55 research outputs found

    Translating land cover/land use classifications to habitat taxonomies for landscape monitoring: A Mediterranean assessment

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    Periodic monitoring of biodiversity changes at a landscape scale constitutes a key issue for conservation managers. Earth observation (EO) data offer a potential solution, through direct or indirect mapping of species or habitats. Most national and international programs rely on the use of land cover (LC) and/or land use (LU) classification systems. Yet, these are not as clearly relatable to biodiversity in comparison to habitat classifications, and provide less scope for monitoring. While a conversion from LC/LU classification to habitat classification can be of great utility, differences in definitions and criteria have so far limited the establishment of a unified approach for such translation between these two classification systems. Focusing on five Mediterranean NATURA 2000 sites, this paper considers the scope for three of the most commonly used global LC/LU taxonomies—CORINE Land Cover, the Food and Agricultural Organisation (FAO) land cover classification system (LCCS) and the International Geosphere-Biosphere Programme to be translated to habitat taxonomies. Through both quantitative and expert knowledge based qualitative analysis of selected taxonomies, FAO-LCCS turns out to be the best candidate to cope with the complexity of habitat description and provides a framework for EO and in situ data integration for habitat mapping, reducing uncertainties and class overlaps and bridging the gap between LC/LU and habitats domains for landscape monitoring—a major issue for conservation. This study also highlights the need to modify the FAO-LCCS hierarchical class description process to permit the addition of attributes based on class-specific expert knowledge to select multi-temporal (seasonal) EO data and improve classification. An application of LC/LU to habitat mapping is provided for a coastal Natura 2000 site with high classification accuracy as a result

    How robust are community-based plant bioindicators? Empirical testing of the relationship between Ellenberg values and direct environmental measures in woodland communities

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    There are several community-based bioindicator systems that use species presence or abundance data as proxies for environmental variables. One example is the Ellenberg system, whereby vegetation data are used to estimate environmental soil conditions. Despite widespread use of Ellenberg values in ecological research, the correlation between bioindicated values and actual values is often an implicit assumption rather than based on empirical evidence. Here, we correlate unadjusted and UK-adjusted Ellenberg values for soil moisture, pH, and nitrate in relation to direct environmental measures for 50 woodland sites in the UK, which were subject to repeat sampling. Our results show the accuracy of Ellenberg values is parameter specific; pH values were a good proxy for direct environmental measures but this was not true for soil moisture, when relationships were weak and non-significant. For nitrates, there were important seasonal differences, with a strong positive logarithmic relationship in the spring but a non-significant (and negative) correlation in summer. The UK-adjusted values were better than, or equivalent to, Ellenberg’s original ones, which had been quantified originally for Central Europe, in all cases. Somewhat surprisingly, unweighted values correlated with direct environmental measures better than did abundance-weighted ones. This suggests that the presence of rare plants can be highly important in accurate quantification of soil parameters and we recommend using an unweighted approach. However, site profiles created only using rare plants were inferior to profiles based on the whole plant community and thus cannot be used in isolation. We conclude that, for pH and nitrates, the Ellenberg system provides a useful estimate of actual conditions, but recalibration of moisture values should be considered along with the effect of seasonality on the efficacy of the system

    Habitat conservation in Italy: the state of the art in the light of the first European Red List of Terrestrial and Freshwater Habitats

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    The importance of taking into account ecosystems, plant communities and habitats for the development of biodiversity conservation strategies is increasingly acknowledged. Recently, the first ever European Red List of Habitats was produced, which provided an evaluation of the extinction risk of EUNIS-based natural and semi-natural habitats in Europe. As assessment unit, it used the habitat intended as a plant community, thus representing a landmark for the role of vegetation science in nature conservation. In the present paper, the results of the European Red List of Habitats are analyzed at the national scale with specific reference to the terrestrial and freshwater habitat types occurring in Italy. More than three-quarters of the assessed European habitat types were recognized for the Italian territory. The distribution of the threat categories reflects approximately the situation at the EU28 level. About 35% of the assessed habitat types are referred to a threat category; no critically endangered habitat is present in Italy. The most frequently used criteria are those related to a reduction in quantity. Some critical issues arising from the analyses are discussed. In particular, the presence of knowledge gaps is pointed out, with remarkable reference to the poor availability of spatial and quantitative data, severely affecting the application of the criteria adopted for the assessment. Descriptions of habitat types from Italy are reported, some of which are representative, emblematic or even exclusive to the Italian territory. The outcomes of the analysis represent the starting point for the future development of a national-scale Red List of Habitats. Results also emphasized how habitat types with a too broad definition pose a limit to a proper evaluation of the regional biogeographic variability, often very high in Italy, with local floristic and phytocoenotic peculiarities which do not find room in the adopted European typology. This is the reason why the development of national subtypes stands as a necessary step for the development of a realistic and effective assessment at the national scale

    A high-resolution bioclimate map of the world: a unifying framework for global biodiversity research and monitoring

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    A broad set of climate-related variables were considered for inclusion in a quantitative model, which partitions geographic space into bioclimate regions. Statistical screening produced a subset of relevant bioclimate variables, which were further compacted into fewer independent dimensions using principal components analysis (PCA). An ISODATA clustering routine was then used to classify the principal components into relatively homogeneous environmental strata. The strata were aggregated into global environmental zones based on the attribute distances between strata to provide structure and support a consistent nomenclature. The global environmental stratification (GEnS) consists of 125 strata, which have been aggregated into 18 global environmental zones. The stratification has a 30 arcsec resolution (equivalent to 0.86 km2 at the equator). Aggregations of the strata were compared with nine existing global, continental and national bioclimate and ecosystem classifications using the Kappa statistic. Values range between 0.54 and 0.72, indicating good agreement in bioclimate and ecosystem patterns between existing maps and the GEnS
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