Impacts of reindeer grazing on soil properties on Finnmarksvidda, northern Norway

Ivar Schjelderup,Tore E Sveistrup,Christian Uhlig

doi:10.7557/2.24.4.1726

Abstract

Numerous investigations have documented changes in vegetation due to reindeer grazing in Finnmark County, Northern Norway. However, rather few studies have focused on impacts of reindeer grazing on soil properties. The aim of this investigation was to identify possible changes in physical and chemical soil properties due to reindeer grazing. Furthermore, root distribution was detected. At four different locations on Finnmarksvidda three sample sites each were selected subjectively according to lichen and plant cover: A) ample, B) reduced, and C) poor lichen and plant cover. It was supposed that differences in lichen and plant cover were due to differences in reindeer grazing intensity. Results showed that the organic layer beneath ample lichen cover had an about 20% higher CEC and a 30—50% higher concentration of plant available Ca and Mg and total Mg compared to those beneath reduced ones. At sites with poor lichen and plant cover, an organic layer was mostly missing. The exposed mineral Eh-horizons at these sites had a significant (P<0.05) higher organic C content, higher CEC, concentrations of total P, Ca and K, and plant available K, when compared to E-horizons beneath better lichen covers. Rooting depth and amounts of plant available water in the rooting zone were lower at sites with reduced and poor lichen cover. A relation was found between soil organic C and CEC for all soil samples, indicating that soil organic matter is an essential key factor for soil fertility at the investigate sites on Finnmarksvidda. Assuming that differences in lichen and plant cover are related to differences in grazing intensity, results indicate that overgrazing by reindeers can cause a significant degradation of the organic layer, followed by significant losses of essential plant nutrients, a reduction in plant available water and consequently soil fertility.

Highlights

Overgrazing is the world's furthermost reason for soil degradation (Oldeman et al, 1991)
The p H in the soil profiles increased with increasing soil depth from about 4.O in the organic layer to approximately 6.O in the mineral C-horizon (Table 1)
Humus beneath ample lichen cover had a significant higher content of organic C and a higher C E C compared to humus beneath moderate lichen cover

Summary

Introduction

Overgrazing is the world's furthermost reason for soil degradation (Oldeman et al, 1991). On Finnmarksvidda there is evidence that soil degradation takes place. Trampling and grazing of lichens and plants by reindeer are today major factors controlling vegetation cover and composition all over the northern Fennoscandia (Våre et al, 1995; Stark et al, 2000; Kumpula, 2001). Johansen & Karlsen, 2000). During the last three decades the investigation on the effects of RangHer, Special Issue No 15, 2004 reindeers on lichen dominated winter pastures has received special attention This is due to the importance of lichens as fodder for the survival of reindeers during winter. The condition of lichen ranges still form one of the most important economic bottlenecks for semidomesticated reindeer management in northern Europe {e.g. Kumpula, 2001)

Methods

Results

Discussion

Conclusion