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.

Intertree competition in uneven-aged ponderosa pine stands

2003 ◽  
Vol 33 (9) ◽  
pp. 1719-1726 ◽  
Author(s):  
C W Woodall ◽  
C E Fiedler ◽  
K S Milner
Keyword(s):  
Pinus Ponderosa ◽  
Ponderosa Pine ◽  
Basal Area ◽  
Growth Efficiency ◽  
Tree Size ◽  
Basal Area Increment ◽  
Diameter Class ◽  
Individual Tree ◽  
Sapwood Area ◽  
Competition Indices

Intertree competition indices and effects were examined in 14 uneven-aged ponderosa pine (Pinus ponderosa var. scopulorum Engelm.) stands in eastern Montana. Location, height, diameter at breast height (DBH), basal area increment, crown ratio, and sapwood area were determined for each tree (DBH >3.8 cm) on one stem-mapped plot (0.2-0.4 ha) in each sample stand. Based on tree locations, various competition indices were derived for each sample tree and correlated with its growth efficiency by diameter class. In addition, trends in individual tree attributes by diameter class and level of surrounding competition were determined. For trees with a DBH <10 cm, growth efficiency was most strongly correlated with the sum of surrounding tree heights within 10.6 m. The index most highly correlated for larger trees was the sum of surrounding basal area within 6.1 m. Regardless of tree size, individual tree growth efficiency, basal area increment, and crown ratio all decreased under increasing levels of competition, with the effect more pronounced in smaller trees. These results suggest that individual trees in uneven-aged stands experience competition from differing sources at varying scales based on their size, with response to competition diminishing as tree size increases.

scholarly journals Analysis of Individual Tree Competition on Diameter Growth of Silver Birch in Estonia

2015 ◽  
Vol 24 (2) ◽  
pp. e023 ◽  
Author(s):  
Kobra Maleki ◽  
Andres Kiviste ◽  
Henn Korjus
Keyword(s):  
Growth Model ◽  
Spatial Competition ◽  
Predictor Variable ◽  
Specific Effect ◽  
Silver Birch ◽  
Spatially Explicit ◽  
Diameter Growth ◽  
Individual Tree ◽  
Spatial Indices ◽  
Competition Indices

<p><em>Aim of study:</em> The present study evaluates a set of competition indices including spatially explicit indices combined with different competitor selection approaches and non-spatially explicit competition indices. The aim was to quantify and describe the neighbouring effects on the tree diameter growth of silver birch trees.<em></em></p><p><em>Area of study:</em> Region throughout Estonia. <em></em></p><p><em>Material and methods:</em> Data from the Estonian Network of Forest Research Plots was used. After quantifying the selected indices, the best non-spatial indices and spatial indices (combined with neighbour selection methods) were separately devised into a growth model as a predictor variable to assess the ability of the diameter growth model before and after adding competition measures. To test the species-specific effect on the competition level, the superior indices were recalculated using Ellenberg’s light indicators and incorporated into the diameter growth model. <em></em></p><p><em>Main results:</em> Statistical analyses showed that the diameter growth is a function of neighbourhood interactions and spatial indices were better growth predictors than non-spatial indices. In addition, the best selections of competitive neighbours were acquired based on the influence zone and the competition elimination angle concepts, and using Ellenberg’s light values had no significant improvement in quantifying the competition effects. <em></em></p><p><em>Research highlights: </em>Although the best ranking spatial competition measures were superior to the best non-spatial indices, the differences were negligible.</p><p><strong>Keywords:</strong> Competition indices; zone of influence; stem diameter increment; <em>Betula pendula </em>Roth<em>.</em><strong></strong></p>

Evaluating the performance of semi-distance-independent competition indices in predicting the basal area growth of individual trees

2010 ◽  
Vol 40 (4) ◽  
pp. 796-805 ◽  
Author(s):  
Thomas Ledermann
Keyword(s):  
Spatial Information ◽  
Growth Models ◽  
Basal Area ◽  
Local Variation ◽  
Small Sample ◽  
Sample Plot ◽  
Competition Index ◽  
Individual Tree ◽  
Tree Increment ◽  
Competition Indices

Recent individual-tree growth models use either distance-dependent or distance-independent competition measures to predict tree increment. However, both measures have deficiencies: the latter because the effects of local variation in spacing are not represented, and the former because they cannot be calculated from normal inventory data for lack of spatial information. To overcome these shortcomings, the new class of semi-distance-independent competition indices was proposed. A semi-distance-independent competition index is a distance-independent competition measure that uses only the trees of a single small sample plot that includes the subject tree. Moreover, a semi-distance-independent competition index can be calculated in an analogous way to a distance-dependent competition index by using sample plot size, tree attributes, and intertree distances. However, many semi-distance-independent competition measures are based on simple tree attributes. Therefore, the objective of this study was to analyze if the semi-distance-independent competition indices explain the variation in measurements of tree increment more or less effectively than a set of classical distance-dependent competition indices. The results show that some of the semi-distance-independent competition indices explain at least as much variation in measurements of tree increment as any of the distance-dependent competition indices.

A New Index Representing Individual Tree Competitive Status

1973 ◽  
Vol 3 (4) ◽  
pp. 495-500 ◽  
Author(s):  
James A. Moore ◽  
Carl A. Budelsky ◽  
Richard C. Schlesinger
Keyword(s):  
Spatial Distribution ◽  
Strong Correlation ◽  
Basal Area ◽  
Tree Size ◽  
Competition Index ◽  
Individual Tree ◽  
Silvicultural Practices ◽  
Basal Area Growth ◽  
Hardwood Species ◽  
Area Growth

A new competition index, modified Area Potentially Available (APA), was tested in a complex unevenaged stand composed of 19 different hardwood species. APA considers tree size, spatial distribution, and distance relationships in quantifying intertree competition and exhibits a strong correlation with individual tree basal area growth. The most important characteristic of APA is its potential for evaluating silvicultural practices.

Development of an Individual-Tree Basal Area Increment Model using a Linear Mixed-Effects Approach

10.3791/60827 ◽  
2020 ◽  
Author(s):  
Wenwen Wang ◽  
Yanfeng Bai ◽  
Chunqian Jiang ◽  
Jinghui Meng
Keyword(s):  
Basal Area ◽  
Mixed Effects ◽  
Basal Area Increment ◽  
Individual Tree ◽  
Linear Mixed Effects

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

Genetic variation in basal area increment phenology and its correlation with growth rate in loblolly and slash pine families and clones

2006 ◽  
Vol 36 (4) ◽  
pp. 961-971 ◽  
Author(s):  
Veronica I Emhart ◽  
Timothy A Martin ◽  
Timothy L White ◽  
Dudley A Huber
Keyword(s):  
Growth Rate ◽  
Growth Traits ◽  
Negative Impact ◽  
Basal Area ◽  
Pinus Elliottii ◽  
Slash Pine ◽  
Basal Area Increment ◽  
Individual Tree ◽  
Basal Area Growth ◽  
Area Growth

We quantified basal area increment phenology over a 2-year period in one loblolly pine (Pinus taeda L.) and four slash pine (Pinus elliottii Engelm. var. elliottii) full-sib families propagated as rooting cuttings. In 2002, basal area growth started in March and stopped in October for both species, while in 2003, initiation and cessation occurred 2 weeks earlier for all families. In both years, peaks in basal area increment occurred in short (2–3 week) periods in the early spring for all families, followed by linear basal area growth until cessation. While there were significant size differences among taxa (species and families) at age 6 and 7 years, genetic differences in basal area growth rate were only expressed during short, discrete time periods primarily in the spring and fall. Basal area growth rate increased during periods when water soil availability increased (up to 300 mm), but an excess in water availability in the soil had a negative impact on growth. Within-family individual-tree broad-sense heritabilities ranged from 0.01 to 0.37 for all traits. In general, heritabilities were higher for growth traits than for phenological traits for all families. Both the strength and direction of correlation estimates of phenological traits with growth rate varied across families and years.

Effects of competitor spacing in a new class of individual-tree indices of competition: semi-distance-independent indices computed for Bitterlich versus fixed-area plots

2008 ◽  
Vol 38 (4) ◽  
pp. 890-898 ◽  
Author(s):  
Albert R. Stage ◽  
Thomas Ledermann
Keyword(s):  
Basal Area ◽  
Area Ratio ◽  
Individual Tree ◽  
Competitive Effects ◽  
New Class ◽  
Distance Effects ◽  
Fixed Area ◽  
Tree Increment ◽  
Competition Indices ◽  
Selection Of

We illustrate effects of competitor spacing for a new class of individual-tree indices of competition that we call semi-distance-independent. This new class is similar to the class of distance-independent indices except that the index is computed independently at each subsampling plot surrounding a subject tree for which growth is to be modelled. We derive the effects of distance for this class as the expected value over independent samples containing a particular subject tree. In a previous paper, we illustrated distance effects implicit in eight indices of the distance-dependent class. Here, we present distance effects of four semi-distance-independent indices: density, sum of diameters, basal area, and tree-area ratio; each determined for small fixed-area plots of 0.04 ha and for Bitterlich samples of 6 m2·ha–1. We show that several members of this new class have distance effects very similar to the distance-dependent class and should, therefore, be equally effective in accounting for competitive effects in individual-tree increment models. The comparisons should inform selection of competition indices and sampling designs for growth modelling.

scholarly journals Individual tree basal area increment models for broadleaved forests in Bhutan

2017 ◽  
Author(s):  
Jigme Tenzin ◽  
Karma Tenzin ◽  
Hubert Hasenauer
Keyword(s):  
Basal Area ◽  
Basal Area Increment ◽  
Individual Tree

Effects of different sources and rates of sulphur on the growth and foliar nutrition of nitrogen-fertilized lodgepole pine

2004 ◽  
Vol 34 (3) ◽  
pp. 728-743 ◽  
Author(s):  
R P Brockley
Keyword(s):  
Tree Growth ◽  
Lodgepole Pine ◽  
Basal Area ◽  
Application Rate ◽  
Basal Area Increment ◽  
Individual Tree ◽  
Modest Improvement ◽  
S Application ◽  
Different Sources ◽  
Foliar S

The effects of nitrogen (N) fertilizer, alone and in combination with different sources and rates of sulphur (S), on foliar nutrients and tree growth are reported over 3 and 6 years, respectively. After 3 years, foliar S levels in the N+S treatments were significantly higher than those in N-only treatments at all six study locations. Temporal patterns of foliar S response varied significantly with S source. When applied as ammonium sulphate (AS), foliar levels increased sharply in year 1 and slowly declined over the next 2 years. Conversely, additions of elemental S (S0), in the form of S0 – sodium bentonite fertilizer, usually did not increase foliar S concentration in year 1, but had increasingly positive effects on foliar S in years 2 and 3. An increase in the S application rate from 50 to 100 kg/ha resulted in only a modest improvement in foliar S concentration for both S sources. Differences in individual-tree basal area increment between N and N+S treatments were statistically significant in only two of six trials. Prefertilization levels of foliar N and sulphate S, and probable induced deficiencies of nonadded nutrients following N fertilization, largely explained basal area and height responses to N and N+S additions at the six study sites. Despite delayed oxidation, S0 was as effective as the more readily available AS in stimulating radial growth after 6 years. However, the relative effectiveness of S source varied with S application rate in two trials. In both cases, basal area increment was positively related to application rate when S was applied as AS. Conversely, the effect of application rate was distinctly negative when S0 was applied. Despite large differences in short-term availability of AS and S0, the results from this study support the conclusion that the two S sources are likely equally effective in alleviating S deficiencies and in promoting tree growth of S-deficient lodgepole pine (Pinus contorta Dougl. var. latifolia Engelm.).

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