More info for the terms:
cover,
density,
fire severity,
forest,
organic soils,
severity,
wildfire,
woodlandTealeaf willow is common on recent burns in lowland black spruce
forests in interior Alaska. One 11-year-old burn had about 4,700
tealeaf, Alaska, and grayleaf willow stems per acre (11,600/ha), and
lesser amounts of spruce and poplar [
37]. Sampling numerous burns in
lowland black spruce types in interior Alaska, Foote [
12] observed that
tealeaf willow averaged 295 stems per acre (728/ha) on 1- to
5-year-old burns, and 771 stems per acre (1,905/ha) on 5- to 30-year-old
burns. Its density probably increases or remains constant for up to 30
years after a forest fire, but thereafter declines as young trees
overtop it [
12].
Since tealeaf willow seeds are dispersed in the summer and remain
viable for only about one week, the season of a fire determines if it
will establish during the first or subsequent postfire years [
30,
36].
Fire severity affects the mode of tealeaf willow postfire recovery.
Following light fires it recovers quickly, sending up new shoots from
undamaged root crowns. Few if any seedlings establish following this
type of burn because organic soil layers, which prevent seedling
establishment, are only partially consumed [
32]. Following severe
fires, however, the primary mode of recovery is seedling establishment.
Severe fires that burn deep into organic soils kill willows but expose
mineral soils, which provide excellent seedbeds. Nine years after a
wildfire in a black spruce woodland in interior Alaska, tealeaf
willow cover reached 24 percent on scarified firelines within the burn,
due to rapid seedling establishment. In the main burn the 6-to
8-inch-thick (15-20 cm) organic layer was only partially burned. Here,
tealeaf willow reestablished by sprouting, and cover after 9 years
was only 3 percent [
32]. Cover in nearby unburned areas was 2 percent.