Pääjärvi is the most researched lake in Finland and among the most researched lakes in the world. It is Finland’s fourth deepest lake, with a maximum measured depth of 85 metres. This contributes to the occurrence in the lake of the glacial relict amphipod Gammaracanthus lacustris, which has a length of 4.5 centimetres. Pääjärvi includes 37 kilometres of shoreline and 17 islands.
Lammi Biological Station monitors Pääjärvi’s water quality with monthly samples taken throughout the year. The quality of water flowing into and out of the lake is monitored with weekly samples taken year round at six running-water sites. These unique time series data already cover several decades. In addition, three streams flowing into Pääjärvi are subject to intensive data collection, using continuous water quality monitoring.
Dozens of small lakes dot the Evo region, enabling research on topics including the effects of commercial forestry, agriculture and beavers on the water ecosystem. The lakes are also suited to research on stratification, bioproduction, biodiversity and acidification.
Lammi Biological Station currently has 37 water quality monitoring sites in Evo. The water quality of these forest lakes and rivers has been monitored since the 1970s with twice-yearly samples. In addition, water quality is monitored intensively in the natural forest lake Valkea-Kotinen.
The Evo Hiking Area is covered by extensive boreal forests over some 5,500 hectares. The area boasts what may be the most spectacular old-growth forests in Southern Finland, namely, Kotinen and Sudenpesäkangas, both of which are nature reserves. These old forests are invaluable for preserving biodiversity. As some of the forests in the area were used commercially until recent years, researchers can study not only forest species, but also the associated effects of commercial forestry.
The University of Helsinki was involved in a working group proposing the establishment of a ‘science national park’ in Evo.
The planned park would have a surface area of some 4,800 hectares, bringing together the existing old forests of Kotinen and Sudenpesäkankangas into a contiguously forested area. It would be highly important for old-forest species, as their habitats have virtually disappeared from Southern Finland.
The park would also make the region more attractive and be useful for Lammi Biological Station and the Häme University of Applied Sciences. The aim would be to put research into practice.
Time in nature is important for everyone, and the park would take into account the needs of both traditional hikers and other user groups.