In the fall of 1984, we randomly sampled and weighed the slash on W5 in order to be able to estimate the amount of biomass and nutrients remaining on the ground following clear cutting and to correct for the amount of aboveground biomass not removed in the clearing.

        1. Data summary
        2. Methods
        3. Plot by plot data summary

1. Data summary

2. Methods

        The sampling scheme was a modification of that used by Louise Tritton and Wayne Martin to study slash in the Cockaponsett State forest in Connecticut.  We chose 33 25 x 25 m grid units, 11 per watershed third, for sampling. On each plot we sampled slash in a 10 x 10 m corner as follows.  All slash > 10 cm in diameter was collected and weighed, using a tripod and scale. In each of the four corners of the 10 x 10 m plot, slash 2 to 10 cm diameter was sampled in a 2 x 2 m plot.  Slash < 2 cm diameter was sampled in a 1 x 1 m plot in the corner of each of the 2 x 2 m plots.  Weights in the field book were recorded in pounds, which is noted specifically throughout.

        The 10 x 10 m plot was located in the NW corner of the larger 25 x 25 m watershed grid unit, unless that was not feasible due to the presence of a stream, or to the proximity of someone else's plot. In such cases, it was moved to the NE corner, and a notation made in the field book.

        Subsamples of each size class were taken. An effort was made to collect samples to include one of each of the species represented in the overall sample, though the sample was not necessarily representative by weight proportion. These samples were placed in plastic bags, labeled, and then weighed at the end of the day.  Once back in the lab, the samples were weighed, then dried at 60 degrees C, and weighed again, for wet to dry weight conversion.  The samples (from the first 19 plots) are now stored in Tom Siccama's lab in New Haven, CT in two large plastic bags.

Notes:

        The criterion for calling wood "slash", as opposed to wood that was presumed dead before the clear cut, was that it must appear "alive" (i.e., the bark is relatively intact, the wood relatively unweathered and undecomposed).  Sometimes the bark was not exactly intact, but had obviously been scraped off by machinery or other trees being dragged over it.  We picked up even tiny pieces on the 1 x 1 m plot, including chips, with some minimum size around 1/4 the diameter of a pencil.

        On logging roads we tried to pick up anything sticking out of the mud, without digging down in the mud to find other woody debris.  It was difficult to make a dead/alive decision on these pieces because they were all very dirty and mostly bark-less, so we categorized most of it as slash. This is probably fairly accurate because anything in the road was most likely deposited during the cut.

        Pieces of slash that crossed the plot boundary were cut off where they left the plot.  Pieces that became smaller than the specified diameter for the size class being collected were cut off where they left the appropriate size class.

3. Plot by plot data summary

Web page created June 2000
by Thomas Siccama and Ellen Denny