Coimbra, Portugal
Coimbra, Portugal

Time filter

Source Type

Graebner R.C.,University of Montana | Callaway R.M.,University of Montana | Montesinos D.,University of Montana | Montesinos D.,Center for Functional Ecology
Plant Ecology | Year: 2012

Comparisons of introduced exotics that invade and those that do not can yield important insights into the ecology of invasions. Centaurea solstitialis, C. calcitrapa, and C. sulphurea are closely related, share a similar life history and were each introduced to western North America from Southern Europe ~100-200 years ago. However, of these three species, only C. solstitialis has become invasive. We collected seeds from different populations for each of the three species both in the native range of Spain and the non-native range of California, measured individual seed mass, and grew plants from these seeds in a greenhouse experiment in Montana. The invasive C. solstitialis had the smallest seeds and seedlings of the three congeners. However, in contrast to its non-invasive congeners, C. solstitialis had the highest relative growth rates when grown in competition. C. solstitialis was also the only species to show significant differences in traits between populations from different ranges, with plants from the non-native range of California demonstrating greater competitive resistance, larger seed size, and larger seedling mass than plants from the native range in Spain. This suggests that C. solstitialis may be evolving toward larger seed and seedling sizes in this non-native range. Relative growth rate showed no inter-regional variation for any species, but was higher for C. solstitialis than its congeners when in competition, and thus may interact with the evolution of larger seeds and plant mass in ways that contribute to the extraordinary invasive success of this species. © 2012 Springer Science+Business Media B.V.


Cruzeiro C.,The Interdisciplinary Center | Cruzeiro C.,University of Porto | Rocha E.,The Interdisciplinary Center | Rocha E.,University of Porto | And 3 more authors.
Journal of Cleaner Production | Year: 2016

Estuarine environments are being constantly pressured by new sources of pollution (e.g. new pesticides) derived from the activities of industry and intensive agriculture. The present study aim at quantify pesticides of three different categories (fungicides, herbicides and insecticides) in the Tagus River basin. Seasonal transition water samples were collected during 2010 and 2011, from seven sites distributed on both margins (north and south) of this estuary. Pesticides were subjected to solid phase extraction and then analyzed using gas chromatography coupled to tandem mass spectroscopy. Data showed that 95% of the analyzed pesticides were measurable in all samples, some being above the 2013/39/EU Directive levels (total loads ranged from 1.4 μg/L, in winter, up to 5.5 μg/L, in spring). Additionally, a panel of selected physicochemical parameters-linked with water quality standards, such as total phosphorous and total nitrogen-revealed high amounts close to the Trancão River mouth. Centered on the concentration addition and independent action models, a two-tiered approach was used to assess the risk of the pesticide mixture, at the maximum concentration found. This reflected the potential risk, mainly to fish. From the results, we conclude that legal quality standards are not being followed in this emblematic ecosystem and so there are risks to the biota. Hence, refined studies are required to identify both sources and impacts of the pesticides, and also to monitor preventive and depollution measures. © 2016 Elsevier Ltd.


Maltez-Mouro S.,Center for Functional Ecology | Maestre F.T.,Area de Biodiversidad y Conservacion | Freitas H.,Center for Functional Ecology
Acta Oecologica | Year: 2010

The analysis of co-occurrence patterns between plant species is being increasingly employed to study biotic interactions at the community level. We investigated changes in such patterns along two different abiotic stress gradients in eight sand-dune plant communities of the western coast of Portugal. We sampled a total of 72 transects consisting on 25 1 m2 quadrats each, and we calculated the standardized effect size for each transect (SES), i.e. the differences between the observed co-occurrence patterns and simulated patterns for a random co-occurrence. The relationships between the average SES values for each site and the abiotic stress gradients, defined by the north-south geographic gradient (a surrogate of the climatic stress) and total plant cover (a surrogate of productivity), were analyzed. The factors driving co-occurrence patterns at smaller spatial scale were also investigated by a stepwise multiple regression analysis. Average SES values were significantly higher than zero in five of the studied sites, indicating lower species co-occurrence than expected by chance. These results suggest that the studied sand-dune communities studied are structured mainly by competitive interactions. At the site scale, SES values were not related to plant cover or the location along the north-south gradient. However, at the transect scale, SES values were inversely explained by different abiotic factors (the geographic position along the north-south gradient and the plant cover). Our results indicate that the magnitude and the shifts in co-occurrence patterns along environmental gradients varied with the spatial scale and the surrogate of abiotic stress considered. © 2009 Elsevier Masson SAS. All rights reserved.


Cruzeiro C.,The Interdisciplinary Center | Cruzeiro C.,University of Porto | Rocha E.,The Interdisciplinary Center | Rocha E.,University of Porto | And 3 more authors.
International Journal of Environmental Analytical Chemistry | Year: 2015

This study describes the simultaneous quantification of 56 pesticides in surface coastal water, supported by the development and validation of a gas chromatography (GC)–ion trap (IT) mass spectrometry (MS) method. Samples (500 mL) were pre-concentrated 2500 times by solid phase extraction (OASISTMHLB). The compounds were identified and quantified, within 35 minutes, by GC tandem mass spectrometry (GC-MS/MS) and GC-MS, respectively. The methodology proved to be highly specific for all target pesticides, with an average linearity of 0.99. Detection limits and recovery rates ranged from 0.4 to 1.3 ng L− 1 and 71% to 120%, respectively. The performance of the method was checked using water samples collected from nine sampling sites along the Ria Formosa Lagoon Natural Park (south of Portugal, n = 54) in each season (2010). The total annual concentrations of all pesticides in each category (fungicides, herbicides and insecticides) were 1.4, 0.6 and 9.0 µg L−1, respectively. Moreover, 89% of the pesticides tested for were detected, 84% could be quantified and 25% had concentrations above the European recommended levels (2013/39/EU). The highest total loads of pesticides were found in the spring, which is in agreement with their seasonal application. Physicochemical parameters such as, nitrites, nitrates, ammonia and phosphates, also indicate poor water quality, supporting the fact that the Ria Formosa lagoon actually needs an effective monitoring programme for effective preservation of its natural reserve status. © 2015 Taylor & Francis.


Corcobado T.,University of Extremadura | Moreno G.,University of Extremadura | Azul A.M.,Center for Functional Ecology | Solla A.,University of Extremadura
Forestry | Year: 2015

Seasonal variations in ectomycorrhizal symbiosis of Quercus ilex trees were studied, with special emphasis on tree health status, Phytophthora cinnamomi root infections and topography. Five Q. ilex forests in western Spain were selected, and ca. 40 000 root tips from 3 declining and 3 non-declining trees per forest were examined. Ectomycorrhizal fungal abundance and P. cinnamomi root infections were quantified seasonally for 2 years, and an assessment was made of the water soil content and physiological status of trees during summer, the most stressful season. Seasonal changes in ectomycorrhizal fungal abundance were higher for Tomentella spp. than those for Russula spp. and Cenococcum geophilum, but these changes were not influenced by topography, tree decline status and P. cinnamomi root infections. Seasonal variations of non-vital tips were conditioned significantly by the decline status of trees. A higher proportion of non-vital tips and a lower proportion of vital non-mycorrhizal tips were observed in declining than in non-declining trees. Abundance of C. geophilum and Tomentella spp. was not influenced by P. cinnamomi root infections but by topography. Abundance of Russula spp. was not influenced by P. cinnamomi root infections but by the decline status of trees. The relationships found between tree physiology and ectomycorrhizal abundance changed significantly depending on the decline status of trees. For the first time, seasonal variations in ectomycorrhizae in P. cinnamomi-infected Q. ilex forests are reported. The low diversity and abundance of ectomycorrhizal fungi associated with declining trees should be further studied in order to uncover causes or consequences of Q. ilex crown transparency. © 2015 © Institute of Chartered Foresters, 2015. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.


Ferreira P.J.T.,University of Coimbra | Gamelas J.A.F.,University of Coimbra | Carvalho M.G.V.S.,University of Coimbra | Duarte G.V.,University of Coimbra | And 2 more authors.
Industrial Crops and Products | Year: 2013

In this work, Ailanthus altissima (tree-of-heaven) wood was analyzed for its chemical, morphological and papermaking properties. The A. altissima wood was cooked under kraft conditions using different active alkali charges and then handsheets were produced with the pulps having a kappa number of 16. Based on structural, strength and optical data it was found that the kraft pulp of A. altissima is not suitable to be used alone for the production of printing and writing papers. Notwithstanding, the handsheets exhibit a favorable value of brightness in comparison to those produced from Eucalyptus globulus pulp (with similar kappa number). Therefore, the wood of A. altissima seems to have a good potential to be used as a partial substitute of the main raw material of the Portuguese pulp industry. In fact, the results showed that when beaten E. globulus and A. altissima pulps were mixed (50:50, w/w), the papermaking properties were comparable to those of beaten eucalypt kraft pulps. Therefore, the use of A. altissima wood seems promising for the production of uncoated wood-free papers, which has advantages both from an economical and environmental perspective. © 2012 Elsevier B.V.


Lillebo A.I.,Center for Environmental and Marine Studies | Valega M.,Center for Environmental and Marine Studies | Otero M.,Center for Environmental and Marine Studies | Pardal M.A.,Marine Life Research | And 3 more authors.
Estuarine, Coastal and Shelf Science | Year: 2010

It has been shown that salt marshes may function as efficient sinks for contaminants, namely for mercury. At the rhizo-sediment Hg may be associated with Mn and Fe oxyhydroxides, precipitated as sulphides or incorporated into organic matter. However, to our knowledge, in situ studies have not focused on the related processes at a daily or tidal cycle scales. Thus, the present work aims to study the effect of a common salt marsh halophyte in temperate latitudes (Sarcocornia perennis) on dissolved Fe, Mn and Hg concentrations in the water column. The in situ approach was carried out at a mercury-contaminated salt marsh and at the adjacent non-vegetated area (distance ≤ 4 m), covering two consecutive tidal cycles in order to include the photosynthetic active period and the night processes. During high tide no daily or spatial effects were observed on the concentrations of Mn, Fe and Hg in the water column, due to the dilution effect of the incoming seawater. During low tide the concentrations of Mn, Fe and Hg were significantly higher in the overlaying water column of the salt marsh. At S. perennis mats the concentration of dissolved total Hg was significantly related with the concentration of Mn (r = 0.459, p = 0.028, n = 23), but not with that of Fe (r = 0.367, p = 0.085, n = 23) while no significant relations were found at the adjacent non-vegetated sediments. This study highlights the complexity of the biogeochemical processes that take place in salt marshes, due to the daily photosynthetic cycle of halophytes and to the tidal action in mesotidal systems. © 2010 Elsevier Ltd. All rights reserved.


PubMed | Center for Functional Ecology and CIIMAR – Interdisciplinary Center of Marine and Environmental
Type: Journal Article | Journal: Environmental monitoring and assessment | Year: 2015

Two novel methods were developed to extract and quantify 56 pesticides in surface waters, considering their content in both dissolved aqueous phase (DAP) and suspended particulate matter (SPM) fractions. These procedures were applied to coastal samples taken seasonally during 2012-2013, from three strategic sampling sites along the Ria Formosa Lagoon (south of Portugal). Briefly, 500 mL of water samples were filtrated, separating both fractions. The DAP fraction was extracted and pre-concentrated by solid-phase extraction (SPE), while the SPM was extracted using ultrasonic extraction technique (USE). Both fractions were then analyzed, and the pesticides were quantified and identified, within 35 min, by gas chromatography (GC) coupled to mass spectrometry (GC-MS and GC-MS/MS), respectively. The extraction of pesticides from the SPM fraction showed average recoveries of 102%, detection limits below 2.2 ng/L, and quantification limits ranging from 0.3 to 6.6 ng/L. Considering the real water samples, 73% of the selected pesticides were quantified in both DAP and SPM fractions (DAP+SPM 2.3 g/L) and their maximum levels were measured in autumn and winter. By category, the global loads of fungicides, herbicides, and insecticides were 407, 323, and 1.6 g/L, respectively. Thirty-one percent of the quantified pesticides exceeded the European directives levels (2008/105/EC and 98/83/EC). From the total loads, the SPM fraction contribution was 32%, showing the importance of measuring pesticides in that fraction. The water physicochemical parameters revealed that the total nitrogen amounts were very high relatively to the legal required values, mainly close to the city of Faro (2.6 mg/L). In light of the above, measures are in need to meet European directives and protect both fauna and humans that use this area for leisure.

Loading Center for Functional Ecology collaborators
Loading Center for Functional Ecology collaborators