The western part of both areas is located on the extensive forested ridge of Mustavuori, where forest types vary from the herb-rich forests on the slopes to the heath forests and rocky forests near the top. Many of the areas are rich in decaying wood, and more is being created all the time. The decaying wood provides habitats for a rich variety of polypore species, including Skeletocutis odora and Rhodofomes roseus, which are near-threatened throughout Finland. The old and varied forests are also home to a variety of bird species, including the threatened white-backed woodpecker, willow tit and European crested tit.
The eastern part of the areas is characterised by the shallow, reedy shores of the bay of Porvarinlahti, which serve as nesting grounds for the near-threatened common snipe. The eastern part of Mustavuori-Porvarinlahti includes the Porvarinlahti meadow, which is managed as a valued meadow and has near-threatened maiden pink growing at its colourful edges. Nature surveys have revealed several new, previously unknown streamlets and springs in the areas.
Both areas are actively used for recreation. In the Mustavuori–Porvarinlahti nature reserve, established in 1987, movement outside the marked paths is prohibited between 1 April and 15 July. The purpose of the prohibition is to prevent disturbance during the bird nesting season. The management and use plans do not propose any other restrictions on movement in the area, but seek to direct movement to marked routes. The most frequently used paths in the area’s forests will be formalised into routes and signposted. The passability of the paths will be maintained by covering areas prone to waterlogging with some kind of paving material or duckboards.
A rest spot and two new nature trails will be established at Kaivoslampi
A viewing platform will be built in the southern part of Mustavuori at Kaivoslampi, which is protected as an ancient relic. The platform will provide visitors with a view of the water-filled quarry. A table and groups of benches will be set up next to the pond. A nature trail will also be created in the mining area to showcase the nature of the surrounding herb-rich forest and the signs of the old mining activity left in the landscape. A circular nature trail will be built in the western part of the Mustavuori-Porvarinlahti nature reserve, accessible from both Mellunmäki and Vuosaari. The new trails and structures are expected to be completed by 2028.
