Treesearch

A warming climate may increase the frequency and severity of stand-replacing wildfires, reducing carbon (C) storage in forest ecosystems. Understanding the variability of postfire C cycling on heterogeneous landscapes is critical for predicting changes in C storage with more frequent disturbance. We measured C pools and fluxes for 77 lodgepole pine (Pinus contorta Dougl. ex Loud var. latifolia Engelm.) stands in and around Yellowstone National Park (YNP) along a 300-year chronosequence to examine how quickly forest C pools recover after a stand-replacing fire, their variability through...

Picture a tranquil landscape with undulating topography, idyllic streams, scenic glades, and verdant vegetation. Left to its own devices, this landscape would gradually become dominated by late successional communities that would slowly shift in response to climate changes over long time periods. This scene often forms the foundation and reference for most land management across the globe. However, this peaceful panorama rarely happens in nature because gradual successional change rarely drives landscape dynamics. Abrupt change is usually the rule, with vegetation development suddenly...

Thirty-three taxa associated with Ips typographus were identified, of which fifteen species were phoretic. The most abundant species were Insectolaelaps quadrisetus (Mesostigmata), Siculobata lentonycha (Oribata), Diapterobates humeralis (Oribata), Ereymetes propescutulis (Prostigmata), Aetiophenax ipidarius (Prostigmate), and an unidentified species of Nanacarus (Astigmata). Eight species - I quadrisetus, Proctolaelaps fiseri, Trichouropoda polytricha, Mexecheles virginiensis, A. ipidarius, E. propescutulis, Bonomota pini, and Boletoglyphus boletophagi - and four genera - Nanacarus,...

Termites carry large amounts of soil into dead wood, and this behaviour complicates efforts to measure their contributions to wood decay. A novel method for isolating termite soil by burning the wood is described, and some preliminary results are presented.

In this issue of the GSD Update, we take a look back at selected studies of the Grassland, Shrubland and Desert Ecosystem Science Program (GSD) that depict its strengths and focus areas. Significant results of recent research and science applications by GSD scientists are highlighted. We identify where program research lines up with the strategic priorities of the USDA Forest Service and the Rocky Mountain Research Station (RMRS). In particular, we spotlight accomplishments in: Understanding and controlling invasive plant species; Assessing changes in ecosystems and landscapes caused by...

Rejects from sulfite pulp mill that otherwise would be disposed of by incineration were converted to ethanol by a combined physical–biological process that was comprised of physical refining and simultaneous saccharification and fermentation (SSF). The energy efficiency was evaluated with comparison to thermochemically pretreated biomass, such as those pretreated by dilute acid (DA) and sulfite pretreatment to overcome recalcitrance of lignocelluloses (SPORL). It was observed that the structure deconstruction of rejects by physical refining was indispensable to effective bioconversion but...

Even as access to transactional data has been transformed by harnessing electronic flows, use of satellite imagery, research access to linked customer level records, and harmonising collections across jurisdictions, official statisticians are under pressure to detect significant turning points within response times and resolutions that cannot be handled by present estimation methods.State space models can be used to combine sources of data efficiently while respecting quality demands in advising government decision making. Specifically we phrase the measure problem as how to combine high...

Paleoenvironmental reconstructions are important for understanding the influence of long-term climate variability on ecosystems and landscape disturbance dynamics. In this paper we explore the linkages among past climate, vegetation, and fire regimes using a high-resolution pollen and charcoal reconstruction from Morris Pond located on the Markagunt Plateau in southwestern Utah, USA. A regime shift detection algorithm was applied to background charcoal accumulation to define where statistically significant shifts in fire regimes occurred. The early Holocene was characterized by greater...

This study introduces a novel tree-ring dataset, with unparalleled spatial density, for use as a climate proxy. Ancillary Douglas fir and pinyon pine tree-ring data collected by the U.S. Forest Service Forest Inventory and Analysis Program (FIA data) were subjected to a series of tests to determine their feasibility as climate proxies. First, temporal coherence between the FIA data and previously published tree-ring chronologies was found to be significant. Second, spatial and temporal coherence between the FIA data and water year precipitation was strong. Third, the FIA data captured the...

The distribution of poly(acrylic acid) (PAA) in model laminates of nanocellulose and poly(vinyl alcohol) (PVOH) was investigated by FTIR chemical imaging. The method was effective in spatially discerning the three components of the composite. PAA can potentially improve the performance of nanocellulose reinforced PVOH by not only crosslinking the PVOH matrix but also improving the adhesion between PVOH and nanocellulose by forming ester linkages with both of them. However, PAA was found to migrate out of the PVOH matrix and concentrate in the nanocellulose layer of the laminate. This led...