ARCTIC A Field Survey of Respiration Rates in Leaves of Arctic Plants
ABSTRACT. In a survey of several plant species found at Churchill, Manitoba, in the transition zone between the low and subarctic regions, we measured leaf respiration in terms of total respiration and alternative pathway respiration rates. Leaves of arctic plants exhibit higher rates of total respi...
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| Format: | Text |
| Language: | English |
| Published: |
1987
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| Online Access: | http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.498.8733 http://pubs.aina.ucalgary.ca/arctic/Arctic41-1-1.pdf |
| Summary: | ABSTRACT. In a survey of several plant species found at Churchill, Manitoba, in the transition zone between the low and subarctic regions, we measured leaf respiration in terms of total respiration and alternative pathway respiration rates. Leaves of arctic plants exhibit higher rates of total respiration and alternative (cyanide insensitive) respiration than temperate species. There is a negative correlation between plant height and alternative pathway activity. Shorter plants have higher rates of alternative pathway respiration. Mo e alternative pathway activity may mean that there is less energy in the form of ATP available for growth. A shorter growth habit keeps these plants in the still air close to the ground. This prevents cooling, water loss and physical damage due to wind abrasion. Thus plants with high rates of altern tive pathway respiration may be better adapted to the arctic environment. The alternative pathway respiration of Orchis roturuiijolia was shown to be under the influence of the biological clock. Key words: Subarctic, plant respiration, alternative pathway, cyanide insensitive RÉSUMÉ. Lors d’une étude sur plusieurs esp&ces de plantes qui poussentà Churchill, au Manitoba, dans la bande de transition entre l’Arctique inférieur et la zone subarctique, on a mesur6 la respiration des feuilles en termes de taux de respiration totale et par voie alt rne. I1 en ressort que les feuilles des plantes de l’Arctique ont des taux plus élevts de respiration totale et alterne (insensible au cyanure) que les e s w e s des régions tempérées. I1 existe une corrélation négative entre la hauteur desplantes et la respiration par voie alterne. Les plantes plus petites ont des taux de respiration par voie alterne plus élevés. Une plus grande activité par voie alterne pourrait signifier qu’il y a moins d’énergie sous forme d ’ ATP (adénosine triphosphate) disponible pour la |
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