 |
| Birch Family: Betulaceae |
Flowers in Catkins
Fruit in Nutlets or nuts
 |
| Genus: Betula Birches |
Of the seven tree species 3 are important.
 |
| Betula papyrifera Paper Birch |
Paper Birch Common names: Canoe Birch, Silver Birch, White Birch
 |
| Paper Birch Range: Trans-continental almost to the northern timberline. |
Paper Birch is a cold climate species, found at all elevations in their northern range.
Survives under varied precipitation.
Likes dry sites on glacial tills - but in Northern Minn. they thrive in the poorly drained soil.
 |
| The Operator |
The Company They (the paper Birch) Keep
- Jack Pine
- Aspen/Poplar
- Balsam Fir
- White Spruce
- Black Spruce
The Life of Betula papyrifera:
Seed dispersal by wind begins about age 15 during August into September. Seed production peeks from age 40 to age 70 years..
A study done in the state of Mass. U.S.A. in 1955 counted 36 million seed per acre. They were using one-chain wide strips cut in the 70 year old birch stand. From that , 36,000 seedlings per acre, became established, growing three to four inches the first year. Compare this to sprouts that grow up to 2 feet the first year. But sprouts have a high mortality rate.
Seed Size ? 1.5 million to the pound.
 |
| Diameter growth hinges more on temperature changes than rainfall. |
Paper Birch can be propagated by cuttings treated with a growth promoter.
These trees mature at 60 to 70 years - that makes them a short lived species?
Some reach 140 years and a few go over the 200 year life.
 |
| 50.2 cm. |
On the OMNR Web Site - Ontario's Tree Atlas - White Birch - the oldest white birch tree in Ontario is recorded in Rainbow Falls Provincial Park as a living , 240 year old birch with a possible diameter of 35 cm. As you can see this birch log in our firewood pile has a Red-Heart stain of 25 cm in a maybe not-so-round diameter of 50.2 cm. I don't think they really looked that hard for a big birch.
 |
| The truck bed is swept of debris. A good stand of birch can run 31 cords to the acre in 50 years. |
From LOG BOOK January 1950 page 4
"Woods Used in Northwestern Ontario Pulp and Paper Industry"
By : Alex Johnson, Pulp Mill Superintendent, Provincial Paper Mill,
Port Arthur, Ontario
"Pulp making separates the tree fibres so they can be reformed into a sheet of paper."
Birch was not used extensively in the past (before 1950) but now more and more is being used for that.
There is a large quantity of it available (1950).
It can be peeled by hand (springtime) or in the drum barkers.
It being a heavier wood = great yield per cord. Oven dry weight = 31 pounds per cubic foot being one third heavier than poplar.
Fibre length = 1.2mm 20% greater than poplar and half as long as spruce. This makes birch "one of the more desirable hardwoods for pulpmaking."
 |
| All set to go home. |
SUFFERING BIRCH
Paper Birch need 'space" to grow and suffer from competition, however 'thinning' doesn't seem to help birch put on growth rate as that process does other species. In natural succession it usually is replaced after one generation by another species. It's part of our "climax" forest of White Spruce and Balsam Fir.
POST LOGGING DECADENCE
When stands are opened up they develop lowered vigor, reduced growth, dying back of twigs and branches followed usually by the death of the tree. (One sees this happen all the time as new country homes landscape to keep their beautiful birch only to have them die within a few years.)
BIRCH DIE BACK
"What's wrong with your birch?"
A visitor to the Nipigon Museum (from Virginia) asked.
Birch die back has nearly the same symptoms as logging decadence .
The tree seems to die from the top down.
However, it can occur in undisturbed stands - so declaring the Boreal Forest off-limits to Industrial activity wouldn't save them.
In the 1930's and 40's an outbreak of birch die back in Eastern Canada and Maine took down almost 70% of the birch trees by 1951.
NO KNOWN DEFINITE CAUSE HAS BEEN IDENTIFIED TO DATE.
While checking out the Internet I found reference to an article "Potential Role of Calcium...reversing die back, but I couldn't get the Site to open. I really wanted that one because when we were mixing cement for our house foundation in 1975, we did it next to a birch clump with die back advancing on the main stem. Lots of 'cement water" flowed around the mixer every day we rinsed it out. The next year that tree took on new life and never looked back. A few years later it did get Bronze birch borer but continued to grow even with its speckled leaves until we had a winter of minus 30 to 40 degrees in January and February - that was the end of the borer and the tree had healthy green leaves from then on.
ROOTLET MORTALITY
Similar symptom to die back ( I can attest to this as I accidentally chopped off a root of the above Birch clump - like twenty feet away from its base. One can't stick a root back together. So I watched as the next few years, one stem lost first one limb and then another until we had to cut that stem off for safety reasons.) Rootlet mortality can come from increased soil temperature - so now we add Climate Change into the mix.
FIRE
Fire is both a killer and a regenerator as it opens areas for airborne seeds to land and germinate.
ANIMALS
Mice, voles, chipmunks, squirrels, rabbits, Porcupine, beaver, deer, moose
SONGBIRDS (not really destructive)
Black capped Chickadee, purple Finch, Common Red poll, Yellow bellied Sapsucker, Pine Sisken, Fox Sparrow, Tree Sparrow, Ruffed Grouse, Spruce Hen, Sharp tailed Grouse.
INSECTS
Luna Moth caterpillar food. Gypsy Moth and the Forest Tent Caterpillar Malucasoma disstria, or as we like to call them Army Worms - march, munch or die. After three years of continued attacks growth falls 86%.
Bronze Birch Borer Agrilis anxius, comes right along after die back or logging decadence sets in - its an insect that infests weakened trees. Not the cause of die back it may aid in the tree's death.
MAN
Besides the obvious tree cutting - stripping the bark from live trees will kill it.
 |
| Red Heart is a reddish-brown discolouration. This defect limits the use of Paper Birch for speciality products. It's wetter and more extensive than heartwood. Cause believed to be a parasite. |
John McLaughlin, OMNR, OFRI, - "White Birch is one of the least defective species averaging less than 5% of 100 year old merchantable volume."
Red Heart is a stain from reaction to enzymes released by non-decay fungi coming in through wounds.
Those of you who followed Walt Kelly's "Pogo" in the 1950's, may remember Albert, the Alligator's impersonation of a dog:
"Birch! Birch!" said Albert, it was the only bark he knew.
A lot of this information comes from 'Silvics of Forest Trees of the United States Agriculture Handbook, No. 271" Forest Service 1965 U.S. Dept. pf Agriculture, Washington D.C. 20250 Pages 93 to 97.
Prepared by the Division of Timber Management Research, Forest Service
Complied and revised by H.A. Fowells, Chief, Branch of Silviculture
Completed by Carl E. Ostrom
Started in 1955 by Division Director F.H. Eyre from information supplied by 10 regional Forest Experiment Stations equalling 127 reports.
Range maps by E. L. Little, Jr. , Forest Service Dendrologist.
No comments:
Post a Comment