Competitive success of natural oak regeneration in clearcuts during the stem exclusion stage

Abstract

We sampled dominant and codominant regeneration on 70 clearcuts, 21–35 years old, on the Hoosier National Forest in southern Indiana, USA, to evaluate influence of site variables on the competitive success of natural oak ( Quercus L.) over time. Collected data was compared with data collected on these same sites 20 years prior. Regression tree analysis indicated aspect, natural region, and oak abundance in preharvest stands had the greatest influence on competitive success (relative density, RD) of oak species in the latter sampling, which was then examined across sites as defined by these three variables. Oak RD increased across all mid- and some lower-slope positions, sites on which oaks are expected to be replaced by faster growing species. Drought events between sampling periods apparently contributed to a decline in RD and vigor of yellow-poplar ( Liriodendron tulipifera L.), a major competitor for growing space. Stump sprouts contributed 45% of dominant oak stems. Mean oak diameters were not significantly lower than those of other species groups, with the exception of yellow-poplar in younger stands and at mid-slope positions. Oak species drought tolerance, relative to more mesic species found on these sites, and the large proportion of oak stump sprouts likely contributed to oak competitive success.

Overstory species composition of naturally regenerated clearcuts in an ecological classification framework

“…removed approximately 20 years prior (Morrissey et al 2009). Harvest volumes from clearcuts (Morrissey et al 2008) indicated that species composition was sufficiently similar to reference stands of Van Kley (1993). At least 45% of oak regeneration was clearly identified as stump sprouts (Morrissey et al 2008), but it is estimated that the actual percentage was higher.…”

“…In the Missouri Ozark Highlands, Sasseen and Muzika (2004) indicated that fire disturbances may override effects of site that typically control succession in the region, suggesting successional pathways may vary across ELTPs as a result of different disturbances. Morrissey et al (2008) observed that Quercus species relative density increased between 1986 and 2004 in relation to site variables including ecological section, aspect, and, to a lesser degree, slope position. It was proposed that Quercus species held a competitive advantage over many co-occurring species, notably site-sensitive species such as L. tulipifera and P. serotina, because of oaks' ability to better tolerate periods of water stress (autogenic) on more xeric sites (allogenic).…”

“…At least 45% of all overstory oaks were of stump sprout origin and were more prominent on lower quality sites (Morrissey et al 2008). Despite relatively low numbers of co-occurring L. tulipifera, P. serotina, and A. rubrum, as indicated by percent volume harvested from clearcut stands (Morrissey et al 2008), their ecological attributes explain prevalence of these species in regenerating stands. Shade intolerance of L. tulipifera and P. serotina implies their reliance on small advance regeneration and seed.…”

Restoring oak forests, woodlands and savannas using modern silvicultural analogs to historic cultural fire regimes

“…Oak stump sprouts are highly competitive and often account for the majority of dominant oaks in the stem exclusion stage (Beck and Hooper, 1986;Gould et al, 2002;Morrissey et al, 2008), but not all oak stumps that result from harvesting produce sprouts (e.g., Johnson, 1977;Weigel et al, 2011), which is why emphasis is placed on development of large oak advance reproduction in the understory to sustain desired oak stocking in the future stand (Johnson et al, 2009). In general, the single-tree selection method is not recommended for oak regeneration (Johnson et al, 2009).…”

Grapevine (Vitis spp.) dynamics in association with manual tending, physiography, and host tree associations in temperate deciduous forests

“…We cannot, however, speculate as to whether yellow poplar or any other species were common host species for grapevines at earlier stages of development. On these same sites, Morrissey et al (2008b) determined that neither yellow poplar nor black cherry showed significant reductions in relative density of dominant and co-dominant trees between the two sample periods, indicating that they remained competitive during that period despite grapevine competition. We speculate that as competition for light resources increased in developing canopies, grapevine densities decreased, perhaps as a result of their shade intolerance.…”