scholarly journals Ertragskundliche Aspekte und Strukturdynamik der Buchen-Lichtwuchsdurchforstung

2018 ◽  
Vol 169 (6) ◽  
pp. 332-339 ◽  
Author(s):  
Joachim Klädtke
Keyword(s):  
Volume Growth ◽  
Basal Area ◽  
Structural Diversity ◽  
Maximum Volume ◽  
Negative Effects ◽  
Single Tree ◽  
Stand Productivity ◽  
Single Tree Selection ◽  
Volume Production ◽  
Equilibrium Growth

Effects of heavy selective thinnings in beech stands with regard to stand productivity and structural diversity Based on thinning trials in beech stands initiated in the early 1970s, the effects of selective thinnings in favour of 100 to 120 future crop trees were analysed with regard to volume productivity and the stands' structural diversity. The results show that these kinds of thinnings reduce volume productivity by approximately 6% compared to the maximum volume growth. The reduction in volume growth is mostly caused by the fact that the strongly released crop trees have reduced their height growth for the benefit of a lateral crown expansion, while basal area growth was not affected. Calculations indicate that silvicultural systems working with only 50 future crop trees per hectare may decrease the maximum volume production by about 12%. Furthermore, the results show that the intense crown releases caused by selection thinnings increase the horizontal and vertical diversity of beech stands, since the trees in the understorey profit from better light conditions. The indices calculated for diameter and height diversity of the selection thinning plots approach the values being typical for single tree selection forests (“Plenterwälder”). Already after three to four consecutive selection thinnings, the beech stands' diameter distributions displayed an exponentionally decreasing shape typical for single tree selection forests close to equilibrium. Growth simulations revealed that it might even be possible to directly transform beech stands by selection thinnings into single tree selection structures. However, presumably negative effects on timber quality to be expected under single tree selection structures should be considered as a critical aspect with regard to theoretically possible transformation.

Growth of Loblolly Pine Stands After the First Five Years of Uneven-Aged Silviculture Using Single-Tree Selection

1994 ◽  
Vol 18 (3) ◽  
pp. 128-132 ◽  
Author(s):  
Paul A. Murphy ◽  
Michael G. Shelton
Keyword(s):  
Pinus Taeda ◽  
Loblolly Pine ◽  
Volume Growth ◽  
Basal Area ◽  
Site Index ◽  
Single Tree ◽  
Single Tree Selection ◽  
Pinus Taeda L ◽  
North Louisiana ◽  
Positive Effect

Abstract The effects of three levels of residual basal area (40, 60, and 80 ft2/ac), maximum dbh (12, 16, and 20 in.) and site index (< 81 ft, 81 to 90 ft, and >90 ft) on the growth of loblolly pine (Pinus taeda L.) stands after 5 yr of uneven-aged silviculture were determined from plots located in south Arkansas and north Louisiana. Designated levels of basal area and maximum dbh were achieved by harvesting; a q factor of 1.2 (using 1 in. dbh classes) was imposed on all plots as closely as possible. Stand-level models were developed for annual per acre net volume growth (merchantable cubic feet, sawtimber cubic feet, and sawtimber board feet, Doyle rule) and annual per acre survivor growth, ingrowth, and mortality components of basal area growth. Growth for all volume measures increased with an increase in basal area. Site index did not significantly affect merchantable cubic-foot growth but had a positive effect on sawtimber growth in both cubic feet and board feet, Doyle. Increases in maximum dbh decreased merchantable and sawtimber cubic-foot growth but increased growth for board-foot volume, Doyle. South. J. Appl. For. 18(3): 128-132.

Plant Community Structure and Composition in Uneven-aged Stands of Loblolly-Shortleaf Pine at Four Basal Area Levels

1995 ◽  
Vol 19 (2) ◽  
pp. 84-88 ◽  
Author(s):  
Philip A. Tappe ◽  
Michael D. Cain ◽  
T. Bently Wigley ◽  
Derik J. Reed
Keyword(s):  
Community Structure ◽  
Plant Community ◽  
Basal Area ◽  
Ground Cover ◽  
Control Treatment ◽  
Plant Community Structure ◽  
Shortleaf Pine ◽  
Single Tree ◽  
Single Tree Selection ◽  
Four Levels

Abstract The effects of overstory pine basal area on plant community structure and composition were assessed in uneven-aged stands of loblolly and shortleaf pines (Pinus taedaL. and P. echinata Mill.) in southern Arkansas. Basal area treatments were 40, 60, 80, and 100 ft2/ac for the merchantable pine component (>3.5 in. dbh) and were maintained on a 6 yr cutting cycle using single-tree selection. Assessments of plant communities were made 10 yr after a single hardwood control treatment. The four levels of pine basal area had no effect on percent ground cover of most plants <3 ft tall, but ground cover from graminoids decreased as pine basal area increased. Vertical cover above loft height increased 33% as overstory basal area increased from 40 to 100 ft2/ac, but basal area had no effect on horizontal cover in height zones between 0 and 10ft. It is concluded that uneven-aged stands of loblolly-shortleaf pine with merchantable basal areas of from 40 to 100 ft²/ac may support similar plant species in the understory and consequently probably provide similar habitat requirements for a variety of game and nongame wildlife. South. J. Appl. For. 19(2):84-88.

A 10-Year Evaluation of Prescribed Winter Burns in Uneven-Aged Stands of Pinus-Taeda L and P. Echinata Mill - Woody Understorey Vegetation Response

1993 ◽  
Vol 3 (1) ◽  
pp. 13 ◽  
Author(s):  
MD Cain
Keyword(s):  
Pinus Taeda ◽  
Prescribed Burning ◽  
Basal Area ◽  
Vegetation Response ◽  
Understorey Vegetation ◽  
Single Tree ◽  
Pine Regeneration ◽  
Single Tree Selection ◽  
Pinus Taeda L

The effects of burning cycles and pine basal area levels were assessed on natural pine regeneration and hardwood development in uneven-aged stands of loblolly and shortleaf pines (Pinus taeda L. and P. echinata Mill.). The treatments included an unburned control and prescribed winter burns at 3-, 6-, and 9-yr intervals. Basal area treatments were 9, 14, 18, and 23 m2 ha-1 for the merchantable-pine component and were maintained on a 6-yr cutting cycle using single-tree selection. Ten years after the study was initiated, density and quadrat stocking of pine regeneration were negatively correlated with overstorey basal area. The 6-yr burning cycle had higher pine density and better quadrat stocking of pine regeneration compared with any other bum treatment mainly because the 6-yr burning cycle coincided with a bumper pine seedcrop and the 6-yr cutting cycle. Recurring fires tended to result in reduced size of hardwood competition but had less impact on hardwood density. When considering a prescribed burning program in uneven-aged stands of loblolly and shortleaf pines, more attention should be given to density, quadrat stocking, and size of established pine regeneration and to expected seedcrops rather than to the prosecution of rigid burning schedules.

Growth following single-tree selection cutting in Québec northern hardwoods

2003 ◽  
Vol 79 (5) ◽  
pp. 898-905 ◽  
Author(s):  
Steve Bédard ◽  
Zoran Majcen
Keyword(s):  
Acer Saccharum ◽  
Sugar Maple ◽  
Basal Area ◽  
Northern Hardwoods ◽  
Diameter Growth ◽  
Selection Cutting ◽  
Single Tree ◽  
Basal Area Growth ◽  
Area Growth ◽  
Single Tree Selection

Eight experimental blocks were established in the southern part of Québec to determine the growth response of sugar maple (Acer saccharum) dominated stands after single tree selection cutting. Each block contained eight control plots (no cut) and eight cut plots. The intensity of removal varied between 21% and 32% and residual basal area was between 18.2 and 21 m2/ha. Ten year net annual basal area growth rates in cut plots (0.35 ± 0.04 m2/ha) were significantly higher (p = 0.0022) than in control plots (0.14 ± 0.06 m2/ha). The treatment particularly favoured diameter growth of stems between 10 and 30 cm in dbh, whose crowns were released by removing neighbouring trees. These results show that if the same net growth rate is maintained in the next decade most of the cut plots will reach their pre-cut basal area in about 20 years after cutting. Key words: northern hardwoods, selection cutting, uneven aged silviculture, basal area growth, diameter growth

scholarly journals Fifty-Year Impacts of the Beech Bark Disease in the Bartlett Experimental Forest, New Hampshire

2006 ◽  
Vol 23 (2) ◽  
pp. 141-143 ◽  
Author(s):  
William B. Leak
Keyword(s):  
New Hampshire ◽  
Basal Area ◽  
Beech Bark Disease ◽  
American Beech ◽  
Individual Tree ◽  
Single Tree ◽  
Single Tree Selection ◽  
Bartlett Experimental Forest ◽  
Selection For ◽  
Disease Free

Abstract Records from the early 1950s on the Bartlett Experimental Forest in New Hampshire showed that the percentage of American beech trees infected with heavy beech scale and Nectria was up to the 80 to 90% range. An inventory of beech bark disease conditions in three stands in 2004 showed that an older, uneven-aged stand managed by individual tree selection for 50 years had over 70% of the basal area in clean- (or disease-free) and rough-barked trees—trees that showed resistance or partial resistance to the disease; 15% of the basal area was clean. In contrast, an adjacent essentially unmanaged stand had well over 60% of the basal area in Nectria-damaged trees—those with sunken bark because of cambial mortality. A young unmanaged stand had a little over 60% of the basal area in mostly rough-barked trees. Records indicate that the amount of beech was not reduced by the disease in any of the inventoried stands. Apparently, single-tree selection over a 50-year period has substantially improved the disease resistance and merchantable potential of the stand.

Effects of diameter distribution on the growth of simulated uneven-aged sugar maple stands

1987 ◽  
Vol 17 (1) ◽  
pp. 1-8 ◽  
Author(s):  
Gerald D. Hansen ◽  
Ralph D. Nyland
Keyword(s):  
Sugar Maple ◽  
Basal Area ◽  
Tree Size ◽  
Diameter Distribution ◽  
Computer Simulation Model ◽  
Maximum Volume ◽  
Size Classes ◽  
Management Objectives ◽  
Stress Maximum ◽  
Volume Production

Effects of diameter distribution on the growth of simulated uneven-aged sugar maple (Acersaccharum Marsh.) stands are described using output from a computer simulation model. Results indicate that the combination of q ratio (a constant ratio between the numbers of trees present in adjacent diameters over the entire range of size classes present), maximum tree size, and basal area should vary depending on management objectives and cutting cycle length. A ratio of 1.2 appears best for describing a diameter distribution to maximize growth of large sawtimber, but larger q ratios are needed in the sapling and pole size classes to insure sufficient numbers of trees to sustain the distribution through the end of a cutting cycle. Retaining trees larger than a 40 cm diameter at breast height offers no advantage when objectives stress maximum volume production. A 50 cm maximum tree size appears better suited for maximizing large sawtimber volume and value growth, but a 40 cm maximum will yield a better compound rate of return on initial stand value. Under all options, longer cutting cycles require lower initial basal area levels.

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.

Proportional basal area method for implementing selection silviculture systems in longleaf pine forests

2014 ◽  
Vol 44 (8) ◽  
pp. 977-985 ◽  
Author(s):  
Dale G. Brockway ◽  
Edward F. Loewenstein ◽  
Kenneth W. Outcalt
Keyword(s):  
Longleaf Pine ◽  
Volume Growth ◽  
Basal Area ◽  
Pinus Palustris ◽  
Selection Systems ◽  
Pine Regeneration ◽  
Large Trees ◽  
Single Tree Selection ◽  
Pass Through ◽  
Specific Species

Proportional basal area (Pro-B) was developed as an accurate, easy-to-use method for making uneven-aged silviculture a practical management option. Following less than 3 h of training, forest staff from a range of professional backgrounds used Pro-B in an operational-scale field study to apply single-tree selection and group selection systems in longleaf pine (Pinus palustris Mill.) stands. Field crews achieved precision levels often within 3%–5% of the 11.5 m2·ha−1 target residual basal area. By aggregating many diameter classes into only three diameter-class groups, Pro-B improves efficiency by requiring tree markers to remember only three fractions, while making a single pass through the stand. Trees of large size, specific species and with good form, broad crowns and cavities can be retained, while adjusting spacing to release residuals. Systematic quantification of marking trees for removal enables different individuals to obtain similar results. Early observations revealed encouraging levels of pine regeneration and stand development, along with continuing good volume growth rates of 3% per year. Although less certain until one or more cutting cycles are completed, these early tests indicate that a stable mature forest structure should develop, which is characterized by the presence of large trees and natural regeneration.

Effect of Hexazinone Rate and Formulation on Loblolly Pine in Broadcast Release Applications

1991 ◽  
Vol 15 (1) ◽  
pp. 54-61 ◽  
Author(s):  
Glenn R. Glover ◽  
Bruce R. Zutter ◽  
Patrick J. Minogue ◽  
Dean H. Gjerstad
Keyword(s):  
Loblolly Pine ◽  
Growth Response ◽  
Foliar Spray ◽  
Basal Area ◽  
Soil Characteristics ◽  
Liquid Formulation ◽  
Maximum Volume ◽  
Sand Surface ◽  
Volume Production ◽  
Pellet Formulation

Abstract Growth response and mortality of loblolly pine were examined 5 or 6 years after broadcast applications of four rates of pellet and liquid (applied as a foliar spray) hexazinone formulations for pine release at seven locations across the South varying in soil characteristics. Adjusted hardwood rootstock density 2 years following treatment was significantly affected by treatment and rate at all locations, and by formulation at five of the seven locations. Pine mortality was positively related to hexazinone rate at four of the study locations. Mortality was significantly higher for the pellet formulation compared to the liquid at the two locations with loamy sand surface soils. Mortality averaged less than 10% for the prescribed rate of both formulations at five of the seven locations, and at a sixth location for the pellet formulation. Mean pine height and dbh responses across hexazinone rates were greater than no treatment (check) at three and five locations, respectively. Response in dbh was positively related to hexazinone rate at three locations, and inversely related to rootstock density 2 years after treatment at six of seven locations. Mean treatment response for pine basal area and total volume (outside bark) per acre were significantly greater than the check at only two locations due to high pine mortality at some locations for 1.4X and 2.0X the prescribed rate. Mean increases in volume of the prescribed rate over the check were 9 and 7% for the pellet and liquid formulations, respectively. Maximum volume production increases across locations were 13% for the pellet formulation and 15% for the liquid formulation. South J. Appl. For. 15(1):54-61.

scholarly journals Application and limitations of growth models for silvicultural purposes in heterogeneously structured forest in Sweden

2013 ◽  
Vol 59 (No. 11) ◽  
pp. 458-473 ◽  
Author(s):  
L. Drössler ◽  
N. Fahlvik ◽  
B. Elfving
Keyword(s):  
Growth Models ◽  
Basal Area ◽  
Single Tree ◽  
Growth Functions ◽  
Basal Area Growth ◽  
Area Growth ◽  
Single Tree Selection ◽  
Spruce Stands ◽  
Selection Forest ◽  
Using Data

The paper addresses the problem of estimating future stand development in heterogeneously structured forests in Sweden; specifically, multi-layered spruce stands and mature pine stands with advanced spruce undergrowth. We first introduce various supporting concepts and models with their empirical databases, model validation and constraints. Secondly, Swedish single-tree growth functions designed for more heterogeneously structured forest are tested using data from inventory plots, a thinning experiment in an uneven-aged forest stand, and yield plots in pristine forest. Future growth of a managed, multi-layered forest was simulated and is compared with other selected functions. Simulation results, expected errors and time constraints are discussed. For most models, projected stand basal area growth deviated 10&ndash;20% from the observed growth in individual stands. In single stands, the deviation ranged from 0 to 60%. Validation periods were often 5&ndash;15 years, sometimes even more than 30 years. For Swedish single-tree basal area growth functions, on average, a 5% overestimate was found for heterogeneously structured forest across Sweden. Observed growth in a boreal single-tree selection forest was underestimated by 12.5% fifteen years after thinning from above.

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