Plant distribution in Newfoundland especially in relation to summer temperatures measured with the sucrose inversion method

• Published in: Canadian Journal of Botany
• Main Author: Damman, A. W. H.
• Format: Article in Journal/Newspaper
• Language: English
• Published: Canadian Science Publishing 1976
• Subjects: Plant Science; Arctic; Rugosa; Newfoundland
• Online Access: http://dx.doi.org/10.1139/b76-170; http://www.nrcresearchpress.com/doi/pdf/10.1139/b76-170

Inadequate climatic data for large parts of Newfoundland hamper detailed analysis of factors controlling species distribution. Average temperatures for the vegetative season were measured over most of Newfoundland, using the sucrose inversion method. On this basis the coldest and warmest areas could be pinpointed, and regional differences could be mapped in considerable detail. The southern and eastern coastal areas are as cold or colder than the highest peaks except those of the Northern Peninsula. Highest average temperatures were recorded in the valleys of southwestern Newfoundland.Four groups of arctic–alpine species could be recognized which show clear geographic patterns controlled by climate; they include species (1) tolerating high summer maxima, (2) limited by high summer temperatures, (3) requiring deep winter snow cover, and (4) restricted to areas without frequent winter thaws.Deciduous forest species reaching Newfoundland occur in areas with highest average summer temperatures. The abrupt floristic changes in the southern part of the Northern Peninsula appear to be controlled primarily by length of vegetative season. In contrast, Alnus rugosa is limited by low summer temperatures and shows clear distributional limits in the northern as well as southeastern parts of the island.