Name
Tree and soil fluxes of methane in the Montane Spruce Biogeoclimatic zone in the Southern Interior of British Columbia
Date & Time
Monday, May 8, 2023, 11:00 AM - 11:15 AM
Description
Upland forests typically are regarded as a net sink for atmospheric methane (CH4) because well-drained soils are inhabited by high affinity methanotrophic bacteria. However, CH4 commonly is generated in trees experiencing heartwood rot caused by fungal pathogens. To date, studies of CH4 emissions associated with heartwood rot have focused largely on deciduous species. The objective of this study was to investigate net CH4 fluxes in an upland conifer forest situated in the Montane Spruce Biogeoclimatic zone in the Southern Interior of British Columbia. The study site consisted of 20 quadrats each measuring 10 m x 10 m. Trees were surveyed for species, location, diameter at 1.35 m height, and evidence of stem fungal infection. Using a portable greenhouse gas analyzer, CH4 flux was measured on trees that had a diameter >20 cm. Four measurements per tree were conducted in approximately equal spacing around the stem by using clay to seal a gas-tight chamber to the bark. Where permitted by ground cover, soil exchange of CH4 with the atmosphere also was measured using a flux chamber. In total, CH4 flux was measured from 61 trees and 12 soil plots. Fewer than 10% of trees exhibited CH4 flux from stems with the majority emitting negligible quantities of CH4 regardless of species, size or health condition. Soil was a consistent sink for atmospheric CH4. In the absence of aquatic sources, the mature forest site investigated in the Montane Spruce zone was a net sink for atmospheric CH4.
Location Name
Maple
Full Address
Banff Park Lodge Resort Hotel & Conference Centre
201 Lynx St
Banff AB T1L 1K5
Canada
Abstract
Upland forests typically are regarded as a net sink for atmospheric methane (CH4) because well-drained soils are inhabited by high affinity methanotrophic bacteria. However, CH4 commonly is generated in trees experiencing heartwood rot caused by fungal pathogens. To date, studies of CH4 emissions associated with heartwood rot have focused largely on deciduous species. The objective of this study was to investigate net CH4 fluxes in an upland conifer forest situated in the Montane Spruce Biogeoclimatic zone in the Southern Interior of British Columbia. The study site consisted of 20 quadrats each measuring 10 m x 10 m. Trees were surveyed for species, location, diameter at 1.35 m height, and evidence of stem fungal infection. Using a portable greenhouse gas analyzer, CH4 flux was measured on trees that had a diameter >20 cm. Four measurements per tree were conducted in approximately equal spacing around the stem by using clay to seal a gas-tight chamber to the bark. Where permitted by ground cover, soil exchange of CH4 with the atmosphere also was measured using a flux chamber. In total, CH4 flux was measured from 61 trees and 12 soil plots. Fewer than 10% of trees exhibited CH4 flux from stems with the majority emitting negligible quantities of CH4 regardless of species, size or health condition. Soil was a consistent sink for atmospheric CH4. In the absence of aquatic sources, the mature forest site investigated in the Montane Spruce zone was a net sink for atmospheric CH4.
Session Type
Breakout Session