenerating plants, for example as nurse logs; a dominant carbon source for heterotrophs; and both a sink and source for essential nutrients (Harmon et al. 1986; Palace et al. 2012). Further, as WD decomposes, resulting fragments and microbial byproducts of the decay process provide a major source of organic matter for soils (Magnússon et al. 2016). Finally, WD can account for up to 20% of...

The South-Central Oregon Adaptation Partnership (SCOAP) was developed to identify climate change issues relevant for resource management on federal lands in south-central Oregon (Deschutes National Forest, Fremont-Winema National Forest, Ochoco National Forest, Crooked River National Grassland, Crater Lake National Park). This science-management partnership assessed the vulnerability of natural resources to climate change and developed adaptation options that minimize negative impacts of climate change and facilitate transition of diverse ecosystems to a warmer climate. The vulnerability...

In California, projections of intensifying wet-dry extremes and shifts in precipitation seasonality suggest that hydrologic droughts may become more frequent in the coast redwood region. An increase in hydrologic drought frequency may be particularly problematic for aquatic species that rely on flow in headwater streams during the region’s June-October dry season. We used a 55-year record of precipitation and streamflow to explore the relationship between meteorological drought and hydrologic drought in the Caspar Creek Experimental Watersheds in north coastal California. The 4.24- km2...

This report represents proceedings of the Allegheny Society of American Foresters training session titled "SILVAH: 50 Years of Science Management Cooperation." This meeting celebrated a unique and long-lasting community of practice that includes forest and natural resource managers and scientists. SILVAH originated in northwestern Pennsylvania in the late 1960s. Over time, the research results, shared efforts, and training sessions led to decision support software and all became known as SILVAH, and the geographic range of the community expanded. This published proceedings includes 12...

This study evaluated the solubility of low-processed wood fibers produced from a low temperature acid hydrotropic fractionation (AHF) in an ionic liquid (IL) 1,5-diazabicyclo[4.3.0]non-5-enium acetate (DBNH[OAc]. Unbleached wood fibers produced from AHF using p-Toluenesulfonic acid (p-TsOH) with or without post-treatments with lignin and hemicelluloses content up to 15% and 25%, respectively, were dissolved directly into the ILDBNH[OAc]. Post-AHF treatments using dilute alkaline and glycerol swelled the cellulose and partially removed residual lignin resulting in improved dissolution....

Nitrogen deposition in the northeastern US changed N availability in the latter part of the twentieth century, with potential legacy effects. However, long-term N cycle measurements are scarce. N isotopes in tree rings have been used as an indicator of N availability through time, but there is little verification of whether species differ in the strength of this signal. Using long-term records at the Fernow Experimental Forest in West Virginia, we examined the relationship between soil conditions, including net nitrification rates, and wood δ15N in 2014, and tested the strength of correlati...

"Weather whiplash" is a colloquial phrase for describing an extreme event that includes shifts between two opposing weather conditions. Prior media coverage and research on these types of extremes have largely ignored winter weather events. However, rapid swings in winter weather can result in crossing from frozen to unfrozen conditions, or vice versa; thus, the potential impact of these types of events on coupled human and natural systems may be large. Given rapidly changing winter conditions in seasonally snow‐covered regions, there is a pressing need for a deeper understanding of such...

Selection cutting is defined as a tool for uneven-aged silviculture. Dependence on diameter distribution by forestry practitioners for identifying stand conditions has led to misuse of selection-like cuttings in even-aged northern hardwood stands. Our study used several long-term data sets to investigate the temporal stability in numbers of trees per diameter class in uneven-aged northern hardwood stands treated with single-tree selection and in 45-year-old second-growth stands treated with selection-like cuttings. We analyzed data from New York, Michigan, and Wisconsin to determine...

Stand basal area of ponderosa pine (Pinus ponderosa var. scopulorum Engelm.) in the US Southwest has little effect on the density of the wood produced, but climatic fluctuations have a strong effect. Wood density increases during drought, particularly if the drought occurs in late winter/early spring. Future droughts, as are predicted to increase in the US Southwest, may lead to production of smaller radial increments of higher density wood in ponderosa pine.

Ice storms are important but understudied disturbances that influence forest structure and function. In 1998, an ice storm damaged forest canopies and led to increased hydrologic losses of nitrogen (N) from the northern hardwood forest at the Hubbard Brook Experimental Forest (HBEF), a Long-Term Ecological Research (LTER) site in New Hampshire, USA. To evaluate the mechanisms underlying this response, we experimentally simulated ice storms with different frequencies and severities at the small plot scale. We took measurements of plant and soil variables before (2015) and after (2016, 2017)...