Rezerwat "Mierków Dry Coniferous Forests" distinguishes itself with its open inland dunes made up of postglacial sands. The highest hill in the area is Białogóra with its height  86,5 meters over the sea level, at the same time being the great vantage point. The other dune banks run at the height of 70-75 meters over the sea level.

The main aim of protection is to sustain biodiversity of coniferous forests ecosystems, from poor psammophilic vegetation and dry coniferous forests covering inland dunesstarting, to fresh and dry coniferous forests, altogether with their fauna and flora finishing.

Diversity of plant communities is here quite small. The tops of the dunes are covered with poor Spergulo-Corynephoretum, altogether with grass - Corynephorus and very plentiful occurrence of mosses and lichen. The largest territory is covered by dry (subcontinental) lichen Scots pine forest (Cladonio-Pinetum) with very meagre ground cover. In the interdunal depressions larger grounds are covered  with fresh coniferous forests, where one can find quite large number of blueberries. There are also dry coniferous forests in mentioned depressions.

Within the area of nature reserve, there were found 26 species of vascular plants. The most strongly represented species are  grasses  and  the family of composite plants.  On the area of  nature reserve, there was found goldilocks aster - Aster linosyris (L.) Bernh., which belongs to endangered and vanishing plant species in Wielkopolska Province and  Pomerania Province. While concerning trees, there occur: Scots pine,common juniper,silver birch, English oak and black locust.

In the nature reserve, there were discovered the presence of almost 60 species of lichen, including 35 species ground plants.

Among ground lichen of the nature reserve, there are several that belong to very rare in the country, namely: Pycnothelia papillaria (Ehrh.) Dufour, Cladonia - cup lichen (Cladonia pocillum), Stereocaulon paschale and Stereocaulon tomentosum.  Stereocaulon tomentosum is threatened species and is put on the National Red List of Lichen threatened with extinction.

The nature reserve fauna is relatively poor due to small diversity of habitats. There were found scarcely 20 clutching bird species, 3 amphibian species, 3 reptile species, 4 mammal species. Characteristic bird species are: woodlark, tawny pipit, European nightjar and coal tit.

Within the discussed area, it was still stated  rare and threatened animal species in the west of Poland and all over the whole country. Among insects, there are: butterfly – mourning cloak and  special care species: long-horned beetle (Acanthoderes clavipes) from Cerambycidae family. This beetle occurs in very sunny places, on stubs and on older coniferous  tree trunks, especially pines.

Among vertebrates, there are tawny pipit, European nightjar and natterjack toad, that can be taken for special care species.

Date and legal act taking the nature reserve under protection: Regulation No. 20 of the Lubusz Governor, dated  April 20, 2006 on the classification as a nature reserve (Voivodeship Official Journal of the Lubusz Province [Dz.U] No 31, item 59).

Protected area: 131,40 ha.