FRST 211 Lectures 27-32

Englemann spruce

Subalpine fir

Silvics of Engelmann Spruce

Successful germination requires seed crop + light + seedbed

Moderately shade tolerant

Partial shade is beneficial (protects from high temperature and drought)

Regenerates on range of substrates: leaf litter, forest floor, decaying wood, mineral soil

Silvics of Subalpine Fir

Regenerates on range of substrates: forest floor, leaf litter or decaying wood

Can regenerate via vegetative layering

Shade tolerant

Good competitor > 50% shade

Slow growth, releases in gaps

Interior Cedar-Hemlock Zone

Interior continental climate, strong orographic effects

 Cool, wet winters; warm, dry summers

 Relatively wet, 25-50% precipitation = snow

 Summer water deficits in many areas

Dominated by upland conifer species

western hemlock

western redcedar

subalpine fir

Douglas-fir

Highest diversity of tree species in BC

Overlap with other BEC zone

Trembling aspen

Silvics of Trembling Aspen

Modest edaphic amplitude

 Slightly Dry to Fresh SMR

 Medium to rich SNR

Shade intolerant

 Higher in seedlings developed from root suckers

Fast-growing

Relatively short-lived

Silvics of Paper Birch

Modest edaphic amplitude

 Fresh to moist SMR

 Medium to rich SNR

Water-demanding species

Associative N-fixation

Nutrient-demanding

 Creates nutrient-rich leaf litter

Alters humus forms

 Mors → mormoders → moders

Paper birch

Positive mixed forest ICH interactions

Mixed forests are resistant to Armillaria

Paper birch microbes hostile to root pathogens, establishing a barrier to spread

This protects conifers

Paper Birch and Forest Productivity

Ectomycorrhizal networks facilitate nutrient and carbon transfer to tree biomass

Associative N-fixation

White spruce

Silvics of White Spruce

Successful germination = water + temperature

Usually shallow-rooted

Range of substrates:

Successful on mineral soil + burned substrates

Less successful on organics and decaying wood, but common in mature forests

Moderately shade-tolerant

Black spruce

Silvics of Black Spruce

Pioneer after severe fires

 Depends on seed availability

 Little competition

Fine-scale gaps in mature forests

300-1000 years

Early to late-succession