THE MODERN AND LATE‐QUATERNARY VEGETATION OF THE DOLL CREEK AREA, NORTH YUKON, CANADA

• Published in: New Phytologist
• Main Author: RITCHIE, J. C.
• Format: Article in Journal/Newspaper
• Language: English
• Published: Wiley 1982
• Subjects: Canada; Doll Creek; Limestone Ridge; Yukon; Tundra
• Online Access: http://dx.doi.org/10.1111/j.1469-8137.1982.tb04489.x; https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1111%2Fj.1469-8137.1982.tb04489.x; https://nph.onlinelibrary.wiley.com/doi/pdf/10.1111/j.1469-8137.1982.tb04489.x

SUMMARY The modern vegetation of the mountainous Doll Creek region consists of tundra on surfaces above roughly 700 m elevation and spruce woodlands on lower slopes and valleys. Ordination of quadrat cover data by detrended correspondence analysis displays the characteristics and relationships of the vegegation. Tundra on non‐calcareous parent materials is distinctive, dominated by Betula glandulosa, Arctostaphylos alpina, Ledum decumbens and Salix arctica . Limestone ridge surfaces, by contrast, support a tundra dominated by Dryas integrifolia, Carex scirpoidea and Cetraria species; lower slopes on limestone are dominated by a Dryas‐Cassiope‐Tomenthypnum cover which also characterizes the ground vegetation of Picea glauca woodlands on lower surfaces. Bottomland mires are dominated by Picea mariana‐Sphagnum woodlands and moraines support a Picea mariana–Betula glandulosaericad community. Larix laricina shares dominance with Picea glauca at treeline on northwest‐facing gulley surfaces where deep and persistent snow appears to be important. A detailed pollen analysis of one site, using percentage and influx diagrams, running means of influx of the main taxa, and a pollen influx‐vegetation representation calibration method, reveals that immediately following the maximum of the latest glacial cycle (18000 B.P.) the area supported a sparse, unproductive herb tundra on the lower montane slopes and a sedge‐grass marsh complex in poorly drained sites. Between 16000 and 12500 14 C years rapid changes in the plant populations occurred, particularly involving species of willow, grass, sedge and herbs. By 12500 the entire area was occupied by a mosaic of treeless communities in response to a slow amelioration of the climate. At 12000 a rapid transition from a warming glacial to a non‐glacial climate stimulated the spread of dwarf shrubs (ericads and birch), increased organic sedimentation, soil humification and paludification, and a gradual increase in spruce until the modern extent and structure of woodland complexes was ...