dc.date.accessioned | 2017-08-16T12:25:34Z | |
dc.date.available | 2017-08-16T12:25:34Z | |
dc.date.created | 2012-06-04T11:04:16Z | |
dc.date.issued | 2012 | |
dc.identifier.citation | Martinsen, Vegard Mulder, Jan Austrheim, Gunnar Hessen, Dag Olav Mysterud, Atle . Effects of Sheep Grazing on Availability and Leaching of Soil Nitrogen in Low-Alpine Grasslands. Arctic, Antarctic and Alpine research. 2012, 44(1), 67-82 | |
dc.identifier.uri | http://hdl.handle.net/10852/57073 | |
dc.description.abstract | Alpine ecosystems are generally nitrogen (N) limited with low rates of N mineralization. Herbivory may affect N cycling and N losses and thus long-term productivity of ecosystems.
Using a controlled grazing experiment in a low-alpine region at Hol, southern Norway, with three density levels of sheep, we determined effects of grazing on in situ availability of inorganic N, potential N mineralization, and mobility of dissolved inorganic N (DIN) and dissolved organic N (DON) in soil water of O-horizons in grazing-preferred grassland habitats. In addition, we studied the within-season and spatial variation of these processes.
The low alpine grasslands at Hol were characterized by small rates of N mineralization and relatively large plant demands for N. Significantly greater rates of potential N mineralization were found at sites with high sheep density compared to those with low density or no grazing. Effects of grazing on bioavailable N (as determined by buried PRS™ exchange resins) were greater at low as compared to high altitudes. At low altitudes, low sheep density reduced amounts of bioavailable N. Nitrogen concentration of plants as a proxy of N availability in soils revealed, however, no significant effects of grazing. There was a strong seasonal effect on inorganic N and DIN∶DON ratios of the soil water, with decreasing values in the course of the growing season, probably due to increasing nutrient demand of plants and/or microbes.
We conclude that grazing may significantly stimulate N-cycling, but not sufficiently to release the system from its strong N deficiency, as we found no evidence for short-term increased risk in N loss via soil water due to herbivore activity. Nitrogen removal through grazing is small compared to the total soil N pool and at high sheep density is about half of the N deposition. This suggests that grazing in grassland habitats in this low alpine ecosystem is sustainable from a nutrient point of view.
© University of Colorado at Boulder, Institute of Arctic and Alpine Research | en_US |
dc.language | EN | |
dc.publisher | Institute of Arctic and Alpine Research | |
dc.title | Effects of Sheep Grazing on Availability and Leaching of Soil Nitrogen in Low-Alpine Grasslands | en_US |
dc.type | Journal article | en_US |
dc.creator.author | Martinsen, Vegard | |
dc.creator.author | Mulder, Jan | |
dc.creator.author | Austrheim, Gunnar | |
dc.creator.author | Hessen, Dag Olav | |
dc.creator.author | Mysterud, Atle | |
cristin.unitcode | 185,15,21,0 | |
cristin.unitname | Institutt for biovitenskap (tidl. BIO) | |
cristin.ispublished | true | |
cristin.fulltext | original | |
cristin.qualitycode | 1 | |
dc.identifier.cristin | 927602 | |
dc.identifier.bibliographiccitation | info:ofi/fmt:kev:mtx:ctx&ctx_ver=Z39.88-2004&rft_val_fmt=info:ofi/fmt:kev:mtx:journal&rft.jtitle=Arctic, Antarctic and Alpine research&rft.volume=44&rft.spage=67&rft.date=2012 | |
dc.identifier.jtitle | Arctic, Antarctic and Alpine research | |
dc.identifier.volume | 44 | |
dc.identifier.issue | 1 | |
dc.identifier.startpage | 67 | |
dc.identifier.endpage | 82 | |
dc.identifier.doi | http://dx.doi.org/10.1657/1938-4246-44.1.67 | |
dc.identifier.urn | URN:NBN:no-59855 | |
dc.type.document | Tidsskriftartikkel | en_US |
dc.type.peerreviewed | Peer reviewed | |
dc.source.issn | 1523-0430 | |
dc.identifier.fulltext | Fulltext https://www.duo.uio.no/bitstream/handle/10852/57073/2/1938-4246-44.1.67.pdf | |
dc.type.version | PublishedVersion | |