Population structure of three dominant sedges under muskox herbivory in the high arctic
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Authors: A. Tolvanen, and G. H. R. Henry
Date: 2000
Journal: Arctic, Antarctic, and Alpine Research
Volume: 32
Number: 4
Pages: 449-455
Summary of Methods: The effects of muskox (Ovibos moschatus) grazing on three plant species (Carex aquatilis ssp. stans, Carex membranacea, and Eriophorum angustifolium ssp. triste) were investigated on an ungrazed lowland site adjacent to Alexandra Fiord (78° 53’ N, 75° 55’ W) and a grazed valley in Sverdrup Pass (79° 09’ N, 78° 10’-81° 20’ W). Age structure, density, biomass, growth and reproduction of tillers were measured and compared among the two sites.
Article Summary / Main Points: Across both the sites, the number of new leaves per tiller per year was constant. At the ungrazed site, tillers lived longer (8 to 10 years) compared with the grazed site (4 to 6 years). As tillers aged on the grazed site, the frequency of grazing increased. Tiller biomass and density of C. stans were considerably lower on the ungrazed site than the grazed site, while C. membranacea and E. triste densities were the same between sites, but biomass was greater at the ungrazed site. Flower stalk heights and leaf lengths were greater for ungrazed tillers. For all species, individual tillers were heavier on ungrazed than grazed sites. C. stans plants had highest proportion of belowground tissue while E.a. ssp. triste plants had lowest. Grazed C. stans and C. membranacea had a higher proportion of both green and below-ground tissue and a lower proportion of attached dead tissue when compared to ungrazed plants. Flowering tillers were, on average, older on the ungrazed site than the grazed site. No seedlings were observed at the grazed site.
Vegetation Types: Riparian and Wetlands
MLRA Ecoregions: Not Applicable
Agrovoc Control Words: Carex Herbivory Wildlife
Article Review Type: Refereed
Article Type: Experimental Research
Keywords: ovibos moschatus, selective herbivory, carex aquatilis, carex membranacea, eriophorum angustifolium, compensation
Annotation: This was a two-year, replicated study and is applicable to sedge and alpine meadows in high arctic, subarctic regions. Since grazing intensity was not controlled or measured, these results are not applicable to livestock management situations, because grazing use levels are how management decisions are made. As with all grazing research the results from this study are most applicable to areas with similar landscapes, classification of herbivores, climatic conditions and timing of grazing events.
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