Tulijoki is an atmospheric forest of 59 hectares, an area characterized by heaths and swamps, located in the village of Nalkki in Puolanka. It includes a kilometre of the Tulijoki river, the clear waters of which appear as a brook flowing through the area. The place being valuable in so many ways, the Finnish Natural Heritage Foundation acquired it in the spring of 2014. In August the foundation bought a small extension to the area on the riverbank.

Less than half of the Tulijoki area is characterized by the swamps with half being labelled by the heath forests, not to mention the few hectares formed by another type of quagmire. The swamps are dominated by pines and the heaths mainly by spruces. More than a quarter of the forests are over 130 years old by the areas dominated by conifers with some being up to 160 years old in the oldest sections. It is thus no wonder that there are birds typical for old forests flying around also in this forest: the treecreeper, the three-toed woodpecker, and the Siberian jay.

There are quite a lot of birches and aspens growing in the forests with the structure of the forests being mostly natural. A considerable amount of decayed wood has been formed here and there. There are also two small areas exposed to a clear-cutting approximately at the turn of the millennium, one in the eastern end and one in the western end.

What increases the diversity of the place is its location by the Tulijoki river, which forms a brook in the area. This is because the river is at its best right there in the forest with its sand bottom and clear water.

The fauna of the river includes the beaver, which becomes obvious when one sees the two dams and the inhabited lodge created in the water. Building its dams, the beaver has managed to produce quite a lot of decayed wood. In addition, there is a flooding swamp, a little wider area with dead trees, found in the eastern end. It appears that the river has also been visited by the otter.

Tulijoki is our 46th conservation area, the second one in the Kainuu region.