Estimation of lichen biomass with emphasis on reindeer winter pastures at Hardangervidda, S Norway

Arvid Odland,Sylvi M Sandvik,Linn L Myrvold,Dag K Bjerketvedt

doi:10.7557/2.34.1.2852

Abstract

Quantification of lichen abundance is important for management of reindeer populations. We measured dry lichen biomass in 876 micro plots (16.5 cm × 16.5 cm) systematically sampled within 219 vegetation plots (2 m × 2 m) from 7 different areas in S Norway. Lichen biomass was quantified as: (a) dry weight in g m-2, (b) lichen height in cm, (c) lichen cover, and (d) lichen volume (lichen height × lichen cover). Lichen biomass decreased with increasing precipitation and increasing altitude. On local scale, the variation in lichen biomass varied strongly with snow conditions. The grazed parts of Hardangervidda had in general a low average lichen biomass (an average mostly lower than 150 g m-2). Lichen biomass was much higher in area where reindeer migration was interfered by human activity. Lichen height and lichen volume were strongly linearly correlated with dry lichen biomass. These proxy methods may therefore be used to predict lichen biomass, but deviations from exact measurements should be expected.

Highlights

Lichen heaths are the most important natural winter pasture resources for both wild and semi-domesticated reindeer (Rangifer tarandus), and the most abundant generas are Cladonia and Flavocetraria
Detrended Correspondence Analysis (DCA) axis 1 describes a gradient from exposed sites with species such as Alectoria spp., Flavocetraria spp., and Arctous alpinus in the left part and meadows with species such as Geranium sylvaticum and Phleum alpinum in the right part
DCA axis 2 represents a gradient from moist low alpine communities with Salix lapponum and S. glauca in the upper part, and snow-bed species mostly at high altitudes in the lower part (Salix herbacea, Diphasium alpinum, Harrimanella hypnoides, Luzula confusa and Juncus tri dus)

Summary

Introduction

Lichen heaths are the most important natural winter pasture resources for both wild and semi-domesticated reindeer (Rangifer tarandus), and the most abundant generas are Cladonia and Flavocetraria. Cladonia-species are the highly preferred reindeer winter diet (Danell et al.,1994), and one reindeer, depending on age and sex, can consume 2–5 kg of lichen dry matter per day (Holleman et Rangifer, 34, (1) 2014 32 (1), 2012. Previous measurements of lichen abundances based on lichen cover or lichen volume measurements in the Hardangervidda area show highly diverging results (Gaare et al.,2005; Falldorf et al, 2014). Based on seven assumptions which have rarely been mentioned when referring his paper (c.f Bjerketvedt, 2013)

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Discussion

Conclusion