Treesearch

Controls on the decomposition rate of soil organic carbon (SOC), especially the more stable fraction of SOC, remain poorly understood, with implications for confidence in efforts to model terrestrial C balance under future climate. We investigated the role of substrate supply in the temperature sensitivity of SOC decomposition in laboratory incubations of coarse-textured North American soils sampled from paired native pine and hardwood forests located across a 20 °C gradient in mean annual temperature (MAT). In this study we show that for this wide range of forest soils, the supply of...

The identification of fungicide residues on crop foliage is necessary to make periodic pest management decisions. The determination of fungicide residue identities currently is difficult and time consuming using conventional chemical analysis methods such as gas chromatography-mass spectroscopy. Different fungicide types produce unique electronic aroma signature patterns when headspace volatiles are analyzed using a multi-sensor array within an electronic–nose device. The advantage of electronic-nose sensor devices over conventional methods is that fungicides may be rapidly identified even...

The Aromascan A32S conducting polymer electronic nose was evaluated for the capability of detecting the presence of off-flavor malodorous compounds in catfish meat fillets to assess meat quality for potential merchantability. Sensor array outputs indicated that the aroma profiles of good-flavor (on-flavor) and off-flavor fillets were strongly different as confirmed by a Principal Component Analysis (PCA) and a Quality Factor value (QF > 7.9) indicating a significant difference at (P < 0.05). the a32s e-nose effectively discriminated between good-flavor and off-flavor catfish at high levels...

Bamboo is a biomass material and has great potential as a bio-energy resource of the future in China. Bamboo pellets were successfully manufactured using a laboratory pellet mill in preliminary work. This study was therefore carried out to investigate the effect of carbonization conditions (temperature and time) on properties of bamboo pellets and to evaluate product properties. It was concluded that carbonization conditions affected the properties of bamboo pellets. The effects of carbonization temperature on some properties such as unit mass loss, pellet absorption, bulk density, unit...

& Context Understanding tree interactions requires an insight into their spatial distribution. & Aims We looked for presence and extent of tree intraspecific spatial point pattern (random, aggregated, or overdispersed) and interspecific spatial point pattern (independent, aggregated, or segregated). & Methods We established twelve 0.64-ha plots in natural bottomland hardwood stands in the southeastern USA. & Results Spatial point pattern analyses (Ripley’s K, L, and L12) indicated that, when species were combined, trees were frequently aggregated and less commonly overdispersed. Plots with...

Pondberry (Lindera melissifolia) is an endangered plant species that occurs in seven southern states. It is a rhizomatous, clonal shrub that usually grows in colonies and has numerous stems with few branches and drooping leaves that give off a spicy odor when crushed. Pondberry is dioecious, with small yellow flowers that bloom in spring and have scarlet drupes that mature in late summer or fall. The species grows in low areas within bottomland hardwood forests in the western part of its range and on the margins of limestone sinks and wet depressions in pine forests in the eastern part....

The silver fir woolly adelgid, Dreyfusia nordmannianae, is the most severe pest occurring on Abies nordmanniana in Central and Northern Europe. The adelgid is particularly damaging to trees in Christmas tree plantations. Dreyfusia nordmannianae is native to the Caucasus region and alien to Europe, where its natural enemy complex is less diverse compared to its area of origin. Mitochondrial and nuclear DNA sequence data from the samples of D. nordmannianae collected in its native range and Europe and from the samples of Dreyfusia piceae and Dreyfusia prelli collected in Europe and North...

Estimating the economic benefits of reduced health damages due to improvements in environmental quality continues to challenge economists. We review welfare measures associated with reduced wildfire smoke exposure, and a unique dataset from California's Station Fire of 2009 allows for a comparison of cost of illness (COI) estimates with willingness to pay (WTP) measures. The WTP for one less symptom day is estimated to be $87 and $95, using the defensive behavior and contingent valuation methods, respectively. These WTP estimates are not statistically different but do differ from a $3...

The ability of N’N-naphthaloylhydroxylamine (NHA) to cause mortality in Reticulitermes flavipes workers pretreated with the chitin synthesis inhibitor diflubenzuron was tested by adding two NHA dusted workers to 100 (2:100) pretreated workers fed either pure microcrystalline alpha-cellulose or diflubenzuron (0.25%) treated microcrystalline cellulose for 30 days prior to adding the two dusted termites. By day 5 post addition, there was a 50% mortality in the diflubenzuron treated termites only. By day 17, the mean survival of cellulose treated termites was 91 +/-2.8% and in the diflubenzuron...

Losses of the soil resources from otherwise productive and well functioning watersheds is often a recurring problem confronting hydrologists and watershed managers. These losses of soil have both on-site and off-site effects on the watershed impacted. In addition to the loss of inherent soil resources through erosion processes, on-site effects can include the breakdown of soil structure, a decline in organic matter and nutrients in the soil, and a reduction in available soil moisture (Morgan 1995, Gregersen et al. 2007, Brooks et al. 2013). The net impact of these on-site effects can be a...