scholarly journals Na effects of heavy thinning on Turkey oak tree and stand increment in the five-year period

2003 ◽  
pp. 81-93
Author(s):  
Martin Bobinac ◽  
Milivoj Vuckovic ◽  
Sinisa Andrasev
Keyword(s):  
Annual Ring ◽  
Basal Area ◽  
Stand Age ◽  
Tree Decline ◽  
Wood Volume ◽  
Diameter Increment ◽  
Ring Diameter ◽  
Turkey Oak ◽  
Oak Tree ◽  
Area And Volume

The effects of heavy thinning on tree and stand increment were studied on sample plots in the artificially established Turkey oak stand, aged 51 years. Before thinning, extremely low height and diameter increments were recorded and also the process of revitalization and tree decline. Heavy thinning at the stand age of 46 years removed 38.0% of trees and 31. 4% of wood volume. Five years later, on the heavily thinned plot, a lower current increment of basal area and volume per ha for 10-13% was measured, while the percentage of volume increment increased for 13%, and the diameter increment of the remaining trees for 17%. In the period after thinning, annual ring diameter increased in model trees for 1. 76- 2. 59 times compared to the previous five-year period.

scholarly journals Effects of heavy thinnings on the increment and selection of trees for tending in Norway spruce monoculture in natural hazard conditions

2017 ◽  
pp. 31-54
Author(s):  
Martin Bobinac ◽  
Sinisa Andrasev ◽  
Andrijana Bauer-Zivkovic ◽  
Nikola Susic
Keyword(s):  
Norway Spruce ◽  
Growth Stage ◽  
Natural Hazard ◽  
Basal Area ◽  
Growth Potential ◽  
Stand Age ◽  
Diameter Increment ◽  
Volume Increment ◽  
Selection Of ◽  
Area And Volume

The paper studies the effects of two heavy selection thinnings on the increment of Norway spruce trees exposed to ice and snow breaks in eastern Serbia. In a thinning that was carried out at 32 years of age, 556 candidates per hectare were selected for tending, and at the age of 40, of the initial candidates, 311 trees per hectare (55.9%) were selected as future trees. In all trees at 41-50 age period, diameter increment was higher by 31%, basal area increment by 64% and volume increment by 67% compared to 32-40 age period. The collective of indifferent trees is significantly falling behind compared to future trees in terms of increment values in both observed periods. However, the value of diameter, basal area and volume increments, of the collective of "comparable" indifferent trees are lower in comparison to the values of increments of future trees by 10-15% in the 32-40 age period, and by 15-21% in the 41-50 age period and there are no significant differences. The results show that heavy selective thinnings, initially directed at a larger number of candidates for tending at stand age that does not differ much from the period of carrying out first "commercial" thinnings, improve the growth potential of future and indifferent trees, where it is rational to do the tree replacement for the final crop in "susceptible" growth stage to snow and ice breaks.

scholarly journals Generalized Nonlinear Mixed-Effects Individual Tree Diameter Increment Models for Beech Forests in Slovakia

Forests ◽  
2019 ◽  
Vol 10 (5) ◽  
pp. 451 ◽  
Author(s):  
Ram P. Sharma ◽  
Igor Štefančík ◽  
Zdeněk Vacek ◽  
Stanislav Vacek
Keyword(s):  
Basal Area ◽  
European Beech ◽  
Site Index ◽  
Development Stage ◽  
Mixed Effects ◽  
Site Quality ◽  
Stand Age ◽  
Sample Plot ◽  
Individual Tree ◽  
Diameter Increment

Individual tree growth and yield models precisely describe tree growth irrespective of stand complexity and are capable of simulating various silvicultural alternatives in the stands with diverse structure, species composition, and management history. We developed both age dependent and age independent diameter increment models using long-term research sample plot data collected from both monospecific and mixed stands of European beech (Fagus sylvatica L.) in the Slovak Republic. We used diameter at breast height (DBH) as a main predictor and other characteristics describing site quality (site index), stand development stage (dominant height and stand age), stand density or competition (ratio of individual tree DBH to quadratic mean diameter), species mixture (basal area proportion of a species of interest), and dummy variable describing stand management regimes as covariate predictors to develop the models. We evaluated eight versatile growth functions in the first stage using DBH as a single predictor and selected the most suitable one, i.e., Chapman-Richards function for further analysis through the inclusion of covariate predictors. We introduced the random components describing sample plot-level random effects and stochastic variations on the diameter increment, into the models through the mixed-effects modelling. The autocorrelation caused by hierarchical data-structure, which is assumed to be partially reduced by mixed-effects modelling, was removed through the inclusion of the parameter accounting for the autoregressive error-structures. The models described about two-third parts of a total variation in the diameter increment without significant trends in the residuals. Compared to the age independent mixed-effects model (conditional coefficient of determination, R c 2 = 0.6566; root mean square error, RMSE = 0.1196), the age dependent model described a significantly larger proportion of the variations in diameter increment ( R c 2 = 0.6796, RMSE = 0.1141). Diameter increment was significantly influenced differently by covariate predictors included into the models. Diameter increment decreased with the advancement of stand development stage (increased dominant height and stand age), increasing intraspecific competition (increased basal area proportion of European beech per sample plot), and diameter increment increased with increasing site quality (increased site index) and decreased competition (increased ratio of DBH to quadratic mean diameter). Our mixed-effects models, which can be easily localized with the random effects estimated from prior measurement of diameter increments of four randomly selected trees per sample plot, will provide high prediction accuracies. Our models may be used for simulating growth of European beech irrespective of its stand structural complexity, as these models have included various covariate variables describing both tree-and stand-level characteristics, thinning regimes, except the climate characteristics. Together with other forest models, our models will be used as inputs to the growth simulator to be developed in the future, which is important for decision-making in forestry.

scholarly journals Utjecaj intenziteta prorjeda na rast azijske bukve (Fagus orientalis Lipsky) u plantažama u Trabzonu na sjeveroistoku Turske

2019 ◽  
Vol 143 (5-6) ◽  
pp. 231-240
Author(s):  
Ayhan Usta ◽  
Ibrahim Turna ◽  
Esengül Genc ◽  
Yavuz Okunur Kocamanoglu ◽  
Selvinaz Yilmaz ◽  
...  
Keyword(s):  
Basal Area ◽  
Average Diameter ◽  
Average Height ◽  
Sample Plot ◽  
Fagus Orientalis ◽  
Thinning Intensity ◽  
Diameter Increment ◽  
Oriental Beech ◽  
Fagus Orientalis Lipsky ◽  
Area And Volume

In this study, the effects of first thinnings having different intensities in oriental beech (Fagus orientalis Lipsky) plantation areas were investigated in terms of diameter and height growth of trees. Sample plots were chosen from oriental beech plantation areas which are within the boundaries of Maçka–Yeşiltepe and Vakfıkebir districts of Trabzon province, Turkey. With removing of 0%, 10%, 25% and 40% of basal area in a hectare of stands which are in sapling stage, sample plots were established by applying thinnings which are in four different intensities (control, light, moderate, strong). After the thinning applications, basal areas were calculated by measuring diameters and heights of trees in established sample plots in order to reveal stand growth. The effects of thinnings were revealed related to some stand characteristics (average diameter, basal area, average height, relative diameter increment, etc.) and determined chosen trees. The effect of thinning intensity on average diameter, basal area, and volume values is statistically important in every two plantations. 2-year results showed that thinning increased the diameter increment significantly, and the increase in diameter increment was positively correlated with the thinning intensity in both experiments. Moreover, increments of diameter, height, basal area, and volume were higher in Maçka-Yeşiltepe experiment than in Vakfıkebir experiment. But, the values of moderate and strong thinning intensities applied in Vakfıkebir were close to each other. When all the results are evaluated, application of strong thinning intensity for Yeşiltepe sample plot, the moderate thinning intensity for Vakfıkebir sample plot is seen appropriate by us in terms of both stand development.

scholarly journals The Difficulty of Predicting Eastern Spruce Dwarf Mistletoe in Lowland Black Spruce: Model Benchmarking in Northern Minnesota, USA

Forests ◽  
2021 ◽  
Vol 12 (7) ◽  
pp. 843
Author(s):  
Ella R. Gray ◽  
Matthew B. Russell ◽  
Marcella A. Windmuller-Campione
Keyword(s):  
Stand Structure ◽  
Black Spruce ◽  
Forest Health ◽  
Basal Area ◽  
Predictive Performance ◽  
Stand Age ◽  
Management Decisions ◽  
Dwarf Mistletoe ◽  
Growing Seasons ◽  
Model Interpretation

Insects, fungi, and diseases play an important role in forest stand development and subsequently, forest management decisions and treatments. As these disturbance agents commonly occur within and across landscapes, modeling has often been used to inform forest planning and management decisions. However, models are rarely benchmarked, leaving questions about their utility. Here, we assessed the predictive performance of a Bayesian hierarchical model through on–the-ground sampling to explore what features of stand structure or composition may be important factors related to eastern spruce dwarf mistletoe (Arceuthobium pusillum Peck) presence in lowland black spruce (Picea mariana (Mill.) B. S. P.). Twenty-five state-owned stands included in the predictive model were sampled during the 2019 and 2020 growing seasons. Within each stand, data related to the presence of eastern spruce dwarf mistletoe, stand structure, and species composition were collected. The model accurately predicted eastern spruce dwarf mistletoe occurrence for 13 of the 25 stands. The amount of living and dead black spruce basal area differed significantly based on model prediction and observed infestation, but trees per hectare, total living basal area, diameter at breast height, stand age, and species richness were not significantly different. Our results highlight the benefits of model benchmarking to improve model interpretation as well as to inform our understanding of forest health problems across diverse stand conditions.

Root rot damage in naturally regenerated stands of spruce and balsam fir in Ontario

1989 ◽  
Vol 19 (3) ◽  
pp. 295-308 ◽  
Author(s):  
R. D. Whitney
Keyword(s):  
Root Rot ◽  
Black Spruce ◽  
Basal Area ◽  
Ground Level ◽  
White Spruce ◽  
Balsam Fir ◽  
Tree Age ◽  
Stand Age ◽  
Root Decay ◽  
Forest Region

In an 11-year study in northern Ontario, root rot damage was heaviest in balsam fir, intermediate in black spruce, and least in white spruce. As a result of root rot, 16, 11, and 6%, respectively, of dominant or codominant trees of the three species were killed or experienced premature windfall. Butt rot, which resulted from the upward extension of root rot into the boles of living trees, led to a scaled cull of 17, 12, and 10%, respectively, of gross merchantable volume of the remaining living trees in the three species. The total volume of wood lost to rot was, therefore, 33, 23, and 16%, respectively. Of 1108 living dominant and codominant balsam fir, 1243 black spruce, and 501 white spruce in 165 stands, 87, 68, and 63%, respectively, exhibited some degree of advanced root decay. Losses resulting from root rot increased with tree age. Significant amounts of root decay and stain (>30% of root volume) first occurred at 60 years of age in balsam fir and 80 years in black spruce and white spruce. For the three species together, the proportion of trees that were dead and windfallen as a result of root rot increased from an average of 3% at 41–50 years to 13% at 71–80 years and 26% at 101–110 years. The root rot index, based on the number of dead and windfallen trees and estimated loss of merchantable volume, also increased, from an average of 17 at 41–50 years to 40 at 71–80 years and 53 at 101–110 years. Death and windfall of balsam fir and black spruce were more common in northwestern Ontario than in northeastern Ontario. Damage to balsam fir was greater in the Great Lakes–St. Lawrence Forest region than in the Boreal Forest region. In all three tree species, the degree of root rot (decay and stain) was highly correlated with the number of dead and windfallen trees, stand age, and root decay at ground level (as a percentage of basal area) for a 10-tree sample.

Inoptimality losses in forest management decisions caused by errors in an inventory based on airborne laser scanning and aerial photographs

2010 ◽  
Vol 40 (12) ◽  
pp. 2427-2438 ◽  
Author(s):  
Md. Nurul Islam ◽  
Mikko Kurttila ◽  
Lauri Mehtätalo ◽  
Timo Pukkala
Keyword(s):  
Input Data ◽  
Laser Scanning ◽  
Basal Area ◽  
Airborne Laser Scanning ◽  
Aerial Photographs ◽  
Stand Age ◽  
Inventory Data ◽  
Airborne Laser ◽  
Mean Diameter ◽  
The Mean

Errors in inventory data may lead to inoptimal decisions that ultimately result in financial losses for forest owners. We estimated the expected monetary losses resulting from data errors that are similar to errors in laser-based forest inventory. The mean loss was estimated for 67 stands by simulating 100 realizations of inventory data for each stand with errors that mimic those in airborne laser scanning (ALS) based inventory. These realizations were used as input data in stand management optimization, which maximized the present value of all future net incomes (NPV). The inoptimality loss was calculated as the difference between the NPV of the optimal solution and the true NPV of the solution obtained with erroneous input data. The results showed that the mean loss exceeded €300·ha–1 (US$425·ha–1) in 84% of the stands. On average, the losses increased with decreasing stand age and mean diameter. Furthermore, increasing errors in the basal area weighted mean diameter and basal area of spruce were found to significantly increase the loss. It has been discussed that improvements in the accuracy of ALS-based inventory could be financially justified.

scholarly journals Stand Structure, Productivity and Carbon Sequestration Potential of Oak Dominated Forests in Kumaun Himalaya

2016 ◽  
Vol 11 (2) ◽  
pp. 466-476
Author(s):  
Bijendra Lal ◽  
L.S. Lodhiyal
Keyword(s):  
Carbon Sequestration ◽  
Primary Productivity ◽  
Tree Species ◽  
Stand Structure ◽  
Basal Area ◽  
Forest Site ◽  
Forest Sites ◽  
Sequestration Potential ◽  
Oak Tree ◽  
Quercus Leucotrichophora

Present study deals with stand structure, biomass, productivity and carbon sequestration in oak dominated forests mixed with other broad leaved tree species. The sites of studied forests were located in Nainital region between 29058’ N lat. and 79028’ E long at 1500-2150 m elevation. Tree density of forests ranged from 980-1100 ind.ha-1. Of this, oak trees shared 69-97%. The basal area of trees was 31.81 to 63.93 m2 ha-1. R. arboreum and Q. floribunda shared maximum basal area 16.45 and 16.32 m2 ha-1, respectively in forest site-1 and 2 while Quercus leucotrichophora shared maximum (35.69 m2 ha-1) in site-3. The biomass and primary productivity of tree species ranged from 481-569 t ha-1 and 16.9-20.9 t ha-1yr-1, respectively. Of this, biomass and primary productivity of oak tree species accounted for 81 to 95 and 78 to 98%, respectively. Carbon stock and carbon sequestration ranged from 228 to 270 t ha-1 and 8.0 to 9.9 t ha-1yr-1, respectively. The share of oak tree species ranged from 81 to 94.7 and 79 to 97%, respectively. The diversity of tree species ranged from 0.03 to 0.16 in forest sites-1, 2 and 3. The diversity of oak species was 0.08-0.16 in all the forest sites. Thus it is concluded that among the oak tree species, Quercus floribunda and Quercus leucotrichophora were highly dominated in the studied forests. The climax form of oak dominated trees in the studied forest sites depicted slightly lower richness and diversity of tree species compared to the forests in the region and elsewhere. As far as dry matter and carbon of forests is concerned, these estimates are close to the earlier reports of forests in the region. Therefore, studied forests have the potential to increase the diversity, productivity and carbon sequestration of forest tree species by providing the adequate scientific conservation and management inputs.

scholarly journals Stand-Level Components of a Growth and Yield Model for Nothofagus Mixed Forests from Southern Chile

Forests ◽  
2020 ◽  
Vol 11 (8) ◽  
pp. 810
Author(s):  
Sebastian Palmas ◽  
Paulo C. Moreno ◽  
Wendel P. Cropper ◽  
Alicia Ortega ◽  
Salvador A. Gezan
Keyword(s):  
Forest Type ◽  
Geographical Area ◽  
Basal Area ◽  
Forest Growth ◽  
Model Systems ◽  
Growth And Yield ◽  
Permanent Plots ◽  
Stand Age ◽  
Yield Model ◽  
Mixed Forests

Reliable information on stand dynamics and development is needed to improve management decisions on mixed forests, and essential tools for this purpose are forest growth and yield (G&Y) models. In this study, stand-level G&Y models were built for cohorts within the natural mixed second-growth Nothofagus-dominated forests in Chile. All currently available (but limited) data, consisting of a series of stratified temporary and permanent plots established in the complete range of this forest type, were used to fit and validate these models. Linear and nonlinear models were considered, where dominant stand age, number of trees, and the proportion of basal area of Nothofagus species resulted in significant predictors to project future values of stand basal area for the different cohorts (with R2 > 0.51 for the validation datasets). Mortality was successfully modeled (R2 = 0.79), based on a small set of permanent plots, using the concept of self-thinning with a proposed model defined by the idea that, as stands get closer to a maximum density, they experience higher levels of mortality. The evaluation of these models indicated that they adequately represent the current understanding of dynamics of basal area and mortality of Nothofagus and companion species in these forests. These are the first models fitted over a large geographical area that consider the dynamics of these mixed forests. It is suggested that the proposed models should constitute the main components of future implementations of G&Y model systems.

scholarly journals Growth After Thinning a 35-Year-Old Natural Stand to Different Loblolly Pine and Hardwood Basal Areas

1997 ◽  
Vol 21 (4) ◽  
pp. 168-174
Author(s):  
Michael G. Shelton ◽  
Paul A. Murphy
Keyword(s):  
Loblolly Pine ◽  
Block Design ◽  
Volume Growth ◽  
Basal Area ◽  
Timber Production ◽  
Product Class ◽  
Randomized Complete Block Design ◽  
Timber Products ◽  
Total Growth ◽  
Area And Volume

Abstract Growth was monitored for 4 yr in a thinned stand in southern Arkansas with three pine basal areas (70, 85, and 100 ft2/ac) and three hardwood basal areas (0, 15, and 30 ft2/ac); pretreatment basal areas averaged 119 and 33 ft2/ac for pines and hardwoods, respectively. Treatments were arranged in a 3 X 3 factorial randomized complete block design with three replicates, yielding 27 permanent 0.20 ac plots. Growth variables were regressed with residual pine and hardwood basal areas. Pine basal area and volume growth increased with the pine stocking level after thinning and decreased with the level of retained hardwoods. For basal area and merchantable volume, hardwood growth largely compensated for losses in the pine component, and thus, hardwood retention had little net effect on the total growth of the stand. The greatest impact of hardwood retention was on the stand's sawtimber growth, because hardwoods did not contribute to this product class. Each 1 ft2/ac of retained hardwood basal area reduced pine sawtimber growth by 6 to 10 bd ft Doyle/ac/yr, depending on the pine stocking. Because large differences existed in the value of timber products, retaining 15 and 30 ft2/ac of hardwoods reduced the value of timber production by 13 and 24%, respectively, at 4 yr after thinning. South. J. Appl. For. 21(4):168-174.

scholarly journals Deriving Stand Structural Complexity from Airborne Laser Scanning Data—What Does It Tell Us about a Forest?

2020 ◽  
Vol 12 (11) ◽  
pp. 1854
Author(s):  
Dominik Seidel ◽  
Peter Annighöfer ◽  
Martin Ehbrecht ◽  
Paul Magdon ◽  
Stephan Wöllauer ◽  
...  
Keyword(s):  
Forest Structure ◽  
Laser Scanning ◽  
Structural Complexity ◽  
Basal Area ◽  
Airborne Laser Scanning ◽  
Stand Age ◽  
Box Dimension ◽  
Forest Types ◽  
3D Point Clouds ◽  
Airborne Laser

The three-dimensional forest structure is an important driver of several ecosystem functions and services. Recent advancements in laser scanning technologies have set the path to measuring structural complexity directly from 3D point clouds. Here, we show that the box-dimension (Db) from fractal analysis, a measure of structural complexity, can be obtained from airborne laser scanning data. Based on 66 plots across different forest types in Germany, each 1 ha in size, we tested the performance of the Db by evaluating it against conventional ground-based measures of forest structure and commonly used stand characteristics. We found that the Db was related (0.34 < R < 0.51) to stand age, management intensity, microclimatic stability, and several measures characterizing the overall stand structural complexity. For the basal area, we could not find a significant relationship, indicating that structural complexity is not tied to the basal area of a forest. We also showed that Db derived from airborne data holds the potential to distinguish forest types, management types, and the developmental phases of forests. We conclude that the box-dimension is a promising measure to describe the structural complexity of forests in an ecologically meaningful way.

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