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

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.

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EFICIÊNCIA DE DUAS VARIAÇÕES ESTRUTURAIS DO MÉTODO DE AMOSTRAGEM DE ÁREA FIXA EM PLANTAÇÕES DE Pinus taeda

FLORESTA ◽

10.5380/rf.v43i4.29928 ◽

2013 ◽

Vol 43 (4) ◽

pp. 621

Author(s):

João Paulo Druszcz ◽

Nelson Yoshihiro Nakajima ◽

Sylvio Pellico Netto ◽

Sebastião do Amaral Machado ◽

Nelson Carlos Rosot ◽

...

Keyword(s):

Pinus Taeda ◽

Relative Efficiency ◽

Block Design ◽

Basal Area ◽

Average Diameter ◽

Breast Height ◽

Variable Diameter ◽

Randomized Block Design ◽

Fixed Area ◽

Pinus Taeda L

Este estudo foi conduzido em três diferentes condições de plantações de Pinus taeda L., sem desbastes, com 10, 9 e 7 anos de idade, 2.000 árvores por hectare e diferentes inclinações no terreno, localizados no Estado do Paraná. O objetivo foi avaliar a eficiência do inventário florestal, utilizando-se a amostragem de área fixa com a estrutura de parcela circular (PC) e conglomerado em cruz (CC), através da análise do comportamento quanto às precisões e eficiências relativas nas estimativas das seguintes variáveis: diâmetro médio (cm), número de árvores por ha, área basal (m2/ha) e volume total (m3/ha). Para isso, utilizou-se o delineamento em blocos casualizados com 40 unidades amostrais para a PC e 10 unidades para o CC, sendo este composto por 4 subunidades circulares. Concluiu-se que, para as variáveis diâmetro médio (cm), número de árvores (N/ha), área basal (m2/ha) e volume total (m3/ha), indica-se a utilização do método de área fixa com PC, tendo em vista a maior eficiência no levantamento dessas variáveis.Palavras-chave: Eficiência relativa; precisão; reflorestamento. AbstractStructural efficiency of two variations of method of sampling of fixed area in plantations of Pinus taeda. This study was carried out in three different stands of Pinus taeda L., unthinned and aged 10, 9 and 7 years. The stands have 2.000 trees per hectare and are located in Parana State. The aim was to evaluate the efficiency of inventories using circular plot (PC) and cross cluster (CC) by analyses of behavior towards accuracies and relative efficiencies for estimation of the following variables: average diameter at breast height, number of trees, basal area and total volume per hectare. For this study, it was taken a sample of 40 units to the PC structure and 10 units for the CC structure, which is composed of four circular subunits, and it was used the randomized block design. It was concluded that for the variable diameter (cm), number of trees (ha), basal area (m2/ha) and total volume (m3/ha) it is indicated the use of PC, since its greater efficiency in the survey of these variables.Keywords: Relative efficiency; accuracy; reforestation.

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AGROFORESTRI BERBASIS ROTAN TERHADAP SOSIAL EKONOMI MASYARAKAT DI BARITO SELATAN

Jurnal Hutan Tropis ◽

10.20527/jht.v4i1.2886 ◽

2017 ◽

Vol 4 (1) ◽

pp. 93

Author(s):

Johanna Maria Rotinsulu ◽

Sosilawaty Sosilawaty ◽

Yanarita Yanarita

Keyword(s):

Random Sampling ◽

Sampling Methods ◽

Simple Random Sampling ◽

The Other ◽

Average Yield ◽

Natural Conditions ◽

Central Kalimantan ◽

Economic Level ◽

The Village ◽

Society Research

South Barito is an area of rattan and rattan production center of the province of Central Kalimantan, on the other hand is one area that has natural conditions very conducive to the development of rattan. This study reveals how patterns in addition to planting and processing of rattan traditionally also analyze the socio-economic level of society. Research conducted in South Barito regency, District Karau in Two Villages is Bangkuang and New Salat. The village of the second sample is determined gardens and population are farmers who cultivate cane with sampling methods by simple random sampling, because the peasant population is homogeneous, the number of samples in each village 34 respondents or 68 farmers overall. The result showed that in general the rattan garden where the studies were not well-maintained, where the average of respondents (45%) said that maintenance is only performed at the time of going to the harvesting or one for rattan planting. Besides the low price of rattan is led to a reduction of land management / rattan gardens intensively. and production of rattan average yield of 2.6 tons ha-1 or 245.5 clumps of cane ha-1. For the villagers of business administration studies despite conditions that are considered less favorable, but they still look forward to the Government's policy to remain aligned to the Farmers Rattan. In addition, because cane is inherited and used as a hallmark of South Barito society in general.Barito Selatan merupakan daerah penghasil rotan dan sentra produksi rotan provinsi Kalimantan Tengah, selain itu merupakan salah satu wilayah yang memiliki kondisi alam yang sangat mendukung bagi perkembangan rotan. Penelitian ini selain untuk mengungkapkan bagaimana pola tanam dan pengolahan rotan secara tradisional juga menganalisis tingkat sosial ekonomi masyarakat. Penelitian dilaksanakan di Kabupaten Barito Selatan, Kecamatan Karau di Dua Desa yaitu Bangkuang dan Salat Baru. Dari kedua Desa tersebut ditentukan kebun sampel dan populasi masyarakat yaitu petani yang mengusahakan rotan dengan metode pengambilan sampel secara simple random sampling, karena populasi petani bersifat homogen, jumlah sampel di masing-masing desa 34 responden atau keseluruhan 68 petani. Dari hasil penelitian diperoleh bahwa pada umumnya kebun rotan di tempat penelitian tersebut tidak terpelihara dengan baik, dimana rata-rata responden (45%) menyebutkan bahwa pemeliharaan hanya dilakukan pada saat akan dilakukan pemanenan atau satu kali selama rotan itu di tanam. Selain itu rendahnya harga rotan sangat berdampak pada berkurangnya pengelolaan lahan/kebun rotan secara intensif. dan hasil produksi rotan rata-rata diperoleh 2,6 ton ha-1 atau 245,5 rumpun rotan ha-1. Bagi masyarakat Desa studi walaupun kondisi tataniaga yang dianggap kurang menguntungkan, namun mereka masih berharap kebijakan Pemerintah tetap berpihak kepada Petani Rotan. Di samping itu karena pada umumnya rotan merupakan warisan dan digunakan sebagai ciri khas masyarakat Barito Selatan.

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SISTEMA DE INVENTÁRIO FLORESTAL PARA SERINGAL NATIVO

FLORESTA ◽

10.5380/rf.v32i1.2351 ◽

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.

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Forest inventory estimation with mapped plots

Canadian Journal of Forest Research ◽

10.1139/x03-209 ◽

2004 ◽

Vol 34 (2) ◽

pp. 493-497 ◽

Cited By ~ 10

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.

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The Efficiency of Sampling Methods for Dendrometric Estimates of Thinned Stands of Pinus taeda L. in Santa Catarina, Brazil

Journal of Agricultural Science ◽

10.5539/jas.v11n17p218 ◽

2019 ◽

Vol 11 (17) ◽

pp. 218

Author(s):

Klerysson Julio Farias ◽

Thiago Floriani Stepka ◽

Marcos Felipe Nicoletti ◽

Luis Paulo Baldissera Schorr ◽

Geedre Adriano Borsoi ◽

...

Keyword(s):

Pinus Taeda ◽

Relative Error ◽

Relative Efficiency ◽

Sampling Methods ◽

Alternative Methods ◽

Santa Catarina ◽

Area Method ◽

Fixed Area ◽

Pinus Taeda L ◽

Installation Time

This study aimed to compare the efficiency of the sampling methods: Fixed Area, Bitterlich, Prodan and Modified Prodan to estimate the commercial volume and other dendrometric estimators for a 34 years old of Pinus taeda L. stands located in Campo Belo do Sul, Santa Catarina, Brazil. It were distributed a total of 10 sample units of the following methods: Fixed Area with 200, 400 and 500 m² of area, Bitterlich, Prodan and Modified Prodan were distributed, both with 6, 7, 8, 9 and 10 trees. In addition to collecting dendrometric data, the installation time of the sample units was timed, whereby the relative efficiency for each method was calculated. The comparison between the harvest volumes and the volumes estimated by the methods was performed by the Skott Knott test, and the results that did not differ statistically were weighted by the parameters of relative error, relative efficiency and proximity to harvest. All variations of the Modified Prodan and Prodan methods had sample insufficiency. The number of trees per hectare presented higher values for the 200 m² Fixed Area method and lower values for Prodan with 10 trees. Prodan with 6 trees got the shortest time. The Bitterlich method obtained sample adequancy at 10% error and presented the best result. Among the alternative methods to Fixed Area, Modified Prodan with 7 trees can be indicated for pilot inventory. However, when more precise results are needed, the Bitterlich method is indicated.

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Precision and accuracy of sampling methods in thinned Pinus taeda L. stands

FLORESTA ◽

10.5380/rf.v52i1.74285 ◽

2022 ◽

Vol 52 (1) ◽

pp. 045

Author(s):

Rodrigo Otávio Veiga Miranda ◽

Felipe De Antoni Zarpelon ◽

Síntia Valério Kohler ◽

Alvaro Augusto Vieira Soares ◽

Izabele Domingues Soares Miranda ◽

...

Keyword(s):

Pinus Taeda ◽

Sampling Methods ◽

Sampling Error ◽

Basal Area ◽

Population Means ◽

Starting Point ◽

Fixed Area ◽

Precision And Accuracy ◽

Pinus Taeda L ◽

Area And Volume

Different sampling methods can be used in forest surveys. It is important to know the precision and accuracy of these sampling methods, and which one is the most appropriate in specific conditions of the forest population. The aim of this study was to compare estimates of a forest inventory performed by different sampling methods with forest census results. The sampling methods evaluated were the fixed-area method and the variable-area methods of Bitterlich, Prodan, and Strand. The data were obtained in a 15-year-old thinned stand of Pinus taeda L., located in the municipality of Teixeira Soares, southern Brazil, with a total area of 12.80 ha. Initially, the forest census was carried out, and subsequently, the sample units for each sampling method were distributed in the stand, with a common starting point. The variables used to compare the sample results with the census means were quadratic diameter, number of trees, basal area, and volume, per hectare. Precision and accuracy were evaluated by sampling error and whether the confidence intervals covered the population means, respectively. The fixed-area and Bitterlich methods stood out in precision for all variables analysed. The fixed-area, Bitterlich and Strand methods with proportion to height provided more accurate estimates. The Prodan method provided inaccurate and imprecise estimates for the variables under analysis, except for the quadratic diameter.

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

Wahana Forestra Jurnal Kehutanan ◽

10.31849/forestra.v12i1.197 ◽

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%.

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COMPARAÇÃO ENTRE OS MÉTODOS DE AMOSTRAGEM DE BITTERLICH E DE ÁREA FIXA COM PARCELA CIRCULAR EM PLANTAÇÃO DE Pinus taeda

FLORESTA ◽

10.5380/rf.v40i4.20326 ◽

2010 ◽

Vol 40 (4) ◽

Cited By ~ 2

Author(s):

João Paulo Druszcz ◽

Nelson Yoshihiro Nakajima ◽

Sylvio Péllico Netto ◽

Mauro Yoshitani Júnior

Keyword(s):

Pinus Taeda ◽

Sampling Method ◽

Sampling Methods ◽

Basal Area ◽

Plot Sampling ◽

Fixed Area ◽

Plot Area ◽

The Mean ◽

Pinus Taeda L

Este estudo objetivou comparar o método de amostragem de Bitterlich e o de área fixa com Parcela Circular. Estes dois métodos foram avaliados quanto à precisão e eficiência na estimativa das variáveis DAP médio, número de árvores, área basal e volume total, por hectare. Foram selecionadas três condições de plantios de Pinus taeda, localizados na fazenda Boa Vista, no município de Carambeí – PR. Na análise simultânea das três condições para as estimativas das variáveis DAP médio e número de árvores, por hectare, o método de amostragem de área fixa com Parcela Circular foi o mais preciso e eficiente. Já para a análise de área basal e volume total, por hectare, o método de amostragem de Bitterlich foi o mais preciso e eficiente. Conclui-se que o método de área fixa com Parcela Circular foi mais preciso e eficiente para a estimativa das variáveis DAP médio e número de árvores, já que se trata de um método no qual a seleção dos indivíduos é proporcional à área da parcela. O método de Bitterlich, por ser um método que faz a seleção dos indivíduos com probabilidade à área basal, foi mais preciso e eficiente para a estimativa das variáveis área basal e volume total.Palavras-chave: Método de amostragem; precisão e eficiência; Pinus taeda. AbstractComparison between Bitterlich and fixed area circular plot sampling methods in Pinus taeda L plantation. This study aimed to compare the Bitterlich sampling method to the fixed area circular plot. These two methods were evaluated with respect to the accuracy and efficiency for estimating the variables mean DBH, number of trees, basal area and total volume per hectare. Three conditions for Pinus taeda plantations were selected. They were located in Boa Vista farm, Carambeí County, State of Paraná. Results showed that the fixed area circular plot was more efficient and accurate to estimate the mean DBH and the number of trees per hectare because it is a method where the trees selection is proportional to the plot area, whereas the Bitterlich method was more efficient and accurate to estimate the basal area and the total volume per hectare because the trees selection is related to the basal area.Keywords: Sampling methods; accuracy and efficiency; Pinus taeda.

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

The Forestry Chronicle ◽

10.5558/tfc70304-3 ◽

1994 ◽

Vol 70 (3) ◽

pp. 304-310 ◽

Cited By ~ 1

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.

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Tree growth and soil fertility in plantations of genetic materials of Eucalyptus spp.

Research Society and Development ◽

10.33448/rsd-v10i4.13692 ◽

2021 ◽

Vol 10 (4) ◽

pp. e2610413692

Author(s):

Eleandro José Brun ◽

Diego Maicon Scheis ◽

Maurício Romero Gorenstein ◽

Flávia Gizele Konig Brun ◽

Evandro Alcir Meyer ◽

...

Keyword(s):

Soil Fertility ◽

Basal Area ◽

The Other ◽

Eucalyptus Urophylla ◽

Lower Growth ◽

Breast Height ◽

Individual Volume ◽

Randomized Design ◽

Completely Randomized Design ◽

The Relationship

Were analyzed the growth and the relationship with soil fertility of genetic materials of Eucalyptus spp. planted in a non-traditional eucalyptus forestry region in Brazil. Five genetic materials were selected, two seminal: Eucalyptus urophylla and E. pellita and three clones: GFMO27, I224, and H13, planted in experimental plots in a completely randomized design. The diameter at breast height (DBH) and total height were measured; basal area and dendrometric variables were calculated, for the ages 24, 36, 48, 60, 72, and 108 months, both statistically compared. The soil was chemically characterized at 108 months of age and correlated with dendrometric variables. The growth of clones H13, I224, and GFMO 27 were superior to the E. pellita and E. urophylla. The levels of N and MO had a significant correlation with the volume and the Al+3 showed a positive correlation with DBH. Clone H13 showed higher values than the other materials, in all variables analyzed, reaching an individual volume of 1.27 m³ at 108 months. The other genetic materials (GFMO27, I244, and E. urophylla) proved to be variable in their growth behavior at different ages, and E. pellita had lower growth. The recommended genetic materials for planting are H13 and E. urophylla.

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