The Červené blato NNR was declared in 1953 and protects a total area of 331.4 ha. The NNR lies in the Jihočeský kraj – South Bohemian Region and in the southern part of the Třeboňsko PLA. The subject of the protection is a forest peatbog with extensive growths of Pinus rotundata – Swiss mountain pine with an undergrowth containing labrador tea (Ledum palustre). A part of the reservation was disturbed in the past by peat extraction. The maximum depth of the peat layer is 7.6 metres but it averages 3 metres in thickness. The disturbed areas are regenerating well and forming a varied mosaic of peatbog biotopes from forest-free to closed forest stands with significant flora and fauna, including glacial relict species.
The natural vegetation community of the peatbogs is stands of Swiss mountain pine (Pinus rotundata) which are up to 200 years old. These forests also have a notably rich shrub layer with labrador tea and species of the cranberry family – predominantly bilberry (Vaccinium myrtillus), bog whortleberry (Vaccinium uliginosum) and marsh andromeda (Andromeda polifolia). Secondary vegetation is represented by succession stages on the areas where peat was formerly extracted. Abundant populations of hare’s-tail cottongrass (Eriophorum vaginatum) and the cranberry Oxycoccus palustris can be found here as well as the rarer round-leaved sundew (Drosera rotundifolia). The moss layer is dominated by Sphagnum mosses and numerous other species of cryophilous forest mosses, lichens and fungi.
The extensive bog pine stands in Červené blato NNR are especially notable for their invertebrate populations, including many tyrphophilous and tyrphobiontic species, some of which have survived here since the Ice Ages. These glacial relicts include butterflies, spiders and beetles. Notable dragonflies include muskeag darner (Aeschna subarctica) and northern white-faced darter (Leucorrhinia rubicunda). Butterflies on the bog include the pug moth (Eupithecia gelidata) and small lappet (Phyloderma ilicifolia) as well as orange underwing (Archiearis parthenias), scallop shell (Reumaptera undulata), scarlet tiger moth (Callimorpha dominula) and silver hook (Deltote uncula).
The extensive forest stands are the home of many forest bird and nesting species include pygmy owl (Glaucidium passerinum), black stork (Ciconia nigra), goshawk (Accipiter gentilis) and hazen hen (Bonasa bonasia).
The reserve is accessible on a themed trail which starts from the Jiříkovo údolí valley from the road between Šalmanovice and Nové Hrady.