ABSTRACT. The focus of the work was to investigate dependency between reindeer density and lichen (Cladonia spp.) ranges in the Finnish semidomesticated reindeer management area. Secondly, we formed a model on the recovery rate of ungrazed woodland lichen ranges (29 sites) after forest fires to evaluate the potential productivity and time needed for Finnish lichen ranges to recover at optimal production. During 1974 -95, 59% of the variation in mean semidomesticated 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. Reindeer 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 explain 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 ranges of 1000 kg dry matter per hectare (d.m./ha) of lichen biomass can be considered adequate to ensure survival of reindeer and continued production of lichen. To maintain this level within the sedentary Finnish grazing system, winter reindeer densities on lichen ranges must remain below 5-7 reindeer/km 2 . According to our model, the maximum amount of living lichen in the 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 lichen stands that contain 2600-2800 kg d.m./ha of living lichen. Using our model 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 this optimum, and the average lichen production was 36% of the possible maximum annual yield. Our model indicates that the Finnish lichen ranges would have to remain ungrazed for an average of 18 years to recover to maximum production levels. However, the average time needed for the lichen ranges to recover to the level of 1000 kg lichen d.m./ha, would be only about 7 years.Key words: Rangifer, reindeer, Cladonia, lichen, pastures, condition, recovery, productivity RÉSUMÉ. Ces travaux portent tout d'abord sur l'étude de la dépendance existant entre la densité du renne et les grands pâturages de lichen (Cladonia spp.) dans le secteur finlandais de gestion du renne semi-domestique. Ensuite, on a conçu un modèle en se fondant sur le taux de récupération, après des incendies de forêt, d'étendues naturelles (29 emplacements) de lichen forestier non pâturées, en vue d'évaluer la productivité potentielle et le temps nécessaire aux grands pâturages de lichen finlandais pour récupérer à une production optimale. De 1974 à 1995, 59 p. cent de la variation dans la densité moyenne du renne semi-domestique (fourchette de 0,7 à 3,0 renne/km 2 de superficie totale des terres), parmi les districts où se trouvent les troupeaux de rennes en Finlande, s'expliquaient par la proportion du territoire qui était couvert par des pâturage...

ABStRACt. During past decades, the amounts of infrastructure and human activity have increased in northern latitudes. Although the effects of human development on wild reindeer and caribou have been widely examined, its effects on semidomesticated reindeer and the reindeer herding environment are still poorly understood. We studied how seven different human activities (population centres, buildings, main roads, forest roads, snowmobile tracks, skiing trails, and gold digging areas) affect the range selection by semi-domesticated reindeer in northern Finnish lapland using GpS tracking data on 29 female reindeer. Data were analyzed using compositional analysis on two spatial scales (home range selection and within-home-range selection) and in three seasonal periods (early winter, late winter, and summer-autumn). Results showed that during winter, reindeer strongly avoided almost all studied human activities when selecting home range areas (for forest roads, the direction of the effect was unclear), but in summer and autumn, only some of those activities were important. Within the selected home range areas, pasture use by reindeer appears to be less sensitive to infrastructure and human activity, probably because reindeer were able to avoid these anthropogenic disturbances at the upper level of habitat selection. the size of the potential cumulative area affected by infrastructure varied seasonally between 27.5% and 39.0% of the study area when calculated on the basis of home range selection, and between 7.2% and 20.3% when calculated from within-home-range selection. the strongest avoidance of infrastructure was found in late winter on both scales of range selection, but weakest avoidance was in early winter for home range selection and in summer for within-home-range selection. Cumulative impacts of different human activities on the usability value of reindeer ranges should be taken into account when planning new land-use operations in the areas important for the reindeer herding.key words: Rangifer tarandus tarandus, semi-domesticated reindeer, reindeer herding, infrastructure, human activity, human disturbance, avoidance, compositional analysis, GpS tracking RÉSuMÉ. Au cours des dernières décennies, la quantité d'infrastructures et d'activités humaines s'est accrue dans les latitudes nordiques. Bien que les incidences du développement humain sur le renne sauvage et le caribou aient été examinées à grande échelle, ses incidences sur le renne semi-domestiqué et sur le domaine vital du renne sont toujours mal comprises. Nous avons étudié la manière dont sept activités humaines différentes (centres de population, bâtiments, routes principales, routes forestières, pistes de motoneige, pistes de ski et zones d'exploitation aurifère) exercent une influence sur la sélection du domaine du renne semi-domestiqué dans la partie finlandaise de la Laponie du nord à l'aide de données de poursuite obtenues au moyen d'un GpS apposé à 29 rennes femelles. les données ont été analysées au moyen d'une analyse compositionnelle fondé...

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The winter ecology of the Northern Goshawk Accipiter gentilis was studied in northern Finland in 1991-95. The data consist of 26 radiomarked hawks, of which 331 day and 299 night positions were located. Average range size was 9894 ha for males (minimum

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