Vegetation

The most typical bushes and trees to be found on alvars are junipers that occur either individually or in groups. The herb layer is low and diverse. The amount of plant biomass per square metre varies from 100-300 g dry weight and varies greatly from year to year depending mainly on moisture conditions. The species composition of alvars is very diverse and unique compared to other Nordic communities. There are species that are found mainly in the steppe areas of southeast Europe, such as the sagebrush (Artemisia rupestris), spring cinquefoil (Potentilla neumanniana), purple milk-vetch (Astragalus danicus), mountain clover (Trifolium montanum), common carline thistle (Carlina vulgaris), Dyer`s woodruff (Asperula tinctoria), snowdrop anemone (Anemone sylvestris). Species typical of alpine meadows grow there: alpine mouse-ear (Cerastium alpinum), alpine meadow-grass (Poa alpina), alpine cinquefoil (Potentilla crantzii). On the Great Alvar (Stora Alvaret) of Öland Island, several endemic taxa have been described, yet in Estonia there are no such well-distinguished taxa. Despite the temporary very unfavourable growth conditions, the species richness on alvars is very great. The high small-scale species richness makes alvars the second most diverse communities in the world after the wooded meadows