The Tectonic Arena Sardona stretches from 520 m above sea level (a.s.l.) eastwards from Ennenda to the Ringelspitz 3247 m a.s.l. Due to different elevations, various climatic and topographic relations and the various geologic substrata, the region features a large diversity in natural habitats. For a northern Alpine region, the estimated 800 different plant species represent a high degree of species diversity.

Lower-lying areas are largely covered by forest communities, with beech-silver fir and spruce forests being the most common. Of particular interest are various forests on unusual sites, e.g. mountain pine on limestone or wetland soils. A notable feature is the occurrence of arolla pine (Pinus cembra) at higher altitudes in the Calfeisen, Murg and Mürtschen valleys; these are the northernmost examples of extensive stands in the whole of Central Europe.

The subalpine alluvial forests in the Chrauchtal (of national importance) and in the Calfeisental are also of particular landscape value. Above the treeline, mountain pastures with mat-grass swards and dwarf shrub heath predominate up to an altitude of approx. 2200 m a.s.l. Higher up, areas free of rocks and debris are covered by alpine swards.

Some of the habitats in the world heritage are of national significance due to their endangerment, beauty and size. These include the "Plau Segnes Sut" flood plain.

Ground water levels control formation of low alpine fens (marshes) as, for example, in Chrauchtal. In contrast, high alpine fens, such as in Murgtal or Mürtschental are supplied only through rainwater and therefore acidic and nutrient-poor. One plant that has adapted to these meagre conditions is the carnivorous round-leaf sundew.

Vegetation on rock scree and talus fans is controlled by the geologic substratum. On the Cassonsgrat, in the neighbourhood of the Glarus thrust, acid and alkaline soils exist with their respective plant communities directly adjacent to one another.

After the extermination of the Alpine ibex, these were reintroduced in 1911 for the first time in Switzerland in a special area banned to hunting in the Graue Hörner region. In June 2010 three bearded vultures were reintroduced into the Calfeisental.