Botany Outing Report: Palaeobotany, Jan 8th, 2018

Happy New Year!

Presentation on January 8th 

On January  8th  we were treated to a fascinating presentation  by Randal Mindell on the palaeobotany of our back yard, the Comox Valley; we learnt about the importance of the fossil plant record and what it tells us about climate change. In the valley there are a number of excellent locations for fossil plant material, including the Cumberland Mines, the river banks of the Puntledge, Trent and others, the seashores in the Oyster River area, and of course Hornby Island.  We were shown the methodology for obtaining information from cross-sections of sandstone or mudstone concretions through acetate peels (see illustration attached). The acetate film will strip off fragments of wood, seeds, roots and leave of gymnosperms and angiosperms that can then be examined under the lenses of a high-powered microsope.

In fine paedagogic form, Randal summarized at the end what he had covered in the presentation – for your information here is that summary.

  • Late Cretaceous (85-70 million years ago):

Lowland swamp and estuary thousands of kilometers to the south, 10? warmer
Ginkgo, Cycadeoids and other exotic gymnosperms
Ancient flowering plants groups- some still present in the area (Cornus), others long gone (Liriodendron,Platanaceae)

  •  Eocene (~45 million years ago):

Beeches, Walnuts, Laurels and many elements now restricted to tropical and subtropical climates.

  •  LARGE GAP
  • Post-Glacial community migrates onto barren landscape from the south starting around 14000 years ago, with pine forests giving way to Tsuga (Hemlock), Thuja (Cedar) and Alnus (Alder). Coast Western Hemlock Biogeoclimatic Zone established.   “Old Growth” forest patches in the area represent remnants of natural landscapes that have developed over 13,700 years.

UPCOMING EVENTS

Monday February 20th  –  Mosses in Seal Bay Park with Randal in the lead.

This will be a week later than usual because of “BC Family Day”. Time and specific location will be announced closer to the time.

all the best,  Alison

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