Because voles and lemmings are key species in the ecosystem, it is important to monitor their populations. For this purpose, we use camera traps that we have placed in the habitats these animals prefer in both of our intensive study sites.

These traps take a picture every time one of them runs by, allowing us to count how many there are and how these species affect each other. The traps are left out all year round and work also under the snow in winter!

In COAT, we also use camera traps to monitor reindeer and moose, snow cover, and plant phenology.

With a warmer climate, shrubs and trees are gradually taking over the tundra. Ground vegetation changes, and dwarf shrubs such as crowberry, blueberry, and dwarf birch are growing into areas where they have not been before. How much can small rodents influence this change?

 To better understand the role of small rodents in the development of the tundra under climate change, we have set up cages in the study areas in Komagdalen and Vestre Jakobselv. In Komagdalen, the cages are in snowbeds, and in Vestre Jakobselv, they are in snowbeds, meadows, and in heather.

We monitor the vegetation and compare the changes that occur inside and outside the cages.

 In the birch forest, the importance of small rodents for the regrowth of ground vegetation and berry production is similarly monitored after leaf-eating insects have been at work.

With a warmer climate, it is expected that the tundra will be subject to overgrowth—a process that is already underway across much of the Arctic.

How will this affect biodiversity, and can grazing animals prevent overgrowth?

In the low Arctic tundra, river valleys with willow thickets and meadow vegetation are important for many grazing animals such as moose, reindeer, and ptarmigan.

In these meadows and the nearby heather in the Bergebydalen study area, we use exclosures to monitor how overgrowth develops in areas with and without grazing animals.

Exclosures are also used to investigate the significance of large grazing animals like reindeer and moose for the forest's ability to recover after attacks by insect defoliators.

We use large box traps to catch red foxes. The traps must be left out for a long time, so that the foxes get used to them being there and become less fearful.

The goal of catching live foxes is to equip them with a GPS collar that sends us the fox's positions every 3 hours. This provides new and important information about the movements and habitat use of the red fox in the low Arctic. For example, is it the same foxes that travel along the coast and further inland on the peninsula? How important are willow thickets, or roads and buildings, for the foxes' choice of paths in the mountains?

We have 9 traps, 5 along the main road between Vadsø and Smellror, one on Gammerabben, and 3 near Gednjekrysset.

Ptarmigan males make a lot of sound in the spring when they are guarding their territory and their mate.

We have placed boxes with small microphones on the Jakobselvvidda plateau and in Komagdalen that record this sound.

We aim to develop methodologies (algorithms) that can distinguish individuals so that we can estimate the number of rock ptarmigans and willow ptarmigans in our study areas.

The listening boxes are also used to monitor many other bird species so that changes in large parts of the bird community can be documented.

There is significant local variation in the growth conditions that plants experience. For example, ground temperature, soil moisture, and the length of the snow-covered season are very different between a snowbed where the snow layer is thick and persists for a long time and a ridge with almost no snow cover. COAT's weather stations cannot describe this great local variation, so we use small loggers. These provide local information on ground temperature throughout the year, as well as when the snow arrives and melts. The loggers will also be used to calibrate landscape/snow models that will be driven by observations from the weather stations.

 Small temperature loggers are used by COAT in most habitats, from birch forests to high-altitude snowbeds in the inner parts of the Varanger Peninsula.