About this Environmental Science article

Gas Exchange of Four Arctic and Alpine Tundra Plant Species in Relation to Atmospheric and Soil Moisture Stress by Douglas A. Johnson; Martyn M. Caldwell is a Environmental Science article available to read on EtoBox.

Gas exchange measurements of two arctic tundra plants, Dupontia fischeri and Carex aquatilis, and two alpine tundra species, Deschampsia caespitosa and Geum rossii, were conducted under a range of atmospheric and soil moisture stress conditions to determine if photosynthetic adaptations to water stress may play a role in the local distributions of these species. Under low soil moisture stress, the species which are normally restricted to wet sites, Dupontia and Deschampsia, exhibited higher net photosynthetic rates than Carex and Geum which are more widely distributed. However, photosynthetic of the wider ranging species was not so abruptly curtailed as that of the wet site species when the plants were exposed to increasing atmospheric or soil moisure stress. Although the depression of photosynthesis with water stress in these tundra species could be partially attributed to reduced stomatal aperture, with decreased soil water potential most of the decline of photosynthesis was due to a greater non-stomatal or residual resistance, indicating a direct impact of water stress on the photosynthetic apparatus. Dark respiration did not increase with enhanced water stress. Stomata of the w

Author

Douglas A. Johnson; Martyn M. Caldwell

Publisher

Springer-Verlag; Springer Verlag; Springer Science and Business Media LLC (ISSN 0029-8549)

Published

1975

Language

EN

Field

Environmental Science (Physical Sciences)