Forest inventory estimation with mapped plots

2004 ◽  
Vol 34 (2) ◽  
pp. 493-497 ◽  
Author(s):  
Paul C Van Deusen
Keyword(s):  
Forest Inventory ◽  
Random Sampling ◽  
Simple Random Sampling ◽  
Mean Squared Errors ◽  
Additional Work ◽  
Fixed Area ◽  
Plot Design

Procedures are developed for estimating means and variances with a mapped-plot design. The focus is on fixed-area plots, and simulations are used to validate the proposed estimators. The mapped-plot estimators for means and variances are compared with simple random sampling estimators that utilize only full plots. As expected, the mapped-plot estimates have smaller mean squared errors than the simple random sampling estimates. The theory for fixed-area plots is easy to apply, although additional work is required to map plots in the field. Corresponding theory for variable plots is developed but not tested with simulations. The difficulty of applying these methods to variable plots is greater, but not prohibitive.

scholarly journals SISTEMA DE INVENTÁRIO FLORESTAL PARA SERINGAL NATIVO

FLORESTA ◽  
2002 ◽  
Vol 32 (1) ◽  
Author(s):  
José de Arimatéa Silva ◽  
Sylvio Péllico Netto
Keyword(s):  
Forest Inventory ◽  
Random Sampling ◽  
Rubber Tree ◽  
Basal Area ◽  
Simple Random Sampling ◽  
Inventory System ◽  
Stratified Random Sampling ◽  
Stage Number ◽  
Second Stage ◽  
Two Stages

Este trabalho teve como objetivo desenvolver um Sistema de Inventário Florestal para seringal nativo. Aplicou-se a Amostragem Inteiramente Aleatória (AIA), em dois estágios: colocação de seringa, no primeiro, e estrada de seringa, no segundo. Foram estimados: número de seringueiras por estrada (N), área basal das seringueiras da estrada (G) e volume da porção explorada do fuste (V). Realizou-se uma pós-estratificação, considerando-se estradas de centro e de margem, aplicando-se a Amostragem Estratificada (AE). Comparou-se a AIA com a AE, com base na eficiência relativa. Os resultados revelaram as seguintes estimativas para as médias estratificadas: N=100; G=19,00 m², V= 62,8 m³. Concluiu-se que a AE revelou-se mais eficiente que a AIA para estimar as variáveis analisadas. Propõe-se que um sistema de inventário para seringal nativo deve combinar: informações de um censo das colocações; um processo de amostragem estratificada; e um método de amostragem cuja unidade de amostra é a estrada de seringa. Forest Inventory System for Rubber Trees Abstract Forest Inventory System for rubber trees. This work had as objective to develop an Inventory System for native rubber tree areas. The Simple Random Sampling (SRS) was applied in two stages: the setting, in the first, and the rubber trees tracks, in the second stage. Number of rubber trees per track (N), basal area of the rubber trees track (G) and volume of the stem portion explored (V) were the parameters estimated. A post-stratification was become fulfilled, considering itself center tracks and river side tracks, applying itself it Stratified Random Sampling (STRS). It was compared SRS with the STRS, on the basis of the relative efficiency. The results showed the following estimates for the stratified means: N=100; G=19,00 m², V = 62,8 m³. It was concluded that the STRS showed more efficient than the SRS to estimate the analyzed variables. It is considered that an Inventory System for native rubber tree areas must match: information of a census of the settings; a process of Stratified Random Sampling; and a sampling method whose unit of sample is the rubber tree track.

scholarly journals Damage in Khaya ivorensis caused by Trigona spinipes in Brazilian savannah

2017 ◽  
Vol 1 (1) ◽  
pp. 40 ◽  
Author(s):  
Rebecca Silva de Moura ◽  
Kellen Rabello de Souza ◽  
Daniel Da Silva Souza ◽  
Gabriel Mendes Santana ◽  
Guilherme Murilo De Oliveira ◽  
...  
Keyword(s):  
Forest Inventory ◽  
Random Sampling ◽  
Sampling Method ◽  
Simple Random Sampling ◽  
First Record ◽  
Apical Part ◽  
African Mahogany ◽  
Brazilian Savannah ◽  
Apical Bud

Trigona spinipes (Dog bee) attack the apical bud of Khaya ivorensis causing atrophy and budding which provoke branches that will depreciate the shaft if not handled. Damage to the culture of K. ivorensis has been reported for Brazil, but never before for the Brazilian savannah. The aim of this study was to survey the dog bee attack and report as first record the presence and damage caused in the African mahogany plantations in the Brazilian savannah. The area has about of 16.6 hectares of African mahogany monoculture in the municipality of Piracanjuba, Goiás. It has been used 21 plots of 400 m², pre-defined and simple random sampling method, in which was carried out forest inventory and observation sprouts the apical part of the stem and consequent artificial pruning of sprouts. Also performing were viewed bees in foraging of activity by cutting the shoots of K. ivorensis. In planting, 6.14% of the trees had regrowth and this percentage may indicate the number of attacked trees. The total trees with regrowth is a large quantity of trees which may develop with problems, generating more than one stem or branch, thereby preclude the affected wood is used for furniture.  

scholarly journals PERBANDINGAN TEKNIK TREE SAMPLING DAN UNIT CONTOH LINGKARAN DALAM MENDUGA POTENSI TEGAKAN HUTAN TANAMAN EKALIPTUS (EUCALYPTUS PELLITA F. MEULL)

2017 ◽  
Vol 12 (1) ◽  
pp. 29-36
Author(s):  
Muhammad Ikhwan ◽  
Emy Sadjati ◽  
Azwin Azwin
Keyword(s):  
Data Collection ◽  
Forest Inventory ◽  
Random Sampling ◽  
Relative Efficiency ◽  
Sampling Method ◽  
Sampling Error ◽  
Simple Random Sampling ◽  
Average Volume ◽  
Entire Area ◽  
Eucalyptus Pellita

The forest inventory is basically a data collection activities. This activity is relatively important, because the effect on further activities. Hence the data collected must have a high enough accuracy. A way of determining the sampling unit is considered to be simpler, easier, and faster is the tree sampling method. The purpose of this study was to quantify the potential large stands of eucalyptus in the Forest of eucalyptus plants in the Faculty of Forestry and calculate the relative efficiency of sample unit. The total area is 0.11 ha of eucalyptus stands. Unit examples used are circular, 4-trees sampling, sampling 5 -trees, and 6-trees sampling is done by simple random sampling method. Potential stands of eucalyptus with method 4 sample trees have an average volume stands perplot is 0.096 m3, with the volume of the stand for the entire area is 111.09 m3 with a sampling error of 43.65%. Potential stands of eucalyptus trees by the method of example 5 has a volume average stocking each plot is 0.091 m3, with the volume of the stand for the entire area is 105.40 m3 with a sampling error of 51%. Potential stands of eucalyptus by using 6 sample trees have an average volume stands each plot was 0.08 m3, with the volume of the stand for the entire area is 92.83 m3 with a sampling error o f 54.77%. Potential stands of eucalyptus with a diameter circular sample plots of 12 m has an average volume stands each plot is 6,37 m3, with the volume of the stand for the entire area is 65.61 m3 with a sampling error of 22.63%.

scholarly journals PENDUGAAN POTENSI TEGAKAN EKALIPTUS (Eucalyptus Pellita F. Meull) MENGGUNAKAN METODE TREE SAMPLING DAN CIRCULAR PLOT

2017 ◽  
Vol 12 (2) ◽  
pp. 41-48 ◽  
Author(s):  
Muhammad Ikhwan ◽  
Emy Sadjati ◽  
Enny Insusanty
Keyword(s):  
Data Collection ◽  
Forest Inventory ◽  
Random Sampling ◽  
Relative Efficiency ◽  
Sampling Method ◽  
Sampling Error ◽  
Simple Random Sampling ◽  
Average Volume ◽  
Entire Area ◽  
Eucalyptus Pellita

The forest inventory is basically a data collection activities. This activity is relatively important, because the effect on further activities. Hence the data collected must have a high enough accuracy. A way of determining the sampling unit is considered to be simpler, easier, and faster is the tree sampl ing method. The purpose of this study was to quantify the potential large stands of eucalyptus in the Forest of eucalyptus plants in the Faculty of Forestry and calculate the relative efficiency of sample unit. The total area is 0.11 ha of eucalyptus stands. Unit examples used are circular, 4-trees sampling, sampling 5 -trees, and 6-trees sampling is done by simple random sampling method. Potential stands of eucalyptus with method 6 sample trees have an average volume stands perplot is 0.07 m3, with the volume of the stand for the entire area is 84.71 m3 with a sampling error of 36,96%. Potential stands of eucalyptus trees by the method of example 8 trees have a volume average stocking each plot is 0.04 m3, with the volume of the sta nd for the entire  area is 43.22 m3 with a sampling error of 51.47%. Potential stands of eucalyptus by using 10 sample trees have an average volume stands each plot was 0.03 m3 with the volume of the stand for the entire area is 39.74 m3 with a sampling error of 53.34%. Potential stands of eucalyptus with a diameter circular sample plots of 12 m has an average volume stands each plot is 7.88 m3, with the volume of the stand for the entire area is 76.72 m3 with a sampling error of 14.43%.

Potential for wider application of 3P sampling in forest inventory

2011 ◽  
Vol 41 (7) ◽  
pp. 1500-1508 ◽  
Author(s):  
P.W. West
Keyword(s):  
Forest Inventory ◽  
Random Sampling ◽  
Simple Random Sampling ◽  
Auxiliary Variable ◽  
Mathematical Approach ◽  
Wood Volume ◽  
Stem Wood ◽  
Timber Sales ◽  
Tree Stem ◽  
Small Forest

Sampling with probability proportional to prediction (3P sampling) is useful where the variable of interest to a forest inventory is costly to measure and where there exists a cheaper to measure auxiliary variable, which correlates positively with the variable of interest. Two forms of 3P sampling, termed “classical” and “point-” 3P sampling, have received some use in forest inventory. However, both have limitations that have restricted their use mainly to estimation of tree stem wood volume for timber sales over small forest areas in North America. A more general form of 3P sampling, termed here “ordinary” 3P sampling, has been all but ignored to date. It has potential for use in inventory of a broad range of forest attributes, both floral and faunal and both commercial and environmental, across large or small forest areas. Using a common mathematical approach, the present work derives the estimators of the population mean for these three forms of 3P sampling. Their properties are compared with simple random sampling through Monte Carlo simulations based on two example forest populations. The work lays a basis from which 3P sampling might develop further and enjoy wider application in forest inventory than has been the case previously.

scholarly journals VOLUMETRIC MODELING OF Pinus taeda L. FROM ORBITAL IMAGES

2022 ◽  
Vol 7 (1) ◽  
pp. 53
Author(s):  
Carla Talita Pertille ◽  
Marcos Felipe Nicoletti
Keyword(s):  
Pinus Taeda ◽  
Forest Inventory ◽  
Vegetation Index ◽  
High Spatial Resolution ◽  
Vegetation Indices ◽  
Simple Random Sampling ◽  
Sensor Data ◽  
Fixed Area ◽  
Pinus Taeda L ◽  
Sentinel 2

This work aimed to investigate the potential of image-derived indices derived from Sentinel-2/MSI images in the volumetric modeling of a stand of Pinus taeda L. located in Bom Retiro, State of Santa Catarina. For this purpose, field data derived from a forest inventory were used, by the fixed area method and simple random sampling with an allocation of 18 circular plots of 400 m². The remotely located data comprised an orbital image from the Sentinel-2/MSI sensor. From this image, 14 average vegetation indices per plot were calculated. These indices were correlated with the volume by plot (m³ 0.04 ha-1) derived from the inventory. The indices with the best correlation for volume by plot (m³ 0.04 ha-1) were the Generalized Difference Vegetation Index (GDVI) and Adjusted Soil Vegetation Index (SAVI) with 0.39 and 0.36, respectively. The best regression model completed using these VIs estimated the volume by plot with R² controls of 0.9402 and Syx of 1.44%. The use of spectral indices generated from Sentinel-2/MSI sensor data enabled the volumetric estimate of the Pinus taeda L. stand, not revealing differences between the volume accumulated by forest inventory and by orbital images. However, it is worth pointing out that new tests be carried out on other forest species and with medium to high spatial resolution sensors.

Die antizipierte Varianz: ein Werkzeug für die Optimierung von Waldinventuren | The anticipated variance: a tool for the optimization of forest inventory

2003 ◽  
Vol 154 (3-4) ◽  
pp. 117-121 ◽  
Author(s):  
Daniel Mandallaz
Keyword(s):  
Spatial Distribution ◽  
Forest Inventory ◽  
Random Sampling ◽  
Poisson Model ◽  
Simple Algebra ◽  
Simple Random Sampling ◽  
Two Stage ◽  
Two Phase ◽  
Forest Inventories ◽  
Mathematical Review

This paper gives a non-mathematical review of the concept of anticipated variance which allows to solve entirely the optimisation problem for two-phase two-stage forest inventories with cluster or simple random sampling, in the sense that the anticipated variance is minimised for given costs. The anticipated variance is the average of the design-based variance under a local Poisson-model for the spatial distribution of the trees. The resulting sampling rules have a clear intuitive background and require only simple algebra to be implemented. The required parameters can be estimated from any pre-existing two-phase inventory. An example based on the Swiss National Inventory illustrates the method.

scholarly journals COMPARAÇÃO DE MÉTODOS DE AMOSTRAGEM EM FRAGMENTOS DE FLORESTA OMBRÓFILA MISTA, EM LEBON RÉGIS, SC

FLORESTA ◽  
2014 ◽  
Vol 44 (3) ◽  
pp. 393
Author(s):  
Saulo Jorge Téo ◽  
Chaiane Rodrigues Schneider ◽  
Luan Demarco Fiorentin ◽  
Reinaldo Hoinacki da Costa
Keyword(s):  
Forest Inventory ◽  
Relative Efficiency ◽  
Sampling Methods ◽  
Statistical Significance ◽  
Basal Area ◽  
Simple Random Sampling ◽  
The Other ◽  
Forest Fragments ◽  
Breast Height ◽  
Fixed Area

O objetivo desta pesquisa foi avaliar e comparar métodos de amostragem de Área Fixa, Bitterlich, Strand e Prodan em fragmentos de Floresta Ombrófila Mista em Lebon Régis, SC. O processo de amostragem utilizada foi aleatória simples. Em cada unidade amostral, foram avaliadas todas as árvores de diâmetro à altura do peito maior ou igual a 5 cm. Para o método de Área Fixa, utilizou-se dimensões 10 x 50 m (500 m²); para Bitterlich e Strand, adotou-se Fator de Área Basal igual a 2; e para Prodan, foram avaliadas as 6 árvores mais próximas. Apenas o método de amostragem da Área Fixa apresentou suficiência amostral, porém também apresentou o maior tempo de execução no campo, com resultados significativamente diferentes dos demais. Já a eficiência relativa apresentou-se maior para o método de Strand, porém sem diferença estatística significativa com relação aos demais. Não houve diferenças significativas entre o número de árvores e área basal por hectare, estimados pelos diferentes métodos de amostragem.Palavras-chave: Inventário Florestal; eficiência relativa; floresta com araucária. AbstractComparison of sampling methods in Mixed Ombrophyllous Forest fragments, in Lebon Régis - SC. The objective of this research was to evaluate and compare sampling methods Fixed Area, Bitterlich, Strand and Prodan, in fragments of Mixed Ombrophyllous Forest, in Lebon Régis, SC state, Brazil. The forest inventory applies a simple random sampling. At each sampling unit, we evaluated every tree with diameter at breast height greater than or equal to 5 cm. For the method of Fixed Area we used dimensions of 10 x 50 m (500 m²), for Bitterlich and Strand we adopted Basal Area Factor equal to 2, and for Prodan we evaluated the 6 nearest trees. Only the Fixed Area method presented sampling sufficiency, however, it presented highest execution time in the field as well, with results significantly different from the other sampling methods. The relative efficiency was higher for Strand, but without statistical significance compare to the other methods. There were no significant differences between the number of trees and basal area per hectare, estimated by the different sampling methods.Keywords: Forest inventory; relative efficiency; araucaria forest. 

Novel entropy estimators of a continuous random variable

2019 ◽  
Vol 10 (02) ◽  
pp. 1950004 ◽  
Author(s):  
Amer Ibrahim Al-Omari ◽  
Abdul Haq
Keyword(s):  
Random Sampling ◽  
Random Variable ◽  
Simple Random Sampling ◽  
Sample Entropy ◽  
Continuous Random Variable ◽  
Mean Squared Errors ◽  
New Novel ◽  
Theoretical Results ◽  
Test For Normality ◽  
Better Than

This paper presents some novel entropy estimators of a continuous random variable using simple random sampling (SRS), ranked set sampling (RSS), and double RSS (DRSS) schemes. The theoretical results of the proposed entropy estimators are derived. The proposed entropy estimators are compared in terms of the bias and the root mean squared errors, theoretically and numerically, with the Vasicek O. [A test for normality based on sample entropy, J. R. Stat. Soc. B 38:54–59, 1976.] entropy estimators using SRS, RSS, and DRSS schemes. It turns out that the new novel entropy estimators are substantially better than the existing Vasicek’s entropy estimators.

scholarly journals Evaluation of forest inventory processes in a forest under concession in the southwestern Brazilian Amazon

2019 ◽  
Vol 49 (2) ◽  
pp. 91-96
Author(s):  
Felipe KAUAI ◽  
Ana Paula Dalla CORTE ◽  
Vinicius CYSNEIROS ◽  
Allan Libanio PELISSARI ◽  
Carlos Roberto SANQUETTA
Keyword(s):  
Forest Inventory ◽  
Random Sampling ◽  
Basal Area ◽  
Stand Density ◽  
Simple Random Sampling ◽  
Relevant Information ◽  
Cluster Sampling ◽  
Two Stage ◽  
Wood Volume ◽  
Management Plans

ABSTRACT Forest inventory procedures are of utmost importance to studies of wood volume stocks, and forest structure and diversity, which provide relevant information to public policies, management plans and ecological research. The present work focused on the performance of inventory techniques in the Amazon region to evaluate wood volume stocks with higher levels of accuracy while maintaining sampling intensity fixed. Two sampling processes were assessed: simple random sampling and two-stage cluster sampling. The processes were evaluated through the allocation of sampling units with different dimensions, and the effectiveness of the generated estimators was analyzed as a function of stand density and basal area. Simple random sampling resulted in the smallest errors, reaching 9% when all species were sampled together. The method depicted forest phytosociological parameters with greater sensitivity, whereas two-stage cluster sampling produced the least accurate estimators and presented slower responses to variation in phytosociological parameters.

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