Early Birch (Betula neoalaskana) Sap

Observation: We have been collecting sap for three years from our birch trees. Really just beginning our almanac on this topic. We are at an elevation of about 1000' feet in South Anchorage. Usually we start getting sap about April 19th. This year we had sap on April 9th! I wonder if the trend will continue and about the observations from other tree tappers. Also whether green up will align as also being early.

I wrote to long time birch tapper Tom Nighswander who has his set up at a located at lower elevation in East Anchorage. Tom wrote: "I started a full two weeks earlier on April 1 and could have started earlier. The word from the Valley is that they had to catch up because they were caught off guard by the early warm weather and these are commercial operations. I have been tapping trees since 1979."