The Long Term Soil Productivity (LTSP) experiment is a U.S. Forest Service led effort to test the effects that organic matter removal, soil compaction, and competition control have forest soil productivity, as measured by tree growth. A replicated experiment was installed on the Croatan National Forest, NC, in winter 1991 and loblolly pine (Pinus taeda
L.) seedlings were planted there in early spring 1992. Experimental treatments included three levels of organic matter removal: stem-only; whole tree; and whole tree plus all forest floor, in combination with three levels of compaction: none; moderate; and severe. Plots were split for competition control treatments. Previous analyses, using all live trees in the measurements plots, indicated that competition control was the sole significant treatment effect on tree height for the first 14 years of this study. In this analysis we used height growth for the 10 trees in each plot identified as dominant or co-dominant. Both organic matter removal and soil compaction treatments have had a significant effect on height growth of dominant and co-dominant trees, suggesting that site preparation may affect merchantable timber production.
Eaton, Robert; Smith, William; Ludovici, Kim. 2010. Growth response of dominant and co-dominant loblolly pines to organic matter removal, soil compaction, and competition control. In: Stanturf, John A., ed. 2010. Proceedings of the 14th biennial southern silvicultural research conference. Gen. Tech. Rep. SRS 121. Asheville, NC: U.S. Department of Agriculture, Forest Service, Southern Research Station. 531-533.