Persistence of suppression effects on peatland black spruce advance regeneration after overstory removal

2000 ◽  
Vol 30 (5) ◽  
pp. 753-760 ◽  
Author(s):  
Arthur Groot ◽  
Hannu Hökkä
Keyword(s):  
Critical Points ◽  
Black Spruce ◽  
Basal Area ◽  
Growth Patterns ◽  
Diameter Growth ◽  
Individual Tree ◽  
Post Harvest ◽  
Advance Regeneration ◽  
Time Of Harvest ◽  
Suppression Effects

The persistence of suppression effects on peatland black spruce (Picea mariana (Mill.) BSP) advance regeneration following overstory removal was examined (i) by analyzing post-harvest growth patterns and (ii) by comparing observed post-harvest growth with predictions from an individual-tree growth model. Analysis of growth patterns revealed critical points (inflections or maxima) in annual basal area, diameter, and height growth series, and in specific volume increment. Critical points occurred at different times (ranging from 1 to 29 years after harvest) for different variables and often occurred earlier for trees with greater height at time of harvest. These critical points do not necessarily coincide with the cessation of persisting suppression, however, since post-harvest growth patterns also reflect current influences on growth. The comparison of observed basal area and diameter growth with model predictions isolated persisting suppression effects. The effects of suppression on basal area and diameter growth decline linearly with time since harvest and become negligible 12 years after harvest. The persistence of suppression effects on basal area and diameter growth is largely independent of the height of the tree at the time of harvest.

The influence of competition on individual white pine thinning response

1986 ◽  
Vol 16 (6) ◽  
pp. 1355-1359 ◽  
Author(s):  
Andrew R. Gillespie ◽  
Harold W. Hocker Jr.
Keyword(s):  
Volume Growth ◽  
Basal Area ◽  
Growth Patterns ◽  
Diameter Growth ◽  
Initial Growth ◽  
White Pine ◽  
Individual Tree ◽  
Periodic Growth ◽  
Growth Equations ◽  
Crown Characteristics

A model predicting white pine (Pinusstrobus L.) diameter growth after thinning included competition, initial diameter, and crown class as independent variables. Model coefficients indicated a decrease in percent 8-year diameter growth with increasing crown suppression, crown competition, or tree size class. Variables selected were superior to age, percent live crown, and prethinning growth. Equations predicting basal area and volume growth were similar in form to diameter growth. Height growth, however, was more closely correlated with crown characteristics and unaffected by competition. Annual growth patterns were similar to periodic growth patterns, revealing decreased growth with increasing competition or crown suppression. Trees having little competition and dominant crowns utilized their growing season longer, with earlier initial growth and faster growth than trees having greater competition or crown suppression. Within a crown class, diameter growth decreased as competition increased. Individual tree competition was seen as the most important factor influencing tree growth that a forester can control.

scholarly journals An Individual-Tree Growth and Yield Prediction System for Uneven-Aged Shortleaf Pine Stands

2000 ◽  
Vol 24 (2) ◽  
pp. 112-120 ◽  
Author(s):  
Michael M. Huebschmann ◽  
Lawrence R. Gering ◽  
Thomas B. Lynch ◽  
Onesphore Bitoki ◽  
Paul A. Murphy
Keyword(s):  
Basal Area ◽  
Growth Patterns ◽  
Growth And Yield ◽  
Prediction System ◽  
Pinus Echinata ◽  
Shortleaf Pine ◽  
Individual Tree ◽  
Basal Area Growth ◽  
Area Growth ◽  
Pine Stands

Abstract A system of equations modeling the growth and development of uneven-aged shortleaf pine (Pinus echinata Mill.) stands is described. The prediction system consists of two main components: (1) a distance-independent, individual-tree simulator containing equations that forecast ingrowth, basal-area growth, probability of survival, total and merchantable heights, and total and merchantable volumes and weights of shortleaf pine trees; and (2) stand-level equations that predict hardwood ingrowth, basal-area growth, and mortality. These equations were combined into a computer simulation program that forecasts future states of uneven-aged shortleaf pine stands. Based on comparisons of observed and predicted stand conditions in shortleaf pine permanent forest inventory plots and examination of the growth patterns of hypothetical stands, the simulator makes acceptable forecasts of stand attributes. South. J. Appl. For. 24(2):112-120.

Individual-tree basal area growth models for jack pine and black spruce in northern Ontario

2004 ◽  
Vol 80 (3) ◽  
pp. 366-374 ◽  
Author(s):  
Lianjun Zhang ◽  
Changhui Peng ◽  
Qinglai Dang
Keyword(s):  
Tree Growth ◽  
Black Spruce ◽  
Basal Area ◽  
Jack Pine ◽  
Mixed Stands ◽  
Northern Ontario ◽  
Individual Tree ◽  
Basal Area Growth ◽  
Wide Range ◽  
Area Growth

Individual-tree models of five-year basal area growth were developed for jack pine (Pinus banksiana Lamb.) and black spruce (Picea mariana (Mill.) BSP) in northern Ontario. Tree growth data were collected from long-term permanent plots of pure and mixed stands of the two species. The models were fitted using mixed model methods due to correlated remeasurements of tree growth over time. Since the data covered a wide range of stand ages, stand conditions and tree sizes, serious heterogeneous variances existed in the data. Therefore, the coefficients of the final models were obtained using weighted regression techniques. The models for the two species were evaluated across 4-cm diameter classes using independent data. The results indicated (1) the models of jack pine and black spruce produced similar prediction errors and biases for intermediate-sized trees (12–28 cm in tree diameter), (2) both models yielded relatively large errors and biases for larger trees (> 28 cm) than those for smaller trees, and (3) the jack pine model produced much larger errors and biases for small-sized trees (< 12 cm) than did the black spruce model. Key words: mixed models, repeated measures, model validation

Predicting basal area increment in a spatially explicit, individual tree model: a test of competition measures with black spruce

2003 ◽  
Vol 33 (3) ◽  
pp. 435-443 ◽  
Author(s):  
Daniel Mailly ◽  
Sylvain Turbis ◽  
David Pothier
Keyword(s):  
Black Spruce ◽  
Basal Area ◽  
Basal Area Increment ◽  
Spatially Explicit ◽  
Competition Index ◽  
Individual Tree ◽  
Spatial Indices ◽  
Crown Shape ◽  
Spruce Stands ◽  
Competition Indices

A current trend in the development of forest stand models is to use spatially explicit, individual-tree information to simulate forest dynamics with increased accuracy. By adding spatial information, such as tree coordinates, crown shape, and size, it is hypothesized that the computation of the model's driving function is improved over traditional competition indices, especially when simulating multistoried stands. In this paper, we want to test whether computationally demanding competition indices outperform traditional indices in predicting mean basal area increment. The study was undertaken in old, uneven-aged black spruce (Picea mariana (Mill.) BSP) stands in northeastern Quebec, Canada. The predictability of individual tree growth rates was related to crown dimensions and other stand and tree variables measured in the field. Data were collected from 90 trees coming from stands of varying site quality (range 9.6–16.5 m height at 50 years, age taken at 1 m) and age (range 66–257 years). Hegyis's distance-dependent competition index was found to be the most strongly correlated competition measure (r = 0.57) with mean basal area growth of the last 20 years. This value, 12% higher than the value obtained from the best distance-independent competition index (r = 0.45), clearly shows that precision gains can be achieved when estimating basal area increment with spatial indices in black spruce stands. Using indices computed from virtual hemispherical images did not prove superior to simpler distance-dependent indices based on their individual correlations with basal area increment. When included in a basal area increment model for the last 20 years of growth, however, the gains in precision were comparable to Hegyi's competition index. This indicates that indices derived from a hemispherical approach have some value in spatially explicit forest simulations models but that further tests using younger stands are needed to confirm this result in black spruce stands.

Testing the Lake States variant of FVS (Forest Vegetation Simulator) for the main forest types of northern Ontario

2004 ◽  
Vol 80 (4) ◽  
pp. 495-506 ◽  
Author(s):  
V. Lacerte ◽  
G R Larocque ◽  
M. Woods ◽  
W J Parton ◽  
M. Penner
Keyword(s):  
Black Spruce ◽  
Basal Area ◽  
Stand Density ◽  
Site Index ◽  
Forest Vegetation ◽  
Forest Vegetation Simulator ◽  
Consistency Analysis ◽  
Northern Ontario ◽  
Individual Tree ◽  
Stand Basal Area

The Lake States variant of the FVS (Forest Vegetation Simulator) model (LS-FVS), also known as the LS-TWIGS variant of FVS, was validated for black spruce (Picea mariana (Mill.) BSP), white spruce (Picea glauca (Moench) Voss), jack pine (Pinus banksiana Lamb.) and trembling aspen (Populus tremuloides Michx.) forests in northern Ontario. Individual-tree data from 537 remeasured sample plots were used. This dataset included different combinations of site index, stand density and age. It was possible to compare observations and predictions for different projection length periods. The validation exercise included a biological consistency analysis, the computation of mean percent difference (MPD) for stand density, stand basal area, top height and quadratic mean diameter (QMD) and the comparison of observed and predicted individual-tree dbh. The biological consistency analysis indicated that LS-FVS logically predicted the effect of site index on top height, stand basal area and QMD for black spruce and jack pine. However, the decrease in stand basal area at young ages was inconsistent with the normal development pattern of the forest stands under study and was attributed to deficiencies in the prediction of mortality. LS-FVS was found to underpredict stand density, stand basal area and top height and to over-predict QMD. Even though there were large errors in the prediction of change in stand density, LS-FVS was nevertheless consistent in the prediction of the shape of the dbh size distribution. Key words: FVS, Forest Vegetation Simulator, validation, biological consistency analysis

An individual-tree basal area growth model for black spruce in second-growth peatland stands

1999 ◽  
Vol 29 (5) ◽  
pp. 621-629 ◽  
Author(s):  
Hannu Hökkä ◽  
Arthur Groot
Keyword(s):  
Growth Model ◽  
Black Spruce ◽  
Basal Area ◽  
Random Parameter ◽  
Considerable Change ◽  
Tree Level ◽  
Individual Tree ◽  
Basal Area Growth ◽  
Second Growth ◽  
Area Growth

A basal area growth model was developed to predict the growth of individual trees in second-growth black spruce (Picea mariana (Mill.) BSP) stands on northeastern Ontario peatlands. The data were derived from stem analysis trees collected in 1985 and 1986 from stands harvested 47-68 years earlier. For a period starting from the date of data collection and going back to 10 years from the harvesting, tree basal area growth, diameters, and stand characteristics were retrospectively calculated at 5-year intervals. To estimate previous mortality, self-thinning relationships for black spruce were applied. In the model, 5-year basal area growth of a tree was expressed as a function of tree diameter, stand-level competition, tree-level competition, and peat thickness. There was considerable change in the growth-size relationship over time. A random parameter approach was applied in model construction to account for the spatial and temporal correlations of the observations. The proposed model explicitly incorporates factors normally included in a "random error" term and, therefore, should provide more sensitive tests of the contributions of the various factors to growth prediction. The estimated model showed only slight bias against the modeling data and the predicted stand basal area development was comparable with that given in other studies.

A new method for evaluating forest thinning: growth dominance in managed Pinus resinosa stands

2010 ◽  
Vol 40 (5) ◽  
pp. 843-849 ◽  
Author(s):  
John B. Bradford ◽  
Anthony W. D’Amato ◽  
Brian J. Palik ◽  
Shawn Fraver
Keyword(s):  
Tree Growth ◽  
Basal Area ◽  
Pinus Resinosa ◽  
Growth Patterns ◽  
Red Pine ◽  
New Method ◽  
Stand Age ◽  
Individual Tree ◽  
Individual Tree Growth

Growth dominance is a relatively new, simple, quantitative metric of within-stand individual tree growth patterns, and is defined as positive when larger trees in the stand display proportionally greater growth than smaller trees, and negative when smaller trees display proportionally greater growth than larger trees. We examined long-term silvicultural experiments in red pine ( Pinus resinosa Ait.) to characterize how stand age, thinning treatments (thinned from above, below, or both), and stocking levels (residual basal area) influence stand-level growth dominance through time. In stands thinned from below or from both above and below, growth dominance was not significantly different from zero at any age or stocking level. Growth dominance in stands thinned from above trended from negative at low stocking levels to positive at high stocking levels and was positive in young stands. Growth dominance in unthinned stands was positive and increased with age. These results suggest that growth dominance provides a useful tool for assessing the efficacy of thinning treatments designed to reduce competition between trees and promote high levels of productivity across a population, particularly among crop trees.

An individual-tree basal area growth model for loblolly pine stands

1996 ◽  
Vol 26 (2) ◽  
pp. 327-331 ◽  
Author(s):  
Paul A. Murphy ◽  
Michael G. Shelton
Keyword(s):  
Loblolly Pine ◽  
Basal Area ◽  
Growth Function ◽  
Logistic Function ◽  
Growth Patterns ◽  
Potential Growth ◽  
Individual Tree ◽  
Basal Area Growth ◽  
Area Growth ◽  
Using Data

Tree basal area growth has been modeled as a combination of a potential growth function and a modifier function, in which the potential function is fitted separately from open-grown tree data or a subset of the data and the modifier function includes stand and site variables. We propose a modification of this by simultaneously fitting both a growth component and a modifier component. The growth component can be any function that approximates tree growth patterns, and the logistic function is chosen as the modifier component. This approach can be adapted to a variety of stand conditions, and its application is demonstrated using data from an uneven-aged loblolly pine (Pinustaeda L.) study located in Arkansas and Louisiana.

scholarly journals Precommercial Thinning in a Ponderosa Pine Stand Affected by Armillaria Root Disease in Central Oregon: 30 Years of Growth and Mortality

1999 ◽  
Vol 14 (3) ◽  
pp. 144-148 ◽  
Author(s):  
Gregory M. Filip ◽  
Stephen A. Fitzgerald ◽  
Lisa M. Ganio
Keyword(s):  
Ponderosa Pine ◽  
Tree Mortality ◽  
Basal Area ◽  
Stand Density ◽  
Root Disease ◽  
Diameter Growth ◽  
Individual Tree ◽  
Precommercial Thinning ◽  
Tree Diameter ◽  
Armillaria Root Disease

Abstract A 30-yr-old stand of ponderosa pine was precommercially thinned in 1966 to determine the effects of thinning on tree growth and mortality caused by Armillaria root disease in central Oregon. After 30 yr, crop tree mortality was significantly (P = 0.02) less in thinned plots than in unthinned plots. Tree diameter growth was not significantly (P = 0.17) increased by thinning. Crop-tree basal area/ac growth was significantly (P = 0.03) greater in thinned plots. Apparently, from a root disease perspective, precommercial thinning of pure ponderosa stands significantly decreases the incidence of crop-tree mortality after 30 yr and significantly increases basal area/ac growth but not individual tree diameter growth. Recommendations for thinning based on stand density index (SDI) are given. West. J. Appl. For. 14(3):144-148.

Evaluation of distance-independent competition indices in predicting tree survival and diameter growth

2019 ◽  
Vol 49 (5) ◽  
pp. 440-446 ◽  
Author(s):  
Shuaichao Sun ◽  
Quang V. Cao ◽  
Tianjian Cao
Keyword(s):  
Loblolly Pine ◽  
Relative Position ◽  
Basal Area ◽  
Diameter Ratio ◽  
Cumulative Distribution ◽  
Permanent Plots ◽  
Diameter Growth ◽  
Individual Tree ◽  
Tree Survival ◽  
Competition Indices

Competition indices play a significant role in modeling individual-tree growth and survival. In this study, six distance-independent competition indices were evaluated using 200 permanent plots of loblolly pine (Pinus taeda L.). The competition indices were classified into three families: (1) size ratios, which include diameter ratio and basal area ratio; (2) relative position indices, which include basal area of larger trees (BAL) and tree relative position based on the cumulative distribution function (CDF); and (3) partitioned stand density index and relative density. Results indicated that different families of competition indices were suitable for different tree survival or diameter growth prediction tasks. The diameter ratio was superior for predicting tree survival, whereas the relative position indices (BAL and CDF) performed best for predicting tree diameter growth, with CDF receiving the highest rank.

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