124 research outputs found

    Assessing the Impacts of Different Initiatives on the Rehabilitation of Pastoral and Silvopastoral Ecosystems: Big Data Oriented Approach

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    Moroccan forests, through the provision of goods and ecosystem services, underpins benefits to local communities and play a crucial role for rural area development. The legal framework recognizes to people, living near public forests, the right to graze their domestic livestock. Over the years, the grazing pressure is at levels far beyond the forestland’s carrying capacity throughout the country. Such pressure has been demonstrated as the main cause of forest cover loss and land degradation in Morocco and still threatening the sustainability of forests. To reduce the heavy grazing pressure on forest ecosystems and ensure their regeneration, several initiatives have been conducted such as the program of compensation for forest areas closed to grazing (CFCG), initiated by Moroccan forestry department. Socio-economic impact assessment of this mechanism was presented within several studies but its effectiveness for forest rangeland rehabilitation remains scarce and very spatially limited. To deal with this concern and to assess vegetation dynamics through various spatial and temporal scales, parcels concerned by CFCG and others within similar conditions was chosen. Time series of remotely sensed spectral indices at each parcel was used for vegetation cover dynamics assessment. Google Earth Engine platform (GEE) was used as computing plateform. As result, the spectral indices trends shown a long-lasting degradation tendency in areas planted without compensation compared to those concerned by CFCG. Such results were also verified using aerial images covering the analyzed parcels. As conclusion, within comparable conditions, CFCG improved vegetation cover trends. The use of GEE Platform simplified the process of treatment of remote sensed imagery and made it easy to assess the state of the vegetation and will be of great use in assessing the impacts of different programs and initiatives on the restoration of pastoral and silvopastoral ecosystems

    Impact of climate change on potential distribution of Quercus suber in the conditions of North Africa

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    Climate change, which is expected to continue in the future, is increasingly becoming a major concern affecting many components of the biodiversity and human society. Understanding its impacts on forest ecosystems is essential for undertaking long-term management and conservation strategies. This study was focused on modeling the potential distribution of Quercus suber in the Maamora Forest, the world’s largest lowland cork oak forest, under actual and future climate conditions and identifying the environmental factors associated with this distribution. Maximum Entropy approach was used to train a Species Distribution Model and future predictions were based on different greenhouse gas emission scenarios (Representative Concentration Pathway RCPs). The results showed that the trained model was highly reliable and reflected the actual and future distributions of Maamora’s cork oak. It showed that the precipitation of the coldest and wettest quarter and the annual temperature range are the environmental factors that provide the most useful information for Q. suber distribution in the study area. The computed results of cork oak’s habitat suitability showed that predicted suitable areas are site-specific and seem to be highly dependent on climate change. The predicted changes are significant and expected to vary (decline of habitat suitability) in the future under the different emissions pathways. It indicates that climate change may reduce the suitable area for Q. suber under all the climate scenarios and the severity of projected impacts is closely linked to the magnitude of the climate change. The percent variation in habitat suitability indicates negative values for all the scenarios, ranging –23% to –100%. These regressions are projected to be more important under pessimist scenario RCP8.5. Given these results, we recommend including the future climate scenarios in the existing management strategies and highlight the usefulness of the produced predictive suitability maps under actual and future climate for the protection of this sensitive forest and its key species – cork oak, as well as for other forest species

    Puntos de inflexión en los gradientes de composición de las comunidades de plantas acuáticas de diferentes continentes

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    Sección: SIBECOL-AIL Meeting in Aveiro-2022[EN] Unravelling patterns and mechanisms of biogeographical transitions is crucial if we are to understand compositional gradients at large spatial extents, but no studies have thus far examined breakpoints in community composition of freshwater plants across continents. Using a dataset of almost 500 observations of lake plant community composition from six continents, we examined, for the first time, if such breakpoints in geographical space exist for freshwater plants and how well a suite of ecological factors (including climatic and local environmental variables) can explain transitions in community composition from the subtropics to the poles. Our combination of multivariate regression tree (MRT) analysis and k-means partitioning suggests that the most abrupt breakpoint exists between temperate to boreal regions on the one hand and freshwater plant communities harbouring mainly subtropical or Mediterranean assemblages on the other. The spatially structured variation in current climatic conditions is the most likely candidate for controlling these latitudinal patterns, although one cannot rule out joint effects of eco-evolutionary constraints in the harsher high-latitude environments and post-glacial migration lags after Pleistocene Ice Ages. Overall, our study supports the foundations of global regionalisation for freshwater plants and anticipates further biogeographical research on freshwater plant communities once datasets have been harmonised for conducting large-scale spatial analyses[ES] Desentrañar los patrones y mecanismos que subyacen a las transiciones biogeográficas es un requisito fundamental a la hora de comprender los gradientes de composición de las comunidades ecológicas a grandes extensiones espaciales, si bien ningún estudio ha examinado explícitamente estos puntos de inflexión para comunidades de plantas acuáticas de diferentes continentes. Utilizando una completa base de datos que condensa un total de casi 500 observaciones individuales sobre las comunidades florísticas lacustres de seis continentes, este trabajo pretende delinear las transiciones biogeográficas en plantas acuáticas a escala global, así como valorar el papel que desempeñan diversos mecanismos ecológicos (a saber, las condiciones climáticas y las características locales del hábitat) sobre estos puntos de inflexión en el espacio geográfico comprendido entre las latitudes subtropicales y los polos. Nuestros resultados obtenidos mediante la ejecución simultánea de árboles de regresión multivariante (MRT) y algoritmos de agrupación por k-medias demuestran la existencia de un punto de inflexión entre las regiones templadas y boreales y los lagos localizados en las bandas subtropicales y en las inmediaciones del Mediterráneo. La estructura espacial que subyace a la distribución de los condicionantes climáticos en nuestro planeta parece ser el principal mecanismo de control de dichas transiciones biogeográficas, si bien estos patrones latitudinales también podrían explicarse en base a constricciones eco-evolutivas en las regiones más septentrionales y a la colonización diferencial de los territorios norteños antaño cubiertos por el hielo durante el Último Máximo Glacial. En síntesis, nuestro estudio proporciona una base teórica preliminar para futuras investigaciones encaminadas a delimitar las unidades geográficas de los principales componentes de la flora acuática contemporánea y también anticipa un creciente interés por los estudios de carácter fitogeográfico en las aguas continentales, si bien los análisis venideros deberán prestar especial atención a la armonización de datos biológicos potencialmente heterogéneos en naturaleza y con orígenes disparesSIJGG was funded by the European Union Next Generation EU/PRTR (grant no. AG325). Academy of Finland supported JH, JGG (grant no. 331957), and JA (grant no. 322652). CFL appreciates financial support from the Spanish Ministry of Science and Technology (grant no. CL2017- 84176R). BAL was supported by National Research, Development, and Innovation Office (grant no. NKFIH, OTKA FK127939) and by the Bolyai János Research Scholarship of the Hungarian Academy of Sciences. SK was supportedby NWO Vidi (grant no. 203098). LR was funded by MESRSI (Ministry of Higher Education, Scientific Research and Innovation of Morocco) as part of the BiodivRestore Program (RESPOND Project) and by the Tour du Valat Foundation. Sampling of the Brazilian coastal lakes was financed by NWO (grant no. W84-549), the National Geographic Society (grant no. 7864-5), and CNPq (grants no. 480122, 490409, 311427

    Plant communities as a tool in temporary ponds conservation in SW Portugal

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    Pond conservationTemporary ponds are seasonal wetlands annually subjected to extreme and unstable ecological conditions, neither truly aquatic nor truly terrestrial. This habitat and its flora have been poorly studied and documented because of the ephemeral character of the flora, the changeable annual weather that has a great effect on the small, herbaceous taxa and the declining abundance of temporary ponds. The objectives of this study are: (a) to define plant community diversity in terms of floristic composition of ephemeral wetlands in SW Portugal, (b) to identify temporary pond types according to their vegetation composition and (c) to identify those ponds that configure the European community priority habitat (3170* – Mediterranean temporary ponds). Vegetation sampling was conducted in 29 ponds, identifying 168 species grouped among 15 plant communities. Soil texture, pH, organic C and N content were measured, but only N and percent of clay appear to be related with the distribution of each community type. The results showed that ephemeral wetlands could be classified into four type: vernal pools, marshlands, deep ponds and disturbed wetlands. Vernal pools correspond to the Mediterranean temporary ponds (3170*), protected as priority habitat under the EU Habitats Directive. Submersed Isoetes species (Isoetes setaceum and Isoetes velatum) represents, together with Eryngium corniculatum, the indicator species for vernal pools. We identify also indicator plant communities of this priority habitat, namely I. setaceum and E. corniculatum– Baldellia ranunculoides plant communities. In this region, the conservation of temporary ponds has so far been compatible with traditional agricultural activities, but today these ponds are endangered by the intensification of agriculture and the loss of traditional land use practices and by the development of touris

    Transport of small anionic and neutral solutes through chitosan membranes: Dependence on cross-linking and chelation of divalent cations

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    Chitosan membranes were prepared by solvent casting and cross-linked with glutaraldehyde at several ratios under homogeneous conditions. The cross-linking degree, varying from 0 to 20%, is defined as the ratio between the total aldehyde groups and the amine groups of chitosan. Permeability experiments were conducted using a side-by-side diffusion cell to determine the flux of small molecules of similar size but with different chemical moieties, either ionized (benzoic acid, salicylic acid, and phthalic acid) or neutral (2-phenylethanol) at physiological pH. The permeability of the different model molecules revealed to be dependent on the affinity of those structurally similar molecules to chitosan. The permeability of the salicylate anion was significantly enhanced by the presence of metal cations commonly present in biological fluids, such as calcium and magnesium, but remained unchanged for the neutral 2-phenylethanol. This effect could be explained by the chelation of metal cations on the amine groups of chitosan, which increased the partition coefficient. The cross-linking degree was also correlated with the permeability and partition coefficient. The change in the permeation properties of chitosan to anionic solutes in the presence of these metallic cations is an important result and should be taken into consideration when trying to make in vitro predictions of the drug release from chitosan-based controlled release systems

    Defining the importance of landscape metrics for large branchiopod biodiversity and conservation: the case of the Iberian Peninsula and Balearic Islands

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    The deficiency in the distributional data of invertebrate taxa is one of the major impediments acting on the bias towards the low awareness of its conservation status. The present study sets a basic framework to understand the large branchiopods distribution in the Iberian Peninsula and Balearic Islands. Since the extensive surveys performed in the late 1980s, no more studies existed updating the information for the whole studied area. The present study fills the gap, gathering together all available information on large branchiopods distribution since 1995, and analysing the effect of human population density and several landscape characteristics on their distribution, taking into consideration different spatial scales (100 m, 1 km and 10 km). In overall, 28 large branchiopod taxa (17 anostracans, 7 notostracans and 4 spinicaudatans) are known to occur in the area. Approximately 30% of the sites hosted multiple species, with a maximum of 6 species. Significant positive co-occurring species pairs were found clustered together, forming 4 different associations of large branchiopod species. In general, species clustered in the same group showed similar responses to analysed landscape characteristics, usually showing a better fit at higher spatial scales.Brazilian Conselho Nacional de Desenvolvimento Cientifico e Tecnologico-CNPq [401045/2014-5]Spanish Ministry of Education, Culture and Sport [FPU014/06783]info:eu-repo/semantics/publishedVersio

    Association of respiratory symptoms and lung function with occupation in the multinational Burden of Obstructive Lung Disease (BOLD) study

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    Background Chronic obstructive pulmonary disease has been associated with exposures in the workplace. We aimed to assess the association of respiratory symptoms and lung function with occupation in the Burden of Obstructive Lung Disease study. Methods We analysed cross-sectional data from 28 823 adults (≥40 years) in 34 countries. We considered 11 occupations and grouped them by likelihood of exposure to organic dusts, inorganic dusts and fumes. The association of chronic cough, chronic phlegm, wheeze, dyspnoea, forced vital capacity (FVC) and forced expiratory volume in 1 s (FEV1)/FVC with occupation was assessed, per study site, using multivariable regression. These estimates were then meta-analysed. Sensitivity analyses explored differences between sexes and gross national income. Results Overall, working in settings with potentially high exposure to dusts or fumes was associated with respiratory symptoms but not lung function differences. The most common occupation was farming. Compared to people not working in any of the 11 considered occupations, those who were farmers for ≥20 years were more likely to have chronic cough (OR 1.52, 95% CI 1.19–1.94), wheeze (OR 1.37, 95% CI 1.16–1.63) and dyspnoea (OR 1.83, 95% CI 1.53–2.20), but not lower FVC (β=0.02 L, 95% CI −0.02–0.06 L) or lower FEV1/FVC (β=0.04%, 95% CI −0.49–0.58%). Some findings differed by sex and gross national income. Conclusion At a population level, the occupational exposures considered in this study do not appear to be major determinants of differences in lung function, although they are associated with more respiratory symptoms. Because not all work settings were included in this study, respiratory surveillance should still be encouraged among high-risk dusty and fume job workers, especially in low- and middle-income countries.publishedVersio
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