scholarly journals Thinning Intensity and Pruning Impacts onEucalyptusPlantations in Brazil

2015 ◽  
Vol 2015 ◽  
pp. 1-10 ◽  
Author(s):  
Gilciano Saraiva Nogueira ◽  
Peter L. Marshall ◽  
Helio Garcia Leite ◽  
João Carlos Chagas Campos
Keyword(s):  
Mixed Model ◽  
Linear Mixed Model ◽  
Eucalyptus Grandis ◽  
Basal Area ◽  
Tree Level ◽  
Quadratic Mean ◽  
Thinning Intensity ◽  
Dominant Height ◽  
Intensity Response ◽  
Quadratic Mean Diameter

A thinning intensity experiment using theEucalyptus grandis×E. urophyllahybrid was conducted at three sites in Bahia State, Brazil. The treatments were a combination of thinning intensities and pruning: 20%, 35%, and 50% basal area removed with no pruning and 35% basal area removed plus pruning (at 27 months). Plots were measured roughly annually from 27 to 165 months. Thinning was implemented on all sites at 58 months and again at 142 months at two of the sites. One of the sites was harvested at 87 months of age. A linear mixed model was applied separately to each installation to test for differences among treatments for mean increment of height, dominant height, quadratic mean diameter, and volume outside bark at the plot level. Additionally, differences in mean monthly increment of basal area and volume outside bark as a percentage of the value at the beginning of the increment period were examined. Increased thinning intensity increased all tree-level variables except dominant height. Pruning had no impact. Observed mortality on all plots was quite low. Thinning intensity response varied among sites and with time since thinning; however, the thinning intensity response was consistent through time among the installations.

Algorithmic versions of black spruce stand density management diagrams

1997 ◽  
Vol 73 (2) ◽  
pp. 257-265 ◽  
Author(s):  
P. F. Newton
Keyword(s):  
Black Spruce ◽  
Initial Density ◽  
Basal Area ◽  
Stand Density ◽  
File Transfer ◽  
Quadratic Mean ◽  
Dominant Height ◽  
Yield Production ◽  
Quadratic Mean Diameter ◽  
Stand Density Management

Algorithmic versions of stand density management diagrams (SDMDs) were developed for natural and managed black spruce (Picea mariana (Mill.) B.S.P.) stands. Specifically, the IBM-compatible PC-based algorithms (1) graphically illustrate site-specific size-density trajectories for eight user-specified initial density regimes, (2) given (1), calculate and subsequent tabulate periodic yield estimates (mean dominant height, density, mean volume, total volume, total merchantable volume, quadratic mean diameter, and basal area), and (3) given (2), graphically illustrate empirically-derived yield production curves for total merchantable volume ha−1 and stems m−3 with user-specified operability criteria superimposed. Instructions on acquiring the executable algorithmic versions including the required graphical subroutines via the Internet are described. Currently, the algorithms are restricted in applicability to central insular Newfoundland. Key words: stand density management diagrams, black spruce, algorithms, microcomputer, World-Wide Web (WWW), hypertext browser, file transfer protocol (FTP).

A Stocking Guide for Southern Bottomland Hardwoods

1995 ◽  
Vol 19 (3) ◽  
pp. 103-104 ◽  
Author(s):  
J. C. G. Goelz
Keyword(s):  
Basal Area ◽  
Bottomland Hardwoods ◽  
Quadratic Mean ◽  
Mean Diameter ◽  
Quadratic Mean Diameter

Abstract A stocking guide was developed from the data of Putnam, et al. (1960). The form of the stocking guide follows Gingrich (1967), although the “B”-line is based on the suggested residual stocking of Putnam, et al. (1960) rather than on minimum full stocking. This stocking guide is similar to the stocking guide for central upland hardwoods constructed by Gingrich, except that 100% stocking is 5-7 ft2² of basal area lower for the southern bottomland guide, across a range of quadratic mean diameter. South. J. Appl. For. 19(3):103-104.

Compatible basal-area growth and yield model for thinned and unthinned stands

1983 ◽  
Vol 13 (4) ◽  
pp. 563-571 ◽  
Author(s):  
Robert L. Bailey ◽  
Kenneth D. Ware
Keyword(s):  
Loblolly Pine ◽  
Basal Area ◽  
Growth And Yield ◽  
Yield Model ◽  
Projection Model ◽  
Quadratic Mean ◽  
Basal Area Growth ◽  
Area Growth ◽  
Mean Diameter ◽  
Quadratic Mean Diameter

A measure of kind and level of thinning is developed and its relationship to other stand attributes such as number of trees, basal area, and volume removed in thinning is quantified. This measure or thinning index is based on the ratio of the quadratic mean diameter of thinned trees to the quadratic mean diameter of all trees before thinning. The thinning index is then logically incorporated into a thinning multiplier from which is derived a compatible basal-area growth projection model to generalize the previous concepts for thinning effects in systems for predicting growth and yield. Empirical tests with data from thinned and unthinned natural stands of loblolly pine, from thinned and unthinned slash pine plantations, and from thinned western larch stands show the model to provide estimates with improved properties. Hence, the thinning index and the thinning multiplier are also proposed for other situations involving effects of thinning.

Partial Calibration of "ONTWIGS": A Forest Growth and Yield Projection System Adapted for Ontario

1994 ◽  
Vol 11 (2) ◽  
pp. 41-46 ◽  
Author(s):  
Bijan Payandeh ◽  
Pia Papadopol
Keyword(s):  
Basal Area ◽  
Forest Growth ◽  
Data Sets ◽  
Prediction Errors ◽  
Northern Ontario ◽  
Quadratic Mean ◽  
Tree Survival ◽  
Mean Diameter ◽  
Quadratic Mean Diameter ◽  
Stand Attributes

Abstract "ONTWIGS" (an adaptation of "LSTWIGS" for Ontario), was partially calibrated for permanent plots data sets from northern Ontario. Stand attributes used for calibration were quadratic mean diameter, number of trees, and basal area/ha. Simple local calibration was accomplished by adjusting tree survival and potential diameter growth coefficients so as to reduce the prediction errors to within 10% of the actual values over a 5-yr period. This resulted in prediction errors ranging from -9.9 to 6.9%, but with an overall average of only: -1.4, 1.0, and 0.2% for the spruce fir data; from -8.5 to 2.8%, but with an overall average of only -0.7, 0.5, and 0.4% for a black spruce drainage and fertilization experiment; and from -6.6 to 9.8%, but with an overall average of only -1.7, 0.0, and -1.8% for an unthinned red pine plantation for number of trees/ha, quadratic mean diameter, and basal area/ha, respectively. Results indicate that "ONTWIGS" may be locally calibrated through simple procedures to increase its prediction accuracy to ±5% of the observed stand attributes, averaging less than 3% for the major timber species in northern Ontario and for short to medium projection periods. However, the uncalibrated model should be used with caution for short terms, only and where no other projection tools are available. More extensive calibrations of "ONTWIGS" on larger and more representative data sets are currently underway. North. J. Appl. For. 11(2):41-46.

scholarly journals Development of Water Tupelo Coppice Stands on the Mobile-Tensaw River Delta for Five Years After Precommercial Thinning and Cleaning

2001 ◽  
Vol 25 (4) ◽  
pp. 165-172 ◽  
Author(s):  
J.C.G. Goelz ◽  
J.S. Meadows ◽  
T.C. Fristoe
Keyword(s):  
Basal Area ◽  
Individual Tree ◽  
Quadratic Mean ◽  
Precommercial Thinning ◽  
Mean Diameter ◽  
Water Tupelo ◽  
Rotation Age ◽  
Large Water ◽  
Quadratic Mean Diameter ◽  
The Individual

Abstract Three 4-yr-old stands (or locations) were selected for treatment. Treatment consisted of two components: (1) thinning water tupelo (Nyssa aquatica L.) stump sprouts and (2) cutting all stems of Carolina ash (Fraxinus caroliniana Mill.) and black willow (Salix nigra Marsh.) (cleaning). Contrary to results in other areas, survival of water tupelo coppice was very high and was not affected by the treatments. Cleaning had little or no positive effect on the individual tree or stand-level variables we measured. Thinning sprout clumps significantly increased diameter growth of water tupelo; the effect of thinning was considerably larger for one location. Stand basal area growth was decreased by thinning sprout clumps. However, quadratic mean diameter was increased by thinning, particularly at one location. Although thinning decreased basal area 5 yr after treatment, the increase in quadratic mean diameter was sufficient for there to be no significant effect of thinning on total volume 5 yr after treatment. Because of this, and in anticipation of imminent natural thinning of the unthinned plots, we suspect that the thinned plots will eventually have significantly greater standing volume than the unthinned plots, at least for the location where density of large sprouts was initially the highest. Rotation age will be decreased for that stand because stems will achieve merchantable size sooner. Thus we consider precommercial thinning of sprout clumps to be a potentially effective practice in stands with a high density of large water tupelo sprouts. South. J. Appl. For. 25(4):165–172.

scholarly journals Managing plantation density through initial spacing and commercial thinning: Yield results from a 60-year-old red pine spacing trial experiment

2020 ◽  
Author(s):  
Nelson Thiffault ◽  
Michael K. Hoepting ◽  
Jeff Fera ◽  
Jean-Martin Lussier ◽  
Guy R. Larocque
Keyword(s):  
Basal Area ◽  
Pinus Resinosa ◽  
Stand Volume ◽  
Quadratic Mean ◽  
Commercial Thinning ◽  
Volume Yield ◽  
Volume Production ◽  
Initial Spacing ◽  
Quadratic Mean Diameter ◽  
Common Target

We report on a 60-year-old Pinus resinosa spacing trial experiment located in Ontario (Canada) that included the combinations between six initial spacings (from 1.2–3.0 m) and the presence/absence of a commercial thinning (CT) regime, and their impacts on quadratic mean diameter (QMD) and stand volume yield. The CT regime, initiated at age 30, targeted a residual basal area (BA) of 38 m2 ha-1 after each of four entries. Without thinning, as initial spacing increased, QMD increased; gross and net volume production peaked in the 2.1–2.4 m spacings. With thinning, similar trends with spacing were evident for QMD, although piece sizes were larger and differences between spacing were lower. The immediate increase of average tree size caused by tree selection explained most of the differences in QMD between thinned and unthinned plots. Thinning to a common target BA resulted in similar standing volume across spacings. Cumulative gross yield was similar between spacings <2.1 m for both unthinned/thinned stands and decreased for thinned plots for wider spacings. Greater net volume production in thinned stands with the narrower spacings confirmed that mortality was captured. Lower gross and net production for wider spacings suggested that thinning resulted in under-utilized growing space.

scholarly journals How much does it take to be old? Modelling the time since the last harvesting to infer the distribution of mature forests in France

2021 ◽  
Author(s):  
Lucie Thompson ◽  
Eugénie Cateau ◽  
Nicolas Debaive ◽  
Frédéric Bray ◽  
André Torre ◽  
...  
Keyword(s):  
Mixed Model ◽  
Linear Mixed Model ◽  
Stand Structure ◽  
Basal Area ◽  
National Forest Inventory ◽  
Managed Forests ◽  
Forest Reserves ◽  
Large Trees ◽  
Generalised Linear Mixed Model ◽  
Good Proxy

AbstractAimThe distribution of mature forests in metropolitan France is poorly known, focuses only on a few sites, and has never been evaluated countrywide. Here, we modelled French forest reserves’ time since the last harvesting operation, then inferred the current statistical distribution of mature forests (i.e. forests over 50 years without harvesting) in France.LocationMetropolitan FranceMethodsWe used forest inventories from forest reserves and managed forests to calibrate a generalised linear mixed model explaining the time since the last harvesting - a proxy for forest maturity - with selected structural attributes and environmental variables. We then projected this model on the independent National Forest Inventory dataset. We thus obtained an updated estimation of the proportion and a rough distribution of mature forest stands in metropolitan France.ResultsWe found that high basal area of very large trees, high volumes of standing and downed deadwood, high diversity of tree-related microhabitats and more marginally diversity of decay stages best characterized the time since the last harvesting. Volumes of stumps and high density of coppices translating legacy of past forest management also distinguished more mature plots. Our projection yielded an estimated 3% of French forests over 50 years without harvesting and a promising proportion for future managed forests if left unharvested.Main conclusionsOur model showed that the time since the last harvesting is a good proxy for forest maturity in French temperate forest. It highlighted the stand structure attributes that are key in characterising those forests with high conservation values. We found that forests with higher levels of maturity seem to be located in more inaccessible places notably mountainous areas. Our projection gives the first robust statistical estimate of the proportion of mature forests in metropolitan France and may serve to report on the status of mature forests.

scholarly journals Relating Forest Attributes with Area- and Tree-Based Light Detection and Ranging Metrics for Western Oregon

2010 ◽  
Vol 25 (3) ◽  
pp. 105-111 ◽  
Author(s):  
Michael E. Goerndt ◽  
Vincente J. Monleon ◽  
Hailemariam Temesgen
Keyword(s):  
Basal Area ◽  
Light Detection And Ranging ◽  
Stem Volume ◽  
Height Distribution ◽  
Light Detection ◽  
Quadratic Mean ◽  
Crown Width ◽  
Mean Diameter ◽  
Forest Attributes ◽  
Quadratic Mean Diameter

Abstract Three sets of linear models were developed to predict several forest attributes, using stand-level and single-tree remote sensing (STRS) light detection and ranging (LiDAR) metrics as predictor variables. The first used only area-level metrics (ALM) associated with first-return height distribution, percentage of cover, and canopy transparency. The second alternative included metrics of first-return LiDAR intensity. The third alternative used area-level variables derived from STRS LiDAR metrics. The ALM model for Lorey's height did not change with inclusion of intensity and yielded the best results in terms of both model fit (adjusted R2 = 0.93) and cross-validated relative root mean squared error (RRMSE = 8.1%). The ALM model for density (stems per hectare) had the poorest precision initially (RRMSE = 39.3%), but it improved dramatically (RRMSE = 27.2%) when intensity metrics were included. The resulting RRMSE values of the ALM models excluding intensity for basal area, quadratic mean diameter, cubic stem volume, and average crown width were 20.7, 19.9, 30.7, and 17.1%, respectively. The STRS model for Lorey's height showed a 3% improvement in RRMSE over the ALM models. The STRS basal area and density models significantly underperformed compared with the ALM models, with RRMSE values of 31.6 and 47.2%, respectively. The performance of STRS models for crown width, volume, and quadratic mean diameter was comparable to that of the ALM models.

scholarly journals Stocking Diagrams for Silvicultural Guideline in Korean Pines and Japanese Larch

Forests ◽  
2020 ◽  
Vol 11 (8) ◽  
pp. 833
Author(s):  
Daesung Lee ◽  
Jungkee Choi
Keyword(s):  
Basal Area ◽  
Stand Density ◽  
Japanese Larch ◽  
Larix Kaempferi ◽  
White Pine ◽  
Individual Tree ◽  
Quadratic Mean ◽  
Mean Diameter ◽  
Quadratic Mean Diameter ◽  
Species Specific

Appropriate management of stand density is necessary to avoid wasted growing space and overcrowding-induced self-thinning and therefore to optimize profitability. We developed a Gingrich-style stocking chart for Korean red pine (Pinus densiflora), Korean white pine (P. koraiensis), and Japanese larch (Larix kaempferi) in Korea. Datasets for even-aged stands were categorized into two censored datasets via relative density based on species-specific stand density indices to assign adequate plots for tree allometry. Censored plot data for maximum density on full stocking were used to develop A-level stocking based on mean individual tree area. In censored plot data for minimum density on full stocking, individual trees represented open-grown trees, and a crown competition factor of 100 was proposed as B-level stocking. Based on parameters estimated from allometry, stocking diagrams comprising quadratic mean diameter, number of trees, and basal area were correctly expressed. A-level stocking at the same quadratic mean diameter revealed that Korean white pine had the most trees and largest basal area, while Japanese larch had the fewest trees and smallest basal area. In contrast, B-level stocking disclosed that Japanese larch had the most trees and basal area, whereas Korean white pine had the fewest trees and smallest basal area. The stocking diagrams suggest that silvicultural treatments for these species should be species-specific.

scholarly journals Analysis of spatial correlation in predictive models of forest variables that use LiDAR auxiliary information

2017 ◽  
Vol 47 (6) ◽  
pp. 788-799 ◽  
Author(s):  
F. Mauro ◽  
V.J. Monleon ◽  
H. Temesgen ◽  
L.A. Ruiz
Keyword(s):  
Spatial Correlation ◽  
Linear Models ◽  
Auxiliary Information ◽  
Basal Area ◽  
Stand Density ◽  
Model Errors ◽  
Quadratic Mean ◽  
Quadratic Mean Diameter ◽  
Model Residuals ◽  
The Impact

Accounting for spatial correlation of LiDAR model errors can improve the precision of model-based estimators. To estimate spatial correlation, sample designs that provide close observations are needed, but their implementation might be prohibitively expensive. To quantify the gains obtained by accounting for the spatial correlation of model errors, we examined (i) the spatial correlation patterns of residuals from LiDAR linear models developed to predict volume, total and stem biomass per hectare, quadratic mean diameter (QMD), basal area, mean and dominant height, and stand density and (ii) the impact of field plot size on the spatial correlation patterns in a standwise managed Mediterranean forest in central Spain. For all variables, the correlation range of model residuals consistently increased with plot radius and was always below 60 m except for stand density, where it reached 85 m. Except for QMD, correlation ranges of model residuals were between 1.06 and 8.16 times shorter than those observed for the raw variables. Based on the relatively short correlation ranges observed when the LiDAR metrics were used as predictors, the assumption of independent errors in many forest management inventories seems to be reasonable and appropriate in practice.

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