Search results for "Environmental chemistry"
showing 10 items of 3248 documents
Tree species flammability based on plant traits: A synthesis.
2021
Abstract The occurrence of large and recurring forest fires has long been associated with fire-prone environments, but this perception has been shifted rapidly in recent decades as Earths' landscapes have become increasingly threatened by severe and unpredictable fires as a result of climate changes. In this regard, the flammability of trees is a topic of great interest for ecology, management, and the development of sustainable restoration and rehabilitation plans. Tree species differ in regard to flammability, and many plant functional traits contribute to flammability at species, community and vegetation level. The relationship between plant traits and flammability at species level is im…
Sodium provides unique insights into transgenerational effects of ocean acidification on bivalve shell formation
2016
Abstract Ocean acidification is likely to have profound impacts on marine bivalves, especially on their early life stages. Therefore, it is imperative to know whether and to what extent bivalves will be able to acclimate or adapt to an acidifying ocean over multiple generations. Here, we show that reduced seawater pH projected for the end of this century (i.e., pH 7.7) led to a significant decrease of shell production of newly settled juvenile Manila clams, Ruditapes philippinarum. However, juveniles from parents exposed to low pH grew significantly faster than those from parents grown at ambient pH, exhibiting a rapid transgenerational acclimation to an acidic environment. The sodium compo…
Downscaling hydrodynamics features to depict causes of major productivity of Sicilian-Maltese area and implications for resource management
2018
Abstract Chlorophyll- a ( CHL-a ) and sea surface temperature ( SST ) are generally accepted as proxies for water quality. They can be easily retrieved in a quasi-near real time mode through satellite remote sensing and, as such, they provide an overview of the water quality on a synoptic scale in open waters. Their distributions evolve in space and time in response to local and remote forcing, such as winds and currents, which however have much finer temporal and spatial scales than those resolvable by satellites in spite of recent advances in satellite remote-sensing techniques. Satellite data are often characterized by a moderate temporal resolution to adequately catch the actual sub-gri…
Bivalve shell formation in a naturally CO2-enriched habitat: Unraveling the resilience mechanisms from elemental signatures
2018
Abstract Marine bivalves inhabiting naturally pCO2-enriched habitats can likely tolerate high levels of acidification. Consequently, elucidating the mechanisms behind such resilience can help to predict the fate of this economically and ecologically important group under near-future scenarios of CO2-driven ocean acidification. Here, we assess the effects of four environmentally realistic pCO2 levels (900, 1500, 2900 and 6600 μatm) on the shell production rate of Mya arenaria juveniles originating from a periodically pCO2-enriched habitat (Kiel Fjord, Western Baltic Sea). We find a significant decline in the rate of shell growth as pCO2 increases, but also observe unchanged shell formation r…
Influence of pesticide use in fruit orchards during blooming on honeybee mortality in 4 experimental apiaries
2016
Samples of dead honey bees (Apis mellifera L.) were collected periodically from 4 different locations during citrus and stone fruit trees blooming season to evaluate the potential impact of agrochemicals on honey bee death rate. For the determination of mortality, dead honey bee traps were placed in front of the experimental hives entrance located in areas of intensive agriculture in Valencian Community (Spain). A total of 34 bee samples, obtained along the monitoring period, were analyzed by means of QuEChERS extraction method and screened for 58 pesticides or their degradation products by LC-MS/MS. An average of four pesticides per honey bee sample was detected. Coumaphos, an organophosph…
Behavior of mixed Chlorophyceae cultures under prolonged dark exposure. Respiration rate modeling
2016
[EN] The behavior of three different microalgal cultures, when exposed for a long period (>48 h) to dark conditions, was studied with a methodology based on respirometry. The cultures were transferred to darkness and the oxygen evolution in the reactors was monitored after successive air injections. Several sequential oxygen uptake rates were thus calculated and a respiration constant, assuming a first order decay of a fraction of the biomass, was obtained by calibration. Initial specific oxygen uptake rates were in the range of 0.9 5.1 mg O2 g TSS−1 h−1 and dark respiration constants in the range of 0.005 0.018 h−1.
Determining Cellulolytic Activity of Microorganisms
2020
Abstract Decomposition of cellulose to glucose requires complex cooperation of glycoside hydrolase enzymes. As a result of glycoside β-1,4 bonds hydrolysis, shorter chains of cellulose, oligodextrin, cellobiose and glucose are created. A number of bacteria and fungi demonstrate the capacity to degrade cellulose. Their activity can be assessed with the use of qualitative and quantitative methods. Qualitative methods with the use of e.g. Congo red, are used in screening studies, however, they do not provide information about the quantity of the produced enzyme. Spectrophotometric methods are more accurate and they measure the quantities of reducing sugars with the use of appropriate substrate…
Assessing the impact of lanthanum on the bivalve Corbicula fluminea in the Rhine River
2018
Abstract Anthropogenic lanthanum predominantly derived from a point source has become an emerging contaminant in the Rhine River, but little is known about its ecotoxicological consequences on bivalve mollusks. A fundamental requirement of aquatic invertebrate adaptation and survival in stressful habitats is the maintenance of energy homeostasis. As such, the present study tested the impact of four dissolved La concentrations (0, 50, 100 and 200 μM) on the energy balance of the bivalve Corbicula fluminea in the Rhine River. Bivalves were collected at four sampling sites which were contaminated by La to different degrees, thereby allowing to understand the degree of their potential acclimati…
Nest guarding behaviour of a temperate wrasse differs between sites off Mediterranean CO2 seeps
2021
Abstract Organisms may respond to changing environmental conditions by adjusting their behaviour (i.e., behavioural plasticity). Ocean acidification (OA), resulting from anthropogenic emissions of carbon dioxide (CO2), is predicted to impair sensory function and behaviour of fish. However, reproductive behaviours, and parental care in particular, and their role in mediating responses to OA are presently overlooked. Here, we assessed whether the nesting male ocellated wrasse Symphodus ocellatus from sites with different CO2 concentrations showed different behaviours during their breeding season. We also investigated potential re-allocation of the time-budget towards different behavioural act…
Solar and atmospheric forcing on mountain lakes
2016
We investigated the influence of long-term external forcing on aquatic communities in Alpine lakes. Fossil microcrustacean (Cladocera) and macrobenthos (Chironomidae) community variability in four Austrian high-altitude lakes, determined as ultra-sensitive to climate change, were compared against records of air temperature, North Atlantic Oscillation (NAO) and solar forcing over the past ~400years. Summer temperature variability affected both aquatic invertebrate groups in all study sites. The influence of NAO and solar forcing on aquatic invertebrates was also significant in the lakes except in the less transparent lake known to have remained uniformly cold during the past centuries due to…