Where There’s Smoke

by Carl Strang

Mid-November brought forest preserve district crews to St. James Farm to conduct controlled burns in the forest. These burns are a normal part of oak woodland ecology in northeastern Illinois, and they help control invasive plants. Occasionally the consequences of the burn extend beyond the brief time when the flames consume the dry leaf litter on the ground, and I noted two such incidents this time around.

Carpenter ants commonly hollow out the base of a tree as they tunnel through the dead wood at the core. If the accumulated sawdust catches a spark from the controlled burn, a slow growing smoldering coal can expand to the point where it consumes a significant amount of the remaining wood.

A victim of that phenomenon was the large white oak that harbored the great horned owl nest last winter.

A victim of that phenomenon was the large white oak that harbored the great horned owl nest last winter.

There had been a larger live stem, and a smaller dead stem (the fractured one in the photo) where the nest had been. The live stem’s base was thinned by the growing coal to the point where it went down, taking the nest stem with it.

The same burn had the remarkable effect of catching in another tree, already knocked down by a storm, which then smoldered for weeks.

Here is the tree 2.5 weeks after the burn, on December 5. The underside of the fallen stem was burning slowly from west to east, and the top of the stem protected the coal from the snowfall.

Here is the tree 2.5 weeks after the burn, on December 5. The underside of the fallen stem was burning slowly from west to east, and the top of the stem protected the coal from the snowfall.

Another heavier snowfall still did not stop the burn, here on December 12. This was a cold day, but a moderate west wind kept the coal alive.

Another heavier snowfall still did not stop the burn, here on December 12. This was a cold day, but a moderate west wind kept the coal alive.

At that point, however, the coal was no longer sheltered. When I returned on the 16th, I found the fire had gone out. It had lasted nearly a month.

 

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St. James Farm Autumn Update

by Carl Strang

This blog has been on hiatus while I work on my annual research summary documents, but I have been paying regular visits to St. James Farm Forest Preserve, the site I monitor and where I soon will begin as volunteer steward. Today’s entry shares some photos from recent weeks.

Winged euonymus adds color to the autumn scene, but is an invasive shrub that will need to be removed at some point.

Winged euonymus adds color to the autumn scene, but is an invasive shrub that will need to be removed at some point.

As leaves come off the trees, bird nests are revealed. This oriole nest had a significant content of synthetic fibers, including fishing line from the nearby ponds. The fuzzy white object hanging below the nest is a fishing lure, the hook not quite visible at this angle.

As leaves come off the trees, bird nests are revealed. This oriole nest had a significant content of synthetic fibers, including fishing line from the nearby ponds. The fuzzy white object hanging below the nest is a fishing lure, the hook not quite visible at this angle.

This silver-spotted skipper still was active on November 16.

This silver-spotted skipper still was active on November 16.

The opossum lay dead in the center of a trail, also on November 16. Cause of death was not evident.

The opossum lay dead in the center of a trail, also on November 16. Cause of death was not evident.

Late autumn migrants included this white-crowned sparrow youngster.

Late autumn migrants included this white-crowned sparrow youngster.

The most unusual stopover duck was a female pintail on the east pond.

The most unusual stopover duck was a female pintail on the east pond.

Another duck worth noting was this male. Accompanied by a female mallard, his huge size and her identity suggest that he may be a mallard-black duck hybrid.

Another duck worth noting was this male. Accompanied by a female mallard, his huge size and her identity suggest that he may be a mallard-black duck hybrid.

 

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