Several of the most important reindeer forage plants in Svalbard were analysed for content of minerals (Na, K, P, Ca, Mg, S, Cl, Fe, Cu, Mn, Zn, Mo and Co) and for content of ash, crude protein, crude fiber, ether extracts and nitrogen free extracts. Some forage plants were also examined in in vitro digestibility trials. The results were compared with results from similar analyses of alpine mountain plants from southern Norway. Also freshly voided fecal samples were analysed for the same components as the forage plants. The Svalbard vegetation had a higher content of Na, Ca, Mg, Cl, Fe and Co, than similar plants from Southern Norway. The content of other elements examined seemed to be more equal in Norway and on Svalbard. Within the Svalbard area plants growing in limestone areas had the highest content of calcium and magnesium. Also plants growing on manured soil below bird cliffs appeared to have high nutritional value. It is furthermore concluded that the closeness to the sea as well as the occurrence of several plants with high mineral content, gave the Svalbard reindeer the possibility to further improve their mineral balance compared with continental reindeer. Also the dietary shift from lichens as a major dietary component in Norway, to mosses on Svalbard, may increase mineral intake, but may also have an inferior effect on digestibility. Although balance experiments and carcass analyses of minerals in Svalbard reindeer are missing, it is concluded that Svalbard reindeer apparently had adequate intake of most mineral elements. In spite of low standing biomass of reindeer forage plants, the quality of the vegetation seemed to compare favourably with continental reindeer pasture.

Ohlson, M. and Staaland, H. 2001. Mineral diversity in wild plants: benefits and bane for moose. -Oikos 94: 442 -454.We studied the mineral nutrition ecology of moose, Alces alces, by a comprehensive examination of concentration levels of 18 elements in browsing plants, and in rumen and distal colon contents, respectively. The plants, in total 14 species, included deciduous and evergreen trees, shrubs, herbs, grasses and aquatic macrophytes. Our study was done in four sites in southern Norway and the plants were sampled in spring, summer, autumn and winter to document seasonal trends. The plants were generally characterized by low concentrations of major elements, very low phosphorus: calcium ratios, and the willow Salix aurita -a preferred browse -had high cadmium concentrations, up to 9 ppm (dry mass). Sodium concentrations in terrestrial plants were significantly under the dietary requirement, while levels were sufficient in aquatic plants, which, however, had high concentrations of toxic heavy metals. We suggest that the moose experience a nutritional dilemma as a strong physiological need for sodium results in an overintake of heavy metals. A selective intake of plants rich in heavy metals was corroborated by high heavy metal concentrations in rumen and distal colon. Over all, the plants were characterized by a marked mineral diversity due to element concentration levels that were highly variable between species and sites. Thus, there is a strong link between plant species diversity and mineral diversity, which has a pivotal role for herbivores. It is concluded that a diversity of plant species is a prerequisite for the mineral diversity that the moose needs to obtain essential minerals, not only in sufficient amounts, but also in physiologically balanced proportions.

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Water, organic matter (OM), N, Ca, P, K, Na, and Cl exchange was estimated in the alimentary tract of reindeer given concentrate or lichen diets alone or supplemented with minerals. Chromic oxide was used as a nondigestible marker and results are discussed in relation to inaccuracies of this marker technique. The pattern of water, OM, and N exchange was similar to other ruminants; over 61% of OM digestion was due to the rumen–reticulum plus omasum and abomasum (stomachs). For the concentrate diet, 40–60% of N digestion occurred in the stomachs. Apparent absorption of Ca, P, and Mg in the stomachs was linearly related to intake. Ca and Mg supplemented to lichens was excreted because of an inability of the intestines to recover mineral secreted into duodenal contents. In contrast, the jejunum absorbed P added to the diet. Excretion of K in feces at 0.076 mM/g fecal dry matter placed a limit on K absorption; it was negative on the lichen diet. Cl was absorbed in the small and large intestines. Supplemental Na, part of the P, Ca, and K, but none of the supplemental Mg added to the lichen diet was absorbed. Lichens appeared to bind some minerals and could thereby place a limit on their absorption.