Treesearch

Softwoods, more specifically Cedars, are a set of tree species known to have extractive components with many different biological activities. Research has shown that certain compounds in Cedars are able to resist various forms of attack (microbial, fungal, insect, etc.). Juniperus virginiana (Eastern Red Cedar, Cupressus/Chamacyparis nootkatensis (Alaskan Yellow Cedar, & Thuja plicata (Western Red Cedar) are commonly studied. Eastern Red is ranked highest above Western Red and Alaskan Yellow in durability, which is a measure of the wood’s resistance to attack. Cedars in particular often...

Aim: To explore the recent (past ~1,000 year) migration history of yellow-cedar (Callitropsis nootkatensis), a climate-threatened tree, which appears to lag behind its potential climatic niche at a leading northern range edge, and infer its continued migration potential under changing climate. Location: Southeast Alaska, USA. Methods: We located 11 leading range edge yellow-cedar stands near Juneau, Alaska, determined their proportional occupancy of modelled habitat and estimated stand ages to determine approximate time of establishment. We used future climate projections to determine the...

The purpose of this chapter is to describe approaches to calculate a conservative and defensible estimate of the marginal value of forests for non-timber forest products (NTFPs). 'Provisioning' is one of four categories of benefits, or services that ecosystems provide to humans and was described by the Millennium Ecosystem Assessment as 'products obtained from ecosystems,' which include food, fuel, wood, and fiber, as well as products such as remedies and crafts. Clearly, any valuation of ecosystem benefits must include the tangible items, or products, that they supply.

Commentary on featured paper in an issue of Tree Physiology.

The terrestrial condition assessment (TCA) evaluates effects of uncharacteristic stressors and disturbance agents on land-type associations (LTAs) to identify restoration opportunities on national forest system (NFS) lands in the United States. A team of agency scientists and managers, representing a broad array of natural resource disciplines, developed a logic structure for the TCA to identify appropriate data sources to support analyses. Primary national data sources included observed insectand pathogen-induced mortality, key critical loads for soil and the atmosphere, long term...

Cellulose nanomaterials (CNs) are new types of materials derived from celluloses and offer unique challenges and opportunities for Raman spectroscopic investigations. CNs can be classified into the categories of cellulose nanocrystals (CNCs, also known as cellulose whisker) and cellulose nanofibrils (CNFs, also known as nanofibrillated cellulose or NFCs) which when produced exist as aqueous suspensions at very low concentrations. Analysis of these suspensions by Raman spectroscopy is especially rewarding in that the CNs can be analyzed in the native hydrated state without special considerat...

The pheromone components of many cerambycid beetles appear to be broadly shared among related species, including species native to different regions of the world. This apparent conservation of pheromone structures within the family suggests that field trials of common pheromone components could be used as a means of attracting multiple species, which then could be targeted for full identification of their pheromones. Here, we describe the results of such field trials that were conducted in nine states in the northeastern, midwestern, southern, and western United States. Traps captured...

The effects of biodiversity on ecosystem functioning generally increase over time, but the underlying processes remain unclear. Using 26 long-term grassland and forest experimental ecosystems, we demonstrate that biodiversity–ecosystem functioning relationships strengthen mainly by greater increases in functioning in high-diversity communities in grasslands and forests. In grasslands, biodiversity effects also strengthen due to decreases in functioning in low-diversity communities. Contrasting trends across grasslands are associated with differences in soil characteristics.

We collected field and remotely sensed data spanning 10 years after three 2003 Montana wildfires to monitor ecological change across multiple temporal and spatial scales. Multiple endmember spectral mixture analysis was used to create post-fire maps of: char, soil, green (GV) and non-photosynthetic (NPV) vegetation from high-resolution 2003 hyperspectral (HS) and 2007 QuickBird (QB) imagery, and from Landsat 5 and 8 imagery collected on anniversary dates in 2002, 2003 (post fire), 2004, 2007 and 2013. Initial estimates of char and NPV from the HS images were significantly correlated with...

Multidecadal trends in areas burned with high severity shape ecological effects of fires, but most assessments are limited to ~30 years of satellite data. We analysed the proportion of area burned with high severity, the annual area burned with high severity, the probability areas burned with high severity and also the area reburned (all severities and high burn severity only) over 133 years across 346,265 ha within the Selway-Bitterroot Wilderness (SBW) Area in Idaho, United States. We used burn severity class inferred from digitised aerial photography (1880-2000) and satellite imagery...