The park was created to protect the deciduous forest and representative wetlands of Mordovia.

The territory is relatively flat or slightly hilly, with a network of ravines in the northern sectors that even out towards the south.

[2] Smolny lies in the East European forest steppe ecoregion (WWF ID#419), a transition zone between the broadleaf forests of the north and the grasslands to the south, cutting across the middle of Eastern Europe from Bulgaria through Russia.

This climate is characterized by large swings in temperature, both diurnally and seasonally, with mild summers and cold, snowy winters.

[2] The floodplain of the meandering Alatyr forms a wetland environment with the biological properties of a eutrophic (Greek: "well-nourished") lake - with rich vegetation, shallow and warm.

In the meadow areas the grasses include Kentucky bluegrass,[6] fescue and foxtail.

[2] The fish of the rivers and lakes include common pike, dace, chub, gudgeon, loach, eel, perch, and silver carp.

The mammals are those typical of forest-steppe forests: elk, wild boar, fox, marten, weasels, and various mice and voles.