scholarly journals Tree Regeneration Structure Following Beech Bark Disease-Motivated Harvests: Factors Associated with Patterns and Management Implications

Forests ◽  
2020 ◽  
Vol 11 (2) ◽  
pp. 180 ◽  
Author(s):  
Lucas M. Elenitsky ◽  
Michael B. Walters ◽  
Evan J. Farinosi

In the northern Appalachian region of North America, mortality of mature American beech (Fagus grandifolia Ehrh.) via the introduced beech bark disease (BBD) can result in dense thickets of beech saplings that inhibit the regeneration of other species. It is unknown if similar structures characterize more recently infested managed forests in the Great Lakes region. If these dense beech sapling layers do exist, management would be aided by knowing which site/regional factors they are associated with and by identifying particular sapling structures that may threaten the sustainability of these forests under current management paradigms. To examine these patterns, we used a natural experiment with sample plots in 69 unevenly aged, selection silviculture-managed, maple (Acer spp.)-dominated northern hardwood stands. Our stands were dispersed across northern Michigan, USA and had undergone BBD-motivated partial harvests favoring beech removal (mean = 5.5 years before measurement). In each stand, we quantified tree regeneration structure in relation to winter deer use (fecal pellet count density), site quality (habitat type), geographic region (Eastern Upper Peninsula and Northern Lower Peninsula), and multiple measures of overstory stand density. We also examined the density effects of taller regeneration strata on subordinate strata. Across sites, the small sapling recruit class (i.e., >137 cm tall and <5 cm diameter at 137 cm tall) was dominated by beech and was often dense (44% of subplots > 2000 stems ha−1 and 16% of subplots > 5000 ha−1) but never exceeded the > 10,000 stems ha−1 reported in the northern Appalachian region. Beech sapling density was higher in the Northern Lower Peninsula, on lower quality sites, at lower postharvest overstory densities, and on sites with higher densities of preharvest overstory beech. In contrast to the beech-dominated small sapling recruit class, seedlings (i.e., <25 cm tall) were generally more species diverse than sapling strata and were dominated by maple species. Although generally dense, seedling density was negatively related to small sapling recruit density, suggesting that saplings may suppress the seedling stratum. The general pattern for the small sapling recruit layer of browsing-insensitive beech (and ironwood, Ostrya virginiana Mill. K. Koch) dominance and low representation of browsing-sensitive species (e.g., Acer spp.) circumstantially supports the notion that regeneration structure is heavily influenced by deer. However, current deer use was generally low in our stands, and relationships with tree regeneration structure were weak. Instead, regeneration structure is likely shaped by a combination of factors operating at long time scales (i.e., legacies of deer browsing pressure, selection silviculture (given beech and ironwood are shade tolerant), overstory composition, and site quality) and by those effects that are more proximal, such as postharvest overstory density. Minimum stocking criteria for species considered desirable for management (e.g., sugar maple and Acer saccharum Marshall) suggest many stands are inadequately stocked in the sapling recruit classes. Although future regeneration dynamics are unclear, current patterns suggest that many stands with high beech/ironwood small sapling recruit densities may require management intervention to overcome insufficient recruitment of species targeted for management.

1998 ◽  
Vol 15 (3) ◽  
pp. 116-123 ◽  
Author(s):  
Peter N. Bakken ◽  
James E. Cook

Abstract The arboreal regeneration of 24 mature, fully stocked forests distributed among 6 common habitat types (Kotar et al. 1988) in north-central Wisconsin were studied. Nineteen of the stands were inventoried in 1992 and 1993; in 1993 an additional 5 stands were included. The density and composition of small (<25 cm) and large (25-150 cm) seedlings were determined, and the relationships of the understory and overstory were investigated. No significant (P < 0.05) differences were found for seedling densities of either size class among habitat types. This was due, in part, to the large variation within most habitat types; this in turn is primarily a function of the temporally variable nature of seedlings. The average densities per habitat type ranged from 3,125-20,200/ha for large seedlings and from 20,208-152,083/ha for the small seedlings. Red and sugar maple strongly dominated the regeneration. Red maple was the most common (88-96%) species in the small seedling size class on the three driest habitat types, and sugar maple (88-99%) on the two most mesic habitat types. In the middle of the site quality gradient, the two maples shared dominance with northern red oak. The level of maple dominance was lower in the large seedling class, ranging from 53-93%. The small seedling size class was significantly related to the amount of maple basal area each year, but the strength of this relationship weakened from 1992 to 1993. The widespread domination by red and sugar maple is a function of their regeneration ecology, shade tolerance, fire suppression, and deer browsing. The seedling composition and densities have important implications for the management of these forests. The regeneration and overstory characteristics suggest that it would be easiest to direct the composition one of several ways on the PMV and AVVib habitat types. Fairly heavy overstory treatments, in conjunction with seedbed preparation, are probably necessary to regenerate significant amounts of species other than sugar maple on the two most mesic habitat types. North. J. Appl. For. 15(3):116-123.


1981 ◽  
Vol 11 (2) ◽  
pp. 288-291
Author(s):  
Bruce W. Wood ◽  
James W. Hanover

A method is described for accelerating growth of sugar maple (Acersaccharum Marsh.) seedlings for early progeny and provenance evaluation and plantation establishment. Outdoor nursery production methods produced relatively small seedlings, few seed-lot differences, and no provenance differences in seedlings 4 and 16 months of age. In contrast, accelerated seedlings exhibited pronounced seed-lot and provenance differences at both ages and had a 29 and 80% height superiority at 4 and 16 months, respectively. Provenance differences in height, budbreak, nodes, and growth flushes revealed by the accelerated treatment and supplemented by seed characteristics indicate existence of Upper and Lower Peninsula races in Michigan. Accelerated growth techniques may have considerable potential for reducing the time required for genotypic evaluation of sugar maple and possibly other tree species, but results must be substantiated by subsequent field observations.


1989 ◽  
Vol 4 (2) ◽  
pp. 52-54 ◽  
Author(s):  
David L. Verbyla ◽  
Richard F. Fisher

Abstract Forest habitat types have been purported to be useful indicators of site quality. This is generally true for habitat types with different dominant tree species. However, few have studied the site indicator value of habitat types with the same dominant tree species. We measured site index (base age 25) from 172 randomly selected plots within the ponderosa pine (Pinus ponderosa) zone of the Dixie National Forest, Utah. The range of site index within any one habitat type was broad. Poor sites occurred on all five habitat types. However, the best sites occurred only on the Pinus ponderosa/Symphoricarpos oreophilus and Pinus ponderosa/Quercus gambelii habitat types. Therefore, habitat type may be useful in predicting the best sites, but only if other site information is used in addition to habitat type. West. J. Appl. For. 4(2):52-54, April 1989.


2006 ◽  
Vol 82 (5) ◽  
pp. 733-744 ◽  
Author(s):  
Nicholas J Buda ◽  
Jian R Wang

Stem analyses data collected in central Ontario stands were used to develop site index (height and age) and site form (height and diameter) models and curves for sugar maple. The suitability of both methods for evaluating sugar maple site productivity was examined. Two different equation forms were evaluated for both site index and site form models. A common modification of Richard's (1959) equation was most suitable for predicting dominant height at index age (site index) and reference diameter (site form). Potential effects of species mixture on sugar maple site index were examined. We found no significant effects on sugar maple height growth and site index in mixed stand conditions common in the region when compared to pure stands. The potential of site form as an alternative to site index was investigated through correlation analyses with site index and other site variables known to influence sugar maple height growth. Site form was not related to site index, nor any site variables related to sugar maple height growth. It is therefore inadequate for evaluating sugar maple site quality. We recommend height growth models and site index curves developed in this study be used to replace those from other regions currently used in central Ontario. Key words: site index, site form, sugar maple, site quality evaluation, mixedwood, uneven-aged


Forests ◽  
2019 ◽  
Vol 10 (3) ◽  
pp. 271 ◽  
Author(s):  
Susan Jones-Held ◽  
Michael Held ◽  
Joe Winstead ◽  
William Bryant

Wind disturbance is an important factor that can affect the development of the forests of the Central Hardwood Region of the United States. However, there have been few long-term studies of the recovery of these systems following wind damage. Long-term studies of protected forest systems, such as Dinsmore Woods in Northern Kentucky, within the fragmented forest of this region are valuable as they provide a resource to document and understand the effect of both abiotic and biotic challenges to forest systems. This study is a 40-year analysis of both overstory and understory changes in the forest system at Dinsmore Woods as the result of damage caused by severe winds in the spring of 1974. The forest was surveyed before and immediately following the windstorm and then at 10-year intervals. Although the windstorm had an immediate effect on the forest, the pattern of damage was complex. The forest canopy (diameter at breast height (DBH) ≥ 30 cm) experienced an irregular pattern of damage while in the subcanopy (DBH ≤ 30 cm) there was a 25% reduction in total basal area. However, the major effects of the windstorm were delayed and subsequently have altered forest recovery. Ten years following the disturbance declines were seen in total density and basal area in the canopy and subcanopy of the forest as a consequence of windstorm damage. In the past 20 years the total basal area of the canopy has increased and exceeds the pre-disturbance total basal area. In contrast, the subcanopy total basal area continued to decline 20 years post-disturbance and has not recovered. Further openings in the canopy and subcanopy due to the delayed windstorm effects helped to establish a dense understory of native shrubs and sugar maple which have affected tree regeneration and is reflected in the continual decline in species diversity in the subcanopy and sapling strata over the 40-year period.


1991 ◽  
Vol 21 (5) ◽  
pp. 606-611 ◽  
Author(s):  
W. F. Stansfield ◽  
J. P. McTague ◽  
R. Lacapa

A dominant-height equation for ponderosa pine (Pinusponderosa Laws.) was constructed utilizing a parameter prediction method and a model by J.E. King. The site-index equation was obtained by inverting the dominant-height equation. A method was examined for indirectly obtaining parameter prediction equations. It proved superior to two direct parameter prediction approaches. Other site-quality variables, such as habitat type groups and elevation, were included in the dominant-height and site-index equations and were successful in refining predictive capability.


2017 ◽  
Vol 83 (9) ◽  
Author(s):  
Dmitriy V. Volokhov ◽  
Jusun Hwang ◽  
Vladimir E. Chizhikov ◽  
Heather Danaceau ◽  
Nicole L. Gottdenker

ABSTRACT Raccoons (Procyon lotor) are successful urban adapters and hosts to a number of zoonotic and nonzoonotic pathogens, yet little is known about their hemoplasma infections and how prevalence varies across habitat types. This study identifies hemotropic Mycoplasma species infection in raccoons from urban and undisturbed habitats and compares hemoplasma infection in sympatric urban cats (Felis catus) from the same geographic region. We collected blood from raccoons (n = 95) on an urban coastal island (n = 37) and an undisturbed coastal island (n = 58) and from sympatric urban cats (n = 39) in Georgia, USA. Based on 16S rRNA gene amplification, 62.1% (59/95) of raccoons and 17.9% (7/39) of feral cats were positive for hemoplasma. There was a greater percentage of hemoplasma-infected raccoons on the undisturbed island (79.3% [46/58]) than on the urban island (35.1% [13/37]; χ2 = 16.9, df = 1, P = 0.00004). Sequencing of the full-length 16S rRNA gene amplicons revealed six hemoplasma genotypes in raccoons, including five novel genotypes that were distinct from three known hemoplasma species identified in the sympatric cats. In addition, the hemoplasma genotypes detected in raccoons were not identified in sympatric cats or vice versa. Although all six hemoplasma genotypes were found in raccoons from urban and undisturbed islands, coinfection patterns differed between sites and among individuals, with the proportion of coinfected raccoons being greater in the undisturbed site. This study shows that raccoons are hosts for several novel hemoplasmas and that habitat type influences infection patterns. IMPORTANCE This study provides information about novel hemoplasmas identified in raccoons (Procyon lotor), which can be used for assessments of the prevalence of these hemoplasmas in raccoon populations and for future studies on the potential pathogenic impacts of these hemoplasmas on raccoon health. Raccoons from the undisturbed habitat had a higher prevalence of hemoplasma infection than urban raccoons. There does not appear to be cross-species transmission of hemotropic mycoplasmas between urban raccoons and feral cats. Raccoons appear to be hosts for several novel hemoplasmas, and habitat type influences infection patterns.


2008 ◽  
Vol 38 (5) ◽  
pp. 1267-1274 ◽  
Author(s):  
Jessica E. Hancock ◽  
Mary A. Arthur ◽  
Kathleen C. Weathers ◽  
Gary M. Lovett

Exotic pests and pathogens, through direct and indirect effects on forest structure and species composition, have the potential to significantly alter forest ecosystem processes, including C cycling. Throughout the northern hardwood forest, beech bark disease (BBD) is causing widespread disruption in forest structure and composition. In the Catskill Mountains of New York, some forests formerly codominated by American beech ( Fagus grandifolia Ehrh.) and sugar maple ( Acer saccharum Marsh.) are shifting to sugar maple dominance. The effects of BBD and a subsequent shift in species composition on annual aboveground net primary production and soil CO2 efflux were examined in eight forest plots selected to represent a gradient of BBD impact. There were no significant trends in aboveground net primary production across this gradient. However, growing season soil CO2 efflux decreased linearly along the BBD gradient, declining by 40%. Although the mechanism controlling this decline is uncertain, the decrease in soil CO2 efflux with BBD impact and a shift to greater composition of sugar maple in litterfall could significantly alter C cycling in northern hardwood stands in the Catskill Mountains.


2014 ◽  
Vol 44 (9) ◽  
pp. 1042-1050 ◽  
Author(s):  
Lisa M. Giencke ◽  
Martin Dovčiak ◽  
Giorgos Mountrakis ◽  
Jonathan A. Cale ◽  
Myron J. Mitchell

Beech bark disease (BBD) has affected the composition, structure, and function of forests containing a significant proportion of American beech (Fagus grandifolia Ehrh.) across North America. BBD spread has been investigated at landscape and regional scales, but few studies have examined spatial patterns of disease severity and spread within stands where forest management mitigation measures can be implemented. We analyzed changes in forest composition between 1985 and 2009 and fine-scale spatial patterns of BBD between 2000 and 2009 in a ∼2 ha northern hardwood stand in the Adirondack Mountains of New York using location and disease severity of beech trees. A bivariate point pattern analysis was implemented to examine spatial patterns of beech thicket formation and BBD spread to beech saplings. Abundance of beech saplings increased near highly diseased canopy beech trees and around dead beech and sugar maple (Acer saccharum Marsh.). Disease severity of beech saplings was highest in close proximity to highly cankered canopy beech trees. Thus, BBD leads to the formation of beech thickets, and thickets are often located where saplings are most likely to become infected, increasing the likelihood that secondary killing fronts will develop and lead to heavy BBD-induced mortality in aftermath northern hardwood forests of North America.


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