Open access publications in the SLU publication database

Abstract

Factors expected to affect reindeer productivity, and their spatial and temporal variation within the reindeer husbandry area in Sweden, were examined through multivariate statistical analyses. Data for the studies were extracted from different mapped databases and statistics from the herding districts. Initially 37 variables presumed to affect reindeer productivity were derived, quantifying variation in topography, climate, snow conditions, insect harassment, vegetation, forage abundance and qualities, and fragmentation of the ranges. A method was proposed, termed ‘reachability’, to quantify in cost-benefit terms the available grazing resources in relation to infrastructural fragmentation. The range-related variables were mapped for the entire reindeer husbandry area on a raster scale of 100 km2. The 37 variables were reduced to 15 using stepwise principal component analyses. These were thereafter used for characterisation of the reindeer herding ranges and for zonation of the Swedish reindeer herding area into seven zones. Furthermore, the 51 reindeer herding districts were divided into 10 groups with the help of cluster analyses. The remaining 15 variables were also related to productivity on the herding-district level with the help of canonical correlation analyses and structural equation modelling, in order to identify the important productivity determining factors, both in spatial and temporal scales. Larger variation in productivity was found between herding districts than between years. Different variables were found important for the between-district and within-district productivity variations, where season lengths and animal densities were significant at both scales. Other important factors were terrain ruggedness, insect harassment, calf slaughter and animal condition previous year. Snow conditions, disturbances and forage quality were not found to have large impact on productivity on this scale. These factors, however, may have been counteracted by husbandry measures and were therefore not easily detectable in relation to slaughter statistics. The most important environmental factors affecting reindeer productivity were used to suggest an ultimate grouping of herding districts into seven administrative groups for administrative planning and management purposes.