Treesearch

Accurately monitoring global vegetation dynamics with modern remote sensing is critical for understanding the functions and processes of the biosphere and its interactions with the planetary climate. The MODerate resolution Imaging Spectroradiometer (MODIS) vegetation index (VI) product has been a primary data source for this purpose. To date, theMODIS teamhad released several versions of VI products that havewidely used in global change studies and practical applications. In this study, we re-examined the global vegetation activity by comparing the recent MODIS Collection 6 (C6) VIs with...

Forest fires cause large emissions of C (carbon), N (nitrogen) and Hg (mercury) to the atmosphere and thus have important implications for global warming (e.g. via CO2 and N2O emissions), anthropogenic fertilisation of natural ecosystems (e.g. via N deposition), and bioaccumulation of harmful metals in aquatic and terrestrial systems (e.g. via Hg deposition). Research indicates that fires are becoming more severe over much of North America, thus increasing element emissions during fire. However, there has been little research relating forest floor and mineral soil losses of C, N and Hg to...

The physical properties and dimensions of foliage are necessary inputs for some fire spread models. Currently, almost no data exist on these plant characteristics to fill this need. In this report, we measured the physical properties and dimensions of the foliage from 10 live shrub and conifer fuels throughout a 1-year period. We developed models to predict relative moisture content, apparent density, length, width, needle length, thickness, stem diameter, and surface area. Seasonal variability of the response variables was found to be adequately explained with a single model, so season-spe...

Although the American pika (Ochotona princeps) continues to receive attention due to documented declines and range retractions, particularly in the Great Basin, thorough range inventories have yet to be completed in many parts of the region. Here we report on recently discovered populations in northwestern Nevada in areas not suspected to support pika activity under current climate regimes. We describe 238 new locations (“sites”) with evidence of past or current occupancy by pikas that cluster into 31 locales, which we interpret as metapopulations or “demes”, in 15 distinct mountain ranges...

To evade endangered timber species laws, unscrupulous importers sometimes attempt to pass protected Dalbergia nigra as look-alike but unprotected, Dalbergia Spruceana. Wood density and fluorescence properties are sometimes used to identify the species. Although these properties are useful and do not require special equipment, they may be less reliable than direct analysis in real time—time of flight mass spectrometry (DART—TOFMS). DART—TOFMS was used to check identities of the D. nigra and D. Spruceana contained in the wood collection of the Forest Products Laboratory (Madison, Wisconsin)....

We review the mechanisms of deleterious nitrogen (N) deposition impacts on temperate forests, with a particular focus on trees and lichens. Elevated anthropogenic N deposition to forests has varied effects on individual organisms depending on characteristics both of the N inputs (form, timing, amount) and of the organisms (ecology, physiology) involved. Improved mechanistic knowledge of these effects can aid in developing robust predictions of how organisms respond to either increases or decreases in N deposition. Rising N levels affect forests in micro- and macroscopic ways from physiologi...

The goal of this study was to update life-cycle assessment (LCA) data associated with I-joist production in the Pacific Northwest (PNW) region of the United States from cradle-to-gate mill output. The authors collected primary mill data from I-joist production facilities per Consortium on Research for Renewable Industrial Materials (CORRIM) research guidelines. Comparative assertions were not a goal of this study.

Highbush blueberry (Vaccinium corymbosum L.) is an important crop grown throughout Florida. Currently, most blueberry growers use honey bees (Apis mellifera L.) to provide pollination services for highbush blueberries even though bumble bees (Bombus spp.) have been shown to be more efficient at pollinating blueberries on a per bee basis. In general, contribution of bumble bees to the pollination of commercial highbush blueberries in Florida is unknown. Herein we determined if managed bumble bees could contribute to highbush blueberry pollination. There were four treatments in this study:...

The southern pine beetle has shown a dramatic decline in outbreak activity over much of the southeastern States since the turn of the 21st century compared to previous decades. Concurrently, from the 1950s through the present day, a twenty-fold increase in pine plantation area has occurred across the region while trends in genetic tree improvement and pine silvicultural advances have seen a marked increase in application towards the end of the 20th century. We examine southern pine beetle outbreaks in the Piedmont and Coastal Plain physiographic provinces of the southeastern U.S. relative...

This report presents a summary of the most recent inventory of Colorado’s forests based on field data collected between 2004 and 2013. The report includes descriptive highlights and tables of area, numbers of trees, biomass, carbon, volume, growth, mortality, and removals. Most sections and tables are organized by forest type or forest-type group, species group, diameter class, or owner group. The report also describes the inventory’s design, inventory terminology, and data reliability. Results show that Colorado’s forest land covers 22.9 million acres. Forty-nine percent (11.1 million...