scholarly journals Predicting Carbon Accumulation in Temperate Forests of Ontario, Canada Using a LiDAR-Initialized Growth-and-Yield Model

2020 ◽  
Vol 12 (1) ◽  
pp. 201
Author(s):  
Paulina T. Marczak ◽  
Karin Y. Van Ewijk ◽  
Paul M. Treitz ◽  
Neal A. Scott ◽  
Donald C.E. Robinson
Keyword(s):  
Carbon Stock ◽  
Temperate Forests ◽  
Species Abundance ◽  
Carbon Accumulation ◽  
Growth And Yield ◽  
Diameter Distribution ◽  
Stem Density ◽  
Yield Model ◽  
Validation Data ◽  
Aboveground Carbon

Climate warming has led to an urgent need for improved estimates of carbon accumulation in uneven-aged, mixed temperate forests, where high uncertainty remains. We investigated the feasibility of using LiDAR-derived forest attributes to initialize a growth and yield (G&Y) model in complex stands at the Petawawa Research Forest (PRF) in eastern Ontario, Canada; i.e., can G&Y models based on LiDAR provide accurate predictions of aboveground carbon accumulation in complex forests compared to traditional inventory-based estimates? Applying a local G&Y model, we forecasted aboveground carbon stock (tons/ha) and accumulation (tons/ha/yr) using recurring plot measurements from 2012–2016, FVS1. We applied statistical predictors derived from LiDAR to predict stem density (SD), stem diameter distribution (SDD), and basal area distribution (BA_dist). These data, along with measured species abundance, were used to initialize a second model (FVS2). A third model was tested using LiDAR-initialized tree lists and photo-interpreted estimates of species abundance (i.e., FVS3). The carbon stock projections for 2016 from the inventory-based G&Y model) were equivalent to validation carbon stocks measured in 2016 at all size-class levels (p < 0.05), while LiDAR-based G&Y models were not. None of the models were equivalent to validation data for accumulation (p > 0.05). At the plot level, LiDAR-based predictions of carbon accumulation over a nine-year period did not differ when using either inventory or photo-interpreted species (p < 0.05). Using a constant mortality rate, we also found statistical equivalency of inventory and photo-interpreted accumulation models for all size classes ≥17 cm. These results suggest that more precise information is needed on tree characteristics than we could derive from LiDAR, but that plot-level species information is not as critical for predictions of carbon accumulation in mixed-species forests. Further work is needed on the use of LiDAR to quantify stand properties before this technique can be used to replace recurring plot measurements to quantify carbon accumulation.

scholarly journals A stand-level multispecies growth model for Appalachian hardwoods

1989 ◽  
Vol 19 (4) ◽  
pp. 405-412 ◽  
Author(s):  
Ernest H. Bowling ◽  
Harold E. Burkhart ◽  
Thomas E. Burk ◽  
Donald E. Beck
Keyword(s):  
Unit Area ◽  
Basal Area ◽  
Species Group ◽  
Arithmetic Mean ◽  
Growth And Yield ◽  
Diameter Distribution ◽  
Individual Species ◽  
Yield Model ◽  
Recovery Method ◽  
Appalachian Hardwoods

A stand-level growth and yield model was developed to predict future diameter at breast height (dbh) distributions of thinned stands of mixed Appalachian hardwoods. The model allows prediction by species group and dbh class. Stand attributes (basal area per unit area, trees per unit area, minimum stand dbh, and arithmetic mean dbh) were projected through time for the whole stand and for individual species groups. Future dbh distributions were obtained using the three-parameter Weibull probability density function and a variation of the parameter recovery method. The recovery method used employed the first two noncentral moments of dbh (arithmetic mean dbh and quadratic mean dbh2) to generate Weibull parameters. Future dbh distributions were generated for the whole stand and every species group but one; the diameter distribution for the remaining species group was obtained by subtraction.

scholarly journals Prediction Comparison of Stand Parameters and Two Ecosystem Services through New Growth and Yield Model System for Mixed Nothofagus Forests in Southern Chile

Forests ◽  
2021 ◽  
Vol 12 (9) ◽  
pp. 1236
Author(s):  
Paulo Moreno-Meynard ◽  
Sebastian Palmas ◽  
Salvador A. Gezan
Keyword(s):  
Ecosystem Services ◽  
Basal Area ◽  
Growth And Yield ◽  
Diameter Distribution ◽  
Tree Level ◽  
Yield Model ◽  
Individual Tree ◽  
Nothofagus Forests ◽  
Level Model ◽  
Stand Parameters

Forest managers need tools to predict the behavior of forests not only for the main stand parameters, such as basal area and volume, but also for ecosystem services such as timber volume and carbon sequestration. Useful tools to predict these parameters are growth and yield model systems with several possible options for modeling, such as the whole stand-level model, with or without diameter distribution generation, individual tree-level model, and compatibility models. However, those tools are scarce or developed mainly for forest plantations that are mostly located in the northern hemisphere. Thus, this study focuses on analyzing predictions of several growth and yield models built for native mixed Nothofagus forests from southern Chile, using the simulator Nothopack. A dataset of 19 permanent plots with three measurements were used for comparing the different models. Individual tree-level simulation presented the best goodness-of-fit statistics for stand parameters and ecosystem services. For example, the basal area gave an R2emp of 0.97 and 0.87 at 6 and 12 years of projection. However, the stand-level simulations with a generation of diameter distribution and both compatibility models showed satisfactory performance, both in accuracy and bias control. The simulator Nothopack, which has the capability of obtaining detailed outputs, is a useful tool to support management plans for these forest ecosystems.

scholarly journals Stand-Level Growth and Yield Component Models for Red Oak–Sweetgum Forests on Mid-South Minor Stream Bottoms

2010 ◽  
Vol 34 (4) ◽  
pp. 161-175 ◽  
Author(s):  
Emily B. Schultz ◽  
J. Clint Iles ◽  
Thomas G. Matney ◽  
Andrew W. Ezell ◽  
James S. Meadows ◽  
...  
Keyword(s):  
Yield Component ◽  
Growth And Yield ◽  
Coefficient Of Determination ◽  
Diameter Distribution ◽  
Red Oak ◽  
Average Height ◽  
Distribution Models ◽  
Yield Model ◽  
Validity Assessment ◽  
Mean Diameter

Abstract Greater emphasis is being placed on Southern bottomland hardwood management, but relatively few growth and yield prediction systems exist that are based on sufficient measurements. We present the aggregate stand-level expected yield and structural component equations for a red oak (Quercus sectionLobatae)-sweetgum (Liquidambar styraciflua L.) growth and yield model. Measurements from 638 stand-level observations on 258 distinct permanent growth and yield plots collected in 1981, 1988, 1994, and 2006 in minor stream bottoms in Mississippi and Alabama provided data for model development. Equations for average height of dominant and codominant red oaks, trees/ac, arithmetic mean diameter, quadratic mean diameter, and volume were selected on the basis of significance of independent variables, coefficient of determination, index of fit, and biological validity assessment. These models produce expected average yields for combined species or species groups in naturally developing stands and provide an average baseline for individuals managing their lands for the red oak–sweetgum complex. Models will be integrated with log grade volume and diameter distribution models that are in concurrent development to produce a growth and yield system capable of comparing management alternatives on a financial basis.

scholarly journals PROGNOSIS OF THE DIAMETER DISTRIBUTION AND CARBON STOCK IN A SECONDARY ATLANTIC FOREST BY MARKOV CHAIN

2018 ◽  
Vol 42 (2) ◽  
Author(s):  
Paulo Henrique Villanova ◽  
Carlos Moreira Miquelino Eleto Torres ◽  
Laércio Antônio Gonçalves Jacovine ◽  
Carlos Pedro Boechat Soares ◽  
Liniker Fernandes da Silva ◽  
...  
Keyword(s):  
Markov Chain ◽  
Carbon Stock ◽  
Growth And Yield ◽  
Diameter Distribution ◽  
P Value ◽  
Ecological Groups ◽  
Pioneer Species ◽  
Forest Fragment ◽  
Number Of Stems ◽  
The Impact

ABSTRACT Growth and yield modeling at the diameter distribution level is an important tool to understand forest dynamics and to predict whether a forest will act as a CO2 emissions source or sink. Therefore, the objective of the present study was to determine the diameter distribution and carbon stock of a forest fragment using the Markov chain to evaluate the impact of growth dynamics on forest carbon capture. Twenty plots of 10x50m were inventoried, between 2010 and 2015, counting the stems with dbh > 5 cm. Diameter distribution was projected for 2015 and 2020, considering the whole fragment and the ecological groups (pioneer and non-pioneer tree species). The volume was determined using allometric equation while biomass and carbon was determined by multiplying the volume by the basic wood density and the carbon content, respectively. The diameter distribution estimated for the fragment and ecological groups did not differ statistically from the values observed using the Kolmogorov-Smirnov test (p-value < 0.05). The number of stems ha-1 estimated in the fragment was from 1,692 in 2015 to 1,841 in 2020. For the pioneer and non-pioneer species, the number of stems ha-1 was from 476 and 1,203 in 2015 to 472 and 1,362 in 2020, respectively. The carbon stock increased 5.69 MgC ha-1, with the greater contribution coming from the non-pioneer species. Therefore, it was concluded that the diameter distribution would remain “J-inverted” and the forest fragment would continue to act as a carbon sink over the coming years.

A Blind Spot in the Use of the Weibull Function for Modeling Diameter Distributions

2020 ◽  
Author(s):  
Adrian Norman Goodwin
Keyword(s):  
Lower Bound ◽  
Blind Spot ◽  
Forest Growth ◽  
Growth And Yield ◽  
Diameter Distribution ◽  
Absolute Difference ◽  
Weibull Function ◽  
Distribution Models ◽  
Difference Statistic ◽  
Diameter Distributions

Abstract Diameter distribution models based on probability density functions are integral to many forest growth and yield systems, where they are used to estimate product volumes within diameter classes. The three-parameter Weibull function with a constrained nonnegative lower bound is commonly used because of its flexibility and ease of fitting. This study compared Weibull and reverse Weibull functions with and without a lower bound constraint and left-hand truncation, across three large unthinned plantation cohorts in which 81% of plots had negatively skewed diameter distributions. Near-optimal lower bounds for the unconstrained Weibull function were negative for negatively skewed data, and the left-truncated Weibull using these bounds was 14.2% more accurate than the constrained Weibull, based on the Kolmogorov-Smirnov statistic. The truncated reverse Weibull fit dominant tree distributions 23.7% more accurately than the constrained Weibull, based on a mean absolute difference statistic. This work indicates that a blind spot may have developed in plantation growth modeling systems deploying constrained Weibull functions, and that left-truncation of unconstrained functions could substantially improve model accuracy for negatively skewed distributions.

Deriving Tree Diameter Growth and Probability of Survival Equations from Successive Diameter Distributions

2008 ◽  
Vol 54 (1) ◽  
pp. 31-35
Author(s):  
Thomas G. Matney ◽  
Emily B. Schultz
Keyword(s):  
General Procedure ◽  
Growth And Yield ◽  
Diameter Distribution ◽  
Diameter Growth ◽  
Individual Tree ◽  
Statistical Probability ◽  
Growth And Survival ◽  
Tree Diameter ◽  
Growth And Yield Models ◽  
Diameter Distributions

Abstract Many growth and yield models have used statistical probability distributions to estimate the diameter distribution of a stand at any age. Equations for approximating individual tree diameter growth and survival probabilities from dbh can be derived from these models. A general procedure for determining the functions is discussed and illustrated using a loblolly pine spacing study. The results from the spacing study show that it is possible to define tree diameter growth and survival probability functions from diameter distributions with an accuracy sufficient to obtain a link between the individual tree and diameter growth and yield models.

A Growth and Yield Model for Improved Eastern Cottonwood Plantations in the Lower Mississippi Delta

1991 ◽  
Vol 15 (4) ◽  
pp. 213-216 ◽  
Author(s):  
Quang V. Cao ◽  
Kenneth M. Durand
Keyword(s):  
Populus Deltoides ◽  
Mississippi Delta ◽  
Basal Area ◽  
Site Index ◽  
Growth And Yield ◽  
Annual Increment ◽  
Yield Model ◽  
Eastern Cottonwood ◽  
Volume Yield ◽  
Growth And Yield Model

Abstract A compatible growth and yield model was developed based on remeasurement data collected from 183 plots on unthinned improved eastern cottonwood (Populus deltoides Bartr.) plantations in the lower Mississippi Delta. The Sullivan and Clutter (1972) equation form was selected for predicting cubic-foot volume yield and projecting volume from site index and initial age and basal area. Yield equations explained 97% and 94%, respectively, of the variations in total outside bark and merchantable inside bark volumes. Mean annual increment of merchantable volume culminated between 8 and 15 years, depending on site index and initial basal area. South. J. Appl. For. 15(4):213-216.

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