Loblolly pine and mixed hardwood stand dynamics for 27 years following chemical, mechanical, and manual site preparation

Abstract

A site-preparation study installed in 1959 in Fayette County, Alabama, U.S.A., provides data to evaluate long-term effects of varying densities of hardwood on loblolly pine (Pinustaeda L.) plantation growth, yield, and stand structure. Six treatments (hand girdle; bulldoze scarification; herbicide applied to axe frill, chain frill, and with an injector; and an untreated check) were installed as a randomized complete block with five replications. Periodic measurements of pine and hardwood size and density show that higher hardwood densities existing early in the pine plantation had a substantial negative effect on loblolly pine survival and basal area yield, with the bulldoze and herbicide treatments having less hardwood and higher survival and stand basal area. Pine total height and diameter at breast height were reduced by increasing hardwood density early in the life of the plantation, but size of surviving trees differed little among treatments at later ages, except on plots where most pine trees were suppressed by hardwoods. Strong relationships between pine basal area per hectare at age 27 and both number of hardwood stems at age 3 and percentage of stand basal area in hardwood at age 6 were noted. These relationships indicate promise for predicting long-term growth and yield of loblolly pine plantations from early measures of hardwood interference.

Effects of organic matter removal, soil compaction and vegetation control on 10th year biomass and foliar nutrition: LTSP continent-wide comparisons

“…Herbaceous competition is often severe initially but effects can diminish markedly with canopy closure and understory shading (Mason and Milne, 1999;Miller et al, 2003a,b). Larger woody competition often produces greater decreases in planted tree biomass as time proceeds, but effects on total stand biomass vary greatly, depending on site and time frame (Glover and Zutter, 1993;Miller et al, 1999Miller et al, , 2003aRose et al, 2006).…”

Plant community response to burning and herbicide site preparation in eastern Louisiana, USA

“…To meet increasing global wood supplies needs, forest managers are being asked to increase forest productivity, which often includes herbicide use as a key component during stand establishment (Glover and Zutter, 1993;Miller and Wigley, 2004;Wagner et al, 2004;Edwards et al, 2006). Use of herbicides in forestry applications occurs worldwide (e.g., Sullivan and Sullivan, 1990) and understory species response to silvicultural treatments is of interest to natural resource managers (e.g., Decocq et al, 2004;Lautenschlager and Sullivan, 2004;.…”

A biologically-consistent stand growth model for loblolly pine in the Piedmont physiographic region, USA

“…It is preferable, however, to use instead the proportion of pine by basal area, p, which is less erratic and more commonly available. We found from the data that p N % p 2 , so we substituted N/p 2 for N. We ignore changes in p over time, no consistent trends are evident in the data (see also Glover and Zutter (1993)). Including species composition produced only a marginal improvement in the fit, but it seems worthwhile for reasons of consistency.…”