A Practical Alternative to Single-Tree Selection?

1993 ◽  
Vol 10 (1) ◽  
pp. 32-38 ◽  
Author(s):  
Gary W. Miller ◽  
H. Clay Smith
Keyword(s):  
Tree Structure ◽  
Single Tree ◽  
Potential Value ◽  
Tolerant Species ◽  
Single Tree Selection ◽  
Shade Tolerant Species ◽  
Individual Trees ◽  
Harvest Method

Abstract When landowners want to develop and maintain an uneven-aged tree structure in eastern hardwood stands, single-tree selection often is suggested as the only advisable, long-term partial regeneration harvest method. Single-tree selection is preferred because it provides a means for improving quality and controlling stocking of the residual stand necessary for sustained yield of desired products. Although studies have shown that single-tree selection is feasible where desirable shade-tolerant species can be regenerated, it is rarely applied because marking stands for harvest can be difficult and time consuming. Instead, diameter-limit cutting is the most common partial regeneration practice used in eastern hardwoods, primarily because it is much easier to apply. Unfortunately, strict diameter-limit cuts do not provide for control of residual stocking or improve the quality of residual trees. However, based on 20-yr results, most objectives of single-tree selection can be attained with flexible diameter-limit harvest guidelines based on potential value increase of individual trees combined with an improvement cut in small sawtimber trees at each periodic cut. North. J. Appl. For. 10(1):32-38.

Effects of Single Tree Selection Harvests on Stand Structure, Species Composition, and Understory Tree Growth in a Sierra Mixed Conifer Forest

1990 ◽  
Vol 5 (2) ◽  
pp. 43-47 ◽  
Author(s):  
R. J. Lilieholm ◽  
L. S. Davis ◽  
R. C. Heald ◽  
S. P. Holmen
Keyword(s):  
Stand Structure ◽  
Diameter Distribution ◽  
Conifer Forest ◽  
Small Tree ◽  
Single Tree ◽  
Mixed Conifer Forest ◽  
Single Tree Selection ◽  
Shade Tolerant Species ◽  
Rates Of Growth ◽  
Understory Tree

Abstract After 20-28 years of single tree selection harvests in initially irregular even-aged stands, stand structure is approaching a target uneven-aged diameter distribution. Seedling stocking in managed stands is nearly three times greater than that of unmanaged stands. Although shade-tolerant species comprise the bulk of most size classes in both managed and unmanaged stands, selection harvests have resulted in adequate quantities of seedlings from all five conifer species, including pines. In managed stands, current small-tree stocking and rates of growth appear adequate to sustain single tree selection harvests over much of a 90-year growth simulation. Simulated peak growth rates of uneven-aged stands compare favorably with actual and anticipated yields from the forest's uneven- and even-aged stands. West. J. Appl. For. 5(2):43-47, April 1990.

scholarly journals Trees do not always act their age: size-deterministic tree ring standardization for long-term trend estimation in shade-tolerant trees

2019 ◽  
Vol 16 (24) ◽  
pp. 4815-4827
Author(s):  
Rachel Dietrich ◽  
Madhur Anand
Keyword(s):  
Tree Ring ◽  
Basal Area ◽  
Ring Formation ◽  
Tree Size ◽  
Growth Trend ◽  
Biological Growth ◽  
Tolerant Species ◽  
Tree Ring Data ◽  
Shade Tolerant Species

Abstract. With increasing awareness of the consequences of climate change for global ecosystems, the focus and application of tree ring research have shifted to reconstruction of long-term climate-related trends in tree growth. Contemporary methods for estimating and removing biological growth trends from tree ring series (standardization) are ill-adapted to shade-tolerant species, leading to biases in the resultant chronologies. Further, many methods, including regional curve standardization (RCS), encounter significant limitations for species in which accurate age estimation is difficult. In this study we present and test two tree ring standardization models that integrate tree size in the year of ring formation into the estimation of the biological growth trend. The first method, dubbed size-deterministic standardization (SDS), uses tree diameter as the sole predictor of the growth trend. The second method includes the combined (COMB) effects of age and diameter. We show that both the SDS and COMB methods reproduce long-term trends in simulated tree ring data better than conventional methods; this result is consistent across multiple species. Further, when applied to real tree ring data, the SDS and COMB models reproduce long-term, time-related trends as reliably as traditional RCS and more reliably than other common standardization methods (i.e. C-method, basal area increments, conservative detrending). We recommend the inclusion of tree size in the year of ring formation in future tree ring standardization models, particularly when dealing with shade-tolerant species, as it does not compromise model accuracy and allows for the inclusion of unaged trees.

scholarly journals When trees don’t act their age: size-deterministic tree-ring standardization for long-tern trend estimation in shade-tolerant trees

2019 ◽  
Author(s):  
Rachel Dietrich ◽  
Madhur Anand
Keyword(s):  
Tree Ring ◽  
Ring Formation ◽  
Tree Size ◽  
Growth Trend ◽  
Biological Growth ◽  
Tolerant Species ◽  
Tree Ring Data ◽  
Shade Tolerant Species ◽  
Multiple Species

Abstract. With increasing awareness of the consequences of climate change for global ecosystems, the focus and application of tree-ring research has shifted to reconstruction of long-term climate-related trends in tree growth. Contemporary methods for removing the biological growth-trend from tree-ring series (standardization) are ill-adapted to shade-tolerant species, leading to biases in the resultant chronology. Further, many methods, including regional curve standardization (RCS), encounter significant limitations for species in which accurate age estimation is difficult. In this study we present and test two tree-ring standardization models that integrate tree size in the year of ring formation into the estimation of the biological growth-trend. The first method, dubbed size deterministic standardization (SDS), uses tree diameter as the sole predictor of the growth-trend. The second method includes the combined (COMB) effects of age and diameter. We show that both the SDS and COMB methods reproduce long-term trends in simulated tree-ring data better than conventional methods – this result is consistent across multiple species. Further, when applied to real tree-ring data, the COMB method is more parsimonious than its than RCS. We recommend the inclusion of tree size in the year of ring formation in future tree-ring standardization models, particularly when dealing with shade-tolerant species, as it does not compromise model parsimony and allows for the inclusion of unaged trees.

scholarly journals Six Decades of Growth and Yield and Financial Return in a Silviculture Experiment in Northern Hardwoods

2021 ◽  
Author(s):  
Maeve C Draper ◽  
Robert E Froese
Keyword(s):  
Financial Performance ◽  
Basal Area ◽  
Long Term Results ◽  
Northern Hardwoods ◽  
Partial Cutting ◽  
Upper Peninsula ◽  
Single Tree ◽  
Single Tree Selection ◽  
Upper Peninsula Of Michigan

Abstract The Cutting Methods Study at the Ford Forest in the Upper Peninsula of Michigan, USA, was established in 1956 and has been maintained continuously on a 10 year cycle. Methods consist of three diameter limits (DL; 13, 30, and 41 cm), single-tree selection to three residual basal area limits (STS; 11, 16, and 21 m2ha−1), and light improvement (LI) focused on improving tree grade. Long-term results show that the 41 cm DL produced the greatest managed forest value and cumulative sawlog production, followed by the STS to 11 m2ha−1 residual basal area. STS treatments and LI were uniformly superior at improving standing tree grade. In contrast, treatments that emphasize removal of large diameter trees while retaining moderate residual basal area (the 41 cm DL and 11 m2ha−1 STS) produced the largest harvest volumes of high-grade sawlogs, driving financial performance. Stand density has declined in all treatments except the 30 and 41 cm DL, where it has increased, and these two treatments have larger abundance of saplings and poles. Alternative partial cutting methods such as selection to lower residual basal areas and medium-intensity diameter-limit cuts thus may provide greater financial returns and higher average quality, and could have implications on regeneration and long-term sustainability. Study Implications: Long-term comparison of alternative partial cutting practices in northern hardwoods in the Upper Peninsula of Michigan over 60 years reveals that Arbogast-based single-tree selection is inferior using financial and volume yield criteria. Alternatives that remove more of the larger trees appear over time to increase regeneration and harvested tree quality, which in turn drives financial performance. However, treatments with extremely high volume removals perform poorly against all others, and have few, if any, redeeming financial, silvicultural, or ecological qualities.

Long-term permanent plot observations of vegetation dynamics in Budongo, a Ugandan rain forest

2000 ◽  
Vol 16 (6) ◽  
pp. 865-882 ◽  
Author(s):  
DOUGLAS SHEIL ◽  
STEPHEN JENNINGS ◽  
PETER SAVILL
Keyword(s):  
Mortality Rate ◽  
Tree Species ◽  
Size Structure ◽  
Series Data ◽  
Forest Plot ◽  
Stem Size ◽  
Tolerant Species ◽  
Large Trees ◽  
Shade Tolerant Species

Species composition and turnover that have occurred in a series of permanent sample plots established during the 1930s and 1940s in Budongo, a semi-deciduous Ugandan forest, are reported. The plots were established as part of a sequence first used to describe forest succession, five of which have been maintained and which were last measured in 1992-1993. One plot (plot 7) provides 53 y of data from old-growth pristine forest. Plot 15 was established in wooded grassland at the forest edge and is now closed high forest. Evaluation of the remaining three plots is complicated by silvicultural interventions carried out in the 1950s. Forty species have been added since the first evaluations and a total of 188 tree species (over 80% of Budongo's forest tree flora, and including two exotics) has now been recorded from within the plots. The pattern of shade-tolerance in the original plot series conforms to patterns expected for succession with an increasing proportion of shade-tolerant species with development, and large stems appearing to ‘lag behind’ smaller stems in this respect. The time series data are less consistent, and while plot 7 increased in the proportion of shade-tolerant stems through time, the proportion of shade-tolerant species actually declines. Stem-turnover (the mean of mortality and recruitment) slowed with implied successional stage. Most species have a higher recruitment than mortality rate and stem numbers have thus increased in all plots. This is most pronounced in the putatively ‘early successional’ plot. Stem size structure has changed within the plots, with an increased proportion of smaller stems. Species show different rates of turnover and these vary from plot to plot and period to period. In plot 7, the overall mortality rate decreased with initial stem size. Estimates imply that some tree species may easily live longer than 500 y after reaching 10 cm DBH, and that 1000 y is possible. The importance of large trees in determining forest dynamics is illustrated by the finding that death of only seven stems in plot 7 contributed over 60% of net basal area losses recorded over the 53-y observation period. Many of the observed patterns were not predicted and could only have been found by long-term studies.

Long-term spatial and structural dynamics in Acadian mixedwood stands managed under various silvicultural systems

2008 ◽  
Vol 38 (3) ◽  
pp. 498-517 ◽  
Author(s):  
Mike R. Saunders ◽  
Robert G. Wagner
Keyword(s):  
Spatial Pattern ◽  
Structural Dynamics ◽  
Spatial Models ◽  
Structural Development ◽  
Natural Areas ◽  
Precommercial Thinning ◽  
Clear Cutting ◽  
Single Tree Selection ◽  
Individual Trees

Using inventory data from a long-term silviculture experiment in east-central Maine, spatial models were developed to analyze 28 years (1974–2002) of stand structural dynamics. Differences in spatial pattern, species mingling, height differentiation, and relative stand complexity index (rSCI) were compared among five treatments: commercial clear-cutting, fixed diameter-limit, 5 year single-tree selection, three-stage shelterwood (both with and without precommercial thinning), and unharvested natural areas. Regardless of treatment, regeneration events (whether induced by natural breakup of the overstory or by harvesting) increased aggregation in spatial pattern and reduced species mingling, more so in the commercial clearcut and fixed diameter-limit treatments where hardwood densities were highest. Regular spatial patterns were rare. Height differentiation values for individual trees and stand-level mean rSCI were generally highest in untreated natural areas and 5 year selection treatments, intermediate in commercial clearcut and fixed diameter-limit treatments, and lowest in three-stage shelterwood treatments. After a brief adjustment period, precommercial thinning in a shelterwood treated stand generally increased species mingling, height differentiation, and rSCI. Two untreated natural areas exhibited divergent pathways of structural development. Dynamics in uneven-aged selection treatments more closely resembled that of the untreated natural areas than did the shelterwood, commercial clearcut, or fixed diameter-limit treatments.

Dynamics of the diameter distribution after selection cutting in uneven- and even-aged northern hardwood stands: a long-term evaluation

2019 ◽  
Vol 49 (12) ◽  
pp. 1525-1539 ◽  
Author(s):  
Sarita Bassil ◽  
Ralph D. Nyland ◽  
Christel C. Kern ◽  
Laura S. Kenefic
Keyword(s):  
Temporal Stability ◽  
Diameter Distribution ◽  
Weibull Function ◽  
Northern Hardwood ◽  
Selection Cutting ◽  
Single Tree ◽  
Second Growth ◽  
Single Tree Selection ◽  
Diameter Distributions

Selection cutting is defined as a tool for uneven-aged silviculture. Dependence on diameter distribution by forestry practitioners for identifying stand conditions has led to misuse of selection-like cuttings in even-aged northern hardwood stands. Our study used several long-term data sets to investigate the temporal stability in numbers of trees per diameter class in uneven-aged northern hardwood stands treated with single-tree selection and in 45-year-old second-growth stands treated with selection-like cuttings. We analyzed data from New York, Michigan, and Wisconsin to determine changes through time in number of trees across 2.5 cm diameter classes, shifts in the shape and scale of the three-parameter Weibull function used to describe the diameter distributions, and dynamics of associated stand attributes. Findings showed that single-tree selection cutting created and sustained stable diameter distributions and uniformity of conditions through consecutive entries in uneven-aged stands. By contrast, these characteristics varied through time in the second-growth stands that had been treated with selection-like cuttings. Analysis also showed that the Weibull shape and scale parameters for stands under selection system migrated towards those of the recommended target diameter distribution in the uneven-aged stands. These parameters diverged from the target with repeated use of selection-like cuttings in the second-growth even-aged stands.

Sign in / Sign up

Export Citation Format

Share Document