Spatial downscaling of alien species presences using machine learningSpatial downscaling of alien species presences using machine learning Peer-Reviewed Journal Publication Δημοσίευση σε Περιοδικό με Κριτές 2018-04-232017enSpatially explicit assessments of alien species environmental and socio-economic impacts, and subsequent management interventions for their mitigation, require large scale, high-resolution data on species presence distribution. However, these data are often unavailable. This paper presents a method that relies on Random Forest (RF) models to distribute alien species presence counts at a finer resolution grid, thus achieving spatial downscaling. A bootstrapping scheme is designed to account for sub-setting uncertainty, and subsets are used to train a sufficiently large number of RF models. RF results are processed to estimate variable importance and model performance. The methodis testedwith an ∼8 ×8km2 gridcontaining floral alien species presence and several potentially exploratory indices of climatic, habitat, land use, and soil property covariates for the Mediterranean island of Crete, Greece. Alien species presence is aggregated at 16 × 16 km2 and used as a predictor of presence at the original resolution, thus simulating spatial downscaling. Uncertainty assessment of the spatial downscaling of alien species’ occurrences was also performed and true/false presences and absences were quantified. The approach is promising for downscaling alien species datasets of larger spatial scale but coarse resolution, where the underlying environmental information is available at a finer resolution. Furthermore, the RF architecture allows for tuning toward operationally optimal sensitivity and specificity, thus providing a decision support tool for designing a resource efficient alien species census.http://creativecommons.org/licenses/by/4.0/Frontiers in Earth Science5Daliakopoulos_et_al_Frontiers in Earth Science_5_2017.pdfChania [Greece]Library of TUC2018-04-23application/pdf2.0 MBfree Daliakopoulos Ioannis Δαλιακοπουλος Ιωαννης Katsanevakis Spyros Κατσανεβακης Σπυρος Moustakas, Aristidis Frontiers Media Alien species Crete Data analytics Downscaling Hydro-ecological data Random forests Vascular plants