Molecular identity crisis: environmental DNA metabarcoding meets traditional taxonomy-assessing biodiversity and freshwater mussel populations (Unionidae) in Alabama.

The use of environmental DNA (eDNA) to assess aquatic biodiversity is a growing field with great potential for monitoring and managing threatened species, like freshwater mussel (Unionidae) populations. Freshwater mussels are globally imperiled and serve essential roles in aquatic systems as a food source and as a natural water filter making their management essential for ecosystem health. Unfortunately, mussel populations are often understudied, and challenges exist to accurately and efficiently describe the full suite of species present.

Detection and accumulation of environmentally-relevant glyphosate concentrations delivered via pulse- or continuous-delivery on passive samplers.

Glyphosate is the most commonly used herbicide globally, which has contributed to its ubiquitous presence in the environment. Glyphosate application rates and delivery to surface water vary with land use. Streams in urban and agricultural catchments can experience continuous delivery of low concentrations of glyphosate and aminomethylphosphonic acid (AMPA), while their presence in forest streams occurs as an episodic pulse following silvicultural application.

Land Use Overrides Stream Order and Season in Driving Dissolved Organic Matter Dynamics Throughout the Year in a River Network.

Anthropogenic land use has increased nutrient concentrations and altered dissolved organic matter (DOM) character and its bioavailability. Despite widespread recognition that DOM character and its reactivity can vary temporally, the relative influence of land use and stream order on DOM characteristics is poorly understood across seasons and the entire flow regime. We examined DOM character and 28-day bioavailable dissolved organic carbon (BDOC) across a river network to determine the relative roles of land use and stream order in driving variability in DOM character and bioavailability throughout the year.

Shifting stoichiometry: Long-term trends in stream-dissolved organic matter reveal altered C:N ratios due to history of atmospheric acid deposition.

Dissolved organic carbon (DOC) and nitrogen (DON) are important energy and nutrient sources for aquatic ecosystems. In many northern temperate, freshwater systems DOC has increased in the past 50 years. Less is known about how changes in DOC may vary across latitudes, and whether changes in DON track those of DOC.

Sensitivity and threshold dynamics of Pinus strobus and Quercus spp. in response to experimental and naturally occurring severe droughts.

Increased drought frequency and severity are a pervasive global threat, yet the capacity of mesic temperate forests to maintain resilience in response to drought remains poorly understood. We deployed a throughfall removal experiment to simulate a once in a century drought in New Hampshire, USA, which coupled with the region-wide 2016 drought, intensified moisture stress beyond that experienced in the lifetimes of our study trees. To assess the sensitivity and threshold dynamics of two dominant northeastern tree genera (Quercus and Pinus), we monitored sap flux density (Js), leaf water potential and gas exchange, growth and intrinsic water-use efficiency (iWUE) for one pretreatment year (2015) and two treatment years (2016-17).

Wildfires lead to decreased carbon and increased nitrogen concentrations in upland arctic streams.

The Central Siberian Plateau is undergoing rapid climate change that has resulted in increased frequency of forest fires and subsequent alteration of watershed carbon and nutrient dynamics. Across a watershed chronosequence (3 to >100 years since wildfire) we quantified the effects of fire on quantity and composition of dissolved organic matter (DOM), stream water nutrient concentrations, as well as in-stream nutrient uptake. Wildfires increased concentrations of nitrate for a decade, while decreasing concentrations of dissolved organic carbon and nitrogen (DOC and DON) and aliphatic DOM contribution for five decades.

Long-term hydrological response to forest harvest during seasonal low flow: Potential implications for current forest practices.

Seasonal changes in the magnitude and duration of streamflow can have important implications for aquatic species, drinking water supplies, and water quality. In many regions, including the Pacific Northwest (U.S.

Survey of Sensitivity to Fatty Acid-Amino Acid Conjugates in the Solanaceae.

Plants perceive insect herbivores via a sophisticated surveillance system that detects a range of alarm signals, including herbivore-associated molecular patterns (HAMPs). Fatty acid-amino acid conjugates (FACs) are HAMPs present in oral secretions (OS) of lepidopteran larvae that induce defense responses in many plant species. In contrast to eggplant (Solanum melongena), tomato (S.

eDNA as a tool for identifying freshwater species in sustainable forestry: A critical review and potential future applications.

Environmental DNA (eDNA) is an emerging biological monitoring tool that can aid in assessing the effects of forestry and forest manufacturing activities on biota. Monitoring taxa across broad spatial and temporal scales is necessary to ensure forest management and forest manufacturing activities meet their environmental goals of maintaining biodiversity. Our objectives are to describe potential applications of eDNA across the wood products supply chain extending from regenerating forests, harvesting, and wood transport, to manufacturing facilities, and to review the current state of the science in this context.

Watershed 'Chemical Cocktails': Forming Novel Elemental Combinations in Anthropocene Fresh Waters.

In the Anthropocene, watershed chemical transport is increasingly dominated by novel combinations elements, which are hydrologically linked together as 'chemical cocktails.' Chemical cocktails are novel because human activities greatly enhance elemental concentrations and their probability for biogeochemical interactions and shared transport along hydrologic flowpaths. A new chemical cocktail approach advances our ability to: trace contaminant mixtures in watersheds, develop chemical proxies with high-resolution sensor data, and manage multiple water quality problems.

Tropical rainforest carbon sink declines during El Niño as a result of reduced photosynthesis and increased respiration rates.

Changes in tropical forest carbon sink strength during El Niño Southern Oscillation (ENSO) events can indicate future behavior under climate change. Previous studies revealed ˜6 Mg C ha  yr lower net ecosystem production (NEP) during ENSO year 1998 compared with non-ENSO year 2000 in a Costa Rican tropical rainforest. We explored environmental drivers of this change and examined the contributions of ecosystem respiration (RE) and gross primary production (GPP) to this weakened carbon sink.

Canopy gradients in leaf functional traits for species that differ in growth strategies and shade tolerance.

In temperate deciduous forests, vertical gradients in leaf mass per area (LMA) and area-based leaf nitrogen (Narea) are strongly controlled by gradients in light availability. While there is evidence that hydrostatic constraints on leaf development may diminish LMA and Narea responses to light, inherent differences among tree species may also influence leaf developmental and morphological response to light. We investigated vertical gradients in LMA, Narea and leaf carbon isotope composition (δ13C) for three temperate deciduous species (Carpinus caroliniana Walter, Fagus grandifolia Ehrh.

How vertical patterns in leaf traits shift seasonally and the implications for modeling canopy photosynthesis in a temperate deciduous forest.

Leaf functional traits are used in modeling forest canopy photosynthesis (Ac) due to strong correlations between photosynthetic capacity, leaf mass per area (LMA) and leaf nitrogen per area (Narea). Vertical distributions of these traits may change over time in temperate deciduous forests as a result of acclimation to light, which may result in seasonal changes in Ac To assess both spatial and temporal variations in key traits, we measured vertical profiles of Narea and LMA from leaf expansion through leaf senescence in a sugar maple (Acer saccharum Marshall) forest. To investigate mechanisms behind coordinated changes in leaf morphology and function, we also measured vertical variation in leaf carbon isotope composition (δ(13)C), predawn turgor pressure, leaf water potential and osmotic potential.

Light acclimation optimizes leaf functional traits despite height-related constraints in a canopy shading experiment.

Within-canopy gradients of leaf functional traits have been linked to both light availability and vertical gradients in leaf water potential. While observational studies can reveal patterns in leaf traits, within-canopy experimental manipulations can provide mechanistic insight to tease apart multiple interacting drivers. Our objectives were to disentangle effects of height and light environment on leaf functional traits by experimentally shading branches along vertical gradients within a sugar maple (Acer saccharum) forest.

Light drives vertical gradients of leaf morphology in a sugar maple (Acer saccharum) forest.

Leaf mass per area (LMA, g m(-2)) is an essential trait for modeling canopy function due to its strong association with photosynthesis, respiration and leaf nitrogen. Leaf mass per area, which is influenced by both leaf thickness and density (LMA = thickness × density), generally increases from the bottom to the top of tree canopies, yet the mechanisms behind this universal pattern are not yet resolved. For decades, the light environment was assumed to be the most influential driver of within-canopy variation in LMA, yet recent evidence has shown hydrostatic gradients to be more important in upper canopy positions, especially in tall evergreen trees in temperate and tropical forests.

Model system resulted from close cooperation.

How to get the best possible comprehensive information system for your particular needs? Try working with an enterprising supplier who would welcome the opportunity to use your facility as a development site. That's what Roanoke (VA) Memorial Hospital did, and the supplier, also based in Roanoke, continues to manage the system.