Treesearch

We analyzed a series of increment cores collected from 260 adult dominant or co-dominant quaking aspen (Populus tremuloides Michx.) trees from national forests across Colorado and southern Wyoming in 2009 and 2010. Half of the cores were collected from trees in stands with a high amount of crown dieback, and half were from lightly damaged stands. We define the level of stand damage based on stand survey data in which lightly damaged stands had average crown dieback of 16% and heavily damaged stands averaged 41%. Upon analysis, two-thirds of the cores collected did not exhibit radial growth...

White-headed woodpeckers (Picoides albolarvatus) are important cavity excavators that recently have become the focus of much research because of concerns over population declines. Past studies have focused on nest site selection and survival but information is needed on factors influencing their space use when away from the nest. We examined space use by white-headed woodpeckers during the nesting (May–Jul) and post-nesting (Jul–Oct) periods and compared the role of environmental factors (e.g., landcover) and socio-demographic factors (e.g., age, breeding success) in home range size and...

Invasive Species Science Updates are designed to keep managers and other users up-to-date with recently completed and ongoing research by RMRS scientists, as well as highlight breaking news related to invasive species issues. The newsletter is produced by the RMRS Invasive Species Working Group (ISWG), which is a core group of scientists who volunteer to coordinate outreach of RMRS invasive species science to managers and the public through this newsletter, our website, and periodic white papers.In this and future issues of the newsletter we want to continue to recognize partnerships and...

New residential construction is a critical driver of the demand for lumber, structural panels and engineered wood products in Canada. For the period 2010 through 2013, residential construction accounted for roughly 23 percent of the lumber consumed in Canada and 47 percent of structural panel usage. Insufficient data concerning imports and exports prevent estimates of the residential share of engineered wood products consumption. The focus of this study is for the year 2013. Based on the data provided by Home Innovation Research Labs survey of home builders, 1.262 billion board feet (bf)...

Precipitation, evapotranspiration (ET), and soil moisture are the key controls for the productivity and functioning of temperate grassland ecosystems in Inner Mongolia, northern China. Quantifying the soil moisture dynamics and water balances in the grasslands is essential to sustainable grassland management under global climate change. We conducted a case study on the variability and characteristics of soil moisture dynamics from 1991 to 2012 by combining field monitoring and computer simulation using a physically based model, MIKE SHE, at the field scale. Our long-term monitoring data...

A novel type of highly flexible and all-solid-state supercapacitor that uses cellulose nanofibril (CNF)/reduced graphene oxide (RGO)/carbon nanotube (CNT) hybrid aerogels as electrodes and H2SO4 poly (vinyl alcohol) PVA gel as the electrolyte was developed and is reported here. These flexible solid-state supercapacitors were fabricated without any binders, current collectors, or electroactive additives. Because of the porous structure of the CNF/RGO/CNT aerogel electrodes and the excellent electrolyte absorption properties of the CNFs present in the aerogel electrodes, the resulting...

Plants of Central Asia have played a significant role in the origin of floras of Eurasia and the Northern Hemisphere. Chesneya, a small leguminous genus occurring in Central Asia, western Asia, and Tibet, is used to establish phylogenetic relationships and discuss the evolutionary and biogeographical history based on sequence data of ITS and trnS-trnG and rbcL.We employed BEAST Bayesian inference for dating, and S-DIVA, Lagrange and BBM for ancestral area reconstruction. Our results indicate that Chesniella should be a separate genus, while Spongiocarpella should be included in Chesneya. A...

Population trends play a large role in species risk assessments and conservation planning, and species are often considered threatened if their recent rate of decline meets certain thresholds, regardless how large the population is. But how reliable an indicator of extinction risk is a single estimate of population trend? Given the integral role this decline-based approach has played in setting conservation priorities, it is surprising that it has undergone little empirical scrutiny. We compile an extensive global dataset of time series of abundance data for over 1300 vertebrate populations...

In felled-tree studies, ratio and regression estimators are commonly used to convert more readily measured branch characteristics to dry crown mass estimates. In some cases, data from multiple trees are pooled to form these estimates. This research evaluates the utility of both tactics in the estimation of crown biomass following randomized branch sampling (RBS). Synthetic generalized regression (GREG) estimators are developed, and their properties examined against standard estimators. It is shown that synthetic GREG estimators with zero or low design-bias can be obtained, and that the...

We attempted to develop new polymorphic SSR primer pairs in walnut using sequences derived from Juglans nigra L. genomic enriched library with GA repeat. The designed 94 SSR primer pairs were subjected to gradient PCR in 12 walnut cultivars to determine their optimum annealing temperatures and to determine whether they produce bands. Then, the primer pairs which had amplification in agarose gel were analyzed in capillary electrophoresis to determine their allele sizes. According to the gradient PCR and capillary electrophoresis results, 60.6% of the SSR primer pairs did not amplify any...