Järvinen’s ancient pine forest is named after A.E. Järvinen (1891–1963), a forester, author, and painter. Järvinen worked for Metsähallitus in Lapland between 1915 and 1958. Naarmankaira was a special place for him, and he spent much time there hunting and fishing. In his many wilderness-themed short stories, Järvinen described what he experienced on these excursions.

In the dry pine forests of Järvinen’s ancient pine forest, the ground layer vegetation consists mainly of lingonberry (Vaccinium vitis-idaea), crowberry (Empetrum nigrum), heather (Calluna vulgaris) and lichen, all of which thrive on the nutrient-poor, sandy soil. Fallen trees provide a growing base for lichens and mosses. The area also includes wetter habitats, such as mires and the shores of Marasenlampi and Ahvenlampi ponds. The mires are poor fens with sedge vegetation and string mires, bordered by dwarf pine bogs where cranberries (Vaccinium oxycoccos), for example, can be found.

The old-growth pine forest provides a habitat for woodpeckers, squirrels, crossbills (Loxia) and capercaillies (Tetrao urogallus), which feed on pine seeds and needles. Reindeer are also commonly seen in the area, drawn by the abundant lichen.

The mires are in places wet and string-like, typical of aapa mires, and they attract waders such as the wood sandpiper (Tringa glareola). Marasenlampi and Ahvenlampi are nutrient-poor ponds inhabited by species such as perch (Perca fluviatilis), pike (Esox lucius), and stocked whitefish (Coregonus lavaretus). Waterfowl such as goldeneyes (Bucephala clangula) are commonly seen on the ponds. The pond waters flow via streams into the Raudanjoki River.