Distribution of Trace Metals in Fine-grained Bed Sediments and Benthic Insects in the Clark Fork River, Montana

The downstream distribution of Cu, Cd, and Pb in fine-grained sediments and benthic insect larvae of the Clark Fork River, Montana is characterized. This river has been heavily con laminated as a result of past mining and smelling operations near its headwaters. Concentrations of all metals in bed sediments displayed a simple exponential downstream decrease through the upper 181 km of the river. The trend suggested metal contamination originated from source(s) in the headwaters, with physical dilution occurring downstream. Additional data suggested floodplain sediments also were contaminated by the original source(s). Secondary inputs from cutbanks in the floodplains may have extended the downstream influence of the contamination. The exponential model predicted that sediment contamination should extend at least 550 km downstream, a result that was verified with data from a separate, independent study. Metal contamination, as observed in all taxa of insect larvae collected from the upper Clark Fork. Concentrations in the insect larvae were highest in the upper 100 km of the river, but downstream trends were more complex than those of the sediments. Some differences in trends occurred among taxa and metals. Areas in the river of enhanced or reduced metal contamination also were apparent. Metal contamination, however, was still evident at 381 km, the most downstream station sampled. Metal concentrations in sediments and insects decreased at the confluences of uncontaminated tributaries, but the influence of tributaries on metal contamination in the Clark Fork River was localized, extending for only 1-2 kin below the confluences

Synecology of the Monotropoideae within Limpy Rock Research Natural Area, Umpqua National Forest, Oregon

Four aspects of the ecology of members of the Monotropoideae (achiorophyllous Ericaceae, referred to here as "monotropes") are presented: (1) a clarified conceptualization of monotrope nutrition based on a detailed literature review, (2) the relationship of monotrope populations to the plant communities of Limpy Rock RNA, (3) a test of Vreeland's hypothesis concerning the influence of overstory trees on the number of Sarcodes sanguinea plants in a forest stand, (4) the population dynamics of the northernmost known occurrence of Sarcodes san guinea. A literature survey provides insight into the development of concepts concerning the nutritional mode of monotropes. The experimental evidence reviewed showed that the fungi involved have little saprobic ability but are ectomycorrhizal with autotrophic plants. Hence, the concept "epiparasite" can be used to describe an indirect relationship in the life history of monotropes. With consideration of the operational environment of monotropes, however, it can be concluded that the term "epiparasite" is not appropriately used in the context of the nutritional mode of monotropes. Members of the Monotropoideae can be viewed as parasites of their mycorrhizal fungi. Some evidence showed growth of the fungi was stimulated by the presence of monotropes. Since the term "parasite" has negative connotations in general usage, the terms 'obligate mycotroph" and "mycotrophic" may be preferred when referring to members of the Monotropoideae. "Mycotrophic" could be strictly applied to only those organisms which depend on fungi for energy; however, the term has long been used in a broad sense interchangeably with "mycorrhizal." Limpy Rock Research Natural Area is located in the south central portion of the Cascade Mountains in Oregon. The 751 ha (1879 ac.) tract encompasses most of the drainage of Dog Creek. Elevation ranges from 525 to 1305 m (1750 - 4350 ft.). The high species diversity of the Limpy Rock area and local concentration of all eight western monotrope species, provided excellent and possibly unique research opportunities. Coniferous forest vegetation was classified by TWINS PAN into six community types: Pseudotsuga menziesiilAcer circinatum (PSME/ACCI), Pseudotsuga menziesiilCornus nuttalliilBerberis nervosa (PS ME/CONU/B ENE), Pseudotsuga rnenziesii-Arbutus menziesii/Gaultheria shallon-Berberis nervosa/Pleridiurn aquilinum (PS ME-A RME/GAS H- BENE/PTAQ), Pseudotsuga menziesii-Calocedrus decurrens/Gaultheria shallo n-Berberis nervosa (PS MECADE/ GAS H-B ENE), Pseudotsuga menziesii-Calocedrus decurrens/Gauliheria shallon-Berberis nervosa (PS ME-PILA/GAS H-B ENE), Pseudotsuga menziesii- Abies concolor/Berberis nervosal Xerophyllurn tenax (PSME-ABCO/ BENE/XETE). Community types were related to several general environmental measures by detrended correspondence analysis and correlation analysis. Allotropa virgata is strongly preferential to plots at the dryer end of the moisture gradient. Monotropa hypopithys shows a preference for higher elevation and cooler types. Pterospora andromedea was not found in any plots but was noted to be widespread throughout the RNA. Hernitoines con gestwn, Monotropa uniflora, Fityopus californica, and Pleuricosporafiinbrioiata were largely restricted to dryer types. No monotropes were found in plots of the PSME/CONU/BENE or PSME-ARME/GASH-BENE/PTAQ community types. Vreeland's (1980) hypothesis concerning predicting the number of Sarcodes in a stand was reviewed and discussed. In particular, his "Influence Factor" was tested with a data base of over 2000 measurements. The results show his hypothesis to be invalid. Population monitoring of the northernmost known population of Sarcodes sanguinea showed that flowering of individual plants in subsequent years was low in frequency. Despite the low rate of flowering recurrence, population levels were relatively stable over the five years of monitoring

Detection of gaseous nerve agent simulants with broadband photoacoustic spectroscopy

While recent high-profile assassination attempts have once again brought nerve agents (NAs) into the spotlight, the current portfolio of NA sensors lack a sufficient combination of high performance and field-deployability. Here, we report a novel optical sensor for the detection of gaseous NAs with a potential to fill this gap. The technique is based on Fourier transform spectroscopy with a supercontinuum (SC) light source and cantilever-enhanced photoacoustic detection providing fast multi-species gas sensing with high sensitivity and selectivity in a sample volume of 7 ml, which becomes advantageous when analysing limited NA samples in the field. We study the fundamental C–H stretch bands of four known NA simulants and achieve detection limits of 64–530 ppb in one minute and recovery times of a few minutes. In the near future, the technique has significant potential to improve through the development of more powerful SC sources further in the mid-infrared region.Peer reviewe

Biomarkers of Heavy Metal Effects in Two Species of Caddisfly Larvae from Clark Fork River, Montana: Stress Proteins (HSP70) and Lysosomal Membrane Integrity

Potential sublethal effects of heavy metals in stream macroinvertebrates were examined with two cellular and biochemical biomarkers in larvae of two caddisflies indigenous to the Clark Fork River, Montana, - Hydropsyche spp. and Arctopsyche grandis. Stress proteins, in particular members of the HSP70 family, are involved in cellular protein homeostasis and repair, and are induced by a variety of stressors, which either damage cellular proteins directly or cause cells to synthesize aberrant proteins. Lysosomes are intracellular organelles that play key roles in the detoxification of both organic and inorganic xenobiotic compounds. Larvae of Hydropsyche spp. were collected from four sites on the Clark Fork (Galen Gage--4.7 km, Goldcreek--85.6 km, Turah--189.7 km, above Flathead--381 km) and a reference site (the Blackfoot River). Larvae of A. grandis were collected from the same sites minus the Galen site. Samples were immediately frozen in liquid nitrogen for HSP70 analysis, or preserved with Tissue Tek, then frozen in liquid nitrogen for the lysosomal stability assay. HSP70 was analyzed by western blotting using monoclonal antibodies. Lysosomal integrity was measured in cryosections by acid labilization with acid phosphatase as a marker enzyme. Results to date show elevated tissue concentrations of Cd, Cu, Pb and Zn and significantly increased levels of HSP70 in Arctopsyche from Goldcreek compared to reference samples. Lysosomal integrity also was compromised in samples from Goldcreek. In Hydropsyche, tissue concentrations of Cd, Cu and Pb from Galen Gage were elevated (4-7 times) relative to the Blackfoot River, but levels of HSP70 did not differ between the two sites. These preliminary results indicate that sublethal effects of metal exposure may differ between species

Relationships between Swiss needle cast and ectomycorrhizal fungus diversity

Swiss needle cast (SNC) is a disease specific to Douglas-fir (Pseudotsuga menziesii) caused by the ascomycete Phaeocryptopus gaeumannii. Here we examine characteristics of the EM fungus community that are potentially useful in predictive models that would monitor forest health. We found that mean EM density (number of colonized root tips/soil core) varied nearly 10-fold among sites of varying levels of SNC, while mean EM fungus species richness (number of species/soil core) varied by about 2.5 times. Strong relationships were found between EM and SNC parameters: EM species richness was positively correlated with both Douglas-fir needle retention (R² = 0.93) and EM density (R² = 0.65); EM density also was significantly correlated with Douglas-fir needle retention (R² = 0.70). These simple characteristics of the EM fungus community could be used to monitor forest health and generate predictive models of site suitability for Douglas-fir. Based on previous findings that normally common EM types were reduced in frequency on sites with severe SNC, we also hypothesized that some EM fungi would be stress tolerant-dominant species. Instead, we found that various fungi were able to form EM with the stressed trees, but none were consistently dominant across samples in the severely diseased areas.This is the publisher’s final pdf. The article is copyrighted by the Mycological Society of America and published by Allen Press Inc. It can be found at: http://www.mycologia.org/.Keywords: Phaeocryptopus gaeumannii, Climate change, Anthropogenic disturbance, Ecosystem healt

Quantum-memory-enhanced dissipative entanglement creation in nonequilibrium steady states

This article investigates dissipative preparation of entangled nonequilibrium steady states (NESS). We construct a collision model where the open system consists of two qubits which are coupled to heat reservoirs with different temperatures. The baths are modeled by sequences of qubits interacting with the open system. The model can be studied in different dynamical regimes: with and without environmental memory effects. We report that only a certain bath temperature range allows for entangled NESS. Furthermore, we obtain minimal and maximal critical values for the heat current through the system. Surprisingly, quantum memory effects play a crucial role in the long-time limit. First, memory effects broaden the parameter region where quantum correlated NESS may be dissipatively prepared and, second, they increase the attainable concurrence. Most remarkably, we find a heat current range that does not only allow, but even guarantees that the NESS is entangled. Thus, the heat current can witness entanglement of nonequilibrium steady states.</p

The effect of clouds and precipitation on the aerosol concentrations and composition in a boreal forest environment

Atmospheric aerosol particle concentrations are strongly affected by various wet processes, including below and in-cloud wet scavenging and in-cloud aqueous-phase oxidation. We studied how wet scavenging and cloud processes affect particle concentrations and composition during transport to a rural boreal forest site in northern Europe. For this investigation, we employed air mass history analysis and observational data. Long-term particle number size distribution (similar to 15 years) and composition measurements (similar to 8 years) were combined with air mass trajectories with relevant variables from reanalysis data. Some such variables were rainfall rate, relative humidity, and mixing layer height. Additional observational datasets, such as temperature and trace gases, helped further evaluate wet processes along trajectories with mixed effects models. All chemical species investigated (sulfate, black carbon, and organics) exponentially decreased in particle mass concentration as a function of accumulated precipitation along the air mass route. In sulfate (SO4) aerosols, clear seasonal differences in wet removal emerged, whereas organics (Org) and equivalent black carbon (eBC) exhibited only minor differences. The removal efficiency varied slightly among the different reanalysis datasets (ERA-Interim and Global Data Assimilation System; GDAS) used for the trajectory calculations due to the difference in the average occurrence of precipitation events along the air mass trajectories between the reanalysis datasets. Aqueous-phase processes were investigated by using a proxy for air masses travelling inside clouds. We compared air masses with no experience of approximated in-cloud conditions or precipitation during the past 24 h to air masses recently inside non-precipitating clouds before they entered SMEAR II (Station for Measuring Ecosystem-Atmosphere Relations). Significant increases in SO4 mass concentration were observed for the latter air masses (recently experienced non-precipitating clouds). Our mixed effects model considered other contributing factors affecting particle mass concentrations in SMEAR II: examples were trace gases, local meteorology, and diurnal variation. This model also indicated in-cloud SO4 production. Despite the reanalysis dataset used in the trajectory calculations, aqueous-phase SO4 formation was observed. Particle number size distribution measurements revealed that most of the in-cloud SO4 formed can be attributed to particle sizes larger than 200 nm (electrical mobility diameter). Aqueous-phase secondary organic aerosol (aqSOA) formation was non-significant.Peer reviewe

Ectomycorrhizal communities of ponderosa pine and lodgepole pine in the south-central Oregon pumice zone

Forest ecosystems of the Pacific Northwest of the USA are changing as a result of climate change. Specifically, rise of global temperatures, decline of winter precipitation, earlier loss of snowpack, and increased summer drought are altering the range of Pinus contorta. Simultaneously, flux in environmental conditions within the historic P. contorta range may facilitate the encroachment of P. ponderosa into P. contorta territory. Furthermore, successful pine species migration may be constrained by the distribution or co-migration of ectomycorrhizal fungi (EMF). Knowledge of the linkages among soil fungal diversity, community structure, and environmental factors is critical to understanding the organization and stability of pine ecosystems. The objectives of this study were to establish a foundational knowledge of the EMF communities of P. ponderosa and P. contorta in the Deschutes National Forest, OR, USA, and to examine soil characteristics associated with community composition. We examined EMF root tips of P. ponderosa and P. contorta in soil cores and conducted soil chemistry analysis for P. ponderosa cores. Results indicate that Cenococcum geophilum, Rhizopogon salebrosus, and Inocybe flocculosa were dominant in both P. contorta and P. ponderosa soil cores. Rhizopogon spp. were ubiquitous in P. ponderosa cores. There was no significant difference in the species composition of EMF communities of P. ponderosa and P. contorta. Ordination analysis of P. ponderosa soils suggested that soil pH, plant-available phosphorus (Bray), total phosphorus (P), carbon (C), mineralizable nitrogen (N), ammonium (NH₄), and nitrate (NO₃) are driving EMF community composition in P. ponderosa stands. We found a significant linear relationship between EMF species richness and mineralizable N. In conclusion, P. ponderosa and P. contorta, within the Deschutes National Forest, share the same dominant EMF species, which implies that P. ponderosa may be able to successfully establish within the historic P. contorta range and dominant EMF assemblages may be conserved.Keywords: Pinus ponderosa, Pine species migration, Climate change, Ectomycorrhizal communities, Pinus contort

Recovery of ectomycorrhizal fungus communities fifteen years after fuels reduction treatments in ponderosa pine forests of the Blue Mountains, Oregon

Managers use restorative fire and thinning for ecological benefits and to convert fuel-heavy forests to fuel-lean landscapes that lessen the threat of stand-replacing wildfire. In this study, we evaluated the long-term impact of thinning and prescribed fire on soil biochemistry and the mycorrhizal fungi associated with ponderosa pine (Pinus ponderosa). Study sites were located in the Blue Mountains of northeastern Oregon where prescribed fire treatments implemented in 1998 and thinning treatments in 2000 included prescribed fire, mechanical thinning of forested areas, a combination of thinning followed by fire, and an untreated control. Soil sampling for this study occurred in 2014 and included four replications of each treatment for a total of 16 experimental units. Differences among treatments in Bray-P, total C and N, and pH were likely driven by the thinning treatments and the resultant deposition of residual slash following harvesting or the consumption of slash by prescribed fire. Similar litter depths across treatments suggest that litter depth stabilizes over time in these forests. After more than a decade of recovery, mycorrhizal fungi in dry inland forests dominated by ponderosa pine that were subjected to fire returned to levels similar to the untreated controls. The results of this study demonstrate the resiliency of these forests to disturbances associated with restoration treatments, providing managers increased flexibility if maintaining abundant and persistent fungal communities for healthy soils is an objective