Treesearch

Magnetostrictive composite known as magnetostrictive nanocellulose membrances (MNMs) were fabricated by embedding Terfeonol-D particles into cellulose nanofibers (CNFs). MNMs inherit flexibility and biodegradability from CNF while exhibiting magnetomechanical responses; as such, the valuable rare-earth (Terfenol-D) particles can be recycled. Various orientations of the Terfenol-D particles were induced in the MNMs, and those with in-plane alignment showed the strongest magnetostrictive effect but the lowest Villari effect. Materials with such a unique combination of properties dovetail...

In January, total housing permits increased to their highest level in 13 years on a seasonally adjusted annualized basis. In December and January, total housing starts recorded their best two months since mid-2006, indicating a substantial year-over-year increase. However, total and single-family starts declined on a month-over-month basis. Total, single- and multifamily completions, and existing sales also decreased monthly. Single-family housing units under construction and single-family completions were negative on a year-over-year basis.

In the present study, very small concentrations of CNCs and CNFs were melt-compounded into PLA using a solvent-free process where poly(ethylene glycol) (PEG) was used to disperse the nanoparticles in PLA. As a comparison, the commercial nucleant, talc, was processed similarly into PLA. CNC and CNF were shown to be efficient nucleants for PLA, similar to talc, and conventional Avrami and Lauritzen-Hoffman analysis of the crystallization behavior was performed for isothermal temperatures from 90 °C to 130 °C across all compositions. From the Avrami analysis, the crystallization rate,...

This report describes a project that tested social media versus traditional postal mailing advertising for a series of forestry Extension educational programs. Forestry Extension clientele have diverse backgrounds and include landowners, urban tree owners, communities, agencies, and others, and vary widely by sociodemographic and ownership characteristics. Such diversity creates challenges for technology transfer, including initial client contact, participation in educational programming, and realization of learning objectives. The Mississippi State University Forestry Extension program...

Abstract Climate change is predicted to result in warmer and drier Neotropical forests relative to current conditions. Negative density-dependent feedbacks, mediated by natural enemies, are key to maintaining the high diversity of tree species found in the tropics, yet we have little understanding of how projected changes in climate are likely to affect these critical controls. Over three years, we evaluated the effects of a natural drought and in situ experimental warming on density-dependent feedbacks on seedling demography in a wet tropical forest in Puerto Rico. In the +4oC warming...

Soil respiration in tropical forests represents a major source of carbon dioxide (CO2) to the atmosphere. The magnitude of this large flux is projected to change in response to climate change, with global implications due to the disproportionate role of tropical forests in the carbon cycle. Evaluating diel patterns of soil respiration concomitantly with biophysical drivers is a valuable approach for elucidating the mechanisms controlling soil respiration. We measured hourly soil respiration rates in a tropical moist forest in Puerto Rico over a 3‐year period using automated chambers, as...

Fine roots play an important role in plant nutrition, as well as in carbon, water, and nutrient cycling. Fine roots account for a third of terrestrial net primary production (NPP), and inclusion of their structure and function in global carbon models should improve predictions of ecosystem responses to climate change. However, studies focusing on underground plant components are much less frequent than those on aboveground structure. This is more marked in the tropics, where one-third of the planet's terrestrial NPP is produced. Some tropical forests have been more represented in the...

Increases in atmospheric carbon dioxide (CO2) concentrations are expected to lead to increases in the rate of tree biomass accumulation, at least temporarily. On the one hand, trees may simply grow faster under higher CO2 concentrations, preserving the allometric relations that prevailed under lower CO2 concentrations. Alternatively, the allometric relations themselves may change. In this study, the effects of elevated CO2 (eCO2) on tree biomass and allometric relations were jointly assessed. Over 100 trees, grown at Duke Forest, NC, USA, were harvested from eight plots. Half of the plots...

Five lichen species were evaluated as element-content pollution bioindicators for a pilot study in Wisconsin and adjacent U.S. states, using data for 20 elements. Goodquality elemental data for aluminum, cobalt, chromium, copper, iron, nitrogen, and sulfur—mostly from nonspecialist U.S. Forest Service Forest Inventory and Analysis staff collections with extensively documented protocols—clearly indicated a site pollution load in the project area. The percentage of nearby land in forest was the strongest predictor for sample collection at study sites of the two most frequent species; such...

The realm of wildland fire science encompasses both wild and prescribed fires. Most of the research in the broader field has focused on wildfires, however, despite the prevalence of prescribed fires and demonstrated need for science to guide its application. We argue that prescribed fire science requires a fundamentally different approach to connecting related disciplines of physical, natural, and social sciences. We also posit that research aimed at questions relevant to prescribed fire will improve overall wildland fire science and stimulate the development of useful knowledge about...