Wendy Anthony wrote:
A number of trees on Mt. Tolmie have opened new green leaves, with flowers, as if it were spring (Figure 1). All other Garry oak trees at this time of year have brown leaves, dropping to ground.
Tom Okey, LEO Network BC coordinator wrote:
Newly opened leaves and flowers of Garry oak trees (Quercus garryana) are not normally produced until the spring. This fall growth and bloom may have resulted from the much warmer than normal climate conditions in 2016 (see Figures 2 and 3). It is also possible that higher than normal precipitation may have triggered this unusual blooming. A quick review of the literature revealed no example of new leaves and flowers in the fall in Quercus (but see comment by Dr. Hebda below), and so it is possible that this is a novel observation. Shifts in the seasonal timing, or phenology of plant and animal species are tracked through the National Phenological Network, through their Nature's Notebook program. A data sheet and sampling protocols are provided for tracking phenological changes in Quercus garryana at this species' Nature's Notebook page. If there were interest in tracking this particular change, such as through the Garry Oak Ecosystems Recovery Team, a LEO Project could also be started employing these protocol and potentially others.
Dr. Richard Hebda wrote:
Scattered new leaves often appear on Garry oak (Quercus garryana) leaves in the fall after the first heavy rains fall, especially on trees growing in shallow soil pockets on rock. Usually this occurs in October and the leaves persist until frost. The appearance of flowers, presumably emerging stamens in this case, is not normal. It will be worthwhile to continue observations of other plants in the region to see if they too are progressing into early spring phenology.
Links:
Wikipedia
Capital Regional District
Garry Oak Ecosystems Recovery Team
BC Ministry of Forests, Lands, and Natural Resources Operations
.
Figure 1. Garry Oak (Quercus garryana) leaves and flowers Nov 1, 2016 (Photo courtesy of Wendy Anthony)
Figure 2. Global temperatures showing 2016 as the warmest year on record
Figure 3. Global map of temperature anomalies showing 2016 as the hottest year so far
Global monthly temperature anomalies with base 1980-2015, superimposed on a 1980-2015 mean seasonal cycle. (Credit: NASA/GISS/Schmidt)
