Future ArcTic Ecosystems (FATE): drivers of diversity and future scenarios from ethnoecology, contemporary ecology and ancient DNA

The Arctic is currently experiencing some of the globally most dramatic ecosystem changes due to climate warming and increased anthropogenic pressure, with important implications for biological conservation and its inhabitants. Indigenous Arctic and Subarctic communities, whose livelihoods are closely linked to their environment and who directly depend on the herding and hunting of large herbivores, will have to adapt to the effects of climate warming and vegetation changes. Building relevant scenarios requires understanding the relative roles of climate, herbivory and increased anthropogenic pressures as large-scale drivers as well as on local scales relevant to biological diversity, ecosystem services and local communities. We are part of a comprehensive inter-disciplinary and international study. We are one of several partners focusing on sedimentary ancient DNA, biogeochemistry and other palaeoecological proxies from the lake sediments, whereas other partners mainly focus on contemporary ecological observations and anthropological investigations of indigenous people's knowledge and interpretations. Our study will bring together the perspectives of local communities and scientific data acquisition throughout the project. This will allow us to investigate ecosystem shifts and build scenarios of transformations of biodiversity and ecosystem services that are of immediate relevance to stakeholders. We have analysed lake sediment cores from Svalbard (lake Tenndammen), Kola Peninsula (Lake Imandra), and Northern Norway (Rumpetrollvatnet in Hammerfest og Sierravannet in Alta) for ancient plant DNA. We found DNA of 156 plant taxa in Svalbard, 204 taxa in Kola Peninsula, 104 in Hammerfest and 100 in Alta. In Svalbard, vegetation appeared to be relatively stable during the last 700 years, whereas in Kola Peninsula vegetation history covered much longer period (last 13,300 cal yrs BP) and clearly reflects regional climatic events. Our studies from N Norway show also a rather stable vegetation despite a large increase in reindeer population over the last 1000 years. Together with our international partners, we are in the process of supplementing this with analyses of mammal DNA, to evaluate how fluctuations in reindeer populations have affected the flora. We have also analysed available scientific and grey literature in four languages to built up the database of published literature for the pan-Arctic areas to assess the linkages between possible ecosystemshifts, biological diversity and ecosystem services.

We obtained paleoecological data from four sites (Svalbard, Kola, 2x N Norway), and our collaborators are in the process of obtaining data to cover the circumarctic region. Our ancient DNA record show relatively little impact of reindeer grazing. In Svalbard, we faced the problem of multiple 14C AMS date reversals, which we resolved by using portable optically stimulated luminescence (pOSL). This new method is sensitive to sub-centennial climate events, and can be used to detect for example floods, as detected in Svalbard. Our paleodata will be integrated with modern ecological knowledge to build transdisciplinary scenarios of future northern ecosystems. There is a huge amount of literature available which might be difficult to extract the relevant information from. To synthesis knowledge from modern ecological studies, we developed a text-processing algorithm that extracts causal relations from literature used it to detect causal relationships relating to the tundra ecosystem.

The Arctic is currently experiencing dramatic ecosystem changes, with immediate effects on ecosystem services connected to food production, climate regulation, natural resources and cultural integrity1. Understanding the relative impacts of climate2, herbivory3,4 and human management on ecosystems, in particular on vegetation, is of paramount importance for their long term sustainability (conservation) as well as for the well-being of indigenous communities across the circumpolar North. These communities directly depend on herding and hunting large herbivores, such as reindeer/caribou and are already struggling to adapt to the effects of climate warming and correlated changes in vegetation5. Well-informed ecosystem management and species conservation is however precluded by the scarcity of long-term (millennia) data sets spanning ancient and contemporary climatic and land use events (Overpeck et al. 2003). Palaeorecords offer a unique possibility to fill this gap as they provide data on long-term ecosystem development, historic events of climate change and land use modification (Willis and Birks 2006). These long-term records provide the basis for developing transdisciplinary scenarios that are ‘ground-truthed’ and refined by the inclusion of local community observations and knowledge extending back decades and generations. By coupling indigenous and scientific analyses and interpretations, fine-grained and broad spatio-temporal scales, and qualitative and quantitative data sets6, scenarios will be created that support decision-making in the face of accelerating socio-ecological transformations throughout the circumpolar North.