Derivation of a competitive index for individual trees from seasonal growth patterns

1984 ◽  
Vol 14 (2) ◽  
pp. 266-270 ◽  
Author(s):  
Frederick W. Smith ◽  
David R. M. Scott
Keyword(s):  
Soil Water ◽  
Leaf Area ◽  
Basal Area ◽  
Growth Patterns ◽  
Seasonal Growth ◽  
Competitive Index ◽  
Primary Mechanism ◽  
Basal Area Growth ◽  
Area Growth ◽  
Individual Trees

A competitive index for lodgepole pine (Pinuscontorta Dougl.) trees in central Oregon is developed from seasonal basal area growth and an indirect estimator of foliar leaf area. Differences in seasonal basal area growth and the ratio of basal area growth to sapwood basal area between trees with and without neighbors are used to document growth reductions owing to the proximity of competing individuals. A regression between basal area growth and sapwood basal area (an estimator of leaf area) is used as a predictor of maximum potential basal area growth for trees growing free of competition. The competitive index is determined as the ratio of actual to potential basal area growth for individual trees. This index standardizes growth against differences in tree size and site conditions. Plant and soil water relations are considered as possible mechanisms of competitive interaction. Moderate minimum seasonal values of predawn leaf pressure potentials (−0.76 to −0.92 MPa) and minor differences between trees in different competitive classes led to the conclusion that soil water may not be the primary mechanism of competition on this site.

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.

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.

Evaluating growth responses to fertilization

1985 ◽  
Vol 15 (5) ◽  
pp. 877-880 ◽  
Author(s):  
L. R. Auchmoody
Keyword(s):  
Basal Area ◽  
Uniform Field ◽  
Growth Responses ◽  
Basal Area Growth ◽  
Nutrient Effects ◽  
Area Growth ◽  
The Mean ◽  
The Difference ◽  
Individual Trees ◽  
Area Response

When fertilizers increase radial growth rates, they also increase the diameter of trees that will be used to compute future basal area responses. If the mean basal area growth per tree is computed for fertilized trees that are larger than the unfertilized trees, the length of time that fertilizers directly affect growth can be overestimated. In this paper, a model that describes mean basal area responses per tree over time as a function of direct nutrient effects and indirect tree-size effects is suggested. Application of the model to a uniform field fertilization experiment shows that after the 1st year, some or all of the average basal area response of individual trees is due to the difference in size between fertilized and unfertilized trees. To evaluate direct fertilizer responses properly, mean basal area growth per tree must be adjusted for the unequal size of fertilized and unfertilized trees.

Factors affecting the relationship between sapwood area and leaf area of balsam fir

1992 ◽  
Vol 22 (11) ◽  
pp. 1684-1693 ◽  
Author(s):  
Marie R. Coyea ◽  
Hank A. Margolis
Keyword(s):  
Leaf Area ◽  
Basal Area ◽  
Tree Height ◽  
Balsam Fir ◽  
Tree Age ◽  
Cross Sectional ◽  
Sapwood Area ◽  
Crown Length ◽  
Basal Area Growth ◽  
Area Growth

The ratio between projected leaf area (LA) and cross-sectional sapwood area (SA) of dominant and codominant balsam fir trees (Abiesbalsamea (L.) Mill.) was determined in 24 forest stands across the province of Quebec. Various physical factors proposed in the Whitehead hydraulic model, and some of the easily measured surrogates of these factors, were tested for their influence on LA:SA ratios. Average growing season vapor pressure deficit, temperature, precipitation, and stand drainage class did not significantly influence LA:SA ratios. On the other hand, LA:SA ratios were positively influenced by sapwood permeability (k), tree height, and crown length. As suggested by the model, there was a positive correlation between sapwood permeability and LA:SA ratio and a negative correlation between tree height or crown length and LA/(SA k). Increases in sapwood permeability with tree age were associated with longer tracheids having larger lumen diameters. Of the various empirical factors tested, only site quality, 5-year basal area growth, and age had a significant influence on LA:SA ratios. Sapwood cross-sectional area at breast height by itself was a reasonable linear predictor of LA for all stands (LA = −0.158 + 0.709 SABH, R2 = 0.75). Using the variables that were previously determined to influence LA:SA ratios, stepwise regressions revealed that only crown length and 5-year basal area growth significantly improved linear predictions of LA based on sapwood area. However, the increase in R2 was relatively modest, i.e., 0.83 for all three independent variables versus 0.75 for SA alone. The results from this study will be useful in integrating physiologically based measurements, such as growth efficiency, into standard forest inventory practices for balsam fir and thus could be beneficial in developing new silvicultural strategies for protecting Quebec's forest resource.

The historical reconstruction of growth efficiency and its relationship to tree mortality in balsam fir ecosystems affected by spruce budworm

1994 ◽  
Vol 24 (11) ◽  
pp. 2208-2221 ◽  
Author(s):  
Marie R. Coyea ◽  
Hank A. Margolis
Keyword(s):  
Leaf Area ◽  
Tree Mortality ◽  
Basal Area ◽  
Spruce Budworm ◽  
Growth Efficiency ◽  
Balsam Fir ◽  
Tree Age ◽  
Basal Area Growth ◽  
Annual Growth Rings ◽  
Area Growth

The growth efficiencies (E; stemwood growth per unit leaf area) of balsam fir (Abiesbalsamea (L.) Mill.) trees from 20 stands were reconstructed over the 30-year period from 1960 to 1989 in order to determine if E could be used to predict tree mortality occurring during and after an epidemic of eastern spruce budworm (Choristoneurafumiferana (Clem.)). Growth efficiencies were reconstructed based on the relationship between age and the number of annual growth rings in the cross-sectional area of heartwood at breast height (R2 = 0.97) and on the previously demonstrated relationship between sapwood area and leaf area of balsam fir across a wide geographic area. Profile and logistic regression analyses demonstrated that apparent E (i.e., the historically reconstructed E) of surviving trees was greater than that of dead trees for every year of the 30-year analysis period. For trees in the 25- to 35-year age-class in 1960, apparent E was the only variable measured prior to the epidemic that was significantly related to balsam fir mortality. For all trees (aged 11 to 46 years in 1960), both tree age and apparent E were significant factors prior to the epidemic. During and following the epidemic, several of the more standard mensurational variables (e.g., diameter and basal area growth) were also significantly associated with balsam fir mortality, but apparent E had the highest levels of significance. Using logistical regression, critical E values below which trees would be predicted to die were calculated as 5-year running averages for the period prior to the epidemic (1960–1968). These were stable at around 0.17 × 10−4 m2 basal area growth•(m2 leaf area)−1•year−1. Following the epidemic, critical E values were again stable but at a lower level of around 0.07. There was a negative exponential relationship between apparent E and leaf area. Furthermore, for the same level of leaf area, surviving trees had a higher apparent E than trees that died, up to approximately 30 m2 of leaf area. These results suggest that growth efficiency should be considered as part of standard forest inventories in the balsam fir zone because of its ease of measure and its apparent ability to provide a sensitive, physiologically based index of forest health. Furthermore, the technique of historically reconstructing E demonstrated in this study may be of interest for other types of dendrochronological research.

Nutrient supply and declines in leaf area and production in lodgepoie pine

1995 ◽  
Vol 25 (4) ◽  
pp. 621-628 ◽  
Author(s):  
Dan Binkley ◽  
F.W. Smith ◽  
Y. Son
Keyword(s):  
Nutrient Limitation ◽  
Leaf Area ◽  
Basal Area ◽  
Nutrient Supply ◽  
Stand Age ◽  
Stand Development ◽  
Age Classes ◽  
Limited Growth ◽  
Basal Area Growth ◽  
Area Growth

In southeastern Wyoming, stand leaf area and production of lodgepoie pine (Pinuscontorta Dougl.) peak early in stand development and then decline. We tested the hypothesis that these declines followed decreasing nutrient supply and increasing nutrient limitation in older forests. Single-tree fertilization plots in 28 stands were used to test for nutrient limitation with stand age and density. Younger stands (<40 year old) had higher net nitrification and mineralization. These stands showed no significant response to fertilization in either needle fascicle weight or basal area growth. All older age-classes responded strongly in both fascicle weight and basal area growth. Foliar analysis indicated that N, P, and K all limited growth in older stands, but basal area increments indicated maximum responses to N alone. We conclude that increasing nutrient limitation in older stands probably accounts for at least part of the decline in stand leaf area and growth. Such declines may be responsive to a range of management activities that improve or impair stand nutrition.

Estimation of a basal area growth model for individual trees in uneven-aged Caspian mixed species forests

2017 ◽  
Vol 29 (5) ◽  
pp. 1205-1214 ◽  
Author(s):  
Zohreh Mohammadi ◽  
Soleiman Mohammadi Limaei ◽  
Peter Lohmander ◽  
Leif Olsson
Keyword(s):  
Growth Model ◽  
Basal Area ◽  
Mixed Species ◽  
Basal Area Growth ◽  
Area Growth ◽  
Individual Trees
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