scholarly journals Evaluation of stand-level hybrid PipeQual model with permanent sample plot data of Norway spruce

2017 ◽  
Vol 47 (2) ◽  
pp. 234-245 ◽  
Author(s):  
Tuomo Kalliokoski ◽  
Harri Mäkinen ◽  
Tapio Linkosalo ◽  
Annikki Mäkelä
Keyword(s):  
Norway Spruce ◽  
Basal Area ◽  
Forest Growth ◽  
Stem Volume ◽  
Permanent Sample Plots ◽  
Crown Structure ◽  
Permanent Sample Plot ◽  
Crown Characteristics ◽  
Linear Regressions ◽  
Process Based Models

The evaluation of process-based models (PBM) includes ascertaining their ability to produce results consistent with forest growth in the past. In this study, we parameterized and evaluated the hybrid model PipeQual with datasets containing traditional mensuration variables collected from permanent sample plots (PSP) of even-aged Norway spruce (Picea abies (L.) Karst.) stands in Finland. To initialize the model in the middle of stand development and reproduce observed changes in Norway spruce crown structure, the built-in empirical relationships of crown characteristics were made explicitly dependent on the light environment. After these modifications, the model accuracy at the whole dataset level was high, with slope values of linear regressions between the observations and simulations ranging from 0.77 to 0.99 depending on the variable. The average bias ranged between −0.72 and 0.07 m in stand dominant height, –0.68 and 0.57 cm in stand mean diameter, –2.62 and 1.92 m2 in stand basal area, and 20 and 29 m3 in stand total stem volume. Stand dynamics after thinning also followed reasonable closely the observed patterns. Accurate predictions illustrate the potential of the model for predicting forest stand growth and forest management effects in changing environmental conditions.

Tree growth as affected by stem and crown structure

Trees ◽  
2021 ◽  
Author(s):  
Hans Pretzsch
Keyword(s):  
Tree Growth ◽  
Scaling Theory ◽  
Tree Age ◽  
Stem Volume ◽  
Projection Area ◽  
Metabolic Scaling ◽  
Crown Structure ◽  
The Future ◽  
Metabolic Scaling Theory ◽  
Crown Characteristics

Abstract Key message Prediction of tree growth based on size or mass as proposed by the Metabolic Scaling Theory is an over-simplification and can be significantly improved by consideration of stem and crown morphology. Tree growth and metabolic scaling theory, as well as corresponding growth equations, use tree volume or mass as predictors for growth. However, this may be an over-simplification, as the future growth of a tree may, in addition to volume or mass, also depend on its past development and aspects of the current inner structure and outer morphology. The objective of this evaluation was to analyse the effect of selected structural and morphological tree characteristics on the growth of common tree species in Europe. Here, we used eight long-term experiments with a total of 24 plots and extensive individual measurements of 1596 trees in monospecific stands of European beech (Fagus sylvatica L.), Norway spruce (Picea abies (L.) Karst.), Scots pine (Pinus sylvestris L.) and sessile oak (Quercus petraea (Matt.) Liebl.). Some of the experiments have been systematically surveyed since 1870. The selected plots represent a broad range of stand density, from fully to thinly stocked stands. We applied linear mixed models with random effects for analysing and modelling how tree growth and productivity are affected by stem and crown structure. We used the species-overarching relationship $$\mathrm{iv}={{a}_{0}\times v}$$ iv = a 0 × v between stem volume growth, $$\mathrm{iv}$$ iv and stem volume, $$v,$$ v , as the baseline model. In this model $${a}_{0}$$ a 0 represents the allometric factor and α the allometric exponent. Then we included tree age, mean stem volume of the stand and structural and morphological tree variables in the model. This significantly reduced the AIC; RMSE was reduced by up to 43%. Interestingly, the full model estimating $$\mathrm{iv}$$ iv as a function of $$v$$ v and mean tree volume, crown projection area, crown ratio and mean tree ring width, revealed a $$\alpha \cong 3/4$$ α ≅ 3 / 4 scaling for the relationship between $$\mathrm{iv}\propto {v}^{\alpha }$$ iv ∝ v α . This scaling corresponded with Kleiber’s rule and the West-Brown-Enquist model of the metabolic scaling theory. Simplified approaches based on stem diameter or tree mass as predictors may be useful for a rough estimation of stem growth in uniform stands and in cases where more detailed predictors are not available. However, they neglect other stem and crown characteristics that can have a strong additional effect on the growth behaviour. This becomes of considerable importance in the heterogeneous mixed-species stands that in many countries of the world are designed for forest restoration. Heterogeneous stand structures increase the structural variability of the individual trees and thereby cause a stronger variation of growth compared with monocultures. Stem and crown characteristics, which may improve the analysis and projection of tree and stand dynamics in the future forest, are becoming more easily accessible by Terrestrial laser scanning.

Volume Equations and Stand Volumes for Unthinned Norway Spruce Plantations in New York

1986 ◽  
Vol 3 (1) ◽  
pp. 7-10 ◽  
Author(s):  
Eric J. Jokela ◽  
Russell D. Briggs ◽  
Edwin H. White
Keyword(s):  
New York ◽  
Norway Spruce ◽  
Basal Area ◽  
Stem Volume ◽  
Soil Drainage ◽  
Quadratic Mean ◽  
Central New York ◽  
Spruce Stands ◽  
Allegheny Plateau ◽  
Using Data

Abstract Total and merchantable stem volume prediction equations (English and metric) were developed using data from 228 trees sampled in 38 unthinned Norway spruce stands varying in age from 45 to 55 years on the Allegheny Plateau in central New York. The equations were used to estimate stand volumes for the 38 sample plantations. The results demonstrate the potential of Norway spruce as a fiber source, having growth rates equal to or exceeding those of native northern conifer species. Average total height of dominant and codominant stems, basal area, quadratic mean diameters, and total and merchantable standing volume for the sample stands ranged from 58-93 ft, 150-239 ft2/ac, 6.5-10.6 in, 5431-8833 ft3/ac, and 4431-8218 ft3;/ac, respectively. The most productive stands were generally found on well-drained to moderately well-drained soils, although Norway spruce grew well over a broad range of soil drainage conditions. North. J. Appl. For. 3:7-10, Mar. 1986.

MODELAGEM DO CRESCIMENTO DE POVOAMENTOS DE Eucalyptus grandis ATRAVÉS DE PROCESSOS DE DIFUSÃO

FLORESTA ◽  
2003 ◽  
Vol 33 (2) ◽  
Author(s):  
Romualdo Maestri ◽  
Carlos Roberto Sanquetta ◽  
Júlio Eduardo Arce
Keyword(s):  
Diffusion Equation ◽  
Tree Mortality ◽  
Diffusion Processes ◽  
Eucalyptus Grandis ◽  
Growth Modeling ◽  
Basal Area ◽  
Forest Growth ◽  
Espírito Santo ◽  
Permanent Sample Plots ◽  
Espirito Santo

A hidrodinâmica apresenta uma teoria sobre fluxo contínuo de líquidos que se assemelha ao processo de dinâmica em um povoamento florestal qualquer. O incremento em diâmetro, sua variância, a mortalidade e o recrutamento de árvores de uma dada classe de diâmetro no tempo t, podem ser representados como um líquido que evolui num tubo de um ponto a outro, cujo fluxo pode ser modelado através da equação de difusão de Kolmogorov (Hara, 1984). Dados de parcelas de inventário permanente da região norte do Estado do Espírito Santo e sul da Bahia, manejados para produção de madeira para celulose, em idades entre 2 e 6 anos, foram utilizados no presente trabalho. A equação de difusão de Kolmogorov foi empregada para modelar as distribuições diamétricas em idade futura. Estimativas foram obtidas e comparadas com os valores reais. Os resultados demonstraram que para o número de árvores por hectare e área basal a metodologia propicia inferências estatisticamente semelhantes ao nível de 95% de probabilidade. A aplicação prática do processo de difusão na modelagem do crescimento de povoamentos de eucalipto de rápido crescimento foi demonstrada. GROWTH MODELING IN Eucalyptus grandis STANDS THROUGH DIFFUSION PROCESSES Abstract Hydrodynamics show a theory on continuous flow of liquids that resembles the forest dynamics in a given forest stand. Diameter increment, its variance, tree mortality, and tree recruitment of a given dbh class in time t may be represented as a liquid flowing in a pipe from a point to another, which may be modeled through the Kolmogorov diffusion equation (HARA, 1984). Data from permanent sample plots of continuous forest inventory established in northern Espírito Santo and southern Bahia States in Brazil, managed for pulp and paper, with ages ranging from 2 to 6 years, were used in the present work. The Kolmogorov diffusion equation was applied to predict diameter distributions in a certain future age. Estimates were obtained and compared to actual data. For number of trees per hectare and basal area the methodology provided similar statistical inferences at 95% of probability level. The practical application of the diffusion process in forest growth modeling in fast growing eucalypt stands was demonstrated.

Site conditions and definition of compositional proportion modify mixture effects in Picea abies – Abies alba stands

2014 ◽  
Vol 44 (10) ◽  
pp. 1281-1291 ◽  
Author(s):  
Markus O. Huber ◽  
Hubert Sterba ◽  
Luzi Bernhard
Keyword(s):  
Picea Abies ◽  
Norway Spruce ◽  
Abies Alba ◽  
Basal Area ◽  
Site Quality ◽  
Stem Volume ◽  
Silver Fir ◽  
European Alps ◽  
Mixture Effects ◽  
Definition Of

For most forest types in the European Alps, little is known about mixture effects on stand productivity. The comparability of studies on mixture effects often suffers from the open methodological question of whether the results depend on the definition of compositional proportion. In this study, data from the Swiss National Forest Inventory were used to investigate how the growth of Norway spruce (Picea abies (L.) Karst.) and silver fir (Abies alba Mill.) is modified by the admixture of the other species and if the mixture effect depends on site, climate, age, or stand density. Stocking proportion (proportion by area) as well as the proportion of relative density index, stem number, basal area, stem volume, and aboveground biomass were used to define compositional proportion, and the results were compared. At low-quality sites, Norway spruce grew faster in basal area as its relative share of composition increased, but this pattern diminished as the site quality increased. At cooler sites, silver fir grew faster as its share of composition decreased, but the pattern reversed at warmer sites. Overyielding was predicted only for 16% of the 679 sites used for this study. Beneficial effects of species mixture were overestimated when species-specific stocking potentials were not considered in the definition of compositional proportion.

scholarly journals Assessment of Stem Volume on Plots Using Terrestrial Laser Scanner: A Precision Forestry Application

Sensors ◽  
2021 ◽  
Vol 21 (1) ◽  
pp. 301
Author(s):  
Dimitrios Panagiotidis ◽  
Azadeh Abdollahnejad ◽  
Martin Slavík
Keyword(s):  
Norway Spruce ◽  
Laser Scanner ◽  
Estimation Methods ◽  
Coefficient Of Determination ◽  
Stem Volume ◽  
Small Scale ◽  
Terrestrial Laser Scanner ◽  
Precision Forestry ◽  
Total Tree ◽  
European Oak

Timber volume is an important asset, not only as an ecological component, but also as a key source of present and future revenues, which requires precise estimates. We used the Trimble TX8 survey-grade terrestrial laser scanner (TLS) to create a detailed 3D point cloud for extracting total tree height and diameter at breast height (1.3 m; DBH). We compared two different methods to accurately estimate total tree heights: the first method was based on a modified version of the local maxima algorithm for treetop detection, “HTTD”, and for the second method we used the centers of stem cross-sections at stump height (30 cm), “HTSP”. DBH was estimated by a computationally robust algebraic circle-fitting algorithm through hierarchical cluster analysis (HCA). This study aimed to assess the accuracy of these descriptors for evaluating total stem volume by comparing the results with the reference tree measurements. The difference between the estimated total stem volume from HTTD and measured stems was 2.732 m3 for European oak and 2.971 m3 for Norway spruce; differences between the estimated volume from HTSP and measured stems was 1.228 m3 and 2.006 m3 for European oak and Norway spruce, respectively. The coefficient of determination indicated a strong relationship between the measured and estimated total stem volumes from both height estimation methods with an R2 = 0.89 for HTTD and R2 = 0.87 for HTSP for European oak, and R2 = 0.98 for both HTTD and HTSP for Norway spruce. Our study has demonstrated the feasibility of finer-resolution remote sensing data for semi-automatic stem volumetric modeling of small-scale studies with high accuracy as a potential advancement in precision forestry.

Ontario's forest growth and yield modelling program: Advances resulting from the Forestry Research Partnership

2008 ◽  
Vol 84 (5) ◽  
pp. 694-703 ◽  
Author(s):  
Mahadev Sharma ◽  
John Parton ◽  
Murray Woods ◽  
Peter Newton ◽  
Margaret Penner ◽  
...  
Keyword(s):  
Tree Species ◽  
Stand Density ◽  
Forest Growth ◽  
Growth And Yield ◽  
Research Partnership ◽  
Wood Supply ◽  
Permanent Sample Plots ◽  
Forestry Research ◽  
Research Activities ◽  
Forest Growth And Yield

The province of Ontario holds approximately 70.2 million hectares of forests: about 17% of Canada’s and 2% of the world’s forests. Approximately 21 million hectares are managed as commercial forests, with an annual harvest in the early part of the decade approaching 200 000 ha. Yield tables developed by Walter Plonski in the 1950s provide the basis for most wood supply calculations and growth projections in Ontario. However, due to changes in legislation, policy, and the planning process, they no longer fully meet the needs of resource managers. Furthermore, Plonski`s tables are not appropriate for the range of silvicultural options now practised in Ontario. In October 1999, the Canadian Ecology Centre- Forestry Research Partnership (CEC-FRP) was formed and initiated a series of projects that collectively aimed at characterizing, quantifying and ultimately increasing the economically available wood supply. Comprehensive, defensible, and reliable forecasts of forest growth and yield were identified as key knowledge gaps. The CEC-FRP, with support from the broader science community and forest industry, initiated several new research activities to address these needs, the results of which are outlined briefly in this paper. We describe new stand level models (e.g., benchmark yield curves, FVS Ontario, stand density management diagrams) that were developed using data collected from permanent sample plots and permanent growth plots established and remeasured during the past 5 decades. Similarly, we discuss new height–diameter equations developed for 8 major commercial tree species that specifically account for stand density. As well, we introduce a CEC-FRP-supported project aimed at developing new taper equations for plantation grown jack pine and black spruce trees established at varying densities. Furthermore, we provide an overview of various projects undertaken to explore measures of site productivity. Available growth intercept and site index equations are being evaluated and new equations are being developed for major commercial tree species as needed. We illustrate how these efforts are advancing Ontario’s growth and yield program and supporting the CEC-FRP in achieving its objective of increasing the supply of fibre by 10% in 10 years while maintaining forest sustainability. Key words: permanent sample plots (PSPs), permanent growth plots (PGPs), normal yield tables, sustainable forest management, NEBIE plot network, forest inventory, Forest Vegetation Simulator

Modèle de prédiction des essences feuillues et résineuses du Québec

1982 ◽  
Vol 12 (2) ◽  
pp. 232-239 ◽  
Author(s):  
Chhun-Huor Ung ◽  
Jean Beaulieu ◽  
Daniel Demers
Keyword(s):  
Prediction Model ◽  
Basal Area ◽  
Growth Conditions ◽  
The State ◽  
Department Of Energy ◽  
Forest Species ◽  
Permanent Sample Plots ◽  
Real Growth ◽  
Basic Characteristics ◽  
Softwood Species

This paper describes a prediction model adopted by the Department of Energy and Resources of Quebec to (i) update temporary sample plots and (ii) project into the future the state of permanent sample plots in Quebec forests. Predicting the growth of a forest species means predicting the state of this species in time. Three basic characteristics mark the state of a species in a given year: number of trees, their total basal area, and their total volume. To date, in Quebec, normal or empirical yield tables have been used to predict the state of some species in ideal or real growth conditions, but these yield tables apply only to pure or almost pure even-aged stands. The prediction model for hardwood and softwood species presented in this paper serves the same purpose as the yield tables; however, it differs from the yield tables in that it can predict the state of each hardwood or softwood species found in pure or mixed, even- or uneven-aged stands. The prediction model was validated for 19 species found in a pilot territory located in the Basse-Gatincau (southwestern Quebec). The paper terminates with a discussion on the limitation of the prediction model and the conditions for its use.

Present-day expansion of American beech in northeastern hardwood forests: Does soil base status matter?

2009 ◽  
Vol 39 (12) ◽  
pp. 2273-2282 ◽  
Author(s):  
Louis Duchesne ◽  
Rock Ouimet
Keyword(s):  
Acer Saccharum ◽  
Sugar Maple ◽  
Basal Area ◽  
Base Cation ◽  
Hardwood Forests ◽  
Fagus Grandifolia ◽  
Soil Base ◽  
Large Area ◽  
American Beech ◽  
Permanent Sample Plots

Recently, sugar maple ( Acer saccharum Marsh.) decline in northeastern North America has been regarded as a major factor structuring hardwood forests by favouring American beech ( Fagus grandifolia Ehrh.) in the understory of maple-dominated stands. To determine whether soil fertility differences associated with sugar maple decline may have promoted the expansion of American beech, we explored the relationships between the soil base status and the sapling and tree strata density and composition, using data from 426 permanent sample plots distributed throughout Quebec. Our results indicate that American beech is currently expanding in the sugar maple range of Quebec. The abundance and proportion of American beech in the sapling stratum are mainly associated with the proportion of American beech in the tree stratum, the relative basal area of dead sugar maple trees, and the base status of soils. In accordance with the many studies reporting on the high sensitivity of sugar maple to the acid–base status of soils and the decline of the sugar maple population, this study supports the hypothesis that soil base cation depletion, caused in part by atmospheric acid deposition, is among the main factors involved in the present-day expansion of American beech over a large area in Quebec.

scholarly journals Sensitivity of managed boreal forests in Finland to climate change, with implications for adaptive management

2007 ◽  
Vol 363 (1501) ◽  
pp. 2339-2349 ◽  
Author(s):  
Seppo Kellomäki ◽  
Heli Peltola ◽  
Tuula Nuutinen ◽  
Kari T Korhonen ◽  
Harri Strandman
Keyword(s):  
Climate Change ◽  
Norway Spruce ◽  
Scots Pine ◽  
Boreal Forests ◽  
Forest Growth ◽  
Forest Land ◽  
Forest Zone ◽  
The North ◽  
Northern Forests ◽  
Climate Change Model

This study investigated the sensitivity of managed boreal forests to climate change, with consequent needs to adapt the management to climate change. Model simulations representing the Finnish territory between 60 and 70° N showed that climate change may substantially change the dynamics of managed boreal forests in northern Europe. This is especially probable at the northern and southern edges of this forest zone. In the north, forest growth may increase, but the special features of northern forests may be diminished. In the south, climate change may create a suboptimal environment for Norway spruce. Dominance of Scots pine may increase on less fertile sites currently occupied by Norway spruce. Birches may compete with Scots pine even in these sites and the dominance of birches may increase. These changes may reduce the total forest growth locally but, over the whole of Finland, total forest growth may increase by 44%, with an increase of 82% in the potential cutting drain. The choice of appropriate species and reduced rotation length may sustain the productivity of forest land under climate change.

scholarly journals How random are predictions of forest growth? The importance of weather variability

2020 ◽  
Author(s):  
Joanna Horemans ◽  
Olga Vindušková ◽  
Gaby Deckmyn
Keyword(s):  
Climate Change ◽  
Uncertainty Analysis ◽  
Climate Models ◽  
Global Climate ◽  
Basal Area ◽  
Random Order ◽  
Forest Growth ◽  
Global Climate Models ◽  
Growth And Yield ◽  
Weather Variability

Quantifying the output uncertainty and tracking down its origins is key to interpreting the results of model studies. We perform such an uncertainty analysis on the predictions of forest growth and yield under climate change. We specifically focus on the effect of the inter-annual climate variability. For that, the climate years in the model input (daily resolution) were randomly shuffled within each 5-year period. In total, 540 simulations (10 parameter sets, 9 climate shuffles, 3 global climate models and 2 mitigation scenarios), were made for one growing cycle (80 years) of a Scots pine forest growing in Peitz (Germany). Our results show that, besides the important effect of the parameter set, the random order of climate years can significantly change results such as basal area and produced volume, and the response of these to climate change. We stress that the effect of weather variability should be included in the design of impact model ensembles, and the accompanying uncertainty analysis. We further suggest presenting model results as likelihoods to allow risk assessment. For example, in our study the likelihood of a decrease in basal area of >10% with no mitigation was 20.4%, while the likelihood of an increase >10% was 34.4%.

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