Page 150 - PC2019 Program & Proceedings

PLANT CANADA 2019

S85. Finding and re-measuring forest carbon plots after fifteen years: Why, how and so what?
Fredeen, A.; L. Gan; C. Elkin
University of Northern BC

The growing urgency around rising CO2 and climate change are demanding action. From a forest
biologist’s perspective, a similar urgency exists with respect to understanding how forest carbon
sequestration and stocks are being impacted by climate change. While forests and forest products contain
significant carbon, recent findings suggest that older boreal trees and forests have become much more
vulnerable in recent decades. To help address this question, we decided to revisit a subset of 17 year-old
forest carbon plots spread out across a 9,250 ha sub-boreal spruce and fir research forest in central British
Columbia to re-measure live tree aboveground biomass (and carbon) in these plots. Twenty-six plots were
ultimately located and re-measured; many of our intended plots had been harvested or could not be
located. Diameters for all standing live trees were re-measured in these plots and their aboveground
carbon contents evaluated and compared with initial values from 2003 and 2004. The results show how
recent volume growth and carbon sequestration levels in live tree carbon stocks have changed in this
common forest type in central BC, and how initial forest state (e.g. age, species composition) influences
the growth or decline in aboveground forest carbon.

Art Fredeen (fredeena@unbc.ca)

S86. Distribution and management of the carrot cyst nematode (Heterodera carotae) in Ontario,
Canada
3
1
1
Blauel, T. ; D. Van Dyk ; K. Vander Kooi ; Q. Yu ; M.R. McDonald
1
2
1 University of Guelph
2 Ontario Ministry of Agriculture, Food and Rural Affairs
3 Agriculture and Agri-Food Canada
The carrot cyst nematode (CCN), Heterodera carotae, is a plant-parasitic nematode that parasitizes
commercial and wild carrots, reducing yield and causing unmarketable forked and stunted roots. The
nematode is present in many European countries, Cyprus, India, Mexico and in the state of Michigan,
USA, and has recently been reported in Ontario, Canada. A survey, field trial and laboratory trial were
conducted to better understand the distribution of, and control options for, this nematode. Between 2016
to 2018, the multi-year survey was conducted by soil sampling 68 carrot fields throughout Ontario. Carrot
cyst nematodes were found in 72% of carrot fields and were only present in fields of muck (high organic
matter) soil. A nematicide/fumigant field trial was conducted in a field naturally infested with CCN in the
Holland Marsh, Ontario and efficacy laboratory trials were conducted at the University of Guelph Muck
Crops Research Station. There were no differences in percent nematode damage and yield among
chemical and biological nematicides and fumigants in the field trial. However, nematicides significantly
reduced the number of living eggs inside CCN cysts by up to 30% compared to the water control in the
laboratory trial. Managing this cyst nematode is complex due to its biology and life cycle. Further
research is continuing to develop effective management options to deal with this new and persistent pest.

Tyler Blauel (tblauel@uoguelph.ca)

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