Each of the nine MOFEP study sites was randomly assigned to even-aged treatment, uneven-aged treatment or control (i.e., no trees were cut), resulting in a randomized complete block design. Treatments were designed to mimic forest management practices commonly administered by the Missouri Department of Conservation. In the even-aged treatment, approximately 10 to 15% of the total forest area was clearcut. Forest thinning was conducted at the same time as clearcutting to increase growing space for residual trees. In the uneven-aged treatment, foresters used small-group and single-tree selection cuts. In both even-aged and uneven-aged sites, a patch of approximately 10% of each site was permanently designated as a reserve and left uncut.
The Missouri Department of Conservation harvested the treatment sites from May 1996 to May 1997. In even-aged sites, clearcuts were 3-13 ha in size, resulting in seven to nine clearcut stands per even-aged site. In addition, foresters thinned 5 to 24% of each site to promote tree growth of selected sizes. A total of 68 to 121 ha were harvested on even-aged sites, resulting in harvested tree volume of 1.8 to 2.2 103 m3 per site. The goal of even-aged management was to create a specific distribution of tree size classes in study sites: 10% in regeneration, 20% in small trees (trees 6-14 cm diameter at breast height [dbh]), 30% in poletimber (14-29 cm dbh), and 40% in sawtimber (>29 cm dbh).
In uneven-aged sites, foresters harvested trees from a combination of
small-group and single-tree selection cuts across an average of 57% of
each site. Small-group cuts ranged from 21 to 43 m in diameter, depending
on aspect. Five percent of the harvested area per uneven-aged site
was treated with small-group cuts (153-267 small-group cuts per site).
Foresters used single-tree selection cuts to obtain a balance of size classes
with 1.5 times more small trees than large trees in the next size class.
During the harvest, foresters cut an estimated 9300 to 25800 trees per
uneven-aged site. The combination of small-group and single-tree
selection cuts yielded a tree volume of 2.2 to 3.2 103 m3 per
site (Kabrick et al. 2002). Thus, in even-aged sites, foresters harvested
15 - 34% of the forest area and large blocks of cut or thinned forest were
interspersed in a matrix of uncut forest. For uneven-aged sites,
harvesting occurred in 41-69% of each site and small areas of cut or thinned
forest were scattered throughout uncut forest.
Gram, W. K., V. L. Sork, R. J. Marquis, R. B. Renken, R. L. Clawson, J. Faaborg, D. K. Fantz, J. LeCorff, J. Lill and P. A. Porneluzi. 2001. Evaluating the effects of ecosystem management: a case study in a Missouri Ozark Forest. Ecological Applications 11(6): 1667-1679.
Gram, W.K., and V.L. Sork. 2001. Association between environmental and genetic heterogeneity in forest tree populations. Ecology 82(7): 2012-2021.
Gram, W. K. and V. L. Sork. 1999. Population density as a predictor of genetic variation for woody plant species. Conservation Biology 13(5): 1079-1087.
Gram, W. K., V. Sork, and R. Marquis. 1997. Synthesis and integration of pre-treatment results from the Missouri Ozark Forest Ecosystem Project (MOFEP). Pages 356-396 in B. L. Brookshire and S. R. Shifley, editors. Proceedings of the Missouri Ozark Forest Ecosystem Project symposium: an experimental approach to landscape research. General Technical Report NC-193, U.S. Department of Agriculture, Forest Service, North Central Forest Experiment Station, St. Paul, MN.
Shifley, Stephen R., and Brian L. Brookshire, editors. 2000. Missouri Ozark Forest Ecosystem Project site history, soils, landforms, woody and herbaceous vegetation, down wood, and inventory methods for the landscape experiment. General Technical Report NC-208. U.S. Department of Agriculture, Forest Service, North Central Forest Experiment Station, St. Paul, MN, 314 p.
Brookshire, Brian L., and Stephen R. Shifley, editors. 1997. Proceedings of the Missouri Ozark Forest Ecosystem Project symposium: an experimental approach to landscape research. General Technical Report NC-193. U.S. Department of Agriculture, Forest Service, North Central Forest Experiment Station, St. Paul, MN, 378 p.
Brookshire, B., and C. Hauser. 1993. The Missouri Forest Ecosystem Project. Pages 289-306 in A. R. Gillespie, G. R. Parker, P. E. Pope and G. Rink, editors. Proceedings of the 9th Central Hardwood Forest Conference. General Technical Report NC-161. U.S. Forest Service, North Central Forest Experiment Station, St. Paul, MN.
Kurzejeski, E. W., R. L. Clawson, R. B. Renken, S. L. Sheriff, L. D.
Vangilder, C. Hauser, and J. Faaborg. 1993. Experimental evaluation
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