University of Twente Student Theses
Addressing the importance of threat maps and resolution in modelling the distribution of the European ground squirrel
Rosario Vazquez Perez, Miriam del (2020) Addressing the importance of threat maps and resolution in modelling the distribution of the European ground squirrel.
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| Abstract: | Protected Areas are not isolated from its surroundings; its management must consider an integrated approach beyond its borders. Threats can direct or indirect damage to the values that the Protected Area should keep. Direct threats can be addressed by the local management of the Protected Area, but indirect threats are more challenging, as the source is not easily traceable. Unfortunately, mapping threats is not extended practice as data availability is a recurrent issue. Since “maps are an invaluable tool to inform and assist decision-making” regardless of how a map was created; a manager will use the available data (Lecours, 2017). As conservation efforts do not always specify standards or guidelines for the production of maps, results can vary dramatically. Another issue is that the final product does not always have feedback from the manager of the resource. The consequences making conservation decisions based on a misinterpretation of maps include loss of trust in science, conservation plans or management plans that do not reach their objectives, financial costs and temporal costs (Guisan et al., 2013; Lecours, 2017). Using species modelling and GLM and linking the environmental variables and the geo-representation of the threats the Author mapped the probable presence given burrow characteristics of the European Ground Squirrel (Spermophilus citellus) in an administrative region context in the Region of Central Macedonia in Greece, considering environmental variables and its reported threats and the effect of fitting the probable presence at different pixel resolutions: 30 x 30, 100 x 100, 500 x 500 and 1000 x 1000 in meters. Mapping the probable presence with only environmental variables at different resolutions did not change the importance in the environmental variables altitude, slope, and soil parent material Fluvial clays, silts and loams. Trying to use the land cover was unsuccessful as by upscaling the pixel resolution, the category in which the presence points was originally shifted to another one in the new resolution. The Author tried a simple approach for the mapping of the threats and linking them to geo-representation the using, density, distance and Boolean. Although including the threats did increase the accuracy of the models at all resolutions, no threat was consistent on being significant at all resolutions. Each resolution had a different mixture of threats that combined with the environmental variables explained the probable presence or absence of the species. The threats that contributed the most to the models were the roads. For the ground squirrel in Central Macedonia, the model with the resolution that has more significant variables and threats, and reflects the most considerable improvement on accuracy by considering the threats, and as well as 2 of 3 of the best accuracy assessments is the 500 resolution. This does however not mean that all the European ground squirrel range of probable habitat should be mapped at this resolution nor that other related species should be mapped this way. It indicates that under the reviewed factors in the study area, these are the relationships. This analysis suggests that at different pixel resolutions in the same extent, it possible to model the presence of the European Ground Squirrel or European Souslik (Spermophilus citellus) given its burrow environmental characteristics. The models were developed by implying that the effect will be the same in the study area, although we know that this generalization is not a reflection of the real world, is a helpful approximation. Finally, mapping threats is essential to conservation efforts, and further research has to be done to translate the concept into a map. And this way to implement efficient science-based natural resources management actions |
| Item Type: | Essay (Master) |
| Faculty: | ITC: Faculty of Geo-information Science and Earth Observation |
| Programme: | Geoinformation Science and Earth Observation MSc (75014) |
| Link to this item: | https://purl.utwente.nl/essays/85205 |
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