Successional trends and apparent Acer saccharum regeneration failure in an oak-hickory forest in central Missouri, USA

Abstract

Permanent vegetation plots established in 1968 at the Baskett Research and Education Area (BREA) were remeasured in 2004/2005 to assess trends in canopy composition, vegetation-environment relationships, and regeneration patterns. Quercus spp. [particularly Quercus alba (white oak)] remained dominant in BREA forests. However, NonmetricMultidimensional Scaling Ordination of a dataset composed of tree importance values from both samples indicated the two most common community types (Dry Ridge and Slope; Mesic Slope) were shifted away from Quercus spp. abundance toward greater importance of Acer saccharum (sugar maple) in ordination space. Plots in glade-like environments shifted toward greater Juniperus virginiana (eastern redcedar) importance. Environmental analysis indicated that soil properties (pH, organic matter, Ca, Mg, and K) and slope position were highly correlated with ordination axes. Saplings of Quercus spp. exhibited greatly reduced abundance in the most recent sample and the reduction in Quercus spp. density was highest in plots with greatest canopy cover. While Acer saccharum saplings were still quite abundant in BREA forests, smaller sapling size classes were becoming notably depleted, reflecting growth of a cohort of plants established before the 1968 sample toward and into tree-sized individuals. Seedlings surveys emphasized that A. saccharum seedlings have become very rare in BREA forests, while Quercus spp. seedling densities are higher, but likely below those needed for eventual adequate recruitment to the canopy. Although a number of mechanisms to explain apparent A. saccharum regeneration failure can be developed, herbivory, recent climate trends (warming late-winter conditions) and increased litter layer depth are the most plausible explanations for the observed scarcity of A. saccharum seedlings. Although increasing importance of A. saccharum in the canopy of BREA forests appears inevitable in coming decades, longer-term trends are unclear given the shortage of seedling regeneration.

Population structure and spatial pattern of predominant tree species in a pine–oak mosaic mixed forest in the Qinling Mountains, China

“…A distinct bottleneck at a DBH of 4 cm indicated that the Q. aliena var. acuteserrata seedlings had high mortality under the forest canopy (Figure 2), which has also been reported previously (Wang & Gao 2005;Belden & Pallardy 2009;Yuan et al 2011;Yu et al 2013a;Huo et al 2014). The Quercus species had a low survival rate between the seedling and sapling stages, because Q. aliena var.…”

Drought and fire suppression lead to rapid forest composition change in a forest-prairie ecotone

“…However, our findings and previous studies supported the conclusion that a dramatic increase in J. virginiana was dependent on fire suppression (Dyksterhuis, 1948;Snook, 1985;Engle and Kulbeth, 1992). Lacking fire to reduce competition from other woody species and stimulate sprouting from exposed dormant buds, Quercus regeneration slowed while regeneration of fire-intolerant J. virginiana increased (Schmidt and Leatherberry, 1995;Gedalof et al, 2006;Bartolomé et al, 2008;Belden and Pallardy, 2009). Increased stand density due to gap filling and J. virginiana regeneration (DeSantis, 2010) further disfavored the light demanding Quercus (Rebertus and Burns, 1997;Nowacki and Abrams, 2008;Shinneman and Baker, 2009).…”

Comparison of soil organic matter dynamics at five temperate deciduous forests with physical fractionation and radiocarbon measurements

“…We collected soil from five deciduous broadleaf forests across the eastern deciduous forest zone in the U.S. that were chosen to cover the range of the Urbanski et al (2007) and Barford et al (2001) b See Belden and Pallardy (2009) and Pallardy et al (1988) (Loeppert and Suarez 1996). For all plots, carbonate concentration was below 0.01 % and inorganic carbon was less than 0.5 % of total soil carbon for surface mineral soils above 15 cm.…”