scholarly journals Early response of Nothofagus antarctica forests to thinning intensity in northern Patagonia

2020 ◽  
Author(s):  
Matias G. Goldenberg ◽  
Marcos Nacif ◽  
Facundo Oddi ◽  
Lucas Garibaldi
Keyword(s):  
Forest Type ◽  
Volume Growth ◽  
Early Response ◽  
Annual Increment ◽  
Basal Diameter ◽  
Stand Volume ◽  
Thinning Intensity ◽  
Northern Patagonia ◽  
Silvicultural Treatments ◽  
Nothofagus Antarctica

Nothofagus antarctica (G. Forst.) Oerst. stands of northern Patagonia (Argentina) have great potential to provide multiple ecosystem services. Nonetheless, the lack of basic information limits the application of silvicultural treatments to this forest type. This study reports the early response to three systematic strip thinning treatments (30, 50, and 70%) carried out during 2013 in a 30-year N. antarctica stand, where control plots (i.e. no thinning) were also established. Subplots were located within each plot. Basal diameters (BD) of all retained stems were measured in the non-vegetative season (winter) of 2016, 2017 and 2018, to calculate basal diameter annual increment (BDI), and stand volume growth. BDI ranged from 1.9 mm year-1 in the control plots to 2.7 mm year-1 at 70% thinning. Relative BDI also responded positively to thinning intensity. Stand volume growth decreased non-linearly with thinning intensity, from 3.36 m3 ha-1 year-1 in the control plots, and 0.71 m3 ha-1 year-1 when thinning was 70%. Smaller differences were observed between control plots, 30% thinning and 50% thinning. Our results show that Nothofagus antarctica forests, in the stem exclusion stage, respond to strip thinning. Thus, silviculture based on this management system could favor the development of retained trees without losing productivity if it remains under 50% intensity. This outcome represents an important incremental contribution to the design of silvicultural interventions in northern Patagonia.

scholarly journals Effects of Thinning Practice, High Pruning and Slash Management on Crop Tree and Stand Growth in Young Even-Aged Stands of Planted Silver Birch (Betula pendula Roth)

Forests ◽  
2021 ◽  
Vol 12 (2) ◽  
pp. 225
Author(s):  
Jens Peter Skovsgaard ◽  
Ulf Johansson ◽  
Emma Holmström ◽  
Rebecka McCarthy Tune ◽  
Clémentine Ols ◽  
...  
Keyword(s):  
Betula Pendula ◽  
Volume Growth ◽  
Stem Diameter ◽  
Silver Birch ◽  
Stand Volume ◽  
Annual Increase ◽  
Stand Growth ◽  
Thinning Intensity ◽  
Betula Pendula Roth ◽  
Increased Risk

The objective was to quantify the influence of thinning, high pruning and slash management on crop tree and stand growth in young even-aged stands of planted silver birch (Betula pendula Roth). This study was based on two field experiments, aged six and eleven years at initiation and re-measured after six and eight years, respectively. Treatments included the unthinned control, moderate thinning mainly from below (removing 28–33% of standing volume), point thinning to favor 300 trees per ha and with no thinning elsewhere in the plot (removing 16–25%), and heavy thinning leaving 600 evenly distributed potential future crop trees per ha (removing 64–75%). Slash management (extraction or retention) was applied to heavily thinned plots. High pruning removing 30–70% of the green crown was carried out in some plots with point or heavy thinning on 300 or 600 trees per ha, respectively. Stand volume growth increased with increasing pre-treatment mean annual volume increment and decreased with increasing thinning intensity as compared to the unthinned control. LS-means estimates indicated a reduction for moderate thinning by 14%, for point thinning by 12% and for heavy thinning (combined with pruning) by 62%. However, in the youngest experiment, heavy thinning (without pruning) reduced growth by 54%. Combining these results with results from a similar experiment in Canada, the reduction in stand volume growth (RedIv%) depending on thinning removal (RemV%), both expressed as a percentage of the unthinned control, was quantified as RedIv% = −23.67 + 1.16·RemV% (calibration range: 30–83%). For heavy thinning (large quantities of slash), slash extraction resulted in no reduction in stand volume growth as compared to slash retention. The instantaneous numeric reduction in the average stem diameter of the 300 thickest trees per ha (D300) due to thinning was 3.5, 15–21% and 955–11% with moderate, point and heavy thinning, respectively. The subsequent average annual increase in D300 during the observation period was 8.5%, 25 and 18%, respectively. In the youngest experiment, pruning in unthinned plots led to a reduction in the annual increase of D300 by 14%, and heavy thinning in unpruned plots led to an increase by 30%. The growth of pre-selected potential future crop trees increased with increasing thinning intensity. In heavily thinned plots, pruning reduced growth increasingly with increasing pruning severity; LS-means estimates indicated 21% larger growth on stem diameter for unpruned trees and 3% for pruned trees. As an adverse side effect, heavily thinned plots with only 600 trees per ha were at increased risk of windthrow for some years after the thinning intervention. In the oldest experiment, 95–21% of the trees in these plots were damaged by wind.

Optimal stand density: a solution

2004 ◽  
Vol 34 (4) ◽  
pp. 846-854 ◽  
Author(s):  
Boris Zeide
Keyword(s):  
High Current Density ◽  
Volume Growth ◽  
Stand Density ◽  
Average Diameter ◽  
Tree Size ◽  
Maximum Volume ◽  
Annual Increment ◽  
Stand Volume ◽  
Diameter Increment ◽  
Crown Closure

The search for a stand density that maximizes total volume growth has continued since the beginning of forestry without producing a definite answer. One of the reasons is that the effect of density on growth is not always separated from those of tree size and age. Such a separation is not easy when the relationship between density and growth is expressed as a graph (Langsaeter's curve). This study develops a simple model that accounts for each main growth predictor individually. It allows one to calculate the density that maximizes volume growth at any given moment (current annual increment of volume). Just as the maximum Reineke's index, this density optimum does not change with age. Fitting the model to long-term data confirms the obvious: because a complete crown closure intercepts more light than a broken canopy, the densest stands produce maximum volume growth. Thus, the current optimal density is equal to maximum density. What is less obvious is that maximum current stand volume growth does not sum up to maximum stand volume. In addition to density, stand volume depends on average tree size, which is larger in less dense stands. The high current density that maximizes volume growth also minimizes diameter increment, which eventually reduces average diameter and stand volume. When density is kept at a stationary (over time) level by thinning, maximum volume is produced by stands with substantially lower density than the current optimum. even higher volume can probably be obtained when density changes with age. The challenge is to find this optimum path of density.

Upland black spruce stand development 17 years after cleaning and precommercial thinning

2005 ◽  
Vol 81 (1) ◽  
pp. 31-41 ◽  
Author(s):  
R L Fleming ◽  
D S Mossa ◽  
G T Marek
Keyword(s):  
Black Spruce ◽  
Basal Area ◽  
Fibre Production ◽  
Stand Development ◽  
Annual Increment ◽  
Stand Volume ◽  
Quadratic Mean ◽  
Precommercial Thinning ◽  
Thinning Intensity ◽  
Four Levels

Density management is often used by silviculturists to guide stand composition and development. We examined the effects of cleaning (hardwood removal) and four levels of precommercial thinning (0, 20, 35 and 50% basal area removal) on stand development in a dense, 24-year-old upland black spruce (Picea mariana [Mill.] BSP) plantation near Beardmore, Ontario. Immediately before treatment, stand densities and basal areas for all species and for black spruce averaged 7375 and 6415 stems ha-1, and 27.9 and 20.5 m2 ha-1, respectively. Seventeen years after treatment, black spruce total stand volume (VT) was higher in the cleaned, unthinned plots (243 m3 ha-1) than in the untreated controls (171 m3 ha-1) while total stand volume increment of all species combined was similar in these two treatments. Compared with cleaning alone, thinning cleaned plots from below increased quadratic mean diameters (DQ) by up to 9% but decreased VT by up to 28%. At plantation age 41, increases in black spruce densities of 1000 stems ha-1 resulted in mean decreases of 0.6 cm in DQ and mean increases of 43 m3 ha-1 in VT. Endemic black spruce stem mortality rates decreased with thinning intensity, with mortality concentrated in the smallest size classes. In some plots, mortality was increased by wind or snow damage, and by root rots. Height increment of dominant trees was unaffected by thinning. Projected yields at age 55 (the physical rotation age—the age at which maximum mean annual increment occurs) suggest the heaviest precommercial thinning could increase quadratic mean diameter from 16.1 to 17.7 cm, but decrease merchantable stand volume from 292 to 225 m3 ha-1. Results indicate that total black spruce fibre yields and product value on these sites will be maximized in denser stands. Cleaning appears to offer greater benefits for black spruce fibre production than precommercial thinning. Key words: black spruce, precommercial thinning, cleaning, density management, projected yields

scholarly journals Developing Growth Models of Stand Volume for Subtropical Forests in Karst Areas: A Case Study in the Guizhou Plateau

Forests ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 83
Author(s):  
Yuzhi Tang ◽  
Quanqin Shao ◽  
Tiezhu Shi ◽  
Guofeng Wu
Keyword(s):  
Growth Models ◽  
Volume Growth ◽  
Site Quality ◽  
Rocky Desertification ◽  
Stand Volume ◽  
Subtropical Forests ◽  
Karst Areas ◽  
Growth Equations ◽  
Global Carbon ◽  
Guizhou Plateau

Forest stand volume is one of the key forest structural attributes in estimating and forecasting ecosystem productivity and carbon stock. However, studies on growth modeling and environmental influences on stand volume are still rare to date, especially in subtropical forests in karst areas, which are characterized by a complex species composition and are important in the global carbon budget. In this paper, we developed growth models of stand volume for all the dominant tree species (groups) (DTSG) in a subtropical karst area, the Guizhou Plateau based on an investigation of the effects of various environmental factors on stand volume. The Richards growth function, space-for-time substitution and zonal-hierarchical modeling method were applied in the model fitting, and multiple indices were used in the model evaluation. The results showed that the climatic factors of annual temperature and precipitation, as well as the site factors of stand origin, elevation, slope gradient, topsoil thickness, site quality degree, rocky desertification type and rocky desertification degree, have significant influences on stand volume, and the topsoil thickness and site quality degree have the strongest positive effect. A total of 959 growth equations of stand volume were fitted with a five-level stand classifier (DTSG–climatic zone–site quality degree–stand origin–rocky desertification type). All the growth equations were qualified, because all passed the TRE test (≤30%), and the majority of the R2 ≥ 0.50, above 70% of the RMSE were between 5.0 and 20.0, and above 80% of the P ≥ 75%. These findings provide updated knowledge about the environmental effect on the stand volume growth of subtropical forests in karst areas, and the developed stand volume growth models are convenient for forest management and planning, further contributing to the study of forest carbon storage assessments and global carbon cycling.

GROWTH AND MORPHOGENESIS IN THE CANADIAN FOREST SPECIES: II. SPECIFIC INCREMENTS AND THEIR RELATION TO THE QUANTITY AND ACTIVITY OF GROWTH IN PINUS RESINOSA AIT.

1957 ◽  
Vol 35 (4) ◽  
pp. 527-572 ◽  
Author(s):  
G. H. Duff ◽  
Norah J. Nolan
Keyword(s):  
Apical Meristem ◽  
Specific Growth ◽  
Volume Growth ◽  
Ring Width ◽  
Pinus Resinosa ◽  
Forest Species ◽  
Annual Increment ◽  
Wood Volume ◽  
Two Measures ◽  
The Mean

Two measures are needed to describe numerically the activity of the internodal cambium in terms of annual increment. These are "specific wood volume increment", a measure of additive growth and "specific increment of cambial area", a measure of multiplicative growth. The mean area of the internodal cambium is the basis of reference for both since it is the measure of that which is active in growth. The former measure of specific growth is numerically equal to ring width and the manner of its factorial control has already been considered. Data for the latter are new.The geometry of the apical meristem and its products is too complex for the ready computation of specific terminal growth, but it can be shown empirically that internode length is a valid measure of apical activity. Analysis of internodal wood volume growth into its three linear components leads to the conclusion that the determinants in control of wood growth act mainly through their effect upon apical activity and upon specific increment of cambial area.

scholarly journals TREE DIAMETER GROWTH FOLLOWING SILVICULTURAL TREATMENTS IN A SEMI-DECIDUOUS SECONDARY FOREST IN CENTRAL BRAZIL

CERNE ◽  
2015 ◽  
Vol 21 (1) ◽  
pp. 117-123 ◽  
Author(s):  
Fábio Venturoli ◽  
Augusto César Franco ◽  
Christopher William Fagg
Keyword(s):  
Radial Growth ◽  
Deciduous Forest ◽  
Secondary Forest ◽  
Basal Area ◽  
Diameter Growth ◽  
Annual Increment ◽  
Tree Diameter ◽  
Central Brazil ◽  
Silvicultural Treatments ◽  
Timber Market

In the Cerrado biome of Brazil, savannas and dry forests are intimately linked and form mosaics. These forests are composed of species of high commercial value, well accepted in the timber market, which causes intensive deforestation on the remaining vegetation. Thus, the management of these forests is an important alternative to reduce deforestation in the remaining vegetation. The objective of this study was to analyze the response of tree species in relation to silvicultural treatments of competition and liana cutting in a semi-deciduous forest in Central Brazil. The results showed that community basal area increased 24% over 4.8 years and the median periodic annual increment in diameter was about 20% higher in plots with silvicultural treatments: 2.9 mm.yr-1 in the control compared to 3.2 mm.yr-1 to 3.6 mm.yr-1 between treatments. This study demonstrated that it is possible to increase the rates of radial growth through silvicultural techniques.

scholarly journals Restoration of Shortleaf Pine (Pinus echinata)-Hardwood Mixtures in Low Quality Mixed Upland Hardwood Stands Using Cluster Planting and Natural Regeneration

Forests ◽  
2020 ◽  
Vol 11 (4) ◽  
pp. 457
Author(s):  
David Clabo ◽  
Wayne Clatterbuck
Keyword(s):  
Natural Regeneration ◽  
Forest Type ◽  
Early Stage ◽  
Timber Harvesting ◽  
Site Preparation ◽  
Pinus Echinata ◽  
Shortleaf Pine ◽  
Burn Treatment ◽  
Basal Diameter ◽  
Cumberland Mountains

Cluster planting of shortleaf pine, along with various site preparation and release treatments, were tested to restore mixed shortleaf pine (Pinus echinata Mill.)–hardwood stands in areas where the shortleaf pine has diminished in recent years. Shortleaf pine–hardwood mixtures were once a common forest type throughout the Cumberland Mountains and Plateau physiographic regions of the southeastern United States. Knowledge of how to restore shortleaf pine–hardwood mixtures is limited throughout shortleaf pine’s large native range. The objectives of this study were to compare planted shortleaf pine and natural hardwood regeneration survival, growth, and composition following various site preparation and early release treatments. Cluster planting and partial timber harvesting were used to reintroduce shortleaf pine and create two-aged stands in the Cumberland Mountains of Tennessee, USA. Results indicated that shortleaf pine survival, basal diameter, and height growth did not differ following four growing seasons among treatments. Natural regeneration stem densities and heights within shortleaf pine clusters did not differ significantly by treatment. Natural regeneration stem densities differed by species group and height class across the site, while the treatment × species interaction term was also significant. At this early stage of stand development, the brown-and-burn treatment appears poised for greater shortleaf pine growth rates than the other treatments. The herbicide treatment had the fewest regenerating hardwoods per hectare and the most desirable hardwood species composition.

scholarly journals Increased Individual Tree Growth Maintains Stand Volume Growth after B-Level Thinning and Crop-Tree Management in Mature Oak Stands

2019 ◽  
Vol 65 (6) ◽  
pp. 784-795
Author(s):  
Jeffrey S Ward ◽  
Jessica Wikle
Keyword(s):  
Tree Growth ◽  
Growth Response ◽  
Volume Growth ◽  
Diameter Growth ◽  
Red Oak ◽  
Individual Tree ◽  
Stand Volume ◽  
Tree Management ◽  
Individual Tree Growth ◽  
Partial Release

AbstractSix study areas were established in 80–125-year-old upland oak stands on average sites to compare stand and individual tree growth response following two active treatments (B-level thinning, crop tree) with an unmanaged control. Initial stocking of 104 percent was reduced to 62 percent and 60 percent on the B-level and crop-tree-management plots, respectively. Approximately 7,200 board feet per acre (International ¼) were harvested on the actively managed plots with upland oaks accounting for 81 percent of pre- and 86 percent of residual stand. Eleven-year diameter and volume growth of oak sawtimber trees was greater on actively managed plots. Growth response increased with degree of release and was maintained for the length of the study. Because of the increased individual tree growth of oaks in response to release, stand volume growth of oak sawtimber did not differ between treatments. In contrast to an 11-year decline of poletimber stocking on unmanaged plots, poletimber stocking increased on managed plots as diameter growth increased in response to partial release. This may increase difficulty of regenerating oak in the future. For those mature red oak stands where traditional regeneration prescriptions will not be implemented or will be delayed, commercial harvests can be conducted without compromising stand volume growth of oak.

scholarly journals RESPON PERTUMBUHAN TANAMAN JATI PLUS PERHUTANI UMUR 11 TAHUN TERHADAP INTENSITAS PENJARANGAN DAN TUMPANG SARI (STUDI KASUS DI BKPH BEGAL KPH NGAWI, PERHUTANI JAWA TIMUR)

2021 ◽  
Vol 15 (1) ◽  
pp. 13-23
Author(s):  
Muhammad Fadhil Amiruddin Sudomo ◽  
◽  
Suryo Hadiwinoto ◽  
Sapto Indrioko ◽  
Budiadi Budiadi ◽  
...  
Keyword(s):  
Growth Response ◽  
Block Design ◽  
First Year ◽  
Annual Increment ◽  
Thinning Intensity ◽  
Management Actions ◽  
Randomized Block Design ◽  
Main Plot ◽  
One Year

Thinning is one of silvicultural management actions in maintaining and increasing growth and quality of standing stands. This study aims to determine growth response of selected teak clone to several intensities of thinning and intercropping. The method was a factorial completely randomized block design (RCBD) with thinning intensity (4 levels): 0% (control = A1), 25% (A2), 50% (A3) and 75% (A4) as the main plot, whileintercropping (2 levels), as the sub plot. The results showed that the Current Annual Increment (CAI) of diameter at breast height (CAI DBH), volume/tree (CAI vol/tree) and volume/hectare (CAI vol/ha) of stands gave a significant positive response to thinning intensity treatment. CAI DBH one year after thinning were 0.79 cm, 1.47 cm, and 2.46 cm; increased by 32%, 145% and 310% at the thinning intensity of 25%, 50% and 75% when they compared with the control (0.59 cm). CAI vol/ha of stand in the first year, namely 11.88 m3/ha, 14.04 m3/ha, and 16.78 m3/ha or with an increase of 9%, 29% and 54% respectively at an intensity of 25 %, 50% and 75% compared to the control.

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