Frost and Sap Yield

[Zucker Lager]

In our area we get 3 to 5 feet of frost, some construction guys I talked to say they have seen it 8 feet deep!!! holy smokes. So a percentage of a trees root ball is in frost. Sap that is taken up by lower growing roots would have to pass through this area to the trunk. So my question is does that effect sap flow? Jay

[Bgreisch]

I can't respond to the how this affects the sap flow. But if there is snow on the ground before it gets to cold frost will not be that deep. You might see frost in a road like 8 feet deep in a cold winter but usually if there is snow that helps insulate the ground from the frost going too deep. At work we inspected a sewer project thru a field this winter and there was only a foot of frost under the snow in SE Wisconsin.

I tapped last weekend in the Merrill area hoping there was some flow this week will find out tonight.

3rd year tapping- 25 taps

[Jeff E]

I am curious how others respond to this. Last year I had north facing slopes that never really produced sap, as that frost was in until May.
We do have deep frost in NW Wisc now. On Monday the Spooner Ag research station measured at there test location, and the frost was 44 inches.

We had only a couple of inches of snow when we had minus 32 weather for several days, weeks of below zero temps.

I am a bit pessimistic about this season. But you never now. We have made a lot of sap in April in the past!

Seems like the biggest sap days are when frost is out, it gets to 45 during the day, and upper 20's at night.

[DrTimPerkins]

Dozens of research studies have shown that forest soils seldom freeze more than a few inches deep. The litter layer insulates the soil. Tree crowns provide some protection from radiative cooling. When there is snow on the ground there is a good bit of insulation. I can only assume the Spooner Ag Res Station is measuring soil temperature in tilled soils, which are quite different from forest soils.

This matter has been discussed before if you're interested. http://mapletrader.com/community/showthread.php?32632-Frozen-ground-and-sap-flow.&highlight=soil+freezing

[Zucker Lager]

This matter has been discussed before if you're interested. http://mapletrader.com/community/showthread.php?32632-Frozen-ground-and-sap-flow.&highlight=soil+freezing[/QUOTE]

Thanks Dr. Tim guess I didn't look hard enough. Lots of good info. We have some trees in both types of settings that you describe, dense woods and open areas some right next to traveled logging roads so it will be something I'll keep in mind when I collect to see how it differs. Thanks Jay