Innovations in cumulative impact studies and applications to aid conservation and sustainable management of Reindeer in Scandinavia

During the last century the world has changed rapidly due to human activities. Climate change and its effects are regular frontpage news, and human land use has changed the earth's surface. For instance, roads and railways often act as barriers for species movements. The result is a 'perfect storm', where movement barriers trap species in places that no longer provide good (climatic) living conditions. To limit the negative consequences of our activities, we need to understand the total effect of all human activities on other species. In this project we focus on reindeer, a highly iconic species for Scandinavia. Reindeer play a pivotal role in alpine and tundra ecosystems, and the lives of many local communities. Notably, they form the pillar of the Sami culture. Despite the relative remoteness of the reindeer ranges, they have not been spared from infrastructure developments, and the effects of climate change are felt globally. A brief overview of all the methods and toolkit development, the results and maps, a list of publications can be found in the Reindeer Web App: https://www.nina.no/Naturmangfold/Hjortedyr/reindeermapsnorway In a team of international researchers, with expertise ranging from ecology to computer sciences, we have developed a conceptual and methodological framework that allows the quantification of the total effects of the different stressors (e.g. renewable energy, transport, tourism, climate) on the reindeer ranges. This framework involves: (i) computing the zone of influence of each different stressor, using the oneimpact R package; (ii) performing habitat suitability and movement modeling to estimate the cumulative impacts; and (iii) model habitat connectivity to quantify and spatial identify functional habitat and movement corridors through the ConScape library. Using this approach, it is possible to estimate habitat loss and fragmentation, identify the main stressors to reindeer habitat in each area, and simulate how additional human activity or mitigation measures might decrease or improve the conditions of reindeer ranges. These results are published in four different scientific papers. We have compiled a large database of reindeer GPS data across Norway and Sweden, as well as environmental variables for Scandinavia, including climate, natural resources, landscape variables, and infrastructure and human activity maps. Combining our approach with this data, we have developed several local and regional analyses to estimate cumulative impacts over reindeer ranges, for both wild and semi-domesticated reindeer. We have found that reindeer responds to a combination of transport infrastructure (roads and railways), industrial development (hydropower reservoirs, and also wind turbines for semi-domesticated reindeer), human settlements (buildings), and tourism activity. The detailed description of the methods and the results for all wild reindeer populations are summarized in two reports (follow link above) and in an interactive Dashboard at: https://view.nina.no/QN. Importantly, we found that the effects of human infrastructure and activity might extend over large distances and are more intense when there is a high density of infrastructure features, whose effects are summed up. For instance, in Hardangervidda wild reindeer population we found cumulative impacts of private cabins and tourist resorts on reindeer, extending up to 10 and 20?km. Although the impact of an isolated private cabin was negligible, the cumulative impact of ‘cabin villages’ could be much larger than that of a single large tourist resort. Finally, we have also extended the statistical approach to estimate the effects of applying mitigation measures for wild reindeer in different areas – namely, changing hydropower and tourist infrastructure in Setesdal Ryfylke, and closing down tourist resorts and trails in Rondane. The results are available in a scientific article.

Anthropogenic activities pose major challenges to sustainability. The cumulative impact of multiple stressors depends upon their interactions and spatio-temporal configurations with respect to each other and to ecosystem flows. Failure to adequately assess long-term cumulative impacts may lead to tipping points and undermine ecosystem functioning. We integrate advances in ecology and computer science to quantify cumulative impacts of any combination of stressors, occurring at specific places and times, on ecosystem performance. We extend the ecological niche concept by integrating movement flows and connectivity. We develop approaches to assess cumulative impacts simultaneously on habitat loss and fragmentation, and quantify the remaining amount of functional habitat. We will develop an open-source software to: calculate multi-stressor impacts, identify vulnerable areas, produce zonation maps, and perform scenario analyses to guide sustainable development. We test the approach on a sensitive key species posing major challenges to sustainable development: reindeer. We build upon decades of studies on > 1000 GPS-monitored reindeer individuals across Boreal, Alpine, sub-Arctic and high Arctic ecosystems in Norway and Sweden to synthesize knowledge, identify tolerance thresholds, and quantify the total impact of all stressors (climate, roads, railways, renewable energy, tourism, forestry, depredation, parasites etc.) on populations. We integrate the cumulative impact into a synthetic index quantifying the habitat functionality of each range, and produce zonation maps ranking sensitive areas for use in management. Finally, we analyse historic and future scenarios to unveil multi-stressor impacts so far, project it in time, and concretely assist sustainable development. To ensure practical relevance we integrate Traditional Ecological Knowledge and scenario analyses based on stakeholders' expertise and requirements within the same analytical framework.