Transformació en un recurs d'educació per a la sostenibilitat

El Jardí de l’Edifici Històric de la Universitat de Barcelona, batejat des del 1995 com a Jardí Ferran Soldevila, es troba ubicat al bell mig de Barcelona, i constitueix un petit pulmó verd de poc menys d’una hectàrea en un dels espais amb major concentració de trànsit i contaminació atmosfèrica de la ciutat. Atès que va ser creat a finals del segle XIX com un jardí amb sentit botànic i que històricament ha servit per fer les pràctiques de botànica de diverses facultats de ciències, aquest espai excedeix la funció estètica de les zones verdes urbanes, i per tant pot esdevenir un recurs educatiu a disposició de tota la societat. El projecte dut a terme comporta la transformació del Jardí d’un espai d’esbarjo i lleure en un recurs d’educació per la sostenibilitat. Aquest canvi no és significatiu en quant a l’aspecte que el Jardí te per al visitant, ja que no varien les espècies presents, el nombre d’exemplars ni la seva ubicació, però sí comporta una variació profunda del paper que ha de jugar aquest espai en el teixit urbà, ja que s’implanten un seguit d’accions encaminades a orientar els visitants envers un millor coneixement de la dinàmica ecològica dels espais verds en l’entorn metropolità, i a fomentar la sensibilització en l’àmbit de la sostenibilitat. Entre els aspectes més innovadors del projecte destaca la senyalització del Jardí. A més dels cartells indicadors dels noms de les espècies i la seva procedència, s’han incorporat plafons de grans dimensions que incorporen informació en relació a factors com la rellevància de les espècies presents, l’agrupació d’aquestes en eixos temàtics d’especial interès, i la relació del Jardí amb l’ecosistema urbà de Barcelona. Aquests plafons serveixen a més per definir itineraris temàtics de visita que, amb dossiers informatius específics, permeten desenvolupar conceptes propis dels àmbits de la botànica, la biogeografia o la sostenibilitat, fent així que el Jardí reforci encara més la seva funció educativa.Peer Reviewe

Natural chemical control of marine associated microbial communities by sessile Antarctic invertebrates

Organisms living in the sea are exposed to fouling by other organisms. Many benthic marine invertebrates, including sponges and bryozoans, contain natural products with antimicrobial properties, since microbes usually constitute the first stages of fouling. Extracts from 4 Antarctic sponges (Myxilla (Myxilla) mollis, Mycale tylotornota, Rossella nuda, and Anoxycalyx (Scolymastra) joubini) and 2 bryozoan species (Cornucopina pectogemma and Nematoflustra flagellata) were tested separately for antifouling properties in field experiments. The different crude extracts from these invertebrates were incorporated into a substratum gel at natural concentrations for an ecological approach. Treatments were tested by submerging plates covered by these substratum gels under water in situ during 1 lunar cycle (28 d) at Deception Island (South Shetland Islands, Antarctica). Remarkably, the butanolic extracts of M. tylotornota and C. pectogemma showed complete growth inhibition of microscopic eukaryotic organisms, one of the succession stages involved in biofouling. Our results suggest that different chemical strategies may exist to avoid fouling, although the role of chemical defenses is often species-specific. Thus, the high specificity of the microbial community attached to the coated plates seems to be modulated by the chemical cues of the crude extracts of the invertebrates tested

Chemical Interactions in Antarctic Marine Benthic Ecosystems

Antarctic marine ecosystems are immersed in an isolated, relatively constant environment where the organisms inhabiting their benthos are mainly sessile suspension feeders. For these reasons, physical and chemical biotic interactions play an essential role in structuring these marine benthic communities (Dayton et al., 1974; Orejas et al., 2000). These interactions may include diverse strategies to avoid predation (e.g. Iken et al., 2002), competition for space or food (e.g. Bowden et al., 2006) and avoiding fouling (e.g. Rittschof, 2001; Peters et al., 2010). For instance, in the marine benthos, one of the most extended effective strategies among sessile soft-bodied organisms is chemical defense, mediated by several bioactive natural products mostly considered secondary metabolites (e.g. Paul et al., 2011). The study of the “chemical network” (chemical ecology interactions) structuring the communities provides information about the ecology and biology of the involved species, the function and the structure of the community and, simultaneously, it may lead to the discovery of new compounds useful to humans for their pharmacological potential (e.g. Avila, 1995; Bhakuni, 1998; Munro et al., 1999; Faulkner, 2000; Lebar et al., 2007; Avila et al., 2008). In the last three decades, the study of marine chemical ecology has experienced great progress, thanks to the new technological advances for collecting and studying marine samples, and the possibility of identification of molecules with smaller amounts of compounds (e.g. Paul et al., 2006, 2011; Blunt et al., 2011)

Bryozoan diversity around the Falkland and South Georgia Islands: Overcoming Antarctic barriers

There are a number of remote archipelagos distributed between 45 and 60 °S. The biota of these islands provide useful information to describe and understand patterns in biodiversity and biogeography as well as potential impacts of climate change on marine ecosystems. They are in key locations either side of the Polar Front but also have limited influence from human activities. Here we investigate one taxon, bryozoans, on South Atlantic shelf habitats of the Falkland (FI) and the sub-Antarctic island of South Georgia (SG). We present new data on spatial distribution in these islands, as well as an analysis of the bryozoological similarities between these and neighbouring regions. A total of 85 species of cheilostome bryozoans (351 samples) were found, belonging to 33 genera, including 18 potentially new genera and 23 new species. Remarkably 68% and 41% of species were reported for the first time at FI and SG, respectively. The highest and the lowest value of species richness and species/genus ratio were found at East (EFI) and West Falkland (WFI), respectively, likely showing a tendency for stronger intrageneric competition. New data from this study were jointly analysed with data from the literature and existing databases, revealing new bathymetric ranges in 32 species. The biogeographic affinities of the bryozoans found give further evidence of the hypothesis of sequential separation of Gondwana and support the changing concept that although the Polar Front acts as a circumpolar biogeographic barrier it is not as impermeable as originally thought. Potential dispersal mechanisms are also discussed

Ecología química en el bentos antártico

El estudio de las interacciones entre los organismos mediadas por sustancias químicas, lo que se denomina ecología química, nos da información sobre la biología de las especies implicadas, el funcionamiento de la comunidad en que viven y nos puede proporcionar además el conocimiento de nuevas sustancias que pueden ser útiles para el ser humano. En el marco de nuestros estudios sobre la ecología química de los invertebrados antárticos, en el proyecto ECOQUIM (2003-2006) se recolectaron numerosas muestras biológicas a partir de las cuales se obtuvieron extractos y sustancias naturales de invertebrados antárticos. En el proyecto ACTIQUIM (2007-actualidad), se ha evaluado el papel ecológico de estos extractos y sustancias naturales mediante experimentos de ecología química in situ (repelencia, defensa ante distintos tipos de macro y micro-depredadores, toxicidad, citotoxicidad y actividad antifouling) y también se ha analizado la actividad antitumoral de algunos compuestos obtenidos recientemente. Nuestros resultados demuestran, entre otras cuestiones, que las defensas químicas en los organismos antárticos son elevadas en las esponjas, los cnidarios, los tunicados, los briozoos, los equinodermos y los moluscos y que por lo tanto, estos grupos pueden ser una fuente rica en metabolitos secundarios con bioactividad, tanto a nivel ecológico como farmacológico

Divergent responses to warming of two common co-occurring Mediterranean bryozoans

Climate change threatens the structure and function of marine ecosystems, highlighting the importance of understanding the response of species to changing environmental conditions. However, thermal tolerance determining the vulnerability to warming of many abundant marine species is still poorly understood. In this study, we quantified in the field the effects of a temperature anomaly recorded in the Mediterranean Sea during the summer of 2015 on populations of two common sympatric bryozoans, Myriapora truncata and Pentapora fascialis. Then, we experimentally assessed their thermal tolerances in aquaria as well as different sublethal responses to warming. Differences between species were found in survival patterns in natural populations, P. fascialis showing significantly lower survival rates than M. truncata. The thermotolerance experiments supported field observations: P. fascialis started to show signs of necrosis when the temperature was raised to 25-26 °C and completely died between 28-29 °C, coinciding with the temperature when we observed first signs of necrosis in M. truncata. The results from this study reflect different responses to warming between these two co-occurring species, highlighting the importance of combining multiple approaches to assess the vulnerability of benthic species in a changing climate world

Physiological stress does not increase with urbanization in European blackbirds:Evidence from hormonal, immunological and cellular indicators

Urbanization changes the landscape structure and ecological processes of natural habitats. While urban areas expose animal communities to novel challenges, they may also provide more stable environments in which environmental fluctuations are buffered. Species´ ecology and physiology may determine their capacity to cope with the city life. However, the physiological mechanisms underlying organismal responses to urbanization, and whether different physiological systems are equally affected by urban environments remain poorly understood. This severely limits our capacity to predict the impact of anthropogenic habitats on wild populations. In this study, we measured indicators of physiological stress at the endocrine, immune and cellular level (feather corticosterone levels, heterophil to lymphocyte ratio, and heat-shock proteins) in urban and non-urban European blackbirds (Turdus merula) across 10 European populations. Among the three variables, we found consistent differences in feather corticosterone, which was higher in non-urban habitats. This effect seems to bedependent on sex, being greater in males. In contrast, we found no significant differences between urban and non-urban habitats in the two other physiological indicators. The discrepancy between these different measurements of physiological stress highlights the importance of including multiple physiological variables to understand the impact of urbanization on species' physiology. Overall, our findings suggest that adult European blackbirds living in urban and non-urban habitats do not differ in terms of physiological stress at an organismal level. Furthermore, we found large differences among populations on the strength and direction of the urbanization effect, which illustrates the relevance of spatial replication when investigating urban-induced physiological responses

El jardí de l’Edifici Històric de la Universitat de Barcelona. Transformació en un recurs d’educació per la sostenibilitat

El Jardí de l’Edifici Històric de la Universitat de Barcelona, batejat des del 1995 com a Jardí Ferran Soldevila, es troba ubicat al bell mig de Barcelona, i constitueix un petit pulmó verd de poc menys d’una hectàrea en un dels espais amb major concentració de trànsit i contaminació atmosfèrica de la ciutat. Atès que va ser creat a finals del segle XIX com un jardí amb sentit botànic i que històricament ha servit per fer les pràctiques de botànica de diverses facultats de ciències, aquest espai excedeix la funció estètica de les zones verdes urbanes, i per tant pot esdevenir un recurs educatiu a disposició de tota la societat. El projecte dut a terme comporta la transformació del Jardí d’un espai d’esbarjo i lleure en un recurs d’educació per la sostenibilitat. Aquest canvi no és significatiu en quant a l’aspecte que el Jardí te per al visitant, ja que no varien les espècies presents, el nombre d’exemplars ni la seva ubicació, però sí comporta una variació profunda del paper que ha de jugar aquest espai en el teixit urbà, ja que s’implanten un seguit d’accions encaminades a orientar els visitants envers un millor coneixement de la dinàmica ecològica dels espais verds en l’entorn metropolità, i a fomentar la sensibilització en l’àmbit de la sostenibilitat. Entre els aspectes més innovadors del projecte destaca la senyalització del Jardí. A més dels cartells indicadors dels noms de les espècies i la seva procedència, s’han incorporat plafons de grans dimensions que incorporen informació en relació a factors com la rellevància de les espècies presents, l’agrupació d’aquestes en eixos temàtics d’especial interès, i la relació del Jardí amb l’ecosistema urbà de Barcelona. Aquests plafons serveixen a més per definir itineraris temàtics de visita que, amb dossiers informatius específics, permeten desenvolupar conceptes propis dels àmbits de la botànica, la biogeografia o la sostenibilitat, fent així que el Jardí reforci encara més la seva funció educativa

Cheilostome bryozoan diversity from the southwest Atlantic region: Is Antarctica really isolated?

During the Cenozoic, the break-up of Gondwana was accompanied by a gradual separation of its components and the subsequent establishment of the Antarctic Circumpolar Current, leading to a relative thermal and biogeographic isolation of the Antarctic fauna. However, the zoogeographical affinities of several taxa from South America and Antarctica have been subject to debate, bringing into question the extent of Antarctic isolation.Herewe present newdata on bryozoan species and their spatial distribution in the Argentine Patagonian (AP) region, as well as an analysis of the bryozoological similarities between deep ranges from Argentina and neighboring regions. A total of 108 species of cheilostome bryozoans (378 samples), belonging to 59 genera was found. Five new genera and 36 new species were found in the AP region, while 71 species were reported for the first time from Argentina. The bathymetric ranges of 94 species (87%) were expanded and a high proportion of the identified species (44.4%) also had an Antarctic distribution. The bryozoological affinities found in the current study between the nearest geographical neighbors are in agreement with the hypothesis of the sequential separation of Gondwana during the Cenozoic. Moreover, a high number of shared species, mainly from the slope, were found in this study between the AP region and Antarctica, thus supporting the idea that the Southern Ocean may have been less isolated over geological time than once thought.Spanish Institute of OceanographyPostprin

Anti‑predatory chemical defences in Antarctic benthic fauna

Antarctic benthic communities are largely structured by predation, which leads to the development of mechanisms of repellence. Among those mechanisms, chemical defences are quite extensive, yet poorly understood. To increase knowledge about the role of chemical defences in the Southern Ocean ecosystems, we assessed the incidence of feeding repellents in sessile and vagile invertebrates from nine phyla: Porifera, Cnidaria, Nemertea, Annelida, Mollusca, Bryozoa, Echinodermata, Hemichordata, and Tunicata (Ascidiacea). Samples were collected at depths of 120–789 m in the eastern Weddell Sea and Bouvet Island, and at depths ranging 0–100 m in the South Shetland Islands. When possible, specimens were dissected to study anatomical allocation of repellents. The common, eurybathic sea star Odontaster validus was chosen to perform feeding repellence bioassays, using diethyl ether (lipophilic) and butanol (hydrophilic) extracts from these samples. Among the 75 species tested, 52 % were studied for the first time for anti-predatory properties. Results provide further evidence of the prevalence of defensive metabolites in Antarctic organisms, with 47 % of the species exhibiting significant repellence within their lipophilic extracts. They also suggest a wider use of nonpolar defensive chemicals. Sessile taxa displayed highest repellence activities, with ascidians, cnidarians, and sponges being the most chemically protected. Overall, the present study indicates that natural products by mediating trophic interactions between prey and their potential predators play an important role in structuring Antarctic benthic ecosystems.Versión del editor2,011