Lolair Lake is situated in a basin which extends itself along the left slope of the lower Valgrisenche. Its shape derives from glacial erosion phenomena creating the depression which was afterwards filled by slimy and peaty deposits. The lithologic substatum is made of mica-schists and minute gneisses of Falda del Gran San Bernardo. Although the territory is not that large in size, the area is characterized by a great variety of environments and species. The lake is surrounded by a concentric vegetational zonation linked to the water environment; in the area of the cane-brake there is the most important habitat, the "Calcareous marshes of Cladium mariscus and of Carex davalliana". The surrounding basin presents an underbrush set out as a mosaic, with edges of spruce fir woods or Scotch pine woods, broadleaf tree woods alternating with shrubs and xerophilous herbaceous species, and a series of abandoned cultivated lands. It is therefore rather significant the contrast between the wetland of the lake and the xerothermic environment of the basin enclosing it, where a station of Potentilla pensylvanica, one of the rarest plants in the Valle d'Aosta region, can be found.
On the rocky cliffs, it is easy to sight the Golden Eagle, the Goshawk, or the Buzzard and, around the lake, characteristic aquatic birds, like the Mallard which nests here and the Moorhen. In the pond and in the surroundings there are Amphibians and Reptiles, like the Common Toad (Bufo bufo), and the Grass snake (Natrix natrix), wheras the lake is populated by Tenches, invertebrates, and numerous families of insects.