Treesearch

Crop lighting is an energy-intensive necessity for nursery production of high-quality native plants and forest tree seedlings. During the winter months (especially in northern USA latitudes) or overcast or cloudy days, the amount of solar radiation reaching greenhouse crops is insufficient resulting in growth cessation, early terminal bud formation, and failure of seedlings to reach target height for outplanting (Tinus, 1995; Lopez and Runkle, 2008). In light of this, nursery growers have added supplemental lighting to increase the daily light integral (DLI), defined as the photosynthetic...

The number of monarch butterflies, charismatic nomads of North America, is rapidly declining. Milkweeds (Asclepias spp.), which are the sole food source for monarch caterpillars, have also experienced a decline throughout the breeding range of this butterfly. Milkweeds can be grown from seeds or vegetatively from root cuttings or rhizomes. Seed germination is often improved with stratification and plants are easily grown with standard propagation methods. However, some species require adjustments to the substrate to reflect unique soil conditions of their natural habitat. We encourage you...

Blackbrush (Coleogyne ramosissima Torr.) is a regionally dominant shrub species found in the transition zone between North American warm and cold deserts where it occupies millions of hectares on National Park Service, Bureau of Land Management, and National Forest lands. Blackbrush habitat is under severe threat of loss from the combined effects of exotic annual grasses, increased fire frequency, and rapid climate change. Attempts to restore blackbrush habitat have met with limited success. This research synthesizes existing information on blackbrush biology and ecology. Our goal is to...

Green consumerism embodies a dilemma inherent in many prosocial and moral actions — foregoing personal gain in favor of a more abstract, somewhat intangible gain to someone or something else. In addition, as in the case of purchasing more expensive green products, there is sometimes a very literal cost that may act as a barrier to engaging in green consumerism. The current review examines endogenous, exogenous, and structural factors that promote green consumerism. We also discuss its potential positive and negative spillover effects. We close by discussing areas of research on green...

This article builds on findings from a synthesis of fire social science research that was published from 2000 to 2010 to understand what has been learned more recently about public response to wildfires. Two notable changes were immediately noted in the fairly substantial number of articles published between 2011 and 2014. First, while over 90% of the articles found in the initial synthesis were US-based studies, roughly half of the articles published since 2010 have been conducted outside the USA, the majority from Australia. Second, while the primary focus of earlier studies was on...

The Ebola virus disease (EVD) epidemic that has stricken thousands of people in the three West African countries of Liberia, Sierra Leone, and Guinea highlights the lack of adaptive capacity in post-conflict countries. The scarcity of health services in particular renders these populations vulnerable to multiple interacting stressors including food insecurity, climate change, and the cascading effects of disease epidemics such as EVD. However, the spatial distribution of vulnerable rural populations and the individual stressors contributing to their vulnerability are unknown. We developed...

Species identification of logs, planks, and veneers is difficult because they lack the traditional descriptors such as leaves and flowers. An additional challenge is that many transnational shipments have unreliable geographic provenance. Therefore, frequently the lowest taxonomic determination is genus, which allows unscrupulous importers to evade the endangered species laws. In this study we explore whether analysis of wood using a Direct Analysis in Real Time (DART) Time-Of-Flight Mass Spectrometer (TOFMS) can assist in making unequivocal species determinations of Dalbergia. DART TOFMS...

Four species of the ectomycorrhizal (ECM) genus Sarcodon (Bankeraceae, Thelephorales, Basidiomycota) are described as new to science. Sarcodon pakaraimensis sp. nov. is described from forests dominated by the ECM trees Pakaraimaea dipterocarpacea (Dipterocarpaceae) and Dicymbe jenmanii (Fabaceae subfam. Caesalpinioideae) in the Pakaraima Mountains of Guyana. Sarcodon portoricensis sp. nov. is described from lower montane wet forest within the El Yunque National Forest of Puerto Rico. Sarcodon quercophilus sp. nov. and Sarcodon umbilicatus sp. nov. are described from Quercus (Fagaceae)...

Large fires or "megafires" have been a major topic in wildland fire research and management for over a decade. There is great debate regarding the impacts of large fires. Many believe that they (1) are occurring too frequently, (2) are burning abnormally large areas, (3) cause uncharacteristically adverse ecological harm, and (4) must be suppressed at all costs. Others believe that large fires can effectively reintroduce fire back into those declining fire-prone ecosystems where fires have been excluded for decades, thereby (1) improving ecosystem health, (2) reducing future fire hazard,...

In this study, cellulose nanocrystals (CNCs) are incorporated into a waterborne epoxy resin following two processing protocols that vary by order of addition. The processing protocols produce different levels of CNC dispersion in the resulting composites. The more homogeneously dispersed composite has a higher storage modulus and work of fracture at temperatures less than the glass transition temperature. Some properties related to the component interactions, such as thermal degradation and moisture content, are similar for both composite systems. The mechanism of dispersion is probed with...