Site Discussions

We have one just outside of Green Bay Wisconsin! We had a couple of weeks recently with temps well below Zero day and night, yet here it is, three times in the past two weeks. I occasionally toss a little bit of dry cat food under the bird feeder to help it out.

I’ve lived in the same home for 20 years and have always entertained gray squirrels.  Last year we had a red squirrel show up and then the problems started.  As your article suggests; the much smaller red squirrel is the aggressor!  Amazing.  He also feeds at different times than the gray squirrels which I think it must prefer.

Hi,we were just watching these pretty birds this morning around our bird feeder.(its Feb.12/2019)We didn’t see them since summer and started to wonder, where they suddenly came from? So I decided to learn more about them and came to your interesting article. Thank you so much, I am sitting here saying..wow and we will definitely look at these birds differently.

Great article.  I plan to have the boundaries of my residential property surveyed so that I can be sure that a retaining wall that I plan to rebuild is on my property.  How can I be sure that the surveyor was accurate?  Is there some warranty or insurance that comes with a survey?  Thanks.

I have a 45’ tree that leans “almost ” correctly.  If I cut it the way it leans the top 15’ will hit the fence. I need it to land 3’ farther to the right . Should I make a partial back cut and put a wedge in the left side then finish the cut to make it fall to the right?

(Posted for Joe:)

I just tapped red and sugar maple trees at the same time using the same type of tap kit.  They are at different locations.  The sugar maples have produced a few gallons of sap in less than a week yet the red maples have produced nothing.  This is with a few days of early sugaring.  The red maples have less sunlight than the sugar maples and are smaller.  The red maples are big enough to tap.  Why haven’t they produced sap?

I too was struck by some of the statements made by Brave Little State in their program “The Pros and Cons of Heating with Wood”, particularly in their carbon calculations.  Here is some recent research to consider:

At a Mohawk Trail Woodlands Partnership meeting in October, UMass researcher Paul Catanzaro presented results of a study he did with Anthony Amato from UVM on the Impact of Forest Management on Carbon.  By reviewing Forest Cutting permits in Massachusetts, they found that most harvesting here is partial cutting, removing about 4Mbf/acre or about 13 metric tons of carbon/acre, cutting roughly 1/3 of the trees at a time.  A typical harvest reduces the net carbon storage/acre by about 17 percent, 10 metric tons/acre from the harvested timber, and another 3 tons from disturbing the duff.  Below surface carbon appears not to change much if BMPs are followed to protect soils from erosion.  By their calculations, the carbon removed in partial harvesting is replaced by new growth primarily of existing trees in about 9 years (at a rate of 1.5 metric/tons per acre per year).  A shelterwood harvest that cuts 2/3s of the net volume would reduce total stored carbon by about 30 percent and would take about 15 years to replace the stored carbon.

This contrasts sharply with the 60 to 100 year carbon replacement scenario cited in the broadcast.  That scenario seemed to be based on the idea that if you cut down a sizable tree, it will take 60 to 100 years for an equal sized tree to grow to replace it.  While that might be true for an isolated tree in the open, it doesn’t reflect actual forest growth.  With the partial cutting common here, the trees uncut use the increased sunlight to grow faster and replace carbon much faster.  Added growth absorbs more carbon than new trees would initially.

Another carbon study was done recently by Mass Wildlife on clearcuts they did to create early successional habitats for wildlife.  The study reportedly that net carbon on the clearcuts was within 2 percent of the total before harvesting after just 6 years regrowth.  Whoa – how can that be?  I thought. There’s no way the trees could have regrown that fast.

I thought about that last weekend when I skied in a family woodlot where we had a seed tree harvest to regenerate an ice damaged stand 4 years ago.  In the snow, the bare new trees seem pretty small and puny compared to the seed trees that tower above them.  There’s no way those sprouts and saplings can hold anywhere near the volume of carbon as the trees that were cut did, even if there are thousands per acre.  Seems obvious, right?  There might be a lot of carbon in the rotting tops that we haven’t cleaned up that are slowly tuning to duff, but that wouldn’t replace all the wood taken out.

But as I whacked around, I suddenly realized that we often spend too much time looking at the trees and overlook the vegetation.  While the new trees in our woods range from 1 foot to 8 feet tall, the forest floor is densely covered by an nearly impenetrable mass of low woody vegetation: blackberries, raspberries, hobble bush, striped maple, fire cherry, which rises to 6 foot high or more in many areas, way more was there before the harvest. It all stores carbon, not permanently, of course, but for that period until the new trees grow tall enough in 5 or 6 years to close their crowns and shade it out.  As the undergrowth dies back, that carbon will then be released and taken up by the fast growing trees.

So carbon storage in a regrowing forest may initially be more horizontal in the brush layer than vertical in the trees we normally measure it in.  Calculating the carbon just in the new trees doesn’t really show us the whole picture.

That insight got me thinking about another part of the broadcast which talked about concerns about particulate emissions from wood burning.  We all know that wood burning, while much more environmentally sustainable than burning fossil fuels, can produce high levels of Pm25 emissions which can pose health issues.  Whenever anyone reloads their stove or furnace, they produce considerable smoke until the combustion gets going. Why, anyone can see that wood burning seems to produce more emissions that fossil fuels.

Or does it?  Some information from an recent study about wood pellet boiler emissions by the UMass Department of Environmental Health Sciences might make you start to rethink that assumption.  Using a state grant, EHS Professor Rick Peltier and his students equipped a van with emissions monitoring equipment and took it around to gather weeks of emissions data at six locations downwind from modern pellet boiler installations.  Because wood burning emissions differ chemically from those from fossil fuels, they could measure which emissions came from pellets and which from nearby fossil fuel systems .

The first finding from their research was that all the pellet boiler installations have very low Pm25 emissions, in most cases much lower than the EPA limits. This shouldn’t be a surprise as the pellet boilers are specifically engineered to burn cleanly with low emissions.  What was surprising, on the other hand, was their finding that the pellet Pm25 emissions were often much less than the Pm25 emissions from neighboring oil-fired systems.  In one example where a pellet boiler heated part of a town building complex and oil boilers heated the rest, the Pm25 oil emissions were so high that a simple way to improve air quality might be to just switch the other buildings over to pellet heat.

It turns out that just because we don’t see obvious smoke when fossil fuel systems fire, that doesn’t mean that they are burning cleanly, particularly as those systems age.  Conversely, while emissions are more visible with wood heating systems,  a lot of what we see may be steam, not particulates.  In the case described in the broadcast where Goddard College installed a central wood-fired heating plant and distribution system to replace 20 oil-fired boilers in individual buildings, the particulate emissions from the modern wood system may turn out to be less than the less visible emissions from the 20 old oil-fired units.

We have a newly-cleared property and just figured out who these guys were. Ours are large, which is why it took me a few tries to identify them. I was overestimating their size on the bird ID. sites. They are bold and seem to look you right in the eye.

Dave -  I read the Petrenko and Friedland paper you referred me to.  I am an engineer by trade and spend much time in test pits analyzing soil.  I also spend at least as much time managing my sugar woods.  All I can say is that the paper is mighty thin gruel to base energy policy on.  It is a limited sampling on one particular not overly common soil type. 

The authors actually state that their results are not statistically significant.  They focus solely on the carbon contained in about 2 feet of soil immediately below the organic soil layer.  They did not even include the carbon in the root fragments within this band.  They sifted them out and threw them away.  They did not look at what went on below this layer.  They certainly did not look at the carbon in the biomass growing in the forest itself.  They made a tacit assumption that the depth of the organic layer itself did not change over time.  In short, they didn’t account for most of the carbon stored in the system they are studying.

The paper is a fine academic exercise, but it is in no way useful in establishing forest/energy policy.  It is way too limited in scope.

We have a small woodlot, 163 acres, and all of our firewood comes off our land, always as a side benefit of doing a selective timber cut, prescribed by our forester, or in onesies and twosies that have fallen down on their own. We’ve also done some patch cuts, 2- or 3-acre clearcuts for wildlife habitat management, leaving dead trees and large slash and trunks in place, and these have dramatically increased, among other things, the number of songbirds on the land. (This certainly benefits “the environment,” irrespective of its effect on carbon storage.)

The selective cuts leave the forest as a whole essentially unchanged, preserving or enhancing the age diversity in the original stand, while releasing healthier stems that promise to be commercially valuable in the future. Every cut also produces several semi loads of chips for one of the regional biomass power plants. The soil is deeply affected only on the skidder trails, most of which were there already.

We burn about six cords a year. Somehow I just cannot believe that the way we have managed our woodlot does not promote carbon storage in the forest to at least the tune of six cords per year. And I expect that a significant proportion of the firewood burned here in Vermont is produced in the same way.

Carbon accounting in forest management is a tricky business, partly because the science is still being explored and partly because, as Mr. Mance points out, wood is used in so many different ways. So I don’t think one can really make a broad statement about whether burning firewood is renewable in the carbon storage sense or not. The devil is in the details. This was part of the message, I think, in the Brave Little State podcast—which was provocative, and that’s a good thing. But I don’t think, all-in-all, that it treated the subject of carbon storage with the sophistication it requires.

We have two come for the cat food. They sleep under the summer house. We’ve had single digit weather and I’m very concerned. I have not seen them in days. I’m hoping to see them soon.

Thanks for your discussion. I like your title “again.” We just have to keep calling out the bad information going round and round. In their effort to be fair I think VPR/BLS gave a littler too much respect to some false equivalencies. We cover carbon, particulates, and how working forests protect against permanent loss to development in our follow-on podcast: https://www.sustainableheating.org/podcast-the-pros-and-cons-of-heating-with-wood/

Thank you so much for this very informative article.  We look forward to hosting many more butterflies this year, as we are continuing to expand our Monarch Way Station,  planting more common and swamp milkweed, and have planted several species specific native plants to attract the butterflies.
Bj Plant and Randall Balog, Sr.

Burning wood is a great example of how the perfect can be the enemy of the good. Some carbon is released, as is true with every form of energy production. But the benefits - biological, economic, social aesthetic - are profound. Thanks, Dave, for giving us such a thoughtful assessment.

Great article! When science and the use of statistics get distorted to support any agenda then we are cheated out of finding a true answer to the problem in question.

I am a retired owner of a forest products company and was taught in forestry school that science should be pure because opinion is not.

Thanks Dave. So pleased we still have intelligence to challenge academia.

The thing that breaks my heart about all this is, having lived with oil heat and wood heat, I would give an appendage to be able to go back to pushing a button and having the house warm. I hate heating with wood. It’s dirty, exhausting, body-straining, creates complex storage problems, and gives me six months of sinusitis. Yeah, the science indicates that burning wood is better than fossil fuels. I’m not going to argue with that. I just think it’s a tragedy that humankind spent so many generations trying to come up with a better way to create warmth and power, only to find it has a long-term negative effect on a global scale. What a BUMMER!

Mr. Mance,

Thank you for a thoughtful response that leaves the door open for further learning and discussion.  Wouldn’t it be nice if that happened more often?

I wish to point out one thing: With regard to carbon dioxide, I’m not sure that burning wood is always better than burning coal, gas, and oil if that wood is being burned to produce power.  The original VPR piece was about heating with wood, so I suspect that’s what you had in mind.  The distinction between heat and power is important given that heating with wood is 3 times more efficient than making power with wood. From purely a carbon standpoint, the news about biomass power often bleeds into biomass heating to negative effect even though the two are very different uses of wood.

Thanks for hearing me out.

Well said, Dave. Especially the point comparing wood harvesting to fossil fuel extraction which always results in adding more carbon to the equation that could have remained locked up.

An old growth forest actually has less carbon-consuming capability than, for example, a recently clear cut forest. Research shows that stomata densities ( where CO2 enters the leaf to be converted to carbohydrate during photosynthesis) are much higher in a dense stand of new growth following a clearcut than in an old growth forest.