Canadian Forest Service Publications

Enhanced water relations of residual foliage following defoliation in Populus tremuloides. 2000. Hart, M.; Hogg, E.H.; Lieffers, V.J. Canadian Journal of Botany 78(5): 583-590.

Year: 2000

Issued by: Northern Forestry Centre

Catalog ID: 21033

Language: English

Availability: Order paper copy (free), PDF (request by e-mail)

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Abstract

Stomatal conductance and leaf water potential of aspen (Populus tremuloides Michx.) were measured in response to defoliation intensity, both in the field and under controlled conditions. There was evidence of increased stomatal conductance in trees with 50 and 98% defoliation, but no change in leaf water potential. Under controlled conditions, stomatal conductance and rate of photosynthesis were measured under high and low vapour pressure deficits (VPD). Under high VPD, overall stomatal conductance and rates of photosynthesis were greatly reduced. However, in both VPD treatments, there was evidence of increased stomatal conductance and compensatory photosynthesis following defoliation. These findings may be due to increases in leaf specific hydraulic conductance following defoliation.