Longevity and persistence of alder west of the tree line on the Seward Peninsula, Alaska

• Published in: Canadian Journal of Botany
• Main Authors: Wilson, Brayton F., Patterson 111, William A., O'Keefe, John F.
• Format: Article in Journal/Newspaper
• Language: English
• Published: Canadian Science Publishing 1985
• Subjects: Plant Science; Seward Peninsula; Tundra; Alaska
• Online Access: http://dx.doi.org/10.1139/b85-262; http://www.nrcresearchpress.com/doi/pdf/10.1139/b85-262

We measured alder plants (Alnus viridis ssp. crispa (Aiton) Turrill) in stands on 11 sites on the Seward Peninsula. Of the plants measured in detail, 70% had multiple stems (largest difference in stem age on a plant was 67 years), 54% had small epicormic shoots, and 59% had partially prostrate stems that could layer. The oldest stems were 35–114 years on alpine tundra, 47–48 years on river cuts, 36 years on moist tundra, and 16–33 years on floodplain. This species appeared to be reproducing by means of seedlings on 8 of 11 sites. Alder pollen percentages in surface samples from seven small ponds were negatively correlated with distance to alder stands. Pollen and 14 C analysis of sediments from a pond near one sample stand showed that alder pollen percentages had decreased over the past 3600 years, but that alder had persisted in the area during this period. Estimates of potential plant age, dependent on assumptions about the production and survival of new stems, ranged from 100 years to unlimited age. The maximum age of stands is at least 100–200 years, but could be up to the 3600 years shown by a continuous pollen record and 14 C analysis.