Spatial And Temporal Trends Of Organic Pollutants In Vegetation From Remote And Rural Areas

Bartrons M., Catalan J., Penuelas J. (2016) Spatial And Temporal Trends Of Organic Pollutants In Vegetation From Remote And Rural Areas. Scientific Reports. 6: 0-0.
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Doi: 10.1038/srep25446

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Persistent organic pollutants (POPs) and polycyclic aromatic hydrocarbons (PAHs) used in agricultural, industrial, and domestic applications are widely distributed and bioaccumulate in food webs, causing adverse effects to the biosphere. A review of published data for 1977-2015 for a wide range of vegetation around the globe indicates an extensive load of pollutants in vegetation. On a global perspective, the accumulation of POPs and PAHs in vegetation depends on the industrialization history across continents and distance to emission sources, beyond organism type and climatic variables. International regulations initially reduced the concentrations of POPs in vegetation in rural areas, but concentrations of HCB, HCHs, and DDTs at remote sites did not decrease or even increased over time, pointing to a remobilization of POPs from source areas to remote sites. The concentrations of compounds currently in use, PBDEs and PAHs, are still increasing in vegetation. Differential congener specific accumulation is mostly determined by continent - in accordance to the different regulations of HCHs, PCBs and PBDEs in different countries - and by plant type (PAHs). These results support a concerning general accumulation of toxic pollutants in most ecosystems of the globe that for some compounds is still far from being mitigated in the near future. © 2016, Nature Publishing Group. All rights reserved.

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Foraging success under uncertainty: Search tradeoffs and optimal space use

Bartumeus, F., Campos, D., Ryu, W.S., Lloret-Cabot, R., Méndez, V., Catalan, J. (2016) Foraging success under uncertainty: Search tradeoffs and optimal space use. Ecology Letters. : 0-0.
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Doi: 10.1111/ele.12660

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Trace metal accumulation as complementary dietary information for the isotopic analysis of complex food webs

Soto D.X., Benito J., Gacia E., García-Berthou E., Catalan J. (2016) Trace metal accumulation as complementary dietary information for the isotopic analysis of complex food webs. Methods in Ecology and Evolution. : 0-0.
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Doi: 10.1111/2041-210X.12546

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Food web structure is a fundamental feature of ecosystems. Stable isotopes (δ15N and δ13C) are used to estimate the relative contribution of food sources to consumer's diets (e.g. mixing models). In complex food webs, the use of δ15N and δ13C measurements cannot always solve trophic interactions and distinguish among aquatic organisms with different feeding habits if little intra- and interspecific isotopic differentiation occurs. We have developed a method to characterize trophic relationships using Bayesian stable isotope mixing models in combination with trace metal data as prior information. Trace metal information is useful because of the high correspondence between trace metal profiles in consumers and their food sources, as we show here in an example of concentrations of fish and their expected dietary items. Trace metal concentration allows a more accurate estimation of relative contributions of food sources to consumer species compared to estimates based only on stable isotope values. We show the improvement of the procedure using four freshwater fish species with well-known feeding habits. The method provides a better estimation of the inter- and intraspecific dietary variability and correspondence with the feeding habits of these species. The approach described shows a considerable potential as a tool to assess trophic links in situations in which stable isotope methods are not conclusive. The method can be applied using other compounds that bioaccumulate in consumers (e.g. persistent organic pollutants). © 2016 British Ecological Society.

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