2000-2050 Annual probability of occurrence maps for the invasive species: Caulerpa cylindracea

Annual probability of occurrence maps for Caulerpa cylindracea. The dataset covers the entire Mediterranean basin, even if the predicted P of occurrence is limited to cover "euphotic" zones (cells with depths greater than 200m are masked). Temporally, it spans from 2000 to 2050. For the future conditions (2020-2050) we follows the RCP8.5 projections scenario. Three possible classification thresholds can be applied, to provide a "scenario exploration". Methodology and results comes from the work of Fianchini et al. (2025), still not available publicly.

Data and Resources

Additional Info

Field Value
Original title Improving MaxEnt Reliability with Multi-Criteria Analysis and Site Weighting: A Case Study on Caulerpa cylindracea
Original abstract The rapid spread of Invasive Alien Species (IAS) underlines the urgent need for predictive modelling to accurately forecast future spread under climate change. Correlative Ecological Niche Models (ENMs) serve this purpose, but often struggle with sampling bias, overfitting and uncertainty quantification and rely on a certain degree of subjectivity, which limits their reliability. We have developed an improved ENM framework using MaxEnt, that integrates standard and site-weighted performance metrics into a multi-criteria decision process to select models that provide a better balance between explanatory power and transferability. To detect overfitting, we introduced delta metrics that measure the dependence of model performance on the weighting scheme. Furthermore, we performed a sensitivity analysis to quantify the classification uncertainty associated with different probability thresholds. We test this approach on Caulerpa cylindracea, one of the most dangerous IAS in the Mediterranean. The selection approach identified an optimal model that showed high and stable performance across all weighting schemes and multiple validation datasets. Both the annual and scenario-based projections show a general shift towards lower habitat suitability, with a statistically significant negative trend in High Suitability areas. The decline suggests that the future spread of C. cylindracea is likely to be limited to currently invaded areas, assuming no adaptation. The high reliability of the model is supported by the extremely low extrapolation risk (0.21% of the predictions under 'strict extrapolation') and the agreement of the response curves with the known ecophysiology of the species. However, the sensitivity analysis of threshold selection shows a non-uniform pattern of classification uncertainty that appears to be related to invasion stage, with the greatest variability observed in recently invaded regions such as the Northern Adriatic. Practical Implication: This framework provides robust predictions of invasion risk while explicitly quantifying uncertainty. The selection procedure, leveraging delta metrics, explicitly include model generalisation ability in the ranking process. The annual suitability projections enable temporal prioritization of control efforts. Threshold sensitivity analysis identifies areas that require more conservative management approaches, improving the quality and cost-effectiveness of intervention strategies.
Topic category
  • types_of_habitat
Sub category Invasive species
Resource language English
Domain area
  • mediterranean_sea
Owner OGS
Provider OGS
Data portal
Presentation form Map (map represented in raster or vector form)
Spatial representation Raster (grid)
Coordinate reference system Other
Web services
    Derives from
    Derived datasets
    Successor of
    Predecessor of
    Temporal extent 2000-01-01
    2050-12-31
    Spatial extent {"type":"Polygon","coordinates":[[[-6.020833333333333,30.16666666666667],[-6.020833333333333,45.958333333333339],[36.27083333333333,45.958333333333339],[36.27083333333333,30.16666666666667],[-6.020833333333333,30.16666666666667]]]}
    Data accessibility Data available on request. Article still not published so avoid external sharing. contact mfianchini@ogs.it
    Validation level Research
    Additional information
    Metadata completeness Draft
    Notes

    Additional info - MSP - Environment

    Species, habitats, ecosystems, pressures

    Field Value
    MSFD Classes
    • Habitats - Seabed
    • Pressure: Biological - Input or spread of non-indigenous species
    MSFD Descriptors/Criteria
    • D2 Non-indigenous species
    • D6 Sea-floor integrity/D1 Biodiversity - benthic habitats
    • D1C4 Population distributional range and pattern
    Non MSFD Classes
      WFD Ecological status

      Additional info - MSP - Oceanographic and CC

      Physics, biochemistry, EOV, ECV

      Field Value
      Variables

        Additional info - MSP - Conservation

        Protected areas, OECM, IBA, EBSA, CCH, IMMA, ...

        Field Value
        Types
          Zonation

          Additional info - MSP - Maritime activities

          Aquaculture, fishing, transport, energy, ...

          Field Value
          Activity types

            Additional info - MSP - Coastal & Land use and planning

            Land use, land cover, planning (strategic, coordination, operational)

            Field Value
            Types
            • Planning - Strategic - National (EU regulated)
            • Planning - Strategic - National (others)
            • Planning - Strategic - Subnational
            • Planning - Strategic - Local
            • Planning - Coordination - Sub-national
            • Planning - Operational-Sub-National

            Additional info - MSP - Socio-economic

            Living and non-living resources, shipping, tourism, energy, ...

            Field Value
            Activity types
              Value types
                Categories

                  Additional info - MSP - Ecosystem Services

                  Provisioning, regulation & maintenance, cultural

                  Field Value
                  CICES classes

                    Additional info - MSP - Legal, Governance & Planning

                    Strategic, legislation, planning, administrative, enforcement

                    Field Value
                    Themes
                    • Environment (e.g. pollution and biodiversity)
                    • Conservation (i.e. Protected areas)
                    Functions
                      Who is in charge?

                      Additional info - MSP - Relevance

                      Relevance of the dataset / resource in supporting the MSP process at different spatial scales and temporal frames

                      Field Value
                      Relevance (spatial and temporal)
                      • International - present - Medium
                      • International - future - High
                      • National - present - Medium
                      • National - future - High
                      • Sub-area - present - Medium
                      • Sub-area - future - Medium
                      • Local - present - Low
                      • Local - future - Low