The Hardangervidda National Park (HNP) is Norway's largest national park, which spans three counties in western and southern central Norway. Designated as a national park in 1981, it is one of the most popular areas for outdoor activities such as hiking, hunting, fishing and camping (www.hardangervidda.com). The area is also currently being used as a grazing area for sheep. As a result, HNP is not only an important area for conservation, but is also an area where management is met with challenges from the human impacts of tourism and of public and traditional use.
HNP is home to the largest population of wild reindeer (Rangifer tarandus) in Europe. Wild reindeer are often considered keystone species of the circumpolar region, because they influence ecosystem processes such as nutrient cycling and primary production (e.g. Olofsson, Stark, & Oksanen, 2004). The reindeer population on the Hardangervidda plateau is the largest herd in Europe, and is therefore important for its ecological value, but also for its economical and recreational value for hunters and landowners (Bjerketvedt, Reimers, Parker, & Borgstrøm, 2014). Thus, a loss of this herd would have a negative impact not only for the ecosystem, but also for the people that depend on these animals for their livelihood. Wild reindeer in HNP have experienced frequent and extreme fluctuations in harvest numbers over the last six decades for several reasons which include; data on herd size is uncertain (due to the sampling effort being unequal between years), there is a lack of data on recruitment and other life stage characteristics, and because there is a high variation in hunting success (Bjerketvedt et al., 2014). Thus, more reliable population data is sorely needed.
There are a number of factors that are known to affect reindeer populations. For example, human infrastructure has been shown to affect reindeer migration and movement corridors directly and indirectly, in both long and short terms (Panzacchi, Van Moorter, Jordhøy, & Strand, 2013). Population fluctuations of reindeer are also affected by climatic variation; high population growth rates have been linked to dry winters, and climate effects are probably more important at high population densities (Aanes, Sæther, & Øritsland, 2000). It has also been suggested that the suitability of winter pastures determines the effect that hunting has on population regulation, where reindeer with access to good winter conditions are regulated by hunting, and those with access to poor conditions are regulated by bottom-up processes (Tveraa et al., 2007). This indicates that hunting should be informed by the availability of good winter grounds for wild reindeer. In the winter, reindeer have been known to dig through up to 150 cm of snow to get to their staple winter diet, lichens. When winter temperatures fluctuate, this causes a melting and re-freezing of snow, making the surface impenetrable for reindeer. This can make an already difficult situation worse, and threatens the animals survival.
The winter on Hardangervidda is long and harsh, and although reindeer are well adapted to this type of climate, they are dependent on finding suitable nutritious summer pastures to last them through the cold. Locals have reported that the animals were often seen in the north and northwest of the national park, but today, they seem to prefer the south as their calving and summer grazing grounds. The reasons for this are unknown, but could be due to this area being more rugged in its terrain, thus being less frequented by tourists.
Human activity is a hindrance to wild reindeer movement, but a changing climate is also likely to be taking its toll. Climate warming is predicted to lead to a change in the timing of spring, and to warmer temperatures all year around. In the spring, this can be a particularly daunting problem, as the timing of calving is highly synchronized with the beginning of the season (Post, Bøving, Pedersen, & MacArthur, 2003; Skogland, 1989), and females are dependent on enough food to be able to feed their young. Furthermore, higher temperatures also increase insect harassment, which has been shown to result in suboptimal feeding and resulting lower body weight (Colman, 2000).
The ECOPOTENTIAL project uses reindeer movement data, climate data, tourist data, field and remote sensing data on vegetation to investigate how reindeer migration patterns have and can change in the light of climate change and human interference. We investigate how temperature, precipitation, and hunting have affected the wild reindeer population in Hardangervidda over the last two decades. Our findings suggest that the population is negatively affected by warmer winter temperature and high harvest rate (Bargmann et al, submitted). Our results show broad trends across Hardangervidda, and give an indication of how region-wide weather patterns and hunting pressure can affect the wild reindeer population. We need this information to be able to inform the management of tourism, but also to tell us what challenges we will face as climate change progresses. This ecological knowledge can be used to inform the optimal management of HNP for its ecosystem benefits, improve the management of its biodiversity, and avoid the worsening of social conflicts within the area.
Aanes, R., Sæther, B. E., & Øritsland, N. A. (2000). Fluctuations of an introduced population of Svalbard reindeer: the effects of density dependence and climatic variation. Ecography, 23(4), 437-443.
Bjerketvedt, D. K., Reimers, E., Parker, H., & Borgstrøm, R. (2014). The Hardangervidda wild reindeer herd: a problematic management history. Rangifer, 34(1), 57-72.
Colman, J. (2000). Behaviour patterns of wild reindeer in relation to sheep and parasitic flies. Dr. Scient. Thesis, University of Oslo,
Olofsson, J., Stark, S., & Oksanen, L. (2004). Reindeer influence on ecosystem processes in the tundra. Oikos, 105(2), 386-396.
Panzacchi, M., Van Moorter, B., Jordhøy, P., & Strand, O. (2013). Learning from the past to predict the future: using archaeological findings and GPS data to quantify reindeer sensitivity to anthropogenic disturbance in Norway. Landscape Ecology, 28(5), 847-859.
Post, E., Bøving, P. S., Pedersen, C., & MacArthur, M. A. (2003). Synchrony between caribou calving and plant phenology in depredated and non-depredated populations. Canadian Journal of Zoology, 81(10), 1709-1714.
Skogland, T. (1989). Comparative social organization of wild reindeer in relation to food, mates and predator abundance. Advances in Ethology, 29, 1-71.
Tveraa, T., Fauchald, P., Gilles Yoccoz, N., Anker Ims, R., Aanes, R., & Arild Høgda, K. (2007). What regulate and limit reindeer populations in Norway? Oikos, 116(4), 706-715.
Bargmann, T, Wheatcroft, E, Imperio, S, & Vetaas, OR (submitted to Population Ecology) Modelling the wild reindeer population in Hardangervidda National Park.
Hummel, C, Provenzale, A, van der Meer, J, Wijnhoven, S, Nolte, A, Poursanidis, D, Janss, G, Jurek, M, Andresen, M, Poulain, B, Kobler, J, Beierkuhnlein, C, Honrado, J, Razinkovas, A, Stritih, A, Bargmann, T, Ziemba, A, Bonet-García, F, Adamescu, MC, and Hummel, H (2017) Ecosystem Services in European Protected Areas: Ambiguity in the Views of Scientists and Managers? PLOS ONE https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0187143
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Last update: May, 2019