ROBERTSON, SUSAN J.* and HUGUES B. MASSICOTTE. Forestry Program, College of Science and Management, University of Northern British Columbia, Prince George, British Columbia, Canada V2N 4Z9. - Ectomycorrhizal fungi associated with naturally regenerating black spruce (Picea mariana) seedlings in wetland and upland forests in central British Columbia.
The diversity and abundance of fungi symbiotically associating with
tree hosts may be influenced by environmental factors such as soil
properties and neighboring plants. In central British Columbia, black
spruce (Picea mariana (Mill.) BSP) typically grows in
Sphagnum–dominated wetlands, either in pure stands or mixed
with tamarack (Larix laricina). These habitats are
characterized by cold, poorly aerated, organic soils with low nutrient
availability. Although black spruce appears to tolerate waterlogged
soil conditions, oxygen deficiency may limit ectomycorrhizal
formation. Black spruce also grows with lodgepole pine (Pinus
contorta var. latifolia) in upland forests, on clay soils
that exhibit seasonal cycles of moisture surplus and deficit. Here,
the ability of black spruce to adapt to the dry soil conditions may be
in part due to its fungal symbionts. This study describes the
ectomycorrhizal (ECM) diversity of black spruce and compares
communities across three different habitat types (black spruce
wetlands, black spruce-tamarack wetlands and black spruce-pine
uplands). Morphological assessment (using light microscopy) resulted
in a total of 49 ECM morphotypes (average 4.9 morphotypes per
seedling); 30 morphotypes constituted less than 1% of the ECM
community. Nine morphotypes occurred in all three habitats, 13 in two
of three habitats, and 27 in a single habitat type. PCR-RFLP analysis
and DNA sequencing techniques aided ECM resolution and helped to
clarify taxonomic identity.
Key words: black spruce, DNA sequencing, ectomycorrhiza, PCR-RFLP, Picea mariana, wetlands