Comparaison de plusieurs types d'unités d'échantillonnage dans la perspective d'un inventaire forestier régional

1994 ◽  
Vol 70 (3) ◽  
pp. 304-310 ◽  
Author(s):  
H. Lecomte ◽  
J. Hébert ◽  
J. Rondeux
Keyword(s):  
Forest Inventory ◽  
Basal Area ◽  
Ease Of Use ◽  
Rectangular Grid ◽  
Area Sampling ◽  
Different Types ◽  
Minimum Number ◽  
Fixed Area ◽  
Concentric Circles ◽  
Regional Forest

This study has been conducted in order to define the guidelines of a permanent forest inventory methodology that could be applied to heterogenous forests located in the southern part of Belgium. Different types of sampling units generally used in European national inventories have been compared: fixed area sampling units (based upon 3 concentric circles), non fixed-area sampling units (Bitterlich plots using basal area factor of 2 and 4) and sampling units based upon a minimum number of trees (including nearly 15 measurable trees). In true conditions of application 259 sampling points have been selected according to a systematic rectangular grid (1.000 m × 500 m).Taking into account different criteria such as precision, cost and ease of use, the fixed-area sampling unit looks like the most adequate among the four types investigated. Key words: regional forest inventory, sampling units.

scholarly journals FITOSSOCIOLOGIA E EXPECTATIVA DE RENDA COM PRODUTOS FLORESTAIS MADEIREIROS E NÃO MADEIREIROS EM ASSENTAMENTO NO PARÁ

Nativa ◽  
2019 ◽  
Vol 7 (1) ◽  
pp. 101
Author(s):  
Josiel Carneiro Pinheiro ◽  
João Ricardo Vasconcellos Gama ◽  
Francisco de Assis Oliveira ◽  
Renato Bezerra da Silva Ribeiro ◽  
Girlene da Silva Cruz
Keyword(s):  
Forest Inventory ◽  
Basal Area ◽  
Forest Products ◽  
Systematic Sampling ◽  
Mixing Coefficient ◽  
Botanical Species ◽  
Number Of Species ◽  
Non Timber Forest Products ◽  
Fixed Area ◽  
Unmanaged Forest

O objetivo deste estudo foi analisar a estrutura e a expectativa de renda gerada pelas espécies arbóreas, considerando produtos florestais madeireiros e não madeireiros nos municípios de Santarém e Placas, Pará (PA). A área de estudo foi na comunidade São Mateus, Projeto de Assentamento do INCRA Moju I e II, município de Placas, PA. Empregou-se inventário florestal com amostragem sistemática de 11 unidades amostrais de área fixa de 50 mx 200 m, totalizando 11 ha. Todos os indivíduos com DAP ≥ 10 cmforam mensurados, considerando diferentes classes de tamanho (CT) e subamostragens. Foram mensurados 903 indivíduos com DAP ≥ 10 cm(501,6 árv.ha-1), distribuídas em 48 famílias e 143 espécies botânicas. As famílias botânicas que apresentaram maior riqueza de espécies foram: Fabaceae (36), Sapotaceae (13), Lecythidaceae (10), Malvaceae (7), Moraceae (7), Annonaceae (5), Burseraceae (5) e Lauraceae (5). As famílias representam 61,5% do número de espécies, confirmando-se que poucas famílias botânicas representam um grande número de espécies em Floresta Ombrófila Densa. O Coeficiente de mistura de Jentsch (QM) apresentou em média 6,31 indivíduos por espécie; a área basal foi de 28,77 m².ha-1; o índice de Shannon Weaver (H') 4,28; a diversidade Máxima (H’máx) 4,96 e a Equabilidade de Pielou (J) 0,86. A floresta não manejada apresentou estoque de espécies com potencial madeireiro e não madeireiro. As atividades de extração de madeira e PFNMs podem gerar lucros por hectare superiores ao salário mínimo e ajudar no complemento de renda das famílias assentadas.Palavras-chave: Fabaceae, manejo florestal, recursos florestais. PHYTOSOCYOLOGY AND EXPECTATION OF INCOME WITH WOOD AND NON-GRADUAL FOREST PRODUCTS IN NESTING IN PARÁ ABSTRACT: The objective of this study was to analyze the structure and income expectation generated by tree species, considering timber and non-timber forest products in the municipalities of Santarém and Placas, Pará (PA). The study area was in the São Mateus community, the Settlement Project of INCRA Moju I and II, municipalityof Placas, PA. The study area was in the São Mateus community, the Settlement Project of INCRA Moju I and II, municipalityof Placas, PA. A forest inventory was used with systematic sampling of 11 sample units of fixed area of 50 mx 200 m, totaling 11 ha. All individuals with DBH ≥ 10 cmwere measured, considering different size classes (CT) and sub-samples. A total of 903 individuals with DBH ≥ 10 cm(501.6 tree-ha-1) were distributed in 48 families and 143 botanical species. The botanical families with the highest species richness were Fabaceae (36), Sapotaceae (13), Lecythidaceae (10), Malvaceae (7), Moraceae (7), Annonaceae (5), Burseraceae (5) and Lauraceae . The families represent 61.5% of the number of species, confirming that few botanical families represent a large number of species in DenseOmbrophylousForest. The Jentsch mixing coefficient (QM) presented, on average, 6.31 individuals per species; the basal area was 28.77 m².ha-1; the Shannon Weaver index (H ') 4.28; the Maximum diversity (H'max) 4.96 and the Pielou Equability (J) 0.86. The unmanaged forest presented stock of species with potential lumber and not timber. Logging activities and NTFPs can generate profits per hectare above the minimum wage and help supplement the incomes of settled families.Keywords: Fabaceae, forest management, forest Resources.

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. 

Contribution to the automation of the calculations involving the forest inventory with the aid of an office computer

1970 ◽  
Vol 20 ◽  
Author(s):  
R. Goossens
Keyword(s):  
Tree Species ◽  
Forest Inventory ◽  
Basal Area ◽  
Annual Increment ◽  
Mixed Stands ◽  
Mean Values ◽  
Standing Trees ◽  
General Program ◽  
Magnetic Card ◽  
The Right

Contribution to the automation of the calculations involving  the forest inventory with the aid of an office computer - In this contribution an attempt was made to perform the  calculations involving the forest inventory by means of an office computer  Olivetti P203.     The general program (flowchart 1), identical for all tree species except  for the values of the different parameters, occupies the tracks A and B of a  magnetic card used with this computer. For each tree species one magnetic  card is required, while some supplementary cards are used for the  subroutines. The first subroutine (flowchart 1) enables us to preserve  temporarily the subtotals between two tree species (mixed stands) and so  called special or stand cards (SC). After the last tree species the totals  per ha are calculated and printed on the former, the average trees occuring  on the line below. Appendix 1 gives an example of a similar form resulting  from calculations involving a sampling in a mixed stand consisting of Oak  (code 11), Red oak (code 12), Japanese larch (code 24) and Beech (code 13).  On this form we find from the left to the right: the diameter class (m), the  number of trees per ha, the basal area (m2/ha), the current annual increment  of the basal area (m2/year/ha), current annual volume increment (m3/year/ha),  the volume (m3/ha) and the money value of the standing trees (Bfr/ha). On the  line before the last, the totals of the quantities mentioned above and of all  the tree species together are to be found. The last line gives a survey of  the average values dg, g, ig, ig, v and w.     Besides this form each stand or plot has a so-called 'stand card SC' on  wich the totals cited above as well as the area of the stand or the plot and  its code are stored. Similar 'stand card' may replace in many cases  completely the classical index cards; moreover they have the advantage that  the data can be entered directly into the computer so that further  calculations, classifications or tabling can be carried out by means of an  appropriate program or subroutine. The subroutine 2 (flowchart 2) illustrates  the use of similar cards for a series of stands or eventually a complete  forest, the real values of the different quantities above are calculated and  tabled (taking into account the area). At the same time the general totals  and the general mean values per ha, as well as the average trees are  calculated and printed. Appendix 2 represents a form resulting from such  calculations by means of subroutine 2.

scholarly journals An approximate point-based alternative for the estimation of variance under big BAF sampling

2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Thomas B. Lynch ◽  
Jeffrey H. Gove ◽  
Timothy G. Gregoire ◽  
Mark J. Ducey
Keyword(s):  
Forest Inventory ◽  
Variance Estimation ◽  
Basal Area ◽  
Volume Estimation ◽  
Delta Method ◽  
Sampling Point ◽  
Variance Estimator ◽  
Computer Simulation Studies ◽  
New Formula ◽  
Estimation Of Variance

Abstract Background A new variance estimator is derived and tested for big BAF (Basal Area Factor) sampling which is a forest inventory system that utilizes Bitterlich sampling (point sampling) with two BAF sizes, a small BAF for tree counts and a larger BAF on which tree measurements are made usually including DBHs and heights needed for volume estimation. Methods The new estimator is derived using the Delta method from an existing formulation of the big BAF estimator as consisting of three sample means. The new formula is compared to existing big BAF estimators including a popular estimator based on Bruce’s formula. Results Several computer simulation studies were conducted comparing the new variance estimator to all known variance estimators for big BAF currently in the forest inventory literature. In simulations the new estimator performed well and comparably to existing variance formulas. Conclusions A possible advantage of the new estimator is that it does not require the assumption of negligible correlation between basal area counts on the small BAF factor and volume-basal area ratios based on the large BAF factor selection trees, an assumption required by all previous big BAF variance estimation formulas. Although this correlation was negligible on the simulation stands used in this study, it is conceivable that the correlation could be significant in some forest types, such as those in which the DBH-height relationship can be affected substantially by density perhaps through competition. We derived a formula that can be used to estimate the covariance between estimates of mean basal area and the ratio of estimates of mean volume and mean basal area. We also mathematically derived expressions for bias in the big BAF estimator that can be used to show the bias approaches zero in large samples on the order of $\frac {1}{n}$ 1 n where n is the number of sample points.

scholarly journals TERRESTRIAL LASER SCANNERS SELF-CALIBRATION STUDY: DATUM CONSTRAINTS ANALYSES FOR NETWORK CONFIGURATIONS

2015 ◽  
Vol XL-2/W4 ◽  
pp. 1-9 ◽  
Author(s):  
M. A. Abbas ◽  
H. Setan ◽  
Z. Majid ◽  
A. K. Chong ◽  
L. Chong Luh ◽  
...  
Keyword(s):  
Laser Scanner ◽  
Network Configuration ◽  
Calibration Technique ◽  
Self Calibration ◽  
Laser Scanners ◽  
Different Types ◽  
Minimum Number ◽  
Calibration Study ◽  
Different Sources ◽  
Selection Of

Similar to other electronic instruments, terrestrial laser scanner (TLS) can also inherent with various systematic errors coming from different sources. Self-calibration technique is a method available to investigate these errors for TLS which were adopted from photogrammetry technique. According to the photogrammetry principle, the selection of datum constraints can cause different types of parameter correlations. However, the network configuration applied by TLS and photogrammetry calibrations are quite different, thus, this study has investigated the significant of photogrammetry datum constraints principle in TLS self-calibration. To ensure that the assessment is thorough, the datum constraints analyses were carried out using three variant network configurations: 1) minimum number of scan stations; 2) minimum number of surfaces for targets distribution; and 3) minimum number of point targets. Based on graphical and statistical, the analyses of datum constraints selection indicated that the parameter correlations obtained are significantly similar. In addition, the analysis has demonstrated that network configuration is a very crucial factor to reduce the correlation between the calculated parameters.

scholarly journals Small Area Estimation of Postfire Tree Density Using Continuous Forest Inventory Data

2021 ◽  
Vol 4 ◽  
Author(s):  
George C. Gaines ◽  
David L. R. Affleck
Keyword(s):  
Forest Inventory ◽  
Mean Squared Error ◽  
Tree Density ◽  
Standard Errors ◽  
Sample Sizes ◽  
Management Planning ◽  
Forest Management Planning ◽  
Continuous Forest ◽  
Sample Data ◽  
Regional Forest

Wildfire activity in the western United States is expanding and many western forests are struggling to regenerate postfire. Accurate estimates of forest regeneration following wildfire are critical for postfire forest management planning and monitoring forest dynamics. National or regional forest inventory programs can provide vegetation data for direct spatiotemporal domain estimation of postfire tree density, but samples within domains of administrative utility may be small (or empty). Indirect domain expansion estimators, which borrow extra-domain sample data to increase precision of domain estimates, offer a possible alternative. This research evaluates domain sample sizes and direct estimates in domains spanning large geographic extents and ranging from 1 to 10 years in temporal scope. In aggregate, domain sample sizes prove too small and standard errors of direct estimates too high. We subsequently compare two indirect estimators—one generated by averaging over observations that are proximate in space, the other by averaging over observations that are proximate in time—on the basis of estimated standard error. We also present a new estimator of the mean squared error (MSE) of indirect domain estimators which accounts for covariance between direct and indirect domain estimates. Borrowing sample data from within the geographic extents of our domains, but from an expanded set of measurement years, proves to be the superior strategy for augmenting domain sample sizes to reduce domain standard errors in this application. However, MSE estimates prove too frequently negative and highly variable for operational utility in this context, even when averaged over multiple proximate domains.

scholarly journals Building condition assessment: adjustments of the Building Performance Indicator (BPI) for university buildings in Brazil

2020 ◽  
Vol 20 (1) ◽  
pp. 215-230
Author(s):  
Francisco Morato Leite ◽  
Renan Alves Volse ◽  
Humberto Ramos Roman ◽  
Fernanda Aranha Saffaro
Keyword(s):  
Research Laboratory ◽  
Performance Indicator ◽  
Ease Of Use ◽  
Maintenance Management ◽  
Building Performance ◽  
Maintenance Strategy ◽  
Building Systems ◽  
Different Types ◽  
University Buildings ◽  
Building Condition

Abstract The Building Performance Indicator (BPI), not fully applied in Brazil, expresses objectively the overall condition of a building based on the performance assessment of the building systems that comprise it. Although BPI was originally developed for hospital facilities, it can be used in different types of buildings since its methodology is generic. The objective of the study is to adjust the BPI to allow its application in the maintenance management of Brazilian university buildings. The stages of the research consist of (1) adjusting the factors and criteria that comprise the BPI; (2) implementing the adapted BPI; and (3) verifying its utility and ease of use. The adjustment and implementation included a building for classrooms and another that houses a teaching and research laboratory, both located at University X. The results obtained allowed the comparison of the overall condition between the inspected buildings, which establishes the intervention priority helping to adopt the most adequate maintenance strategy.

scholarly journals Zur Auswirkung der Hangneigungskorrektur auf Schätzwerte im Schweizerischen Landesforstinventar (LFI) | Investigation of the effect of the slope correction method as applied in the Swiss National Forest Inventory of estimates

2001 ◽  
Vol 152 (6) ◽  
pp. 215-225 ◽  
Author(s):  
Michael Köhl ◽  
Peter Brassel
Keyword(s):  
Forest Inventory ◽  
Basal Area ◽  
Correction Method ◽  
National Forest Inventory ◽  
National Forest ◽  
Average Deviation ◽  
Forest Inventories ◽  
Slope Correction ◽  
Number Of Stems ◽  
Elliptical Area

For forest inventories on slopes, it is necessary to correct the test areas, because the circular areas, when projected, become elliptical. Based on 93 samples from the Swiss National Forest Inventory (FNI), it was determined whether the simplified method, which increases the radius to match that of the elliptical area, leads to a distortion of the results. An average deviation of 2% was found between the FNI estimated values and the actual values for the basal area and the number of stems. For estimations of smaller units, greater distortions of the results are expected.

On the subsistence practices of the Shi’erqiao Culture: focused on zooarchaeology

2012 ◽  
Vol 12 (1) ◽  
Author(s):  
Kunyu He
Keyword(s):  
Early Stage ◽  
Subsistence Strategies ◽  
Chengdu Plain ◽  
Factors Influencing ◽  
Animal Remains ◽  
Different Types ◽  
Minimum Number ◽  
Minimum Number Of Individuals ◽  
Archaeological Cultures ◽  
Number Of Individuals

AbstractThrough the analyses of the number of identified specimens (NISP), minimum number of individuals (MNI) and estimation of meat available from the animal remains unearthed from representative sites of the Chengdu Plain Type and Eastern Chongqing Type of the Shi’erqiao Culture, this paper discusses the subsistence strategy of this culture. The results show that the meat resources of the Chengdu Plain Type were mainly domesticated animals, while those of the Eastern Chongqing Type were mainly hunted animals. This paper draws the conclusion that in the early stage of human civilization, the subsistence strategies of different types of the same archaeological culture might be different, while those of different archaeological cultures might be similar; the factors influencing the subsistence strategies are mainly the natural environment, regional economic traditions, and population pressures.

M-Payment Solutions and M-Commerce Fraud Management

2011 ◽  
pp. 192-213 ◽  
Author(s):  
Seema Nambiar ◽  
Chang-Tien Lu
Keyword(s):  
Value Chain ◽  
Mobile Security ◽  
Ease Of Use ◽  
Operating Costs ◽  
Mobile Payment ◽  
Mobile Banking ◽  
General Introduction ◽  
The Third ◽  
Different Types

Mobile security and payment are central to m-commerce. The shift from physical to virtual payments has brought enormous benefits to consumers and merchants. For consumers it means ease of use. For mobile operators, mobile payment presents a unique opportunity to consolidate their central role in the m-commerce value chain. Financial organizations view mobile payment and mobile banking as a way of providing added convenience to their customers along with an opportunity to reduce their operating costs. The chapter starts by giving a general introduction to m-payment by providing an overview of the m-payment value chain, lifecycle and characteristics. In the second section, we will review competing mobile payment solutions that are found in the marketplace. The third section will review different types of mobile frauds in the m-commerce environment and solutions to prevent such frauds.

Sign in / Sign up

Export Citation Format

Share Document