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.

Growth response to thinning and its relation to site resources in Eucalyptusregnans

1995 ◽  
Vol 25 (1) ◽  
pp. 69-80 ◽  
Author(s):  
P.W. West ◽  
G.H.R. Osier
Keyword(s):  
Biomass Production ◽  
Tree Growth ◽  
Aboveground Biomass ◽  
Growth Response ◽  
Radiation Absorption ◽  
Light Use Efficiency ◽  
Individual Tree ◽  
Individual Tree Growth ◽  
Use Efficiency ◽  
Individual Trees

The factors determining individual tree growth response are examined during the 4 years following thinning in experiments in even-aged, 8- or 12-year-old regrowth Eucalyptusregnans F. Muell. forest at two sites in southern Australia. At one site, a vigorous understorey dominated by a sedge developed after the thinning. At that site, light-use efficiency by the trees was unaffected by thinning and the aboveground biomass production by the trees in the thinned stand was substantially less than that in the unthinned stand. At the other site, little understorey developed, light-use efficiency by trees in the thinned stand was greater than that in the unthinned stand, and aboveground biomass production was unaffected by thinning even though the leaf weight of the thinned stand was far below that of the unthinned stand. Where the understorey developed, it was concluded that it competed successfully with the trees for water, thereby reducing production in the thinned stand when compared with the unthinned stand. The individual tree growth response that occurred in the thinned stand at that site appeared to be due soley to the extra light available to individual trees following the canopy opening. Where the understorey did not develop, it was concluded that individual tree growth response was due not only to the extra light available to individual trees but also to the increased availability of belowground resources, most probably soil water. Application of a pre-existing stand growth model suggested that at that site the tendency for increased growth resulting from extra water availability in the thinned stand was just balanced by decreased growth due to lower radiation absorption by the reduced canopy, so that net production was unaffected by thinning.

scholarly journals Individual Tree Diameter Growth Models of Larch–Spruce–Fir Mixed Forests Based on Machine Learning Algorithms

Forests ◽  
2019 ◽  
Vol 10 (2) ◽  
pp. 187 ◽  
Author(s):  
Qiangxin Ou ◽  
Xiangdong Lei ◽  
Chenchen Shen
Keyword(s):  
Machine Learning ◽  
Tree Growth ◽  
Growth Models ◽  
Tree Size ◽  
Diameter Growth ◽  
Individual Tree ◽  
Mixed Forests ◽  
Tree Diameter ◽  
Individual Tree Growth ◽  
The Individual

Individual tree growth models are flexible and commonly used to represent growth dynamics for heterogeneous and structurally complex uneven-aged stands. Besides traditional statistical models, the rapid development of nonparametric and nonlinear machine learning methods, such as random forest (RF), boosted regression tree (BRT), cubist (Cubist) and multivariate adaptive regression splines (MARS), provides a new way for predicting individual tree growth. However, the application of these approaches to individual tree growth modelling is still limited and short of a comparison of their performance. The objectives of this study were to compare and evaluate the performance of the RF, BRT, Cubist and MARS models for modelling the individual tree diameter growth based on tree size, competition, site condition and climate factors for larch–spruce–fir mixed forests in northeast China. Totally, 16,619 observations from long-term sample plots were used. Based on tenfold cross-validation, we found that the RF, BRT and Cubist models had a distinct advantage over the MARS model in predicting individual tree diameter growth. The Cubist model ranked the highest in terms of model performance (RMSEcv [0.1351 cm], MAEcv [0.0972 cm] and R2cv [0.5734]), followed by BRT and RF models, whereas the MARS ranked the lowest (RMSEcv [0.1462 cm], MAEcv [0.1086 cm] and R2cv [0.4993]). Relative importance of predictors determined from the RF and BRT models demonstrated that the competition and tree size were the main drivers to diameter growth, and climate had limited capacity in explaining the variation in tree diameter growth at local scale. In general, the RF, BRT and Cubist models are effective and powerful modelling methods for predicting the individual tree diameter growth.

Use of pretreatment increment data in evaluating tree growth response to fertilization

1985 ◽  
Vol 15 (1) ◽  
pp. 18-22 ◽  
Author(s):  
T. M. Ballard ◽  
N. Majid
Keyword(s):  
Tree Growth ◽  
Growth Response ◽  
Stand Structure ◽  
Foliar Spray ◽  
Branch Length ◽  
Absolute Magnitude ◽  
Individual Tree ◽  
Individual Tree Growth ◽  
Length Increment ◽  
And Control

The use of pretreatment increment can lead to improved estimates of individual and average tree growth response to fertilization, by helping to adjust for site as well as stand structure differences between fertilized and control areas. It has applications in research using either single-tree or plot fertilization, and also in estimating responses to operational fertilization. Particularly useful equations are R = Af − (Bf)av(Au/Bu) and I = av(Af/Bf) − av(Au/Bu), where R is an estimate of the absolute magnitude of individual tree growth response to fertilization; A and B are increment after and before fertilization, and f and u denote fertilized and unfertilized trees, respectively; av signifies the average of several replicates; and I is an index of whether response has occurred. Equations were evaluated by examining branch length increment data from foliar spray application of iron and copper to Pinuscontorta Dougl. (lodgepole pine) and of nitrogen and iron to Pseudotsugamenziesii (Mirb.) Franco (Douglas-fir).

scholarly journals Crop Tree Release Increases Growth of Mature Red Oak Sawtimber

2002 ◽  
Vol 19 (4) ◽  
pp. 149-154 ◽  
Author(s):  
Jeffrey S. Ward
Keyword(s):  
Forest Cover ◽  
Quercus Rubra ◽  
Volume Growth ◽  
Diameter Growth ◽  
Red Oak ◽  
Tree Management ◽  
Significant Difference ◽  
Tree Thinning ◽  
Annual Volume ◽  
Epicormic Branches

Abstract Crop tree thinning plots were established in five stands of mature red oak (Quercus rubra, Q. velutina, and Q. coccinea) sawtimber in 1995. Initial stand ages ranged from 74 to 94 yr old with mean crop tree diameters ranging from 10.9 to 15.4 in. Growth of crop trees was monitored for the next 6 yr. The upper age limit at which oaks respond to crop tree management (high thinning) is at least 90 yr old. Although there was no significant difference in diameter growth between released and unreleased trees for the first 2 yr after release, diameter growth of released trees was significantly greater during each of the subsequent 4 yr. Crop tree release increased diameter growth of sawtimber red oak by 53%. Annual volume growth (International 1/4) increases ranged from 95% for 11 in. trees to 25% for 20 in. trees. Growth of crop trees has not decreased, relative to control trees, 6 yr after release. Formation of new epicormic branches on the butt log was largely limited to the slowest growing trees. Crop tree management should be considered as a method of managing sawtimber oak stands where maintaining high forest cover and noncommodities attributes are important considerations.

scholarly journals Crop-Tree Release Increases Growth of Black Birch (Betula lenta L.) in Southern New England

2007 ◽  
Vol 24 (2) ◽  
pp. 117-122 ◽  
Author(s):  
Jeffrey S. Ward
Keyword(s):  
New England ◽  
Growth Response ◽  
Volume Growth ◽  
Diameter Growth ◽  
Tree Management ◽  
Southern New England ◽  
Canopy Trees ◽  
Mean Diameter ◽  
Betula Lenta ◽  
Time Required

Abstract Black birch (Betula lenta L.) has become an increasingly important component of northeastern forests in recent decades. In 1996ߝ97, plots were established in five stands to examine diameter and volume growth response of black birch to crop-tree release. The stands were from 20 to 99 years old, and mean crop-tree diameters ranged from 4.8 to 13.8 in. Growth of crop trees was monitored for 8 years. Over the 8-year period, diameter and volume growth of completely released poles (4.6ߝ10.5 in. in diameter) were twice that of unreleased poles. Increased growth was noted the 1st year after release and showed no indication of decreasing after 8 years. Release did not affect diameter growth of small sawtimber crop trees (10.6ߝ13.5 in. in diameter) until the 3rd year after release. However, after 8 years, diameter and volume growth were nearly 40% greater than for unreleased trees. Release had negligible effect on diameter and volume growth of medium sawtimber crop trees (more than 13.5 in. in diameter). If crop-tree management was initiated in young stands of black birch poles (mean diameter of upper canopy trees was 4.5 in.), then the time required to grow those trees to diameters of 13.5 in. could be reduced by nearly 50%.

scholarly journals Testing Lake States TWIGS: Five-Year Growth Projections for Upland Hardwoods in Northern Lower Michigan

1996 ◽  
Vol 13 (4) ◽  
pp. 182-188 ◽  
Author(s):  
Patrick J. Guertin ◽  
C. W. Ramm
Keyword(s):  
Sugar Maple ◽  
Diameter Growth ◽  
Red Oak ◽  
Time Interval ◽  
Northern Red Oak ◽  
Red Maple ◽  
White Oak ◽  
Validation Data ◽  
Individual Tree ◽  
Lake States

Abstract Five-year diameter growth, basal area growth, and mortality for five upland hardwood species in northern Lower Michigan were compared to projections from Lake States TWIGS. The species studied were northern red oak, white oak, other red oak (pin oak and black oak combined), sugar maple, and red maple. The validation data consisted of individual tree measurements from 44 stands across 10 ecological land types on the Manistee National Forest. The stands were measured in 1986 and 1991; during this time interval stands experienced a drought and outbreaks of leaf defoliators. For individual dbh classes, 5 yr diameter growth was predicted within ± 0.3 in. for all species. Mean errors for BA projections were within ± 5 ft²/ac for all species, and mean error for trees/ac ranged from - 33 for other red oak to + 16 for sugar maple. Although precision was variable, Lake States TWIGS provided accurate predictions of 5 yr diameter growth for the five species tested. Projections of mortality were less accurate. North. J. Appl. For. 13(4):00-00.

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