Full text of this article is only available in PDF format.

Jonathan J. Ruel (email), Matthew P. Ayres

Variation in temperature responses among populations of Betula papyrifera.

Ruel J. J., Ayres M. P. (1996). Variation in temperature responses among populations of Betula papyrifera. Silva Fennica vol. 30 no. 2–3 article id 5582. https://doi.org/10.14214/sf.a9227

Abstract

How will global warming affect southern populations of boreal trees? In paper birch, Betula papyrifera (Betulaceae), alpine trees with an evolutionary history of relatively cool summers may be more sensitive to climate warming than valley populations. We evaluated this scenario by growing seedlings from different populations in four temperature treatments (mountain field site, valley field site, and two greenhouse rooms).

Populations from low elevations germinated earlier and had higher germination success than population from high elevations (16.8 vs. 22.0 d; 72% vs. 11%). At the valley site, seedlings from native populations grew faster than seedlings from higher elevations (mean ± SE = 0.25 ± 0.02 vs. 0.09 ± 0.04 mm · cm-1 · d-1) while at the mountain site, all seedlings grew at similar rates. Seedling grown in cooler environments had higher root : shoot ratios, perhaps to compensate for temperature limitations in nutrient uptake by roots. Leaf area varied among populations but was not affected by environmental differences across the field sites. Net photosynthetic rates at valley temperatures were higher for seedlings grown in the valley than for seedling grown in the mountains or the warm greenhouse (12.0 vs. 10.3 and 5.8 μmoles · m-2 · s-1), perhaps due to adaptive phenotypic adjustments. Climatic warming could rapidly produce important phenotypic changes in birch trees (e.g. decreased root : shoot ratio, reduced growth in alpine populations). On a longer time-scale, warming could also result in genetic changes as natural selection favours valley genotypes in alpine sites where they are presently rare.

Keywords
Betula papyrifera; adaptation; photosynthesis; growth; temperature; climate warming; elevation

Published in 1996

Views 3973

Available at https://doi.org/10.14214/sf.a9227 | Download PDF

Creative Commons License CC BY-SA 4.0

Register
Click this link to register to Silva Fennica.
Log in
If you are a registered user, log in to save your selected articles for later access.
Contents alert
Sign up to receive alerts of new content

Your selected articles
Send to email
Parviainen J., (1985) Growth of young Scots pine, Norway spruce, siber.. Silva Fennica vol. 19 no. 4 article id 5249 (remove) | Edit comment
Huuri O., (1965) The effects of storage in cones on the viability.. Acta Forestalia Fennica vol. 78 no. 5 article id 7158 (remove) | Edit comment
Smolander H., (1984) Measurement of fluctuating irradiance in field s.. Acta Forestalia Fennica vol. 0 no. 187 article id 7634 (remove) | Edit comment
Ruel J. J., Ayres M. P. (1996) Variation in temperature responses among populat.. Silva Fennica vol. 30 no. 2–3 article id 5582 (remove) | Edit comment
Your search results