Change search
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Effects of herbivory on arctic and alpine vegetation
Stockholm University, Faculty of Science, Department of Botany.
2007 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

The distribution of plant species and functional traits in alpine and arctic environments are determined by abiotic conditions, but also by biotic interactions. In this thesis, I investigate interactions among plants and herbivory effects on plant community composition and plant functional traits in three different regions: Swedish Lapland, Beringia (USA/Russia) and Finnmark (Norway). Reindeer grazing was found to be extensive in southern Lapland and had limited effects on plant community composition and seedling germination. However, reindeer presence was found to influence plant functional traits, particularly in the subalpine birch forest. Tall herbs were lower and had lower SLA when reindeer were present, while small herbs showed an opposite pattern. The contrasting effects on the two herb groups are probably explained by a competitive release for small herbs when the tall herbs are suppressed by reindeer. Rodents had the largest relative impact on plant community composition in southern Lapland and this is consistent with the study from Finnmark, where rodents heavily affected dwarf shrubs on predator-free islands. With no predators present, vole densities increased profoundly and almost depleted some dwarf shrub species. These results support the idea that small mammals in arctic and alpine tundra are controlled by predators (i.e. top-down). However, a decrease in the nutritional quality in a sedge after defoliation gives support for the idea that small mammals are regulated by plant quality (i.e. bottom-up). In Beringia, small and large herbivores differed in the relation to plant community composition, since large herbivores were related to species richness and small herbivores were related to plant abundance. Plant functional traits were related only to large herbivores and standing crop of vascular plants.

Place, publisher, year, edition, pages
Stockholm: Botaniska institutionen , 2007. , 38 p.
Keyword [en]
herbivory, reindeer, rodents, functional traits, plant species composition, arctic, alpine, tundra, seed limitation, Carex bigelowii
National Category
Biological Sciences
Research subject
Plant Ecology
Identifiers
URN: urn:nbn:se:su:diva-6746ISBN: 91-7155-396-7 (print)OAI: oai:DiVA.org:su-6746DiVA: diva2:196974
Public defence
2007-04-20, föreläsningssalen, Botanicum, Lilla Frescativägen 5, Stockholm, 10:00
Opponent
Supervisors
Available from: 2007-03-29 Created: 2007-03-27Bibliographically approved
List of papers
1. The impact of disturbance and seed availability on germination in alpine vegetation in the Scandinavian mountains
Open this publication in new window or tab >>The impact of disturbance and seed availability on germination in alpine vegetation in the Scandinavian mountains
2007 (English)In: Arctic, Antarctic and Alpine research, ISSN 1523-0430, E-ISSN 1938-4246, Vol. 39, no 3, 449-454 p.Article in journal (Refereed) Published
Abstract [en]

The availability of seeds and microsites are limiting factors for many plant species of different vegetation types. We have investigated the existence of such limitations in two habitats, an alpine heath and a subalpine birch forest, where abiotic factors are hypothesized to be the main determining factor of plant species distributions. Both habitats are characterized by a short growing season and cold temperatures, and the alpine heath is also constrained by low productivity. A seed addition experiment including six vascular plants, selected by different functional traits and occurrence, showed that seed limitation was an important factor in these habitats. Removal of the aboveground biomass (controlled disturbance) increased germination only for some species. The effect of reindeer presence was found to be of less importance, probably due to low and varying densities of reindeer. To conclude, we found that seed limitation was the most important factor limiting the distribution of our studied species in the two alpine environments.

Place, publisher, year, edition, pages
Colorado: Institute of Arctic and Alpine Research, University of Colorado, 2007
National Category
Ecology
Identifiers
urn:nbn:se:su:diva-24185 (URN)10.1657/1523-0430(06-024)[LINDGREN]2.0.CO;2 (DOI)
Available from: 2007-03-29 Created: 2007-03-27 Last updated: 2017-12-13Bibliographically approved
2. The effect of different herbivore groups on the vegetation in subalpine birch forests and alpine heaths
Open this publication in new window or tab >>The effect of different herbivore groups on the vegetation in subalpine birch forests and alpine heaths
Manuscript (Other academic)
Identifiers
urn:nbn:se:su:diva-24186 (URN)
Note
Part of urn:nbn:se:su:diva-6746Available from: 2007-03-29 Created: 2007-03-27 Last updated: 2010-01-13Bibliographically approved
3. Herbivory and plant biodiversity in an arctic environment
Open this publication in new window or tab >>Herbivory and plant biodiversity in an arctic environment
Show others...
Manuscript (Other academic)
Identifiers
urn:nbn:se:su:diva-24187 (URN)
Note
Part of urn:nbn:se:su:diva-6746Available from: 2007-03-29 Created: 2007-03-27 Last updated: 2010-01-13Bibliographically approved
4. Defense mechanisms against grazing: a study of trypsin inhibitor responses to simulated grazing by the sedge Carex bigelowii
Open this publication in new window or tab >>Defense mechanisms against grazing: a study of trypsin inhibitor responses to simulated grazing by the sedge Carex bigelowii
2007 (English)In: Oikos, ISSN 0030-1299, E-ISSN 1600-0706, Vol. 116, no 9, 1540-1546 p.Article in journal (Refereed) Published
Abstract [en]

Trypsin inhibitors have been suggested to constitute an inducible defense in the sedge Carex bigelowii, and some former studies suggest that this might be a cause for the cyclic population dynamics in many alpine and arctic small mammals, for example lemmings (Lemmus lemmus). We investigated this further by using a method of simulated grazing (clipping) at different intensities, in three different habitats with varying resource availability, with different harvest times (hours after clipping), and two different stages of ramets (reproductive/vegetative) in a study from the Swedish mountain range. Our results do not indicate that C. bigelowii has an inducible defense constituted by an increase in trypsin inhibitor activity (TIA), but rather that the amount of soluble plant proteins (SPP) is lowered in wounded plants. The responses were somewhat different in the three habitats, with ramets growing in the marsh showing the highest ratio of TIA to SPP, due to low amounts of SPP. We did not find any significant effects of harvest time, or of the stage of the ramet that could support the hypothesis of an inducible defense. To conclude, we could not find any evidence for an inducible defense consisting of trypsin inhibitors in Carex bigelowii ramets, but we did find variations in the amount of SPP that may have nutritional consequences for herbivores.

National Category
Biological Sciences
Identifiers
urn:nbn:se:su:diva-24188 (URN)10.1111/j.0030-1299.2007.15481.x (DOI)
Available from: 2007-03-29 Created: 2007-03-27 Last updated: 2017-12-13Bibliographically approved
5. Predators indirectly protect tundra plants by reducing herbivore abundance
Open this publication in new window or tab >>Predators indirectly protect tundra plants by reducing herbivore abundance
Show others...
2004 In: Oikos, ISSN 0030-1299, Vol. 106, no 1, 85-92 p.Article in journal (Refereed) Published
Identifiers
urn:nbn:se:su:diva-24189 (URN)
Note
Part of urn:nbn:se:su:diva-6746Available from: 2007-03-29 Created: 2007-03-27Bibliographically approved

Open Access in DiVA

fulltext(301 kB)897 downloads
File information
File name FULLTEXT01.pdfFile size 301 kBChecksum SHA-1
fc129c85a352b75bea801a1795707818305a8cc919069128d3a1c7be7872c1d6de4b2219
Type fulltextMimetype application/pdf

By organisation
Department of Botany
Biological Sciences

Search outside of DiVA

GoogleGoogle Scholar
Total: 897 downloads
The number of downloads is the sum of all downloads of full texts. It may include eg previous versions that are now no longer available

isbn
urn-nbn

Altmetric score

isbn
urn-nbn
Total: 955 hits
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf