Vegetation, klima og graesning i et sub- og lavarktisk omraade.

alaska alimentation des animaux animal ecology animal feeding animal production arctic tundra climatic factors ecologia animal ecosistema ecosystems especies facteur climatique grazing grazing lands grazing systems greenland groenland groenlandia habitat habitats noruega norway ovin ovinos pastoreo plant production production animale reindeer renne reno sheep sistemas de pastoreo site factors soil types species tierras de pastoreo toundra arctique tundra artica type de sol vegetation