Grini ( Latvian: Grīņi, Grīņu rezervāts ) is a nature reserve located in the Liepaja district of Latvia , on the Baltic Sea .
The reserve was founded in 1936 , its area is 1076 hectares (1063 hectares are covered with forests). The climate of the reserve is seaside, with cool summers and relatively mild winters. The average annual temperature is 6.5 ° C, the average July temperature is 16 ° C, January –3 ° C; annual precipitation is 600-800 mm. The reserve serves to study the peculiar biogeocenosis of the Baltic coast and the unique place of growth of swamp heather. Approximately 80% of the reserve is covered with pine and birch woodlands with a dense shrub or grass cover. This type of vegetation is locally called greenis (hence the name of the reserve). Depending on the microrelief, two types of greenis are distinguished: sphagnum-heather (in elevated areas) and sedge-molinium (in lower areas covered with hummocks). In the sphagnum-heather greenis, the tree layer is formed by pine trees, the lower layer - by a continuous cover of heather, xerophytic lichens and hygrophytic mosses, there is no undergrowth. Pine trees also form a tree layer in sedge-moss greeninis, but with a considerable admixture of birch, in some places undergrowth of willow, interspersed with buckthorn and juniper. Between the bumps sedges are common, marsh bedstraw, loosestrife loosestrife, meadow calf, molinia.