26 research outputs found

    Danube Delta Biosphere Reserve (D.D.B.R.): reed dynamics within actual context

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    The reed beds are widely considered in Europe as ecologically and economically beneficial areas. I n The Danube Delta Biosphere Reserve (D.D.B.R.), reed is by far the dominant species and reed marshes cover more than 220,000 ha (Hanganu et al 2002). Presently, certain areas of reed beds are selected for burning or harvesting during the winter by private companies. Other surfaces are harvested in green, mown by the inhabitants as cattle food. Comparing the present period with the harvest campaigns from the ‘60 th until the ‘80 , we can say that the actual pressure on reed’s biodiversity is reduced. All above aspects of management practices and their influence on reed beds succession and th conservation of biodiversity are discussed. Beside the current reed type description and comparison with biometrical data from Chifu et al (1993), we present their distribution, in relation with type of substrate and hydrology, by reed complexes.Online ISSN 2065-7647; Printed ISSN 2066-762

    Assessment of Romanian alpine habitats spatial shifts based on climate change prediction scenarios

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    Shifts in the ecosystems distribution as the result of climate change are of interest for decision-makers in biodiversity conservation at local and European level. This paper presents the use of modeling technique, Maxent (Maximum entropy modeling) and BIOCLIM (environmental envelope model), to estimate the impact of climate change on the Alpine bioregion of Continental Europe for improving the management policy in support of stopping biodiversity loss. The European Union priority habitat 6230 occurring in mountain areas and sub-mountain areas of the Carpathians was selected for modeling being of high priority conservation status in the Natura 2000 network of protected area. Maxent and BIOCLIM were used to create spatial distribution models for Mesophilous oligotrophic mountain pasture and Subalpine oligotrophic pastures. Models were run with 1950–2000 averaged bioclimatic data and double atmospheric CO2 concentration scenario in perspective of the year 2050. In our analyses we have included once all 6320 mapped habitat with Nardus grasslands. Under 1950–2000 climate scenario, both models exhibited high AUC values (> 0.9). The predicted geographical distribution of Mesophilous oligotrophic mountain pasture and Subalpine oligotrophic pastures coded as VNG and PON habitat modeled by Maxent and BIOCLIM shows differences between the modeling approaches, with Maxent predicting smaller areas (12% less) of suitable habitat than BIOCLIM. For the future climate scenario (double CO2) the surface with PON+VNG decreases by 31% for Maxent and 26% for BIOCLIM. However both models show significant shifts of the Nardus habitat due to climate change. The distribution maps obtained indicate vulnerability areas to biodiversity loss and of interest to be monitored. The output of models will contribute to the Black Sea Catchment Observation Systems to be further accessible to scientists, decision-makers and the general public

    Change detection in floodable areas of the Danube delta using radar images

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    International audienceIn the wetlands of the Danube delta floodplain, flooding is a major natural risk. The coastal wetlands have been seriously impacted by floods in 2002, 2005, 2006 and 2010. Using hydrological and satellite observations acquired in 2009 and during the summer of 2010, this paper tackles the issue of forecasting risk based on land cover information and observations. A major objective of this methodological work consists in exploring several types of data from the Japanese ALOS satellite. These data are used to illustrate a multitemporal radar data processing methodology based on temporal entropy analysis that enables change detection in the floodable areas of the Danube delta

    Towards Innovative Governance of Nature Areas

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    How can the governance of nature areas foster the sustainability of ecosystems? This is discussed with regard to larger threats on ecosystems despite larger global nature areas that reach 19 million km2 of land along with larger costs per area unit. Moreover, monetization of nature with payments for ecosystem services is sometimes demanded for justification of the nature areas; however, this does not resolve the threats but faces scientific and ethical scrutiny. An alternative is the governance that incubates sustainable innovations in the nature areas for broad dissemination which generates interests in the sustainability of ecosystems. Opportunities are due to demands for ethical products, ecotourism and images of nature which generate USD 1100 billion in global markets. Sustainable innovations of using reed for insulation walls, furniture panels and upholstery in the EU can generate a few hundred million dollars in addition to present roof thatching, fodder and fuels if good functional qualities of the reed products are developed. Their functionalities can be supported by the inclusive economics, CO2 storage, treatment of water pollution, richer biodiversity, and other ethical qualities. The governance of nature areas can prevent the present deadlock but needs the development of technical and entrepreneurial capabilities

    IEEE JOURNAL OF SELECTED TOPICS IN APPLIED EARTH OBSERVATIONS AND REMOTE SENSING SYNERGY BETWEEN LiDAR, RADARSAT-2 AND SPOT-5 IMAGES FOR THE DETECTION AND MAPPING OF WETLAND VEGETATION IN THE DANUBE DELTA

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    International audienceWetlands are among the most productive natural environments on Earth, as they harbor exceptional biological diversity. For this paper, our study site was the Danube Delta. The biodiversity of the Danube Delta is extraordinary and it possesses one of the largest reed beds in the world. The main goal of our paper was to recognize, characterize and map the main vegetation units of the Danube Delta. The paper emphasizes the importance of the joint use of LiDAR measurements (acquired in May 2011), RADARSAT-2 radar data (acquired on 4 June 2011) and SPOT-5 optical data (acquired on 25 May 2011). LiDAR data allow for the characterization of vegetation height within centimeter accuracy (10 cm). The radar measurements are based on C-band, providing additional information about the structure of the vegetation cover. The simultaneous acquisition of HH, HV, VV and VH polarizations enabled us to discriminate between the targets, depending on their responses to the various polarizations, by calculating their polarimetric signatures. By linking multispectral LiDAR and radar data, information can be obtained about vegetation reflectance and height as well as the backscattering mechanism, allowing for improved mapping and characterization accuracy (90.60% mean accuracy). An accuracy assessment of the classification results was evaluated against the vegetation data recorded in the field
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