scholarly journals A Method for the Development of Dynamic Site Index Models Using Height–Age Data from Temporal Sample Plots

Forests ◽  
2019 ◽  
Vol 10 (7) ◽  
pp. 542
Author(s):  
Jarosław Socha ◽  
Luiza Tymińska-Czabańska
Keyword(s):  
Forest Management ◽  
Site Index ◽  
Height Growth ◽  
Strategic Decisions ◽  
Growth Trend ◽  
Potential Productivity ◽  
Forest Sites ◽  
Using Data ◽  
Temporal Sample ◽  
Index Estimation

Knowledge of the potential productivity of forest sites is fundamental for making strategic decisions in forest management. Site productivity is usually evaluated using the site index, and therefore the development of site index models is one of the crucial tasks in forest research and forest management. This research aims to develop an effective method for building top-growth and site index models using data from temporary sample plots (TSP). Exploiting the advantages of the generalised algebraic difference approach (GADA), the proposed method overcomes the limitations of the guide curve method that has been to date used in site index modelling using TSPs data and allows to obtain only a set of anamorphic site index curves. The proposed approach enables the construction of dynamic site index models with polymorphism and variable asymptotes. Such models better reflect local, site-specific height growth trajectories and therefore allow more appropriate site index estimation. We tested the proposed method using data collected from 5105 temporary sample plots in Poland. Our results indicate that growth trend estimates using height–age measurements of TSPs may be valuable data for modelling top height growth. For these reasons, the proposed method can be very useful in forest management.

Early Height Growth and Site Index for Planted Red Pine in North Central Ontario

1995 ◽  
Vol 12 (1) ◽  
pp. 23-29
Author(s):  
William H. Carmean ◽  
James S. Thrower
Keyword(s):  
Growth Curves ◽  
Analysis Data ◽  
Site Index ◽  
Height Growth ◽  
Red Pine ◽  
North Central ◽  
Breast Height ◽  
Excellent Growth ◽  
Index Estimation ◽  
Best Estimates

Abstract Height-growth, site-index curves, and growth intercepts were developed from internode and stem-analysis data using dominant trees in 25 plots located in red pine plantations aged 26 to 37 yr. Height-growth curves were based on breast-height age because growth below breast height (1.3 m) was slow and erratic. Growth intercepts using the first three to five internodes above 1.5 m gave the best estimates of site index (dominant height at 20 yr breast-height age)for trees that were between 3 and 5 yr breast-height age; site-index estimation equations gave the best estimates for trees older than 10 yr breast-height age. These computed height-growth curves and growth intercepts and observed site index in north central Ontario were similar to other regions. The excellent growth observed in this study suggests that red pine should be given greater emphasis in future reforestation programs in north central Ontario. North. J. Appl. For. 12(1): 23-29.

scholarly journals Height Growth Models for High-Elevation Subalpine Fir, Engelmann Spruce, and Lodgepole Pine in British Columbia

2000 ◽  
Vol 15 (2) ◽  
pp. 62-69 ◽  
Author(s):  
Han Y. H. Chen ◽  
Karel Klinka
Keyword(s):  
British Columbia ◽  
Growth Models ◽  
Lodgepole Pine ◽  
Site Index ◽  
High Elevation ◽  
Logistic Function ◽  
Height Growth ◽  
Potential Productivity ◽  
Subalpine Fir ◽  
Engelmann Spruce

Abstract To estimate potential productivity of the high-elevation Engelmann Spruce and Subalpine Fir (ESSF) zone of British Columbia forests, the height growth models developed from low-elevation forests are currently used to estimate site indices of subalpine fir (Abies lasiocarpa), Engelmann spruce (Picea engelmannii), and lodgepole pine (Pinus contorta). Whether these models are adequate to describe height growth of high-elevation forests is of concern. We sampled a total of 319 naturally established, even-aged, and undamaged stands with breast height age ≥50 yr (165 for subalpine fir, 87 for Engelmann spruce, and 67 for lodgepole pine) ranging widely in climate and available soil moisture and nutrients. In each sampled stand, three dominant trees were destructively sampled for stem analysis. Height growth models developed from fitting data to a conditioned logistic function explained > 97% variation in height for all three study species. Examined by residual analysis, no models showed lack of fit. These models provided more accurate estimates of site index than the currently used models developed from low-elevation stands or different species. It is recommended that the models developed in this study be applied to estimate site index of the three species in the ESSF zone in British Columbia. West. J. Appl. For. 15(2):62-69.

scholarly journals Changes in trends of the height growth of spruce and pine derived from continuous measurements in forest management plans of Kostelec nad Černými lesy and on pilot research plots in the Czech Republic

2012 ◽  
Vol 50 (No. 7) ◽  
pp. 327-337
Author(s):  
J. Sequens ◽  
M. Křepela ◽  
D. Zahradník
Keyword(s):  
Forest Management ◽  
Growth Parameters ◽  
Growth Curves ◽  
Growth Conditions ◽  
Management Plan ◽  
Height Growth ◽  
Forest Growth ◽  
Growth Trend ◽  
Continuous Measurements ◽  
Management Plans

In changing growth conditions, methodical procedures should concentrate on the investigation of processes currently under way in forests. Many studies have shown that present models of forest growth parameters differ from previous surveys as far as for instance the height is concerned. Causes of these phenomena have not been satisfactorily explained although various hypotheses are investigated. In our study, we present partial results of the investigation of height growth within a sixty-five-year period, based on the analysis of data obtained from seven forest management plans in the management-plan area of Kostelec nad Černými lesy (Kostelec n. Č. l.) and continuous measurements on pilot research plots in the period of 1965–1994. The comparison of mean height growth curves obtained by the curve fitting of the values of empirical data signifies by their different course and increasing kurtosis a dependence on the calendar year when the measure was taken. It signifies an increasing height growth trend of both species in the given area.

A numerical method for the solution of a base-age-specific site index model

1993 ◽  
Vol 23 (12) ◽  
pp. 2487-2489 ◽  
Author(s):  
Yonghe Wang ◽  
Bijan Payandeh
Keyword(s):  
Numerical Solution ◽  
Numerical Method ◽  
Site Index ◽  
Height Growth ◽  
Specific Site ◽  
Growth Equation ◽  
North Central ◽  
Index Model ◽  
Site Index Model ◽  
Index Estimation

A numerical solution was derived for previously published site index equations for trembling aspen (Populustremuloides Michx.). Data from aspen stands in north central Ontario were used to verify the validity and accuracy of the numerical method. With the numerical solution, only the height-growth equation is employed to estimate (i) height from site index and age and (ii) site index from height and age. The numerical method simplified site index estimation and improved its accuracy for aspen stands in north central Ontario.

scholarly journals Optimising pasture and grazing management decisions on the Cicerone Project farmlets over variable time horizons

2013 ◽  
Vol 53 (8) ◽  
pp. 796 ◽  
Author(s):  
Karl Behrendt ◽  
Oscar Cacho ◽  
James M. Scott ◽  
Randall Jones
Keyword(s):  
Simulation Model ◽  
Strategic Decision ◽  
Stochastic Dynamic ◽  
Economic Returns ◽  
Strategic Decisions ◽  
Trade Offs ◽  
Using Data ◽  
Time Frames ◽  
The Impact ◽  
Stocking Rates

This study addresses the problem of balancing the trade-offs between the need for animal production, profit, and the goal of achieving persistence of desirable species within grazing systems. The bioeconomic framework applied in this study takes into account the impact of climate risk and the management of pastures and grazing rules on the botanical composition of the pasture resource, a factor that impacts on livestock production and economic returns over time. The framework establishes the links between inputs, the state of the pasture resource and outputs, to identify optimal pasture development strategies. The analysis is based on the application of a dynamic pasture resource development simulation model within a seasonal stochastic dynamic programming framework. This enables the derivation of optimum decisions within complex grazing enterprises, over both short-term tactical (such as grazing rest) and long-term strategic (such as pasture renovation) time frames and under climatic uncertainty. The simulation model is parameterised using data and systems from the Cicerone Project farmlet experiment. Results indicate that the strategic decision of pasture renovation should only be considered when pastures are in a severely degraded state, whereas the tactical use of grazing rest or low stocking rates should be considered as the most profitable means of maintaining adequate proportions of desirable species within a pasture sward. The optimal stocking rates identified reflected a pattern which may best be described as a seasonal saving and consumption cycle. The optimal tactical and strategic decisions at different pasture states, based on biomass and species composition, varies both between seasons and in response to the imposed soil fertility regime. Implications of these findings at the whole-farm level are discussed in the context of the Cicerone Project farmlets.

Validation of forest height–age models

1996 ◽  
Vol 26 (5) ◽  
pp. 810-818 ◽  
Author(s):  
Gordon D. Nigh ◽  
Vera Sit
Keyword(s):  
Forest Management ◽  
Confidence Intervals ◽  
Error Variance ◽  
Site Index ◽  
Random Coefficients ◽  
Multivariate Technique ◽  
Forest Height ◽  
Preliminary Validation ◽  
Age Model ◽  
Validation Procedure

Forest height–age models are used in forest management to estimate height and (or) site index. It is useful to know the bias and precision of these models in order to evaluate their applicability. Methods are available for validating the models; however, many problems exist with the methods because of a lack of independence in the data and nonconstant error variance across a range of ages. A validation procedure is presented that overcomes these problems by using a multivariate technique (random coefficients) to model the structure of the errors associated with the models. Confidence intervals for bias and precision can then be constructed based on the error structure. This method of validation was demonstrated on the white spruce (Piceaglauca (Moench) Voss) height–age model for British Columbia, Canada. The preliminary validation showed the model to be unbiased for estimating both height and site index; however, its precision was poor.

Linking climate, gross primary productivity, and site index across forests of the western United States

2011 ◽  
Vol 41 (8) ◽  
pp. 1710-1721 ◽  
Author(s):  
Aaron R. Weiskittel ◽  
Nicholas L. Crookston ◽  
Philip J. Radtke
Keyword(s):  
Climate Change ◽  
Growth Models ◽  
Gross Primary Production ◽  
Site Index ◽  
Nonparametric Model ◽  
Climate Change Scenarios ◽  
Geographic Scale ◽  
Potential Productivity ◽  
The One ◽  
The Relationship

Assessing forest productivity is important for developing effective management regimes and predicting future growth. Despite some important limitations, the most common means for quantifying forest stand-level potential productivity is site index (SI). Another measure of productivity is gross primary production (GPP). In this paper, SI is compared with GPP estimates obtained from 3-PG and NASA’s MODIS satellite. Models were constructed that predict SI and both measures of GPP from climate variables. Results indicated that a nonparametric model with two climate-related predictor variables explained over 68% and 76% of the variation in SI and GPP, respectively. The relationship between GPP and SI was limited (R2 of 36%–56%), while the relationship between GPP and climate (R2 of 76%–91%) was stronger than the one between SI and climate (R2 of 68%–78%). The developed SI model was used to predict SI under varying expected climate change scenarios. The predominant trend was an increase of 0–5 m in SI, with some sites experiencing reductions of up to 10 m. The developed model can predict SI across a broad geographic scale and into the future, which statistical growth models can use to represent the expected effects of climate change more effectively.

scholarly journals Pan-European sustainable forest management indicators for assessing Climate-Smart Forestry in Europe

2020 ◽  
pp. 1-10
Author(s):  
G. Santopuoli ◽  
C. Temperli ◽  
I. Alberdi ◽  
I. Barbeito ◽  
M. Bosela ◽  
...  
Keyword(s):  
Forest Management ◽  
Sustainable Forest Management ◽  
Management Strategies ◽  
Forest Policy ◽  
The State ◽  
Forest Damage ◽  
Tree Species Composition ◽  
Mitigation And Adaptation ◽  
Management Indicators ◽  
Using Data

The increasing demand for innovative forest management strategies to adapt to and mitigate climate change and benefit forest production, the so-called Climate-Smart Forestry, calls for a tool to monitor and evaluate their implementation and their effects on forest development over time. The pan-European set of criteria and indicators for sustainable forest management is considered one of the most important tools for assessing many aspects of forest management and sustainability. This study offers an analytical approach to selecting a subset of indicators to support the implementation of Climate-Smart Forestry. Based on a literature review and the analytical hierarchical approach, 10 indicators were selected to assess, in particular, mitigation and adaptation. These indicators were used to assess the state of the Climate-Smart Forestry trend in Europe from 1990 to 2015 using data from the reports on the State of Europe’s Forests. Forest damage, tree species composition, and carbon stock were the most important indicators. Though the trend was overall positive with regard to adaptation and mitigation, its evaluation was partly hindered by the lack of data. We advocate for increased efforts to harmonize international reporting and for further integrating the goals of Climate-Smart Forestry into national- and European-level forest policy making.

scholarly journals Generalizability and Accuracy of Site Index Estimation Model with Ensemble Learning

2009 ◽  
Vol 42 (1) ◽  
pp. 53-67
Author(s):  
Yasushi MINOWA ◽  
Norifumi SUZUKI ◽  
Kazuhiro TANAKA
Keyword(s):  
Ensemble Learning ◽  
Site Index ◽  
Estimation Model ◽  
Index Estimation
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