A comparative ecological study of Norwegian mountain plants in relation to possible future climatic change

Abstract

Mountain plants constitute an important part of the Norwegian flora. They are also believed to be the plant group in Norway most threatened by the expected climatic warming due to an enhanced greenhouse effect in the near future. In this study the distributions of 107 mountain Norwegian vascular plants were modelled in relation to present‐day climate using Gaussian logit regression. Most species are found to have a surprisingly broad amplitude to mean July and January temperatures, suggesting that a 2°C increase in summer temperature and 4°C increase in winter temperature (as expected with a 2×CO2 increase) may not have a dramatic direct effect on most of the species investigated. A comparative study between estimated July and January temperature optima and tolerances and other ecological attributes such as habitat characteristics, dispersal mechanisms, range sizes and other climatic optima and tolerances was done using multivariate analysis. The results suggest that species most vulnerable to climatic warming, namely the species with narrow July and January temperature tolerances, are characterized by small range sizes and small population sizes, i.e. they are nationally rare species. Furthermore, these vulnerable species are found in all habitats along the major moisture gradient in alpine vegetation. A classification of the species into Rabinowitz's seven forms of rarity confirms that the species most vulnerable to climatic warming are characterized by being habitat specialists with a small geographic range size.

Arctic alpine vegetation change over 20 years

“…These results, as well as ours, do not support modeled predictions of large changes in mountaintop floras (Guisan & Theurillat, 2000;Theurillat & Guisan, 2001). On the other hand, our results are consistent with observations that most Nordic alpine plants have relatively broad temperature tolerances and thus might show little response to warming (Saetersdal & Birks, 1997).…”

“…5a), suggesting that species loss was similar along the entire gradient. The most likely scenario for the loss of richness is a decline in abundance of relatively rare species (Saetersdal & Birks, 1997), resulting in their absence from the sampled vegetation. Lastly, our results confirm a trend for larger changes in relatively moderate environments and less change in harsher environments.…”

After 33 Years, Trees More Frequent and Shrubs More Abundant in Northeast U.S. Alpine Community

“…The Montana species have severely limited geographic distributions and/or are regionally rare, while the Northeast species are globally widespread and sometimes abundant in the region (Bliss, 1963). Narrow geographic ranges and small population sizes are known to make species vulnerable to climatic warming (Saetersdal and Birks, 1997). Our results suggest that having a small niche or geographic range makes species more vulnerable than does having a northern distribution.…”

Distribution and habitat properties of Carex pulicaris and Pedicularis sylvatica at their range margin in NW Poland

“…In general, marginal populations (on the range boundary) are more frequently exposed to stress conditions [22,23], besides they are more sensitive to habitat changes [24]. In the case of C. pulicaris and P. sylvatica, a specific water-soil environment is a vital factor determining their occurrence.…”