Tundra plant responses to experimental and natural temperature changes (scientific paper)

• Main Author: Ulf Molau
• Format: Report
• Language: English
• Published: Botanical Institute, Goeteborg University 2001
• Subjects: Latnjajaure; Cassiope tetragona; Dryas octopetala; Memoirs of National Institute of Polar Research; Polar Research; Polygonum viviparum; Ranunculus nivalis; Subarctic; Tundra; Lapland
• Online Access: https://nipr.repo.nii.ac.jp/?action=repository_uri&item_id=2399; http://id.nii.ac.jp/1291/00002399/; https://nipr.repo.nii.ac.jp/?action=repository_action_common_download&item_id=2399&item_no=1&attribute_id=18&file_no=1

The present five-year study of tundra plant responses to temperature variation is the first longer-term study emanating from the International Tundra Experiment (ITEX). Fieldwork was carried out at the Latnjajaure Field Station in a subarctic-alpine environment in northern Swedish Lapland during 1993-97. Five species were studied : Cassiope tetragona, Dryas octopetala, Eriophorum vaginatum, Polygonum viviparum (four years only), and Ranunculus nivalis. Experimental warming was established by using standardized open-top chambers (OTCs) according to the ITEX protocol. Assessed response variables include phenology, growth, and reproduction. All species responded positively to experimental warming by an accelerated flowering phenology and by increased propagule weight. In vegetative growth all species except the evergreen C. tetragona increased significantly in the warming treatment. After three years some long-term effects have built up, particularly in reproductive effort, e. g., an increase in ovule number per flower. Summer climate was very variable during the study period, and the target species responded much stronger to the warming treatment in the coldest than in the warmest years. The importance of long-term studies in tundra ecosystems is highlighted.