Long-Term Evolution of Composition and Structure after Repeated Group Selection Over Eight Decades

2020 ◽  
Author(s):  
Nicole Rogers ◽  
Anthony W. D'Amato ◽  
William Leak
Keyword(s):  
Group Selection ◽  
Stand Structure ◽  
Fagus Grandifolia ◽  
Long Term Results ◽  
Northern Hardwood Forests ◽  
Composition And Structure ◽  
Shade Tolerant Species ◽  
Bartlett Experimental Forest ◽  
Developmental Dynamics

: In northeastern North America, group selection is frequently used in northern hardwood forests to maintain uneven-aged stand structure and promote regeneration of tree species spanning a range of shade tolerances. For this study, long-term application of group selection at the Bartlett Experimental Forest, New Hampshire, USA provided a unique opportunity to address cohort and stand level progression after 80-years of treatment. Cohort-level evolution reflected successional and developmental dynamics associated with even-aged forest systems, whereas aggregate, stand-level conditions were consistent with expectations for uneven-aged systems. As cohorts aged, diameter distributions progressed towards descending monotonic forms and species composition transitioned from shade-intolerant species to shade-tolerant species. Standing deadwood and downed woody material in cohorts followed trajectories of aging even-aged stands through time. Although American beech (Fagus grandifolia Ehrh.) was a primary species across cohorts and at the stand level, stand level regeneration included a mixture of ecologically and commercially valuable species. These long-term results offer important insights into emergent cohort and stand-level conditions and processes that may affect continued recruitment of desirable compositional and structural conditions in stands managed using group selection over numerous cutting cycles.

Variations in beech bark disease and its effects on species composition and structure of northern hardwood stands in central New England

1984 ◽  
Vol 14 (4) ◽  
pp. 565-574 ◽  
Author(s):  
Mark J. Twery ◽  
William A. Patterson III
Keyword(s):  
Species Composition ◽  
New England ◽  
Beech Bark Disease ◽  
Northern Hardwood ◽  
Disease Mortality ◽  
Composition And Structure ◽  
Understory Composition ◽  
Bartlett Experimental Forest ◽  
Compositional Changes

The extent of beech bark disease was examined on 41 permanent inventory plots in western Massachusetts and on 25 plots in Bartlett Experimental Forest in New Hampshire. The amounts of disease-caused mortality and defect were correlated to differences in species composition and 12 other site variables. Stands dominated by hemlock had significantly more beech mortality than other stands. Importance of both beech and yellow birch decreased on plots with beech bark disease mortality. Hemlock benefited most from the loss of beech. Beech bark disease has not noticeably changed understory composition on these plots. In the long term, beech bark disease appears to have caused minor compositional changes on most of the areas studied.

Elevated mortality of residual trees following single-tree felling in northern hardwood forests

2006 ◽  
Vol 36 (5) ◽  
pp. 1255-1265 ◽  
Author(s):  
John P Caspersen
Keyword(s):  
Tree Mortality ◽  
Community Dynamics ◽  
Stand Structure ◽  
Hardwood Forests ◽  
Natural Mortality ◽  
Northern Hardwood Forests ◽  
Substantial Impact ◽  
Northern Hardwood ◽  
Single Tree

In this paper, I examine tree mortality in northern hardwood forests subjected to single-tree felling. Mortality risk was estimated as a function of growth prior to harvest and time since harvest. This allowed me to separately quantify mortality due to (1) natural processes, (2) intentional felling, and (3) stress and (or) felling damage (postcut mortality). The long-term rate of mortality due to natural causes was 1.5% per year. The intentional felling of trees increased the average mortality to 3.1%, and postcut mortality of residual trees increased the average an additional 0.2%–3.3% (the latter reflects both the direct negative effects of harvesting and the indirect positive effect of releasing residual trees from suppression). Thus, from a population-level perspective, the increased mortality caused by stress and (or) felling damage to residual trees was small compared to that caused by both natural mortality and tree felling. However, the long-term population average obscures more dramatic (though transient) effects of felling on small trees (DBH <10 cm), for which mortality rates increased by as much as 5% immediately after felling. This increase is several times greater than the natural mortality rate for small trees and may therefore have a substantial impact on stand structure and community dynamics.

scholarly journals Forest Dynamics after Five Decades of Management in the Romanian Carpathians

Forests ◽  
2021 ◽  
Vol 12 (6) ◽  
pp. 783
Author(s):  
Gheorghe-Marian Tudoran ◽  
Avram Cicșa ◽  
Maria Boroeanu ◽  
Alexandru-Claudiu Dobre ◽  
Ionuț-Silviu Pascu
Keyword(s):  
Forest Dynamics ◽  
Stand Structure ◽  
Stand Density ◽  
Research Areas ◽  
Composition And Structure ◽  
Management Plans ◽  
Romanian Carpathians ◽  
The Stability ◽  
Near Future

Research Highlights: Management of the risks forests are exposed to is based on the dynamics of the composition and structure of the stands and the forest. Background and Objectives: This study aimed to document the dynamics of the composition and structure of stands and forest in the Romanian Carpathians over the last five decades, as well as estimate the forecast composition of the forest in the near future (i.e., 2070). Materials and Methods: The obtained results were based on long-term monitoring and analysis of the species and structures in the stands in long-term research areas (over five decades). We performed an inventory of all the trees (on 7.5 ha) in order to characterize the stand structure in sampling plots of 0.25–1.0 ha, located in representative stands of five forest formations. Bitterlich sampling was performed in order to determine the composition of each stand (on 2930.4 ha). The future composition was established in accordance with the characteristics of the natural forest types and was based on seedling dynamics and forest management plans. Results: In mixed beech–coniferous stands, over the last five decades, the area of beech has increased by 38%, while conifers have decreased proportionally—fir by 31% and spruce by 5%. The seedling area increased from 23% to 65%, with fir contributing 22% to the composition and beech 42%. Stand density decreased by an average of 14%, with the current increment decreasing by 3.8%. The slenderness index for fir decreased from 73 to 61. In the near future, there will be an increase in the proportion of fir, from 15 to 33%, and a reduction in beech, from 49 to 45%. The proportion of spruce will be reduced from 17 to 12%. Conclusions: Based on the forest dynamics, management adaptation strategies need to be developed to improve the stability of the forest ecosystems.

Short- and Long-Term Results of Alternative Silviculture in Peatland Black Spruce in Minnesota, USA

2019 ◽  
Vol 66 (2) ◽  
pp. 256-265 ◽  
Author(s):  
Brian D Anderson ◽  
Marcella A Windmuller-Campione ◽  
Matthew B Russell ◽  
Brian J Palik ◽  
Douglas N Kastendick
Keyword(s):  
Stand Structure ◽  
Black Spruce ◽  
Structural Complexity ◽  
Basal Area ◽  
Long Term Results ◽  
Dwarf Mistletoe ◽  
Single Tree Selection ◽  
Alternative Silvicultural Systems ◽  
Compositional Diversity

Abstract Across the boreal forest in North America, the black spruce (Picea mariana) cover type is ecologically and economically important, occupying roughly 10 percent of Minnesota’s, USA 17.4 million acres (7.0 million hectares) of forestland. Traditionally managed through clearcut regeneration harvests, alternative silvicultural systems are being increasingly used in Canada. Here, we examine the 10- and 57-year effects of six silvicultural treatments (clearcut strips, clearcut patches, thinning, group selection, single-tree selection, shelterwood) on stand structure and dynamics in lowland black spruce. Treatments were installed in 1948 in northern Minnesota, and remeasured and re-treated 10 years later. A subset of the clearcut strips, clearcut patches, and shelterwood treatments were remeasured in 2017. After 10 years, diameter growth of residual stems varied by treatment, with the shelterwood experiencing the greatest growth, and basal area increased in all but the shelterwood treatment. Over the long term, the shelterwood exhibited larger diameters and heights and greater crown ratios, basal area, structural complexity, and compositional diversity than the clearcuts. Our results suggest that managers may consider using a shelterwood instead of traditional large clearcuts to achieve increased structural and compositional diversity, particularly when eastern spruce dwarf mistletoe (Arceuthobium pusillum) does not necessitate a traditional clearcut.

scholarly journals The Composition and Height of Saplings Capturing Silvicultural Gaps at Two Long-Term Experiments in Managed Northern Hardwood Forests

Forests ◽  
2019 ◽  
Vol 10 (10) ◽  
pp. 855 ◽  
Author(s):  
Knapp ◽  
Webster ◽  
Kern
Keyword(s):  
Group Selection ◽  
Northern Hardwoods ◽  
Northern Hardwood Forests ◽  
Northern Hardwood ◽  
Advance Regeneration ◽  
Second Growth ◽  
Selection Experiments ◽  
Tree Retention ◽  
Present Group

Managing forests for mixtures of canopy species promotes future resilience and mitigates risks of catastrophic resource loss. This study describes the compositions, heights, and locations within openings of gap-capturing saplings in two long-term group-selection experiments in managed northern hardwoods. We expected opening size to affect the composition of gap-capturing saplings and that composition would match advance regeneration where relatively large stems remained following harvest. We also expected sapling height to respond positively to opening size, but plateau in gap areas above 200 m2, and legacy-tree retention to negatively affect sapling height. In two group-selection experiments, we found that the composition of gap-capturing saplings was not affected by opening size at 15 and 23 years post-harvest, respectively, and that composition matched advance regeneration only when larger stems (>2.5 cm breast height, dbh) were removed during harvest. Gap-capturing sapling composition did not match the surrounding canopy in either study site. Sapling height was positively correlated with gap area, but, as we expected, plateaued in larger openings. In openings without legacy-retention, gap area did not significantly predict sapling height in openings larger than 100–200 m2, whereas this threshold was between 300–400 m2 in openings with single legacy-tree retention. Sapling height was negatively associated with distance into openings when legacy-trees were present. Group selection appears to recruit modestly higher proportions of shade-midtolerant and intolerant species to the canopy compared to adjacent unmanaged second-growth or managed, uneven-aged northern hardwoods.

scholarly journals Composition and Structure of Reproduction in Group Selection Openings after 20 Years in a Southern Appalachian Mixed-Hardwood Forest

2021 ◽  
Author(s):  
W Henry McNab ◽  
Theodore M Oprean
Keyword(s):  
Group Selection ◽  
Stand Structure ◽  
Acer Rubrum ◽  
Stem Density ◽  
Mature Trees ◽  
Yellow Poplar ◽  
Southern Appalachian ◽  
Tolerant Species ◽  
Early Results ◽  
Composition And Structure

Abstract Following harvests by even-aged methods in mixed-hardwood forests, desirable oak (Quercus spp. L.) reproduction can be quickly overtopped by shade-intolerant pioneer species. In a long-term, operational-scale study of uneven-aged management by group selection, we inventoried 10- and 20-year-old reproduction following two harvest entries in a mature, dry-mesic southern Appalachian upland hardwood stand. Our study objectives included evaluating the species composition and structure of reproduction in relation to opening size (0.05 ha to 0.41 ha), position in openings (center or edge), uneven-aged diameter structure, and evidence supporting the delayed oak dominance hypothesis. Opening size had no effect on reproduction from either entry. After 10 years (but not 20) yellow-poplar (Liriodendron tulipifera L.) stem density and basal area were greater in opening centers; oaks were greater at edges. Position did not affect red maple (Acer rubrum L.) or other tolerant species. Diversity significantly increased between 10 and 20 years, suggesting evidence supporting the delayed oak dominance hypothesis. Early results from this study suggest that small openings can be used to regenerate desirable midtolerant and intolerant species in Appalachian mixed-hardwood stands on intermediate quality sites where uneven-aged stand structure is important for timber management and other goals such as visual appearance and early successional habitat. Study Implications Periodic harvests of small groups (0.05 to 0.41 ha) of mature trees in dry-mesic Appalachian oak-dominated, mixed-hardwood stands, followed by site preparation and competition release treatments to control undesirable shade tolerant species, can result in openings stocked with desirable shade midtolerant and intolerant reproduction after 20 years. Centers of openings will be dominated by yellow-poplar, but oak reproduction can be most prevalent around the periphery. Group selection is a flexible method of uneven-aged management that can be used to meet regeneration objectives and related goals such as early successional habitat and visual quality.

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