Estudio preliminar de la estructura interna del subtipo fitoclimático VI (IV)1 de Allué (1990). Aplicaciones fitoclimáticas

In this paper we try to establish a preliminary methodology for analyzing vegetation structures included in Allué´s (1990) phytoclimatic subtypes, and their phytoclimatic implications. One of the most geographically extensive subtypes (VI(IV)1) has been chosen, which comprises a considerable number of syntaxa.En este trabajo se pretende establecer una metodología preliminar para analizar en profundidad las estructuras de vegetación que están presentes en los subtipos fitoclimáticos de Allué (1990), así como sus implicaciones fitoclimáticas. Se ha elegido para este estudio uno de los subtipos más extensos territorialmente (VI(IV)1), en el que están representados un número considerable de sintáxones

1,2-stereochemical induction in the Pd^II-catalyzed conjugate addition of boronic acids

Palladium(II) catalysis has been used in the substrate-controlled 1,2-chiral induction of the conjugate addition of boronic acids to enantiopure α,β-unsaturated ketones and esters without competition from the Mirozoki-Heck reaction. Bedford's palladacycle was found to control the stereoselectivity without the need for additional chiral ligands. We report that the PdII-catalyzed conjugate addition reaction between boronic acids and acyclic ketones or esters that bear a hydroxyl substituent at their γ-position (glyceraldehyde derivatives) can afford high levels of anti stereoselection, comparable to those reported previously using more expensive RhI catalysts. On the other hand, high levels of syn stereoselectivity were observed with acyclic esters that bear an amino substituent at their γ-position (serine derivatives). In this case, the levels of stereoselection could be enhanced by using cyclic derivatives derived from Garner's aldehyde.Peer Reviewe

Relationship between legacy and emerging organic pollutants in Antarctic seabirds and their foraging ecology as shown by δ13C and δ15N

Foraging ecology and the marine regions exploited by Antarctic seabirds outside of breeding strongly influence their exposure to persistent organic pollutants (POPs). However, relationships between them are largely unknown, an important knowledge gap given that many species are capital breeders and POPs may be deleterious to seabirds. This study investigates the relationship between Antarctic seabird foraging ecology (measured by δC and δN) and POPs accumulated in their eggs prior to breeding. Organochlorinated pesticides, polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs), and dechlorane plus (DP) were measured in eggs of chinstrap, Adélie, and gentoo penguins (Pygoscelis antarctica, P. adeliae, P. papua), as well as south polar skua (Catharacta maccormicki), sampled on King George Island. Total POP levels were as follows: skua (3210 ± 3330 ng/g lipid weight) > chinstrap (338 ± 128 ng/g) > Adélie (287 ± 43.3 ng/g) > gentoo (252 ± 49.4 ng/g). Trophic position and pre-breeding foraging sites were important in explaining POP accumulation patterns across species. The most recalcitrant compounds were preferentially accumulated in skuas, occupying one trophic level above penguins. In contrast, their Antarctic endemism, coupled with influence from cold condensation of pollutants, likely contributed to penguins exhibiting higher concentrations of more volatile compounds (e.g., hexachlorobenzene, PCB-28 and − 52) than skuas. Regional differences in penguin pre-breeding foraging areas did not significantly affect their POP burdens, whereas the trans-equatorial migration and foraging sites of skuas were strongly reflected in their pollutant profiles, especially for PBDEs and DPs. Overall, our results provide new insights on migratory birds as biovectors of POPs, including non-globally regulated compounds such as DP, from northern regions to Antarctica.This study is part of the project:“Estudos bioecológicos em Pingüins(Pygoscelis antarctica,P. papuaeP. adeliae) e skuas (CatharactamaccormickiieC. lonnbergii): determinação de micropoluentes e níveisde estresse através de métodos de amostragem não invasivos,”spon-sored by CNPq/MCT 557049/2009-1 and FAPERJ (E-26/111.505/2010).The authors are indebted to the Brazilian Navy, which provided logisti-cal support in Antarctica through the“Secretaria da Comissão Intermin-isterial para os Recursos do Mar”(SECIRM). Chemical and stableisotopes analysis were performed in partnership with researchersfrom the Department of Instrumental Analysis and EnvironmentalChemistry of the Institute of Organic Chemistry (IQOG-CSIC), Spain.CSIC and MAGRAMA (Projects EG042010,14CAES001) are acknowl-edged forfinancialsupport.JLR acknowledgeshis contract under project14CAES001. For their assistance with the collection of eggshell samples,the authors thank Juliana Bell, Adriana Pessôa, and Moacir Silva. Forother important contributions, the authors thank Larissa Cunha, GabrielOliveira, Petrus Galvão, Izidro Ferreira,Valéria Vasconcelos, andJaqueline Guida

Past and present trophic position and decadal changes in diet of Yellow-legged Gull in the Azores Archipelago, NE Atlantic

This study evaluates the trophic position of adult Yellow-legged Gulls Larus michahellis atlantis resident in the Azores archipelago in the past (1921–1928) and in the present (2009–2010), and analyses the decadal variation in the diet of breeding birds from the 1990s to the 2000s for three main colonies (Topo Islet, Baixo Islet and Mistério da Prainha). Using mixing models, we compared stable isotope signatures of nitrogen and carbon in adult breast feathers between birds from 1921 to 1928 (held in museum collections) and 2009 to 2010, jointly with both isotopic signatures of their main prey groups (fish, goose barnacles (Lepas anatifera), seabirds, mammals and refuse). The diet of breeding birds was analysed using pellets collected in 1989, 1995, 1996, 2004, 2009 and 2010. Stable isotopes analysis (SIA) results were in accordance with the results provided from the analysis of pellets, showing a relatively recent and significant change in the diet of adult gulls. In particular, SIA revealed a significant decrease in the trophic position of Yellow-legged Gulls in the Azores, over the last 89 years in response to the decrease in the consumption of seabirds and fish and, an increase in the consumption of marine invertebrates (goose barnacles) and refuse. The analysis of pellets confirmed the significant decrease in the fish ingested, whereas the ingestion of lower trophic level prey (i.e. goose barnacles, mammals and refuse) increased. Both methods reflect the feeding plasticity and opportunistic foraging behavior of this species, and are in accordance with patterns described for continental Europe.We acknowledge the support given by Fundação para a Ciência e Tecnologia, Portugal, to Patricia Pedro (SFRH/BD/ 40095/2007)