[3] Pierīga, Gauja is on the right bank of the lower reaches Ādaži military poligone and its adjacent territories.

[5] In total 51 species of flora (2) and fauna (49) are protected under EU Nature directives.

[2] Two species of flowering plants - cutleaf anemone (Pulsatilla patens) and sand pink (Dianthus arenarius subsp.

Protected invertebrates are the marsh fritillary (Euphydryas aurinia) and large white-faced darter (Leucorrhinia pectoralis).

Protected birds are the tawny pipit (Anthus campestris), golden eagle (Aquila chrysaetos), lesser spotted eagle (Aquila pomarina), short-eared owl (Asio flammeus), hazel grouse (Bonasa bonasia), bittern (Botaurus stellaris), nightjar (Caprimulgus europaeus), white stork (Ciconia ciconia), black stork (Ciconia nigra), short-toed eagle (Circaetus gallicus), marsh harrier (Circus aeruginosus), roller (Coracias garrulus), corncrake (Crex crex), whooper swan (Cygnus cygnus), white-backed woodpecker (Dendrocopos leucotos), middle spotted woodpecker (Dendrocopos medius), black woodpecker (Dryocopus martius), ortolan bunting (Emberiza hortulana), merlin (Falco columbarius), red-breasted flycatcher (Ficedula parva), great snipe (Gallinago media), pygmy owl (Glaucidium passerinum), crane (Grus grus), little bittern (Ixobrychus minutus), red-backed shrike (Lanius collurio), woodlark (Lullula arborea), bluethroat (Luscinia svecica), osprey (Pandion haliaetus), honey buzzard (Pernis apivorus), three-toed woodpecker (Picoides tridactylus), grey-headed woodpecker (Picus canus), golden plover (Pluvialis apricaria), little crake (Porzana parva), spotted crake (Porzana porzana), Ural owl (Strix uralensis), barred warbler (Sylvia nisoria), black grouse (continental subspecies) (Tetrao tetrix tetrix), capercaillie (Tetrao urogallus) and wood sandpiper (Tringa glareola).