Browsing by Author "Nielsen, Jessica"

As a part of global biodiversity loss, pollinating species are declining rapidly. This decline is driven by the loss, degradation and fragmentation of semi-natural grasslands and meadows, primary habitats of pollinating species. Therefore, ensuring connectivity between habitats becomes crucial. As urbanization is putting pressure on green spaces, planners need tools to find areas where conservation efforts are most critical. In this thesis, I aim to 1) model the connectivity network of pollinator habitats in the city of Tampere and 2) evaluate the usability of my analysis for urban planning purposes. Using Least Cost Path (LCP) analysis, I modelled ecological connectivity for pollinating insects in the Tampere region. Connectivity in this context means how easily pollinating insects can move between different areas. I examined two distinct groups of pollinators in my analysis: butterflies (Family: Lepidoptera) and bumblebees (genus: Bombus). Relying on land cover data and green infrastructure maintenance class data, I first identified suitable habitats for my model taxa. Then I created a map layer indicating how resistant different areas were to pollinator movement, based on expert opinions. Using the habitat patches as starting and ending points of movement and the resistance layer to bring more realism to the non-habitat matrix of my model, two fixed distances that pollinators are known to travel were utilized – 200 m and 500 m, respectively. Then, to evaluate the usability of the LCP analysis for planning purposes I conducted a SWOT analysis together with city experts. Results show a shortage of pollinator habitats in Tampere’s city center. This lack of pollinator habitats has led to a division of the connectivity network into two parts: a western and an eastern network. Road verges and areas under power lines appear to play a connecting role for both butterflies and bumblebees, linking larger habitat patches together. The most significant limitations to my analysis include an administrative approach to habitat definition, generalist model taxa and the use of relative data values, i.e., expert opinion. While my results have limitations and should be considered together with other material, they provide valuable insights into identifying important meadows and forested areas for pollinators and addressing connectivity gaps.