Warm temperatures drive emergence of early willow buds, pollen and honey bee activity.
Observation: Beekeepers keep track of early season pollen sources. Willows are of particular interest since their pollen provides a high quality protein that bees utilize during brood rearing. There were reports of willow trees shedding pollen as early as March 13th in the Palmer area this year. The image attached was taken on the morning of March 23th, in Potter Valley (south side of Anchorage) at elevation 1000'. Bees were observed ferrying pollen to an overwintered hive that same afternoon; a good sign indicating that an actively laying queen had made it through the winter.
The Environmental Health Services from the Municipality of Anchorage tracks pollen levels. Here is an Annual Pollen Counts starting in 2010-2015. A table showing pollen seasons is available from Aurametrix. It is interesting data suggesting that our willow pollen is very early this year.
LEO says: According to Aurametrix, "Alaska's Aerobiology is similar to Northern Europe, with some tree patterns resembling northern states of US. Pollination of poplar - food for honey bees - starts in April - as in Michigan. Birch is very high in May - as in Russia and Scandinavia. Grass is active in June and July. A core pollen season of prophylactic and clinical urgency in Fairbanks and Anchorage is defined from May 10 to June 5."