Treesearch

Streams and rivers of the Luquillo Experimental Forest, Puerto Rico, have been the subject of extensive watershed and aquatic research since the 1980s. This research includes understanding stream export of nutrients and coarse particulate organic matter, physicochemical constituents, aquatic fauna populations and community structure. However, many of the streams and watersheds studied do not appear in standard scale maps. We document recent collaborative and multi-institutional work to improve hydrological network information and identify knowledge gaps. The methods used to delimit and...

The Marcell Experimental Forest (MEF) in northern Minnesota, USA, with hydrological research and monitoring of peatland catchments in a low-topographic relief landscape, contrasts with the mountainous terrain that typifies most research catchments. Six research catchments were instrumented and hydrological and meteorological monitoring was initiated during 1960. Paired-catchment studies, which started during 1969, have been used to assess land management and environmental change effects on forests, water availability, and biogeochemistry. Over the decades, the research and collaborations...

An active group of expert birders have been monitoring spring and fall raptor migration across the Mackinac Straits for the past several years. These birders are members of Mackinac Straits Raptor Watch (MSRW; https://www.mackinacraptorwatch.org/), a nonprofit group dedicated to the research and conservation of raptors in the Straits of Mackinac. Nearly daily spring counts started in 2012 near the tip of Michigan's Lower Peninsula in Mackinaw City, and nearly daily fall counts struted in 2018 in the Upper Peninsula (UP) at Point LaBarbe, which is less than 2 miles west of where the...

The mission of the USDA Forest Service is to sustain the health, diversity, and productivity of the Nation’s forests and grasslands to meet the needs of present and future generations. All Forest Service activities, conducted through the National Forest System, Forest Service Research and Development, and State and Private Forestry, are intended to help sustain forests and grasslands now and into the future. The Forest Service manages over 193 million acres (78 million hectares) of National Forests and Grasslands for sustainable multiple uses to meet the diverse needs of people, ensure the...

All wood is composed of cellulose, lignin, hemicelluloses, and minor amounts (usually less than 10%) of extraneous materials contained in a cellular structure. Variations in the characteristics and proportions of these components and differences in cellular structure are what give the wood its unique physical properties, such as heavy or light, stiff or flexible, hard or soft. The properties of a single species are relatively constant within limits; therefore, selection of wood by species alone may sometimes be adequate. However, to use wood to best advantage and most effectively in...

This assessment uses historical observations and datasets, as well as studies conducted in contemporary reference landscapes (i.e., those with active fire regimes and minimal management impacts) to define the natural range of variation (NRV) for red fir (Abies magnifica) and subalpine forests in northwestern California and southwestern Oregon. Comparisons between historical and current conditions in the assessment area suggest that many of the ecological attributes of red fir and subalpine forests are within the NRV; however, some conditions and processes are also approaching or are...

High-elevation Quercus rubra forests in the Appalachian Mountains represent a transition zone between temperate mixed-Quercus forests that dominate lower elevations (<1350 m) and Picea-Abies forests at high (>1530 m) elevations. Little information exists specific to the response to disturbance, including timber harvesting, in these forests. In this study, we examined the long-term (22 years) effects of alternative regeneration methods – group selection harvests (GSH) and shelterwood with high (SWH; 9.0 m2/ha) and low (SWL; 5.0 m2/ ha) residual basal area, and undisturbed control (CON) – on...

Properties of cellulose nanocrystals (CNCs) depend upon their supramolecular structures, which are important to understand in order to optimize their applications. In this investigation, the structures of CNCs produced upon 48–64% H2SO4 hydrolysis of hydrothermally-treated poplar, bleached kraft pulp cotton microcrystalline cellulose, bacterial cellulose, tunicin, and cladophora cellulose were comparatively analyzed. TEM provided information on the morphological aspects. Raman, MAS-NMR, and XRD provided information on one aspect of the supramolecular organization, namely, crystallinity...

Since 2000, the Black Hills National Forest has experienced several disturbances that have reduced standing live sawtimber volume which will affect future harvest levels. To evaluate options concerning the future timber management program, we conducted a quantitative analysis to determine how mortality from these disturbances and potential growth rates will impact short-, mid-, and long-term sustainable sawtimber harvest levels of ponderosa pine (Pinus ponderosa var. scopulorum Dougl. ex Laws.). In 2019, there was 5,995,428 CCF (hundreds of cubic feet) standing live ponderosa pine sawtimber...

Understanding how drivers of ecological disturbance operate across scales is important in an era of increasing disturbance activity. Severe and extensive Dendroctonus bark beetle outbreaks across western North America have left in their wake dominance by shade-tolerant and commonly late-seral trees such as subalpine fir (Abies lasiocarpa), which can foster resilience of forest cover. However, subalpine fir decline (SFD) is a poorly understood phenomenon that has killed trees across millions of hectares in western North America with unknown consequences for future forest resilience. How...