Tuesday, March 08, 2005

Saga of the spruce

The great spruce was part of a grove of towering spruce, white pine and balsam fir that was an important part of our initial attraction to this forty acres of land. The trees were most likely around at the end of the 19th century, a remnant of the great pine forests that once covered this area. The young trees stood next to a small bog, between the main line of the St. Croix Logging Railroad and a small siding. This railroad, used to transport logs to the St. Croix River, where they were floated downstream to mills in Stillwater, was only used for a few years in the 1890's. The grades of these railroads are still visible today and we keep the siding cleared as a trail.

A 1939 aerial photo shows these trees surrounded by open pasture land. Towards the road, a sand and gravel pit is visible, mining the riverine soils deposited by a glacial outwash stream at the end of the last Ice Age. This stream was probably the precursor to Sand Creek. Today one of the best of a limited number of brook trout streams in the area, Sand Creek was ditched and straightened in 1918 or 1919, possibly in an effort to drain swamps for agricultural use.

The great spruce was spared the ravages of the 1894 Hinckley fire, which burned out several miles to the south and west, and the 1918 Moose Lake fire, which reached its limit to the north.

The great spruce was showing signs of aging when we first saw it. Lichens covered much of the trunk and branches. Many of the lower branches were already dead; these were cut close to the trunk to clear space next to the cabin we were building. The remaining knobs, up to a foot or so in length, continue to serve as footholds for adventurous tree climbers.

The fate of the spruce was sealed in 2001 when a strong burst of wind during a thunderstorm knocked the top off about 25 feet up. At this point the trunk was still about 20 inches in diameter; fortunately it did not fall on the cabin. The spruce gradually succumbed to the loss of its main energy-collecting branches.

We were in no hurry to remove the remains of the giant spruce. Branches were cleared, the fallen upper trunk was rolled to the edge of the woods where it remains now, but we marvel as the great spruce in its death continues to give life. Wood boring insects audibly gnaw the layer just below the bark, providing food for woodpeckers. I saw my first ever black backed woodpecker foraging on the spruce; this species is uncommon around here, being a boreal forest native. The canopy of branches, devoid of needles, still provides perches for chickadees, redpolls, pine grosbeaks, goldfinches, and others as they visit our bird feeder just below. And to a six month old kitten, the spruce provides a jungle gym of entertainment. I watched, laughing, the other day as the apparently fearless feline climbed up 25 feet to where the upper trunk broke off. It ventured out to the edges of branches 2 inches in diameter. Finally it crawled back to the main trunk where my son "rescued" it. Back inside, the kitten smelled wonderful. I breathed in its fur the scent of old wood, dried resin, and bark, the gifts to a new generation of life in the endless circle.

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