EUCALYPTUS STAND SAMPLE PLOTS COMPARED: FIXED AREA AND FIXED NUMBER OF TREES

ABSTRACT This study compares sampling methods based on plots of fixed area and based on a fixed number of trees. The study was conducted in a Eucalyptus forest surveyed using three plot types: rectangular with fixed area, circular with fixed area and fixed number of trees. The estimation accuracies were evaluated for the average diameter per plot and for the number of stems, the basal area and the volume per plot. The null hypothesis of equality between the sampling methods was assessed by t-test. No significant differences were found between the three sampling methods.

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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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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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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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Precision, efficiency and cost of shapes of fixed area plots for plantation ages of Pinus taeda L. in Santa Catarina State

Scientia Agraria Paranaensis ◽

10.18188/sap.v19i2.23274 ◽

2020 ◽

Vol 19 (2) ◽

pp. 124-131

Author(s):

Alois Zator Filho ◽

Myrcia Minatti ◽

Antonio Pedro Fragoso Woycikievicz ◽

Jonathan William Trautenmuller ◽

Nelson Yoshihiro Nakajima

Keyword(s):

Lower Cost ◽

Sampling Error ◽

Basal Area ◽

Average Diameter ◽

Measurement Time ◽

Efficiency Cost ◽

Fixed Area ◽

Different Shapes ◽

Pinus Taeda L ◽

Area And Volume

Generally, the forest populations are extensive and frequently require to be inventoried in short term, where the implementation of forest inventory is closely linked to the sampling theory. With objective to compare three different shapes of fixed area plots to estimate parameters of the forest as average diameter, basal area, the number of trees and volume per hectare, evaluating the respective precision, relative efficiency, cost and measurement time in four different ages. The rectangular plot had presented better precision to estimate the average DBH, number of trees and basal area and the circular plot with better precision for volume per hectare. About efficiency, the square plot had presented the best efficiency for the variable average DBH, basal area and volume and the circular plot was the most efficient for the numbers of trees ha-1. The square plot also had shown the lower cost and measurement time to estimate the variables evaluated. The rectangular plot had presented the best precision in the estimative of the variables, as well as, the lower sampling error in the most of the cases evaluated in this study, following the circular plot, and the square plot with lower precision. In relation to the efficiency, the square plot had presented the best performance and the rectangular plot the worst performance in all age classes and evaluated variables. The square plots as the best plot shape to estimate the variables average DBH, number of trees, basal area and volume per hectare.

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

FLORESTA ◽

10.5380/rf.v44i3.32687 ◽

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.

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THE EFFECT OF COMIC STRIPS ON SECONDARY EFL STUDENTS’ READING COMPREHENSION AND WRITING ABILITY

ENGLISH JOURNAL OF INDRAGIRI ◽

10.32520/eji.v2i2.236 ◽

2018 ◽

Vol 2 (2) ◽

pp. 43-57

Author(s):

M. Ridhwan ◽

Muhammad Taufik Ihsan ◽

Naskah Naskah

Keyword(s):

Reading Comprehension ◽

Hypothesis Testing ◽

Null Hypothesis ◽

Test Group ◽

T Test ◽

Comic Strips ◽

Writing Ability ◽

Paired Sample ◽

And Control ◽

Test Treatment

The purpose of this study was to investigate the significant effect of using comic strips strategy toward students’ reading comprehension and writing ability at MTsN 1 Pekanbaru. A Quasi-Experimental by Non-equivalent Pre-test and Post-test Group was applied as a designed for study. The sample was two classes (VIII 3 and VIII 4) consisting 20 students of treatment class, and 20 students of control class. The data were computed using SPPS 20.0 to analyze Independent sample t-test and Paired sample t-test. The finding of this study revealed that there was a significant effect on students’ reading comprehension by using comic strips strategy, it shown on paired sample t-test; treatment class was 77 and control class was 64.5, the hypothesis testing showed the result of post T-test -7.149, then score of sig.(2-tailed) is 0.000, if we act to null hypothesis (Ho) that is 0.05, it means that the score of sig.(2-tailed) was smaller than score of Ho. The data also revealed that there was a significant effect on students’ writing ability, it shown on paired sample t-test; treatment class was 79.6 and control class was 54.2, the hypothesis testing showed the result of post T-test -21.9, then score of sig.(2-tailed) is 0.000, if we act to null hypothesis (Ho) that is 0.05, it means that the score of sig.(2-tailed) was smaller than score of Ho. Therefore, the null hypothesis was rejected and the alternative hypothesis was accepted. From those data it can be summarized that there is a significant effect of using comic strips strategy on students’ reading comprehension and writing ability.

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Koalas continue to occupy their previous home-ranges after selective logging in Callitris - Eucalyptus forest

Wildlife Research ◽

10.1071/wr06126 ◽

2007 ◽

Vol 34 (2) ◽

pp. 94 ◽

Cited By ~ 26

Author(s):

Rodney P. Kavanagh ◽

Matthew A. Stanton ◽

Traecey E. Brassil

Keyword(s):

Home Range ◽

Basal Area ◽

Selective Logging ◽

Home Ranges ◽

Phascolarctos Cinereus ◽

Eucalyptus Forest ◽

South Wales ◽

Callitris Glaucophylla ◽

One Year ◽

Cypress Pine

The koala (Phascolarctos cinereus) is a charismatic, high-profile species whose conservation needs are commonly perceived to be incompatible with logging. However, koala biology and the results of chronosequence studies elsewhere suggest that this species may tolerate a degree of habitat alteration caused by logging. In this study, 30 koalas, five in each of six areas available for logging within a mixed white cypress pine (Callitris glaucophylla)–Eucalyptus forest in north-western New South Wales, were radio-tracked for one year during 1997–1998 to determine their movements, home-range sizes and tree preferences. Five months after the study began, three of these areas were logged selectively for sawlogs and thinnings of the white cypress pine, a tree that is important to koalas for daytime shelter. This removed about one-quarter of the stand basal area, but the eucalypt component was unaffected. The remaining three areas were left undisturbed as controls. Radio-tracking continued in all six areas for another seven months. Koalas continued to occupy all or part of their previous home-ranges after selective logging, and home-range sizes remained similar between logged and unlogged areas. Home-ranges for both sexes overlapped and were ~12 ha for males and 9 ha for females. Koala survival and the proportions of breeding females were similar in logged and unlogged areas. The principal food trees of the koala were red gums, mainly Eucalyptus blakelyi and E. chloroclada, and the pilliga box (E. pilligaensis), none of which were logged in this study. These results suggest that selective logging for white cypress pine does not appear to adversely affect koala populations and that koalas may not be as sensitive to logging as previously thought. Further work is required to determine thresholds in the level of retention of koala food trees in logging operations.

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Applying shadowing technique to improve students' listening achievement

Language and Education Journal ◽

10.52237/lej.v5i1.155 ◽

2020 ◽

Vol 5 (1) ◽

pp. 47-56

Author(s):

Fitri Maini ◽

Rachmanita

Keyword(s):

Null Hypothesis ◽

Sampling Method ◽

Critical Value ◽

T Test ◽

Control Group ◽

Tenth Graders ◽

Tenth Grade ◽

Quasi Experimental ◽

The Mean ◽

Experimental Group

This study tried find the students’ improvement in listening achievement after having taught by using the shadowing technique. The method used was a quasi-experimental that involved two groups, namely the control group and experimental group. The population of this study was all the tenth graders of SMA Negeri 3 Unggulan Kayuagung with a total number of 198 tenth graders. Purposive sampling method was applied to select the sample involved 72 tenth graders. In collecting the data, try out the test was used to get the desirable questions that would be used in the pretest and posttest to both groups in the control and experimental group. To verify the hypothesis, the normality and homogeneity of the data were firstly analyzed before being continued to be analyzed by using a t-test. Based on the result of data analysis in an independent sample t-test, there were some findings found. First, the mean score of a posttest (75.56) in the experimental group was higher than the pretest (69.03) in the control group. Secondly, the value of tobtained was 2.77 at the significant level of p<0.05 in two-tailed testing with df = 70, the critical value of ttable was 1.99. Since the value of tobtained was higher than ttable, the null hypothesis (Ho) was rejected and the research hypothesis was accepted. In conclusion, it showed that the shadowing technique could improve the tenth-grade students’ listening achievement at SMA Negeri 3 Unggulan Kayuagung.

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THE EFFECT OF USING EDMODO APPLICATION ON THE STUDENTS’ WRITING SKILL OF ANALYTICAL EXPOSITION TEXT AT SMAN 4 PALANGKA RAYA

Intensive Journal ◽

10.31602/intensive.v4i2.5744 ◽

2021 ◽

Vol 4 (2) ◽

pp. 17

Author(s):

Enggal Pinanggih ◽

Ristati Ristati ◽

Wahyuningsih Usadiati

Keyword(s):

Null Hypothesis ◽

Data Distribution ◽

Critical Value ◽

T Test ◽

Teaching English ◽

Writing Ability ◽

Writing Test ◽

Writing Skill ◽

Dependent Sample ◽

T Distribution

This research was conducted to find out the effect using Edmodo application on the students’ writing skill of analytical exposition text at SMAN 4 Palangka Raya. Data of the students score of writing Analytical Exposition text was collected using writing test, and the hypothesis testing was examined based on t-test for normally because the data distribution was normal. A test in form of writing analytical exposition text was used the instrument to collect the data needed. Then, the data were analyzed by using parametric statistic dependent sample T – test because the data were normally distributed. The writer took conclusion based on statistical result. The result of this research shows that the critical value for students T distribution was 1.734 the critical value t0 was t05 {19} = 1.729. Because 1.734 is greater than 1.729, null hypothesis was rejected. Thus, it can be concluded that there was significant effect of using Edmodo Application in writing Analytical Exposition Text gained by eleventh grade of SMAN 4 Palangka Raya. Thus, Edmodo Application had been successful in improving students’ writing ability of Analytical Exposition text. The researcher suggest that the teacher should provide an appropriate media in teaching English, especially for Analytical Exposition Text and made Edmodo Application as reference to him/her to use it for making students’ attracted to the material.

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Improving Students’ Writing Skill by Using Wholesome Scattering Game

EEdJ: English Education Journal ◽

10.32923/eedj.v1i1.1790 ◽

2021 ◽

Vol 1 (1) ◽

pp. 39-47

Author(s):

Dina Novrieta ◽

Sopi Nurisa

Keyword(s):

Null Hypothesis ◽

Alternative Hypothesis ◽

Writing Skills ◽

Sampling Technique ◽

T Test ◽

Control Group ◽

Paired Sample ◽

Significant Difference ◽

Writing Skill ◽

Academic Year

The aim of this research is to describe the implementation of Wholesome Scattering Game in improving students’ writing skills on descriptive text and to find out whether there is a significant difference between students who were taught by using Wholesome Scattering Game and the students who were not. This research used quantitative approach focusing on experimental research which was conducted at SMAN 2 Sungaiselan in academic year 2019/2020. The researcher used purposive sampling technique and two classes were taken as samples, with 69 students (35 students for the control group and 34 students for the experimental). The result of the test was analyzed by using statistical analysis of Paired sample t-test and Independent sample t-test. The finding showed that the students who were taught by using Wholesome Scattering Game got higher score than those who were taught by using non-Wholesome Scattering Game. It means that the alternative hypothesis (Ha) was accepted, while the null hypothesis (Ho) was rejected. It could be concluded that there was a significant difference between students who were taught by using Wholesome Scattering Game and the students who were taught without using Wholesome Scattering Game.

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