Search results for "environmental change"
showing 10 items of 93 documents
THE EVALUATION OF STABLE ISOTOPIC RATIOS 13C AND 15N IN HUMIC ACIDS ALONG A FEN PEAT PROFILE
2019
Mires are known as consistent environmental archives, but humic acids are the fraction of peat that is most recalcitrant and refractory to organic matter degradation, thus data on environmental changes during mire development can be recorded into them. This work was focused on the studies of stable isotopic ratios delta carbon-13 and delta nitrogen-15, and their distribution in humic acids within fen peat layers of different depths and peat composition. The variations in delta carbon-13 reflect isotopic variations in peat-forming plants over time and can be considered as a function of photosynthetic pathway that is being used to fix carbon dioxide. At the same time, variations in delta nitr…
Fuzzy Quantification of Common and Rare Species in Ecological Communities (FuzzyQ)
2020
Abstract1. Most species in ecological communities are rare whereas only a few are common. This distributional paradox has intrigued ecologists for decades but the interpretation of species abundance distributions remains elusive.2. We present Fuzzy Quantification of Common and Rare Species in Ecological Communities (FuzzyQ) as an R package. FuzzyQ shifts the focus from the prevailing species-categorization approach to develop a quantitative framework that seeks to place each species along a rare-commonness gradient. Given a community surveyed over a number of sites, quadrats, or any other convenient sampling unit, FuzzyQ uses a fuzzy clustering algorithm that estimates a probability for eac…
Population changes in Czech passerines are predicted by their life-history and ecological traits
2010
A species’ susceptibility to environmental change might be predicted by its ecological and life-history traits. However, the effects of such traits on long-term bird population trends have not yet been assessed using a comprehensive set of explanatory variables. Moreover, the extent to which phylogeny affects patterns in the interspecific variability of population changes is unclear. Our study focuses on the interspecific variability in long-term population trends and annual population fluctuations of 68 passerine species in the Czech Republic, assessing the effects of eight life-history and five ecological traits. Ordination of life-history traits of 68 species revealed a life-history grad…
Ocean acidification through the lens of ecological theory
2015
© 2015 by the Ecological Society of America. Ocean acidification, chemical changes to the carbonate system of seawater, is emerging as a key environmental challenge accompanying global warming and other humaninduced perturbations. Considerable research seeks to define the scope and character of potential outcomes from this phenomenon, but a crucial impediment persists. Ecological theory, despite its power and utility, has been only peripherally applied to the problem. Here we sketch in broad strokes several areas where fundamental principles of ecology have the capacity to generate insight into ocean acidification's consequences. We focus on conceptual models that, when considered in the co…
Long-term analysis (1863–2002) of environmental change in the Capo Feto area (Mediterranean sea)
2004
The area of Capo Feto represents one of the few remaining salt-marshy zones in Sicily. It lies within a site of importance for the Community (defined as a “sito di importanza comunitaria” (SIC)), which also includes Margi Spanò and Margi Milo. The Capo Feto and Margi Spanò marshlands have also been identified by the Ministry for the Environment as an area deserving special protection (“zona a protezione speciale” (ZPS)). Moreover, in 1999, 150 ha of the Capo Feto area were included in a project for environmental rehabilitation as part of the European Union “Life-Nature 2000” programme (Comitato Tecnico-Scientifico Area di Capo Feto, 1997). Prior to this, the area had become somewhat degrade…
Recent environmental history of a large, originally oligotrophic lake in Finland: a palaeolimnological study of chironomid remains
1993
The sedimentary chironomid stratigraphy in short-core samples covering approx. the past 150 years was studied in the northernmost basin of Lake Paijanne, southern Finland (62° 11′ N, 25° 48′ E). The basin has received effluent loading from the wood-processing industry and municipal waste water. Four developmental stages were distinguished based on the changes in chironomid assemblages: 1. Pre-industrial stage (dated by the210Pb method as covering approximately the period 1838–1936), 2. Stage of increasing pollution (approx. 1944–1973), 3. The ‘black decade’, or the period of worst pollution (approx. 1973–1983), and 4. Water protection stage (approx. 1983 onwards). During the first stage the…
Functional spatial contextualisation of the effects of multiple stressors in marine bivalves
2018
Abstract. Many recent studies have revealed that the majority of environmental stressors experienced by marine organisms (ocean acidification, global warming, hypoxia etc.) occur at the same time and place, and that their interaction may complexly affect a number of ecological processes. Here, we experimentally investigated the effects of pH and hypoxia on the functional and behavioural traits of the mussel Mytilus galloprovincialis, we then simulated the potential effects on growth and reproduction dynamics trough a Dynamic Energy Budget (DEB) model under a multiple stressor scenario. Our simulations showed that hypercapnia had a remarkable effect by reducing the maximal habitat size and r…
Testing the effects of temporal data resolution on predictions of the effects of climate change on bivalves
2014
a b s t r a c t The spatial-temporal scales on which environmental observations are made can significantly affect our perceptions of ecological patterns in nature. Understanding potential mismatches between environmen- tal data used as inputs to predictive models, and the forecasts of ecological responses that these models generate are particularly difficult when predicting responses to climate change since the assumption of model stationarity in time cannot be tested. In the last four decades, increases in computational capacity (by a factor of a million), and the evolution of new modeling tools, have permitted a corresponding increase in model complexity, in the length of the simulations,…
Variation in spawning time promotes genetic variability in population responses to environmental change in a marine fish.
2015
Common-garden experiments suggest that the response of Atlantic cod larvae to temperature differs among populations that spawn at different times of year. Populations appear to be adapted to the temperatures experienced during the larval stage at a small spatial scale, despite a lack of physical barriers to gene flow.
A legacy of contrasting spatial genetic structure on either side of the Atlantic-Mediterranean transition zone in a marine protist
2012
The mechanisms that underpin the varied spatial genetic structures exhibited by free-living marine microorganisms remain controversial, with most studies emphasizing a high dispersal capability that should redistribute genetic diversity in contrast to most macroorganisms whose populations often retain a genetic signature of demographic response to historic climate fluctuations. We quantified the European phylogeographic structure of the marine flagellate Oxyrrhis marina and found a marked difference in spatial genetic structure, population demography, and genetic diversity between the northwest Atlantic and Mediterranean Sea that reflects the persistent separation of these regions as well …