Association of a Mediterranean type diet with age-related macular degeneration in the EUREYE study

Investigative Ophthalmology & Visual Science Volume 56 Issue 7 Pages 3760-3760

Fish as ecological indicators in Mediterranean freshwater ecosystems

Podeu escriure el text directament o arrossegar-lo des d'un altre document L'objectiu d'aquesta tesi és contribuir a l'ús dels peixos continentals com a indicadors de l'estat ecològic a la conca Mediterrània. En el primer treball es va detectar que encara que tots els índex biològics estaven correlacionats significativament, els peixos integren i expressen els estressos de manera i a una escala diferents, aportant una informació complementària als altres índexs. Al segon article es van estudiar els cabals de sis conques catalanes. S'ha mostrat que els règims hídrics estan alterats amb una tendència a la disminució del cabal i del nivell dels aqüífers. S'ha detectat quatre mètriques de peixos que es troben significativament afectades en zones més castigades per manca d'aigua degut a l'activitat humana. Es discuteix la necessitat de conèixer en profunditat el règim hídric de cada conca abans d'utilitzar els índex biològics. Al tercer article es va detectar que la composició d'espècies capturades va variar significativament al llarg del buidat amb un augment de l'alburn (A. alburnus) a les aigües pelàgiques durant els dies de pitjor qualitat de l'aigua, confirmant que l'alburn és més tolerant a la mala qualitat de l'aigua que la madrilleta vera (R. rutilus) i suggereix el seu potencial com a bioindicador. La condició d'aquestes dues espècies va canviar significativament al llarg del buidat de manera molt estreta amb la qualitat de l'aigua. Al quart capítol es va estudiar la biologia dels peixos d'un embassament altament contaminat (Flix). El percentatge de DELT anomalies i la presència de paràsits externs era major en la zona impactada que als punts de control i els valors més alts de pes eviscerat i pes del fetge estaven als punts de control. Les respostes van ser diferents per cada espècie i la carpa va ser la que va mostrar més clarament els impactes.

Quantifying turbulent mixing and oxygen fluxes in a Mediterranean-type, microtidal estuary

Experiments were carried out on an intermittent estuary during its closed (summer) and open (winter) states to identify the physical processes responsible for vertical mixing across the halocline, and to quantify vertical fluxes of oxygen and salt between water layers. During the blocked phase a two-layer structure was observed, with a brackish surface layer overlying old seawater. Within a deep basin the wind-driven turbulent mixing was consistent with the measured surface-layer turbulent dissipation, but the dissipation in the bottom layer appeared to be driven by internal seiching. In the shallow regions of the estuary vertical fluxes of dissolved oxygen were indicative of oxygen demand by respiration and remineralization of organic material in bottom water and sediments. During the estuary's open phase a three-layer structure was observed, having a fresh, river-derived surface layer, a middle layer of new seawater, and a bottom layer of old seawater. In the shallower regions surface-layer turbulent diffusion was consistent with the strong, gusty winds experienced at the time. The dissolved oxygen of the incoming seawater decreased to very low values by the time it reached the upstream deep basin as a result of the low cross-pycnocline oxygen flux being unable to compensate for the oxygen utilization. At least 50 % of the cross-pycnocline salt fluxes in the shallow reaches of the open estuary are suggested to be driven by Holmboe instabilities.

Mediterranean-type climate in the South Aegean (Eastern Mediterranean) during the Late Miocene: Evidence from isotope and element proxies

The present-day climate in the Mediterranean region is characterized by mild, wet winters and hot, dry summers. There is contradictory evidence as to whether the present-day conditions (“Mediterranean climate”) already existed in the Late Miocene. This thesis presents seasonally-resolved isotope and element proxy data obtained from Late Miocene reef corals from Crete (Southern Aegean, Eastern Mediterranean) in order to illustrate climate conditions in the Mediterranean region during this time. There was a transition from greenhouse to icehouse conditions without a Greenland ice sheet during the Late Miocene. Since the Greenland ice sheet is predicted to melt fully within the next millennia, Late Miocene climate mechanisms can be considered as useful analogues in evaluating models of Northern Hemispheric climate conditions in the future. So far, high resolution chemical proxy data on Late Miocene environments are limited. In order to enlarge the proxy database for this time span, coral genus Tarbellastraea was evaluated as a new proxy archive, and proved reliable based on consistent oxygen isotope records of Tarbellastraea and the established paleoenvironmental archive of coral genus Porites. In combination with lithostratigraphic data, global 87Sr/86Sr seawater chronostratigraphy was used to constrain the numerical age of the coral sites, assuming the Mediterranean Sea to be equilibrated with global open ocean water. 87Sr/86Sr ratios of Tarbellastraea and Porites from eight stratigraphically different sampling sites were measured by thermal ionization mass spectrometry. The ratios range from 0.708900 to 0.708958 corresponding to ages of 10 to 7 Ma (Tortonian to Early Messinian). Spectral analyses of multi-decadal time-series yield interannual δ18O variability with periods of ~2 and ~5 years, similar to that of modern records, indicating that pressure field systems comparable to those controlling the seasonality of present-day Mediterranean climate existed, at least intermittently, already during the Late Miocene. In addition to sea surface temperature (SST), δ18O composition of coral aragonite is controlled by other parameters such as local seawater composition which as a result of precipitation and evaporation, influences sea surface salinity (SSS). The Sr/Ca ratio is considered to be independent of salinity, and was used, therefore, as an additional proxy to estimate seasonality in SST. Major and trace element concentrations in coral aragonite determined by laser ablation inductively coupled plasma mass spectrometry yield significant variations along a transect perpendicular to coral growth increments, and record varying environmental conditions. The comparison between the average SST seasonality of 7°C and 9°C, derived from average annual δ18O (1.1‰) and Sr/Ca (0.579 mmol/mol) amplitudes, respectively, indicates that the δ18O-derived SST seasonality is biased by seawater composition, reducing the δ18O amplitude by 0.3‰. This value is equivalent to a seasonal SSS variation of 1‰, as observed under present-day Aegean Sea conditions. Concentration patterns of non-lattice bound major and trace elements, related to trapped particles within the coral skeleton, reflect seasonal input of suspended load into the reef environment. δ18O, Sr/Ca and non-lattice bound element proxy records, as well as geochemical compositions of the trapped particles, provide evidence for intense precipitation in the Eastern Mediterranean during winters. Winter rain caused freshwater discharge and transport of weathering products from the hinterland into the reef environment. There is a trend in coral δ18O data to more positive mean δ18O values (–2.7‰ to –1.7‰) coupled with decreased seasonal δ18O amplitudes (1.1‰ to 0.7‰) from 10 to 7 Ma. This relationship is most easily explained in terms of more positive summer δ18O. Since coral diversity and annual growth rates indicate more or less constant average SST for the Mediterranean from the Tortonian to the Early Messinian, more positive mean and summer δ18O indicate increasing aridity during the Late Miocene, and more pronounced during summers. The analytical results implicate that winter rainfall and summer drought, the main characteristics of the present-day Mediterranean climate, were already present in the Mediterranean region during the Late Miocene. Some models have argued that the Mediterranean climate did not exist in this region prior to the Pliocene. However, the data presented here show that conditions comparable to those of the present-day existed either intermittently or permanently since at least about 10 Ma.

Database on the molluscan fauna from the Mediterranean Reef Ecosystems (CorMolDB - Part I)

In the Mediterranean Sea, infralittoral and circalittoral rocky bottoms (from 15 to 120 m) are characterized by a biogenic habitat, named "coralligenous", formed by the concretion of calcareous organisms, mainly algal thalli, and- to a lesser extent- by animal skeletons. This complex habitat is inhabited by a rich fauna that belongs to different taxonomic groups. Sponges, bryozoans, cnidarians and ascidians are the most common sessile organisms that inhabit the area while crustacean and molluscs are the common mobile organisms. Little information on the diversity of the molluscs that thrive in the coralligenous habitat is known while this information is highly important for biodiversity management purposes. After thoroughly studying the available and accessible published literature, a database for the molluscs of the coralligenous habitat has been designed and implemented for the collection and management of this information. From its index compilation more than 511 species of molluscs have been recorded so far from the coralligenous formations, the majority of which belongs to the class Gastropoda (357 sp.) followed by the Bivalvia (137 sp.), Polyplacophora (14 sp.), Cephalopoda (2 sp.) and Scaphopoda (1 sp.). Among these, the gastropod Luria lurida (Linnaeus, 1758) and Charonia lampas (Linnaeus, 1758), the endemic bivalve Pinna nobilis Linnaeus, 1758 and the endolithic bivalve Lithophaga lithophaga (Linnaeus, 1758), are protected by international conventions.

Climatic regulation of seed dormancy and emergence of diverse Malva parviflora populations from a Mediterranean-type environment

Malva parviflora L. (Malvaceae) is rapidly becoming a serious weed of Australian farming systems. An understanding of the variability of its seed behaviour is required to enable the development of integrated weed management strategies. Mature M. parviflora seeds were collected from four diverse locations in the Mediterranean-type climatic agricultural region of Western Australia. All of the seeds exhibited physical dormancy at collection; manual scarification or a period of fluctuating summer temperatures (50/20 degrees C or natural) were required to release dormancy. When scarified and germinated soon (1 month) after collection, the majority of seeds were able to germinate over a wide range of temperatures (5-37 degrees C) and had no light requirement. Germination was slower for seeds stored for 2 months than seeds stored for 2 years, suggesting the presence of shallow physiological dormancy. Seed populations from regions with similar annual rainfall exhibited similar dormancy release patterns; seeds from areas of low rainfall (337-344mm) were more responsive to fluctuating temperatures, releasing physical dormancy earlier than those from areas of high rainfall (436-444mm). After 36 months, maximum seedling emergence from soil in the field was 60%, with buried seeds producing 13-34% greater emergence than seeds on the surface. Scanning electron microscopy of the seed coat revealed structural differences in the chalazal region of permeable and impermeable seeds, suggesting the importance of this region in physical dormancy breakdown of M. parviflora seeds. The influence of rainfall during plant growth in determining dormancy release, and hence, germination and emergence timing, must be considered when developing management strategies for M. parviflora.

Xavier Quintana: "cal conservar els valors ecològics del territori"

La possibilitat que els aiguamolls del Baix Ter es converteixin en un parc natural és cada cop més a prop. La càtedra d'Ecosistemes Litorals Mediterranis té molt a veure en el procés de definició del futur Parc

Impacts of changing climate and land use on vegetation dynamics in a Mediterranean ecosystem: insights from paleoecology and dynamic modeling

Forests near the Mediterranean coast have been shaped by millennia of human disturbance. Consequently, ecological studies relying on modern observations or historical records may have difficulty assessing natural vegetation dynamics under current and future climate. We combined a sedimentary pollen record from Lago di Massacciucoli, Tuscany, Italy with simulations from the LandClim dynamic vegetation model to determine what vegetation preceded intense human disturbance, how past changes in vegetation relate to fire and browsing, and the potential of an extinct vegetation type under present climate. We simulated vegetation dynamics near Lago di Massaciucoli for the last 7,000 years using a local chironomid-inferred temperature reconstruction with combinations of three fire regimes (small infrequent, large infrequent, small frequent) and three browsing intensities (no browsing, light browsing, and moderate browsing), and compared model output to pollen data. Simulations with low disturbance support pollen-inferred evidence for a mixed forest dominated by Quercus ilex (a Mediterranean species) and Abies alba (a montane species). Whereas pollen data record the collapse of A. alba after 6000 cal yr bp, simulated populations expanded with declining summer temperatures during the late Holocene. Simulations with increased fire and browsing are consistent with evidence for expansion by deciduous species after A. alba collapsed. According to our combined paleo-environmental and modeling evidence, mixed Q. ilex and A. alba forests remain possible with current climate and limited disturbance, and provide a viable management objective for ecosystems near the Mediterranean coast and in regions that are expected to experience a mediterranean-type climate in the future.

Stem CO2 efflux and its contribution to ecosystem CO2 efflux decrease with drought in a Mediterranean forest stand

tThe rate of metabolic processes demanding energy in tree stems changes in relation with prevailing cli-matic conditions. Tree water availability can affect stem respiration through impacts on growth, phloemtransport or maintenance of diverse cellular processes, but little is known on this topic. Here we moni-tored seasonal changes in stem CO2efflux (Fs), radial growth, sap flow and non-structural carbohydrates intrees of Quercus ilex in a Mediterranean forest stand subjected since 2003 to either partial (33%) through-fall exclusion (E) or unchanged throughfall (C). Fsincreased exponentially during the day by an effectof temperature, although sap flow attenuated the increase in Fsduring the day time. Over the year, Fsalso increased exponentially with increasing temperatures, but Fscomputed at a standard temperatureof 15?C (F15s) varied by almost 4-fold among dates. F15swas the highest after periods of stem growth anddecreased as tree water availability decreased, similarly in C and E treatments. The decline in F15swas notlinked to a depletion of soluble sugars, which increased when water stress was higher. The proportionof ecosystem respiration attributed to the stems was highest following stem growth (23.3%) and lowestduring the peak of drought (6.5%). High within-year variability in F15smakes unadvisable to pool annualdata of Fsvs. temperature to model Fsat short time scales (hours to months) in Mediterranean-type for-est ecosystems. We demonstrate that water availability is an important factor governing stem CO2effluxand suggest that trees in Mediterranean environments acclimate to seasonal drought by reducing stemrespiration. Stem respiratory rates do not seem to change after a long-term increase in drought intensity,however.

Problems of dynamic in mediterranean forests

The mediterranean forest ecosystems constitute a complex unit which is marked off the Northern and middle European ones by its climate, ecology and management.The ecosystems are related to a climate with estival droughtlasting from 1 to 6 months and the peculiar species which constitute them are generally not worth much.The anthropic pressure exerts especially by grazing and moreover they have been stricken by dramatic fires for many decades. Their large variety related to the bioclimatic and edaphic heterogeneity of the region can explain why the data concerning their functioning and dynamics are still fragmentary. Besides, their ecological and pedological characteristics make uneasy the use of schemes and patterns designed for middle european forests.

Synergy of extreme drought and shrub invasion reduce ecosystem functioning and resilience in water-limited climates

Extreme drought events and plant invasions are major drivers of global change that can critically affect ecosystem functioning and alter ecosystem-atmosphere exchange. Invaders are expanding worldwide and extreme drought events are projected to increase in frequency and intensity. However, very little is known on how these drivers may interact to affect the functioning and resilience of ecosystems to extreme events. Using a manipulative shrub removal experiment and the co-occurrence of an extreme drought event (2011/2012) in a Mediterranean woodland, we show that native shrub invasion and extreme drought synergistically reduced ecosystem transpiration and the resilience of key-stone oak tree species. Ecosystem transpiration was dominated by the water use of the invasive shrub Cistus ladanifer, which further increased after the extreme drought event. Meanwhile, the transpiration of key-stone tree species decreased, indicating a competitive advantage in favour of the invader. Our results suggest that in Mediterranean-type climates the invasion of water spending species and projected recurrent extreme drought events may synergistically cause critical drought tolerance thresholds of key-stone tree species to be surpassed, corroborating observed higher tree mortality in the invaded ecosystems. Ultimately, this may shift seasonally water limited ecosystems into less desirable alternative states dominated by water spending invasive shrubs.

Influence of road noise disturbances on black vulture nesting area: Case of "Cabeza de Hierro" state in Spanish Mediterranean Central Mountain

The real and potential road influence on soundscape is considered a relevant management aspect that can assess the negative effects of massive visitants on such sensitive species -that have been living for centuries in the area-. As a first approach to the study of human disturbances sound impact, acoustic engineering tools allow us to model noise pollution caused by the main road that crosses the state ?Cabeza de Hierro? (M-604). For these preliminary results we use the French method XPS 31-133, recommend at EU level. Noise emission levels in black vulture nesting area are analyzed to understand the influence of human activities on rural areas and road management on biodiversity conservation. This approach develops a useful tool to make compatible the public enjoyment of forest services such as recreation or landscape scenary, the conservation of biodiversity as well as a suitable social and economic activity level ?timber and firewood harvesting, industry?- at the region.

Crop rotation and residues influence N2O emission and N efficiency rather than tillage under a rainfed Mediterranean agroecosystem

Conservation tillage and crop rotation have spread during the last decades because promotes several positive effects (increase of soil organic content, reduction of soil erosion, and enhancement of carbon sequestration) (Six et al., 2004). However, these benefits could be partly counterbalanced by negative effects on the release of nitrous oxide (N2O) (Linn and Doran, 1984). There is a lack of data on long-term tillage system study, particularly in Mediterranean agro-ecosystems. The aim of this study was to evaluate the effects of long-term (>17 year) tillage systems (no tillage (NT), minimum tillage (MT) and conventional tillage (CT)); and crop rotation (wheat (W)-vetch (V)-barley (B)) versus wheat monoculture (M) on N2O emissions. Additionally, Yield-scaled N2O emissions (YSNE) and N uptake efficiency (NUpE) were assessed for each treatment.

Crossing forest thresholds: inertia and collapse in a Holocene sequence from south-central Spain

A Holocene palaeoecological sequence from Villaverde, south-central Spain, is presented. The pollen stratigraphy is used to infer past vegetation changes within a catchment area that represents the boundary between semi-arid, plateau and mountain vegetation. From c. 9700–7530 cal. yr BP, Pinus is dominant, probably as a result of a combination of a relatively dry climate and natural fire disturbance. From c. 7530–5900 cal. yr BP, moderate invasion by Quercus appears to be a migrational response following increased moisture and temperature, but in part shaped by competitive adjustments. From c. 5900–5000 cal. yr BP, the pine forests are replaced by deciduous-Quercus forests with an important contribution from Corylus, Betula, Fraxinus and Alnus. Mediterranean-type forests spread from c. 5000 to 1920 cal. yr BP coincident with expansions of Artemisia, Juniperus and other xerophytes. From c. 1920–1160 cal. yr BP, Pinus becomes dominant after a disturbance- mediated invasion of the oak forests. Human impact upon the regional landscape was negligible during the Neolithic, and limited in the Bronze and Iron Ages. Local deforestation and the expansion of agro-pastoral activities occur after c. 1600 cal. yr BP.