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Coarse Woody Debris Missouri Ozark Forest Ecosystem Project. Randy G. Jensen Stephen R. Shifley Brian L. Brookshire David R. Larsen Laura A. Herbeck. Wildlife habitat Birds.......... 36 Species Mammals... 11 Species Reptiles........ 8 Species Nutrient cycling
Missouri Ozark Forest Ecosystem Project
Randy G. Jensen
Stephen R. Shifley
Brian L. Brookshire
David R. Larsen
Laura A. Herbeck
0.5 acre plots
70+ per site; 648 total
(Snags, DDW% cover)
0.25 acre plots
11 per site, overlaid
(all DDW characteristics)
No pre-treatment effects
Mean = 241
Gradual increase in the amount of dead wood
Perhaps double the current volume
Harvested Stands (EAM or UAM)
Dramatic increase in the amount of down wood
Regeneration harvesting (substantial)
Because boles are removed increase % cover faster than volume
Down wood should increase on all sites
Snags eventually become down wood
Short term increase in snags = long term increase in down woodAnticipated Treatment Effects: Down Wood
Snags (standing dead trees) are closely linked to CWD because snags ultimately add to the pool of CWD.
CWD was inventoried in 1990-1991, 1994-1995 and 1999-2000 (post-treatment) using line transects .
Total combined length of transects was 27.75 miles of which about 1 mile of transect (total) passed through clearcuts. The 8,855 pieces of measured down wood covered about 1 mile of transect length or roughly 3.6 percent of the ground area (all MOFEP sites combined).Key Findings (1)
Prior to the 1997 harvest treatments there were no significant differences among treatment groups . The volume and percent coverage of CWD approximately doubled before and after harvest treatments, even on the control plots.
Prior to harvest treatments, snags comprised about 5 sq.ft. basal area/ac with roughly 1 snag for every 10 to 12 live trees by dbh class.Key Findings (2)
Little is known about rates of decomposition for snags and down wood.
Periodic harvesting, particularly uneven-aged management with periodic thinning treatments, may eliminate trees that are prone to die and thus over time reduce the number of snags relative to untreated stands.Future Research (1)
The Forest Service Forest Inventory and Analysis (FIA) program is now collecting CWD data on a small proportion of plots as part of their on-going state-wide inventories. The FIA CWD sampling is just beginning, and results from the periodic MOFEP CWD inventories can serve as a reference point from which to evaluate the early FIA results.Future Research (2)
(Jenkins and Parker)
No change in ratio of snags to live trees.
Modest increase in mean snag size.
Thinning (EAM or UAM)
Reduce number of snags in long run.
Girdling nonmerchantable stems will increase snags in the short run.
Regeneration harvesting (EAM or UAM)
Felling snags during harvesting will greatly decrease snags...BUT
Girdling nonmerchantable stems could greatly increase snags in short term
Any harvesting will alter the ratio of snags to live treesAnticipated Treatment Effects: Snags
Blocking probably not very helpful in grouping treatment areas for these characteristics.
Too bad, but not a big deal.
Dead wood flows from overstory to understory.
Snags and down wood volumes vary with stand age/condition
Management allows opportunity to control rates of snag accumulation and movement of wood from overstory to forest floor.Conclusions
Felling nonmerchantable stems will decrease the number of snags and increase the relative amount of down wood on the forest floor.
Girdling nonmerchantable stems will increase snags and delay input of some down wood.
Any harvesting will alter the ratio of snags to live trees.Prognostications
Surface Area (sq.ft/ac)
Ground covered (%)
Snag Basal Area (sq.ft/ac)
Big Spring (30)
Snag Ratio (%)
Down Wood Volume (cu.ft/ac)
Snags per Acre