Search results for "Climate"

The functional trait-based approach to investigate life history traits in marine invertebrates to predict effects of global climate change on ecosyst…

2013

Empirical links between natural mortality and recovery in marine fishes

2017

Probability of species recovery is thought to be correlated with specific aspects of organismal life history, such as age at maturity and longevity, and how these affect rates of natural mortality ( M ) and maximum per capita population growth ( r max ). Despite strong theoretical underpinnings, these correlates have been based on predicted rather than realized population trajectories following threat mitigation. Here, we examine the level of empirical support for postulated links between a suite of life-history traits (related to maturity, age, size and growth) and recovery in marine fishes. Following threat mitigation (medium time since cessation of overfishing = 20 years), 71% of 55 tem…

Palladium-Catalyzed Direct Arylation of Heteroaromatics with Activated Aryl Chlorides Using a Sterically Relieved Ferrocenyl-Diphosphane

2012

International audience; The palladium-catalyzed direct arylations at C3 or C4 positions of heteroaromatics are known to be more challenging than at C2 or C5 positions. Aryl chlorides are also challenging substrates for direct arylation of heteroaromatics. We observed that in the presence of a palladium-catalyst combining only 0.5 mol % of Pd(OAc)2 with the sterically relieved new ferrocenyl diphosphane Sylphos, the direct arylation at C3 or C4 of oxazoles, a benzofuran, an indole, and a pyrazole was found to proceed in moderate to high yields using a variety of electron deficient aryl chlorides. Turnover numbers up to 176 have been obtained with this catalyst. Assessment of the electron-don…

Survey of condition of light and humidity microclimate in some work and/or study areas

2012

Terrestrial Inputs Drive Seasonality in Organic Matter and Nutrient Biogeochemistry in a High Arctic Fjord System (Isfjorden, Svalbard)

2020

Climate-change driven increases in temperature and precipitation are leading to increased discharge of freshwater and terrestrial material to Arctic coastal ecosystems. These inputs bring sediments, nutrients and organic matter (OM) across the land-ocean interface with a range of implications for coastal ecosystems and biogeochemical cycling. To investigate responses to terrestrial inputs, physicochemical conditions were characterized in a river- and glacier-influenced Arctic fjord system (Isfjorden, Svalbard) from May to August in 2018 and 2019. Our observations revealed a pervasive freshwater footprint in the inner fjord arms, the geochemical properties of which varied spatially and seaso…

Temperature effects explain continental scale distribution of cyanobacterial toxins

2018

Insight into how environmental change determines the production and distribution of cyanobacterial toxins is necessary for risk assessment. Management guidelines currently focus on hepatotoxins (microcystins). Increasing attention is given to other classes, such as neurotoxins (e.g., anatoxin-a) and cytotoxins (e.g., cylindrospermopsin) due to their potency. Most studies examine the relationship between individual toxin variants and environmental factors, such as nutrients, temperature and light. In summer 2015, we collected samples across Europe to investigate the effect of nutrient and temperature gradients on the variability of toxin production at a continental scale. Direct and indirect…

Climate change influences on aviation: A literature review

2020

While the aviation sector has long been referenced as contributing to the causes of climate change, the need for aviation to adapt to the consequences of climate change has not been as well researched or considered. The paper is a systematic quantitative literature review on climate change and aviation, which aims to explicate significant issues affecting aviation in a changing climate and to identify the aviation industry responses on climate change and adaptation. There are 46 references involved in the detailed assessment, selected according to variables such as methodology, paper outcomes and industry stakeholder. This emergent aviation and climate change adaptation literature could be …

Recent changes in chironomid communities and hypolimnetic oxygen conditions relate to organic carbon in subarctic ecotonal lakes

2018

A key question in aquatic elemental cycling is related to the influence of bottom water oxygen conditions in regulating the burial and release of carbon under climate warming. In this study, we used head capsules of Chironomidae larvae to assess community and diversity change between the past (estimated as Pre-Industrial Period) and present and to reconstruct changes in hypolimnetic oxygen conditions from 30 subarctic ecotonal lakes (northeastern Lapland) using the top-bottom paleolimnological approach applying surface sediment (topmost 0-2 cm) and reference (4-5 cm) samples. Subsequently, we tested the findings against dissolved organic carbon (DOC) concentration of the sites. We found tha…

Accounting for littoral primary production by periphyton shifts a highly humic boreal lake towards net autotrophy

2016

1. The prevailing view that many humic lakes are net heterotrophic is commonly based on pelagicmeasurements alone. Poor light conditions in humic lakes are assumed to constrain littoral primaryproduction (PP), such that the littoral zone has been considered an insignificant contributor towhole-lake PP. However, that assumption is based on models and inferences from pelagic processeswhich do not take littoral zone structure into account. Many lakes have an extensive ring of aquaticvegetation lying near the water surface, which provides substratum for epiphytic algae under well-illuminated conditions.2. We measured both pelagic and littoral PP and community respiration (CR) in Mekkoj€arvi, a s…

Increasing temperature and productivity change biomass, trophic pyramids and community‐level omega‐3 fatty acid content in subarctic lake food webs

2021

Climate change in the Arctic is outpacing the global average and land-use is intensifying due to exploitation of previously inaccessible or unprofitable natural resources. A comprehensive understanding of how the joint effects of changing climate and productivity modify lake food web structure, biomass, trophic pyramid shape and abundance of physiologically essential biomolecules (omega-3 fatty acids) in the biotic community is lacking. We conducted a space-for-time study in 20 subarctic lakes spanning a climatic (+3.2 degrees C and precipitation: +30%) and chemical (dissolved organic carbon: +10 mg/L, total phosphorus: +45 mu g/L and total nitrogen: +1,000 mu g/L) gradient to test how temp…