Hb. Delong et al., MICROSITE EFFECTS ON FIRST-YEAR ESTABLISHMENT AND OVERWINTER SURVIVALOF WHITE SPRUCE IN ASPEN-DOMINATED BOREAL MIXEDWOODS, Canadian journal of forest research, 27(9), 1997, pp. 1452-1457
First-summer establishment and overwinter survival of planted and seed
ed white spruce (Picea glauca (Moench) Voss) germinants were assessed
in five microsites in the understory of trembling aspen (Populus tremu
loides Michx.) dominated boreal mixedwood stands. Mineral soil mounds,
rotten logs, large exposed patches of mineral soil, normal LFH forest
floor, and small screefed patches of mineral soil were examined. The
mounds and rotten logs had the highest soil temperature, lowest soil s
trength, and accumulated the least amount of deciduous leaf litter whe
reas the small screefs were at the other extreme. First-summer establi
shment of planted seedlings was greatest on the rotten logs, mounds, a
nd large exposed patches; the large exposed patches had the highest es
tablishment of seeded trees. Over 85% of the planted seedlings that we
re in good condition in September survived the winter. Overwinter surv
ival of seeded trees was least on small screefed patches, but survival
of these trees was increased by covering them with small plastic cups
. Low soil temperature, high seedbed strength, and high vegetation cov
er were associated with reduced seedling establishment whereas high li
tter accumulation was associated with reduced overwinter survival.