Change search
ReferencesLink to record
Permanent link

Direct link
The effect of snow on plant chemistry and invertebrate herbivory: Experimental manipulations along a natural snow gradient
Umeå University, Faculty of Science and Technology, Department of Ecology and Environmental Sciences.
Swedish University of Agricultural Sciences, Southern Swedish Forest Research Centre, P.O. Box 49, SE-230 53 Alnarp, Sweden.
School of Biological and Biomedicinal Sciences, Institute of Ecosystem Science, University of Durham, Durham DH1 3LE, UK.
Umeå University, Faculty of Science and Technology, Department of Ecology and Environmental Sciences. (Arcum)
2010 (English)In: Ecosystems (New York. Print), ISSN 1432-9840, E-ISSN 1435-0629, Vol. 13, no 5, 741-751 p.Article in journal (Refereed) Published
Abstract [en]

Changing snow conditions have strong effects onnorthern ecosystems, but these effects are rarelyincorporated into ecosystem models and our perceptionof how the ecosystems will respond to awarmer climate. We investigated the relationshipsbetween snow cover, plant phenology, level ofinvertebrate herbivory and leaf chemical traits inBetula nana in four different habitats located along anatural snow cover gradient. To separate the effectof snow per se from other differences, we manipulatedthe snow cover with snow fences in threehabitats. The experimentally prolonged snow coverdelayed plant phenology, but not as much as expectedbased on the pattern along the natural gradient.The positive effect of the snow treatment onplant nitrogen concentration was also weaker thanexpected, because plant nitrogen concentrationclosely followed plant phenology. The level ofherbivory by leaf-chewing invertebrates increasedin response to an increased snow cover, at least atthe end of the growing season. The concentrationof phenolic substances varied among habitats,treatments and sampling occasions, indicating thatB. nana shrubs were able to retain a mosaic ofsecondary chemical quality despite altered snowconditions. This study shows that the effect of thesnow cover period on leaf nitrogen concentrationand level of herbivory can be predicted based ondifferences between habitats, whereas the effect ofa changed plant phenology on plant nitrogenconcentration is better explained by temporaltrends within habitats. These results have importantimplications for how northern ecosystemsshould respond to future climate changes.

Place, publisher, year, edition, pages
Springer, 2010. Vol. 13, no 5, 741-751 p.
Keyword [en]
Tundra, snow, natural gradient, experimental manipulation, nitrogen, phenolics, herbivory, phenology, Betula nana
National Category
Biological Sciences
URN: urn:nbn:se:umu:diva-30410DOI: 10.1007/s10021-010-9351-4ISI: 000280260100009OAI: diva2:282794
Available from: 2009-12-22 Created: 2009-12-21 Last updated: 2016-05-20Bibliographically approved
In thesis
1. The Effect of Snow on Plants and Their Interactions with Herbivores.
Open this publication in new window or tab >>The Effect of Snow on Plants and Their Interactions with Herbivores.
2010 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

The ongoing climate changes are predicted to accelerate fast in arctic regions with increases in both temperatures and precipitation. Although the duration of snow cover is generally expected to decrease in the future, snow depth may paradoxically increase in those areas where a large amount of the elevated precipitation will fall as snow. The annual distribution and duration of snow are important features in arctic ecosystems, influencing plant traits and species interactions in various ways. In this thesis, I investigated the effect of snow on plants and their interactions with herbivores by experimentally increasing the snow cover by snow fences in three different habitats along an environmental gradient in Abisko, northern Sweden.

I found that the snow cover mattered for plant quality as food for herbivores and herbivore performance. An enhanced and prolonged snow cover increased the level of insect herbivory on dwarf birch leaves under field conditions. Autumnal moth larvae feeding on leaves that had experienced increased snow-lie grew faster and pupated earlier than larvae fed with leaves from control plots. These findings indicated that plants from snow-rich plots produced higher-quality food for herbivores. My studies showed that differences in snow-lie explained parts of the within-year spatial and seasonal variation in plant chemistry and patterns of herbivory in this arctic landscape. The relationship between leaf nitrogen concentration and plant phenology was consistent between treatments and habitats, indicating that snow per se, via a delayed phenology, was controlling the nitrogen concentration. The relationship between leaf age and level of herbivory was positive in the beginning of the growing season, but negative in the end of the growing season, indicating an increasing importance of plant palatability and a decreasing importance of exposure time in determining the level of herbivory throughout the growing season. The concentrations of phenolics varied among habitats, treatments and sampling occasions, suggesting that these plants were able to retain a mosaic of secondary chemical quality despite altered snow conditions. Furthermore, the nutrient limiting plant growth, according to N:P ratio thresholds, appeared to shift from nitrogen to phosphorus along the topographic gradient from snow-poor ridges to more snow-rich heathlands and fens. Snow addition had, however, no significant effect on other nutrient concentrations than nitrogen and no significant effect on the leaf N:P ratio, indicating that differences in snow cover could not explain the variation in plant nutrient concentrations among habitats. In a five-year study, I found opposing inter-annual effects of increased snow on plant chemistry. In contrast to earlier results, the effect of snow-lie on plant nitrogen concentration was predominantly negative. However, the effect of increased snow cover on the level of herbivory remained predominantly positive. The strong within-year relationship between snow-melt date (via plant phenology) and plant nitrogen concentration and level of herbivory could not predict inter-annual variation in the effect of snow manipulation. I did not find any conclusive evidence for a single factor causing the inter-annual opposing effect of snow addition, but the results indicated that interactions with summer and winter temperatures might be important.

In conclusion, this thesis showed that climate-induced changes in snow conditions will have strong effects on plant traits and plant-herbivore interactions. However, alterations in snow cover do not influence all plant traits and the effect may vary in time and space.

Place, publisher, year, edition, pages
Umeå: Print&Media, 2010. 59 p.
Snow, arctic ecosystem, plant-herbivore interactions, phenology, nitrogen, phenolics, experimental manipulation, natural gradient, inter-annual variability
National Category
Biological Sciences
urn:nbn:se:umu:diva-30444 (URN)978-91-7264-923-1 (ISBN)
Public defence
2010-01-22, Lilla Hörsalen (KB3A9), KBC-huset, Umeå, 10:00 (English)
Available from: 2009-12-29 Created: 2009-12-22 Last updated: 2009-12-29Bibliographically approved

Open Access in DiVA

No full text

Other links

Publisher's full text

Search in DiVA

By author/editor
Torp, MikaelaOlofsson, Johan
By organisation
Department of Ecology and Environmental Sciences
In the same journal
Ecosystems (New York. Print)
Biological Sciences

Search outside of DiVA

GoogleGoogle Scholar
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

Altmetric score

Total: 48 hits
ReferencesLink to record
Permanent link

Direct link