Site Classification From Air Photos in a Forest Inventory

1981 ◽  
Vol 57 (6) ◽  
pp. 265-266 ◽  
Author(s):  
G. M. Bonnor ◽  
K. C. Morrier
Keyword(s):  
Classification System ◽  
Forest Inventory ◽  
Site Index ◽  
Site Quality ◽  
Site Classification ◽  
Subsequent Test ◽  
Forest Inventories ◽  
Numerical Assessment ◽  
Eastern Ontario ◽  
A Site

A site classification system using 5-metre site index classes was applied in an inventory in eastern Ontario. ir photos and data on site index obtained from fiels work were used by photo interpreters to assign site index classes to individual stands. In a subsequent test of the procedures, the accuracy of the classification was found to be 76 percent. This accuracy, while acceptable, can be increased.The method is intended for use in extensive (regional, provincial) forest inventories and provides an objective (numerical) assessment of site quality.

scholarly journals Standortkartierung im Lehr- und Forschungswald der ETH in Sedrun | Site mapping in the ETH Research Forest of Sedrun

2009 ◽  
Vol 160 (2) ◽  
pp. 27-36
Author(s):  
Jacques Doutaz ◽  
Hans-Ulrich Frey ◽  
Harald Bugmann
Keyword(s):  
Classification System ◽  
Sustainable Forest Management ◽  
Structural Characteristics ◽  
Site Classification ◽  
Classification Methods ◽  
Site Type ◽  
Forest Sites ◽  
Site Mapping ◽  
A Site ◽  
Site Types

Phytosociology has advanced in various respects since the fundamental groundwork was laid, which was mainly concerned with developing a classification system of vegetation units. Current site classification methods for forests consider not only floristic aspects, but also pedological, topographic and structural characteristics of forest stands. During the summer of 2007, a site mapping was carried out in the ETH Research Forest near Sedrun (Switzerland). This paper describes the methods employed, and it evaluates the applicability thereof based on case studies. Site mapping is based on expert opinion, and as such it includes a certain degree of generalization and subjectivity in the evaluation of stands and their assignment to a site type. However, we propose that site classification constitutes a suitable tool for describing and characterizing the complexity of forest sites. The accurate description of site types strongly facilitates the interpretation and the applicability of a classification system in decision support for sustainable forest management.

AN EVALUATION OF SEVERAL METHODS OF ESTIMATING SITE INDEX OF IMMATURE STANDS

1952 ◽  
Vol 28 (3) ◽  
pp. 63-74 ◽  
Author(s):  
John W. Ker
Keyword(s):  
Basal Area ◽  
Site Index ◽  
Site Quality ◽  
Average Height ◽  
Office Procedure ◽  
Minimum Sample ◽  
A Site ◽  
The University ◽  
Site Classes

The use of dominant heights for the estimation of site index is compared with the use of the average of dominant and codominant heights. Data collected on the University Research Forest are presented to illustrate the variability in tree heights and diameters within the two upper crown classes in well-stocked stands of immature Douglas fir.HeightIt is shown that the use of dominant heights reduces considerably the number of measurements required for a site index determination of given accuracy. Minimum sample sizes are given for three limits of accuracy for use in different site qualities. A general field and office procedure is outlined for the determination of minimum sample size in stands other than those described.DiameterThe use of diameter in site determination is discussed. Site indices based on the height of the tree of mean diameter, the height of the tree of mean basal area, and mean height are compared.ConclusionsQuick estimates of site quality can best be obtained by the measurement of total height of sample dominant trees, selected at random. For this purpose, tables are presented which list the average height of dominant trees by age and site classes for use in stands of Douglas fir, and western hemlock, respectively.

Topoedaphic unit analysis: A site classification system for reclaimed mined lands

CATENA ◽  
1993 ◽  
Vol 20 (3) ◽  
pp. 289-301 ◽  
Author(s):  
Kelly Krabbenhoft ◽  
Don Kirby ◽  
Mario Biondini ◽  
Gary Halvorson ◽  
Dave Nilson
Keyword(s):  
Classification System ◽  
Site Classification ◽  
A Site ◽  
Unit Analysis

scholarly journals PERFORMANCE DA MODELAGEM PARA CLASSIFICAÇÃO DE SÍTIOS FLORESTAIS EM BASES DE DADOS COM OUTLIERS

Nativa ◽  
2021 ◽  
Vol 9 (1) ◽  
pp. 54-61
Author(s):  
Pábulo Diogo de Souza ◽  
Carlos Alberto Araújo Júnior ◽  
Christian Dias Cabacinha ◽  
Leandro Silva de Oliveira ◽  
Celso Dotta Lopes Junior ◽  
...  
Keyword(s):  
Radial Basis Function ◽  
Basis Function ◽  
Multilayer Perceptron ◽  
Forest Inventory ◽  
Eucalyptus Grandis ◽  
Site Index ◽  
Site Classification ◽  
Forest Site ◽  
Forest Sites ◽  
Forest Site Classification

As informações utilizadas para estimativa da capacidade produtiva de sítios florestais provêm de bases de dados de inventário florestal que podem conter observações discrepantes (outliers). Assim, torna-se necessário a análise de consistência para exclusão destes. Porém, os outliers podem representar determinado padrão de crescimento existente na floresta, logo a exclusão destes pode ser uma ação equivocada. Objetivou-se comparar a performance de diferentes técnicas de modelagem para classificação de sítios florestais, considerando uma base de dados com a presença de outliers. Utilizou-se pares de dados de idade e altura dominante (HD) de parcelas permanentes de Eucalyptus urophyla x Eucalyptus grandis localizadas no norte de Minas Gerais. Foi simulado um outlier de HD. A base de dados foi modelada, com e sem presença de outliers, por regressão linear (RL) e redes neurais artificiais Multilayer Perceptron (MLP) e Radial Basis Function (RBF). Os métodos foram analisados por meio dos critérios estatísticos de precisão: bias, raiz quadrada do erro médio, correlação de Pearson, erro médio percentual e gráfico de dispersão residual. A MLP foi superior para estimativa do índice de sítio. Portanto, a MLP é indicada para classificação de sítios florestais quando há presença de outliers na base de dados. Palavras-chave: índice de sítio; inventário florestal; dados discrepantes.   Performance of modeling for classification of forest sites in databases with outliers   ABSTRACT: The information used to estimate the productive capacity of forest sites comes from forest inventory databases that may contain discrepant observations (outliers). Thus, consistency analysis is required to exclude these. However, the outliers may represent a certain growth pattern existing in the forest, so their exclusion may be a mistaken action. The objective was to compare the performance of different modeling techniques for forest site classification, considering a database with the presence of outliers. We used pairs of data of age and dominant height (HD) of permanent parcels of Eucalyptus urophila x Eucalyptus grandis located in the north of Minas Gerais. A HD outlier was simulated. The database was modeled, with and without the presence of outliers, by linear regression (RL) and artificial neural networks Multilayer Perceptron (MLP) and Radial Basis Function (RBF). The methods were analyzed by means of precision statistical criteria: bias, square root of mean error, Pearson correlation, mean percentage error and residual scatter plot. The MLP was superior for site index estimation. Therefore, the MLP is indicated for forest site classification when there are outliers in the database. Keywords: site index; forest inventory; discrepant data.

scholarly journals SITE QUALITY CURVES FOR AFRICAN MAHOGANY PLANTATIONS IN BRAZIL

CERNE ◽  
2016 ◽  
Vol 22 (4) ◽  
pp. 439-448 ◽  
Author(s):  
Andressa Ribeiro ◽  
Antonio Carlos Ferraz Filho ◽  
Margarida Tomé ◽  
José Roberto Soares Scolforo
Keyword(s):  
Site Index ◽  
Growth And Yield ◽  
Site Quality ◽  
Site Classification ◽  
Site Class ◽  
African Mahogany ◽  
Dominant Height ◽  
Curve Method ◽  
Dominant Height Growth ◽  
The Stability

ABSTRACT Site quality estimation is an important tool in forest management since it is useful for modeling growth and yield for even-aged stands. Data from African mahogany (Khaya ivorensis A. Chev.) Brazilian plantations were used to develop a model to predict dominant height growth, comparing dynamic base-age invariant site index models with the guide curve method (static models). For the evaluation of the candidate models qualitative and quantitative criteria were used. We also verified the stability of the candidate models, preferring a model providing fewer site class changes when predicting site index from different ages. The Lundqvist-Korf function fitted with the guide curve method proved to be effective and accurate for site classification and dominant height predictions of African mahogany stands. The range of observed site index, at a reference age of 15, was between 17 and 33 meters.

A site model for Pyrenean oak (Quercus pyrenaica) stands using a dynamic algebraic difference equation

2005 ◽  
Vol 35 (1) ◽  
pp. 93-99 ◽  
Author(s):  
João P Carvalho ◽  
Bernard R Parresol
Keyword(s):  
Site Index ◽  
Site Quality ◽  
Parameter Estimates ◽  
Quercus Pyrenaica ◽  
Error Statistics ◽  
Site Model ◽  
Dominant Height ◽  
Richards Function ◽  
Algebraic Difference ◽  
A Site

This paper presents a growth model for dominant-height and site-quality estimations for Pyrenean oak (Quercus pyrenaica Willd.) stands. The Bertalanffy–Richards function is used with the generalized algebraic difference approach to derive a dynamic site equation. This allows dominant-height and site-index estimations in a compatible way, using any desirable base age and allowing estimations to be time independent, which are important properties for site models. The database contains all possible height-growth intervals. The model is fitted considering residual autocorrelation, giving more efficient parameter estimates. Finally, the model behavior is analyzed by calculating error statistics from dominant-height and site-index estimations at different ages.

Site classification in a mixed hardwood forest (Hallerbos, Belgium) with a homogeneous ground vegetation dominated by Hyacinthoides non-scripta (L.) Chouard ex. Rothm.

1994 ◽  
Vol 59 ◽  
Author(s):  
D. Maddelein ◽  
B. Muys ◽  
J. Neirynck ◽  
G. Sioen
Keyword(s):  
Tree Species ◽  
Ph Value ◽  
Soil Analysis ◽  
Base Cation ◽  
Site Quality ◽  
Ground Vegetation ◽  
Site Classification ◽  
Species Classification ◽  
Tree Species Composition ◽  
Understorey Vegetation

The  forest of Halle (560 ha), situated 20 km south of Brussels is covered by a  beech (Fagus sylvatica)  forest, locally mixed with secundary species (Tilia,  Fraxinus, Acer, Quercus,... ). In almost all  stands, herbal vegetation is dominated by bluebell (Hyacinthoides  non-scripta).     The research intended to classify 36 plots of different tree species  composition according to their site quality. Three classification methods  were compared: the first one based on the indicator value of the understorey  vegetation, a second one on the humus morphology and a last one on some  quantitative soil characteristics. According to the plant sociological site  classification, the plots have the same site quality. However, humus forms  differ apparently and significant differences were found in pH value and base  cation saturation of the soil, abundance and biomass of earthworms and  biomass of the ectorganic horizon. Tree species proved to be the main cause  of these differences.     The results illustrate that the herbal vegetation is not always a reliable  indicator of site quality. In the case of a homogeneous vegetation dominated  by one or more indifferent species, classification on humus morphology or  soil analysis are more appropriate. In the forest of Halle, the tree species  is probably the main cause of the observed differences in site quality.

On the error of estimates from successive forest inventories with SPR

1987 ◽  
Vol 17 (5) ◽  
pp. 442-447
Author(s):  
Tiberius Cunia
Keyword(s):  
Forest Inventory ◽  
Random Sampling ◽  
Regression Coefficients ◽  
Partial Replacement ◽  
Forest Inventories ◽  
Continuous Forest ◽  
Regression Functions ◽  
The Given ◽  
Linear Regressions ◽  
Continuous Forest Inventory

The approach used by Cunia to combine the error from sample plots with the error from volume or biomass tables when Continuous Forest Inventory (CFI) estimates of current values and growth are calculated is extended to the CFI systems using Sampling with Partial Replacement (SPR). The formulae are derived for the case of SPR on two measurement occasions when (i) volume or biomass tables are constructed from linear regressions for which an estimate of the covariance matrix of the regression coefficients is known, and (ii) the sample plots or points are selected by random sampling independently of the given volume or biomass regression functions.

scholarly journals Mapping forest age using National Forest Inventory, airborne laser scanning, and Sentinel-2 data

2020 ◽  
Vol 7 (1) ◽  
Author(s):  
Johannes Schumacher ◽  
Marius Hauglin ◽  
Rasmus Astrup ◽  
Johannes Breidenbach
Keyword(s):  
Forest Inventory ◽  
Regression Models ◽  
Laser Scanning ◽  
Site Index ◽  
National Forest Inventory ◽  
Airborne Laser Scanning ◽  
National Forest ◽  
Practical Applications ◽  
Airborne Laser ◽  
Sentinel 2

Abstract Background The age of forest stands is critical information for forest management and conservation, for example for growth modelling, timing of management activities and harvesting, or decisions about protection areas. However, area-wide information about forest stand age often does not exist. In this study, we developed regression models for large-scale area-wide prediction of age in Norwegian forests. For model development we used more than 4800 plots of the Norwegian National Forest Inventory (NFI) distributed over Norway between latitudes 58° and 65° N in an 18.2 Mha study area. Predictor variables were based on airborne laser scanning (ALS), Sentinel-2, and existing public map data. We performed model validation on an independent data set consisting of 63 spruce stands with known age. Results The best modelling strategy was to fit independent linear regression models to each observed site index (SI) level and using a SI prediction map in the application of the models. The most important predictor variable was an upper percentile of the ALS heights, and root mean squared errors (RMSEs) ranged between 3 and 31 years (6% to 26%) for SI-specific models, and 21 years (25%) on average. Mean deviance (MD) ranged between − 1 and 3 years. The models improved with increasing SI and the RMSEs were largest for low SI stands older than 100 years. Using a mapped SI, which is required for practical applications, RMSE and MD on plot level ranged from 19 to 56 years (29% to 53%), and 5 to 37 years (5% to 31%), respectively. For the validation stands, the RMSE and MD were 12 (22%) and 2 years (3%), respectively. Conclusions Tree height estimated from airborne laser scanning and predicted site index were the most important variables in the models describing age. Overall, we obtained good results, especially for stands with high SI. The models could be considered for practical applications, although we see considerable potential for improvements if better SI maps were available.

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