Condition, potential recovery rate, and productivity of lichen (Cladonia spp.) ranges in the Finnish reindeer management area

The focus of the work was to investigate dependency between reindeer densit y and lichen (Cladonia spp.) ranges in the Finnish semidomesticated reindee r management area. Secondly, we formed a model on the recovery rate of ungr azed woodland lichen ranges (29 sites) after forest fires to evaluate the p otential productivity and time needed for Finnish lichen ranges to recover at optimal production. During 1974-95, 59% of the variation in mean semidom esticated reindeer density (range: 0.7-3.0 reindeer/km(2) of the total land area) among the reindeer herding districts in Finland was explained by the proportion of Land area covered by Lichen ranges in these districts. Reind eer densities were highest in the districts where lichen ranges covered 20% to 30% of the area. Reindeer density on the total land area did not explai n the condition of Lichen ranges, but 58% of the condition was explained by the reindeer density on the lichen ranges. A condition level for lichen ra nges of 1000 kg dry matter per hectare (d.m./ha) of lichen biomass can be c onsidered adequate to ensure survival of reindeer and continued production of lichen. To maintain this level within the sedentary Finnish grazing syst em, winter reindeer densities on lichen ranges must remain below 5-7 reinde er/km(2). According to our model, the maximum amount of living lichen in th e woodland lichen stand at the climax stage is on average about 7000 kg d.m ./ha. The maximum annual yield of lichen (175 kg d.m./ha) is produced by li chen stands that contain 2600-2800 kg d.m./ha of living lichen. Using our m odel and our 1995-96 data, we calculated that the average lichen biomass on lichen ranges in the Finnish reindeer management districts was 13.0% of th is optimum, and the average lichen production was 36% of the possible maxim um annual yield. Our model indicates that the Finnish lichen ranges would h ave to remain ungrazed for an average of 18 years to recover to maximum pro duction levels. However, the average time needed for the lichen ranges to r ecover to the level of 1000 kg lichen d.m./ha, would be only about 7 years.