scholarly journals Application of Point Sampling Method in Estimation of Stand Basal Area in Community Forest

2018 ◽  
Vol 1 (1) ◽  
pp. 45-54
Author(s):  
Budi Mulyana ◽  
Rohman Rohman ◽  
Ris Hadi Purwanto
Keyword(s):  
Direct Measurement ◽  
Sampling Method ◽  
Sampling Methods ◽  
Basal Area ◽  
Community Forest ◽  
Point Sampling ◽  
Community Forests ◽  
Average Value ◽  
The Difference ◽  
Materials Used

Estimation of the potency of community forest is usually done with the census approach for each forest. Sampling methods to estimate the potency of community forest are still rare. The size of community forest is relatively small, scatter, and less irregular shape, therefore the estimation of community forest potency using sampling plot is difficult to apply. The approach of sampling without a plot (plotless/ point sampling) was cheaper and faster compare to the method of sample plots and direct measurement (census) in predicting basal area. The objective of this research is determining the difference in the average value of basal area using direct measurement of stand (census) and point sampling methods. The research was carried out for 4 months in 30 community forests at Kemuning Village, Gunungkidul District. Materials used to estimate basal area with point sampling method were Spiegel Relascope and Bitterlich Stick with the value of Basal Area Factor 1. Parameters measured were diameter at breast high (dbh) for census method and the number of trees were categorized in or border for point sampling method. The result was analyzed statistically using unpaired t-student. The result showed that the average of basal area of tree in community forest with point sampling method were no significantly different from the average of basal area with census method (α = 1%). Therefore, the point sampling method can be considered as a tool in inventory at community forest

New and composite point sampling estimates

2010 ◽  
Vol 40 (11) ◽  
pp. 2234-2242 ◽  
Author(s):  
John Paul McTague
Keyword(s):  
Sampling Method ◽  
Sampling Methods ◽  
Basal Area ◽  
Population Parameters ◽  
Critical Height ◽  
Sampling Methodology ◽  
Stand Volume ◽  
Point Sampling ◽  
Repeated Sampling ◽  
Angle Count Sampling

A new estimator for basal area is introduced that is based on the concepts of angle count and angle summation sampling. Using the ratio of the angle count basal area factor and the angle summation (borderline) factor, it is possible to estimate stand volume without measuring the diameters and distances of the trees included in the sample. Employing simulation of repeated sampling in a 40 ha forest of known population parameters, it is demonstrated that the new sampling methodology is unbiased and weakly correlated with conventional angle count sampling. Hence, considerable gains in efficiency are made by combining the two sampling methods with composite estimators. Two applications are explored with the new composite point sampling estimates, including the use of the big basal area factor sampling method and critical height sampling using a Max and Burkhart taper formulation.

Changes in vegetation characteristics following a decade of community forest management in mid-western Uganda

2020 ◽  
Vol 22 (3) ◽  
pp. 323-338 ◽  
Author(s):  
C. Mawa ◽  
F. Babweteera ◽  
J.R.S. Tabuti ◽  
D.M. Tumusiime
Keyword(s):  
Forest Management ◽  
Basal Area ◽  
Forest Sector ◽  
Community Forest Management ◽  
Community Forest ◽  
Community Members ◽  
Community Forests ◽  
Forest Condition ◽  
Vegetation Characteristics ◽  
Using Data

The last three decades have witnessed shifts in forest governance in favour of more inclusive approaches. In Uganda, two main approaches have been embraced in the forest sector: collaborative forest management and community forest management. However, there is scanty empirical evidence on how the latter has affected the forest condition over time. Using data from two bio-physical surveys (2006 and 2016) and Key Informant Interviews, this study examined changes in vegetation characteristics in two de facto community forests (Ongo and Alimugonza) over a 10-year period. The basal area and stem densities of tree species locally preferred for poles and charcoal declined in both forests due to extractive uses, some of which were illegal. The densities of those preferred for timber increased as a result of their heightened protection by the community members. However, the community members still faced challenges of apprehending rulebreakers due to the high costs involved and their informal recognition as responsible bodies since the two forests have not yet been declared "community forests" as required by law. The gains made by the approach amidst these challenges demonstrate its potential to achieve conservation goals.

scholarly journals KONTRIBUSI KOMPOSISI VEGETASI DALAM PENYIMPANAN DAN SERAPAN KARBON DI HUTAN RAKYAT DESA NEGARA RATU II KECAMATAN NATAR KABUPATEN LAMPUNG SELATAN

2019 ◽  
Vol 2 (2) ◽  
pp. 112
Author(s):  
Dian Afriansyah ◽  
Duryat Duryat ◽  
Hari Kaskoyo
Keyword(s):  
Sampling Method ◽  
The Body ◽  
Cluster Sampling ◽  
Carbon Uptake ◽  
Body Parts ◽  
Community Forest ◽  
Variance Test ◽  
Community Forests ◽  
Non Destructive ◽  
Public Forests

Tree stands in community forest have potential to absorb carbon in the air by storing in the body parts of the tree.  This study aims to determine the effect of community forest’s stand types on the number of reserves and carbon uptake.  The sampling method used is the cluster sampling method to determine the sample.  Biomass data are collection destructive and non destructive methods.  Estimation of biomass is carried out using the allometric equations.  Measurement of carbon content using the formula from BSN (2011) x 0.47.  Comparative  analysis of carbon reserves and removals uptake using the variance test  and 5 % BNT test.  Public  forests in the Negara Ratu II village with gold teak stands have carbon reserves and removals (135.87 tons/ha and 499,00 ton/ha). the most significant compared to community forests with other types of stands. While the reserve value and carbon uptake between white teak (44.86 tons/ha and 164.63 tons/ha), acacia (54.13 tons/ha and 191.20 tons/ ha), red jabon (51.20ton/ha and 187.90 tons/ha), white jabon (59.51 tons/ha and 218.40 tons/ha), is no different.  

scholarly journals Pengembangan Bahan Ajar Biologi Materi Virus Berbasis SocioScientific Issues (SSI) untuk Meningkatkan Kemampuan Berpikir Kritis Siswa

2021 ◽  
Vol 11 (1) ◽  
pp. 87-104
Author(s):  
Diyana Septiningrum ◽  
Nur Khasanah ◽  
Nur Khoiri
Keyword(s):  
Critical Thinking ◽  
Thinking Skills ◽  
Critical Thinking Skills ◽  
Teaching Material ◽  
Teaching Materials ◽  
Average Value ◽  
Teachers And Students ◽  
The Difference ◽  
Materials Used ◽  
Expert Validation

The purpose of research is to know the characteristics, feasibility and effectiveness of developing teaching materials viruses based on Socio-Scientific Issues (SSI) to improve critical thinking skills. Research method using Research and Development (RD) with a 4D step (define, design, develop, disseminate) Thiagarajan et all. The subjects of the study are 34 students class X MIPA 1 as the experimental class and 34 students class X MIPA 4 as the control class. The eligibility of teaching material is derived from the results of expert validation questionnaires, responses of biology teachers and students' responses, and effectiveness of critical thinking skills from the results of the test questions pretest and posttest. The results of the characteristics teaching material viruses based SSI include: cover, introduction, news analysis, material, summary, evaluation, bibliography and glossary. The results of the eligibility from the material expert validation questionnaire were 88,67%, 94,67% of media experts, 83,55% of teacher responses and 82,29% of students' responses. The effectiveness of teaching materials used was obtained from the difference in the average value of experimental learning outcomes of 81.84 and 76.84 kontrol class with tcount = 4.338 and ttable = 1.6682 which means tcount ttable and Ha accepted, concluded that there were differences in posttest results experimental class with kontrol class. The n-gain results obtained the value of the experimental class of 0.63 and the control class of 0.54 with their respective categories being moderate. So it can be concluded that the use of biological material teaching material based on Socio-Scientific Issues (SSI) is effective to improve students' critical thinking skills class X SMA 12 Semarang.

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

FLORESTA ◽  
2010 ◽  
Vol 40 (4) ◽  
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.

Penampilan Fenotipik Delapan Genotipa Jagung Lokal Manokwari Hasil Penggaluran Generasi Pertama

Agrotek ◽  
2018 ◽  
Vol 4 (7) ◽  
Author(s):  
Nouke Lenda Mawikere ◽  
Amelia S. Sarungallo ◽  
Diyah A. Aribowo ◽  
Efa Gultom
Keyword(s):  
First Generation ◽  
Seed Color ◽  
Hybridization Method ◽  
Recommended Dosage ◽  
Single Row ◽  
Average Value ◽  
Color Differences ◽  
The Difference ◽  
Materials Used ◽  
Organic And Inorganic Fertilizers

<em>The objective of this study was to obtain the package information about� the characteristics of first generation of eight genotypes of Manokwari-local corn which made strain based on seed color differences. The materials used in this study were eight genotypes of Manokwari-local corn, organic and inorganic fertilizers according to recommended dosage, and pesticides. Planting was done in the farmer�field located in Beach� Amban, Manokwari. The study was designed using a single row and eight� local corn genotipes which were planted in one seedbed with a size of 4m x 1.5m. Hybridization method used was artificially self-pollinating. The variables measured� were� plant- height character, stem character, leave character, cobs character, and seed character. Data analysis was done using T-test of the difference between the average value for each variable observed.� Eight genotypes of� Manokwari-local corn� which have been evaluated on the characteristics of their vegetative and generative were vary. The highest percentage of seed color in a uniform cob was found in a population of� Red-Kebar genotypes ( 94.4 % ) and the lowest in Purple-Anggi population ( 13.3 % ).</em>

scholarly journals Quota Sampling as an Alternative to Probability Sampling? An Experimental Study

2014 ◽  
Vol 19 (1) ◽  
pp. 56-66 ◽  
Author(s):  
Keming Yang ◽  
Ahmad Banamah
Keyword(s):  
Presidential Elections ◽  
Sampling Method ◽  
Sampling Methods ◽  
Response Rate ◽  
Probability Sampling ◽  
Two Factors ◽  
The Difference ◽  
Quota Sampling ◽  
Student Society ◽  
Experimental Survey

In spite of the establishment of probability sampling methods since the 1930s, non-probability sampling methods have remained popular among many commercial and polling agents, and they have also survived the embarrassment from a few incorrect predictions in American presidential elections. The increase of costs and the decline of response rates for administering probability samples have led some survey researchers to search for a non-probability sampling method as an alternative to probability sampling. In this study we aim to test whether results from a quota sample, believed to be the non-probability sampling method that is the closest in representativeness to probability sampling, are statistically equivalent to those from a probability sample. Further, we pay special attention to the effects of the following two factors for understanding the difference between the two sampling methods: the survey's topic and the response rate. An experimental survey on social capital was conducted in a student society in Northeast England. The results suggest that the survey topic influences who responded and that the response rate was associated with the sample means as well. For these reasons, we do not think quota sampling should be taken as an acceptable alternative to probability sampling.

scholarly journals EFFICIENCY OF THE BITTERLICH POINT SAMPLING AND THE METHOD OF FIXED AREA SAMPLING WITH STRUCTURAL VARIATIONS IN Pinus taeda PLANTATIONS

FLORESTA ◽  
2015 ◽  
Vol 45 (3) ◽  
pp. 523
Author(s):  
João Paulo Druszcz ◽  
Sebastião Do Amaral Machado ◽  
Nelson Yoshihiro Nakajima ◽  
Nelson Carlos Rosot ◽  
Roberto Tuyoshi Hosokawa
Keyword(s):  
Pinus Taeda ◽  
Sampling Method ◽  
Basal Area ◽  
Structural Variations ◽  
Point Sampling ◽  
Fixed Area ◽  
The Mean ◽  
The Cross ◽  
Pinus Taeda L ◽  
The City

AbstractThis study aimed to compare two methods of sampling, one is the method of variable area represented by the Bitterlich point (PB) sampling and the other is the method of fixed area represented by circular plots (PC) with structural variation, the cross sampling cluster (CC) and the line sampling cluster (CL). Precision and efficiency in estimation of the variables mean DBH (cm), number of trees (N/ha), basal area (m2/ha) and total volume (m3/3) in three plantation conditions of Pinus taeda L., located in the city of Carambeí, Paraná, were assessed. In simultaneous analysis of the three conditions to estimate the mean DBH and number of trees per hectare variables, the sampling method of fixed area with Circular Plot (PC) was the most accurate and efficient. The Bitterlich point sampling method (PB) was more accurate and efficient for the estimation of basal area and total volume variables. The two structures of sampling method of the fixed area with Cross Cluster (CC) and with Line Cluster (CL) demonstrated good results being the line cluster superior to the cross cluster.ResumoEficiência do método de amostragem de Bitterlich e de área fixa com variações estruturais em plantações de Pinus taeda. O estudo visou comparar dois métodos de amostragem, sendo eles o de área variável, o qual foi representado pelo método Ponto de Bitterlich (PB) e o de área fixa, representado pela Parcela Circular (PC) e as variações estruturais em Conglomerado em Cruz (CC) e Conglomerado em Linha (CL) com subunidades circulares. Foram avaliadas a precisão e eficiência para a estimativa da variável DAP médio (cm), número de árvores (N/ha), área basal (m2/ha) e volume total (m3/ha), em três condições de plantações, localizadas no município de Carambeí, PR. Na análise simultânea das três condições para a estimativa da variável DAP médio (cm) e número de árvores (N/ha), o método de área fixa com Parcela Circular (PC) foi o mais preciso e eficiente. Para a estimativa da variável área basal (m2/ha) e volume total (m3/ha), o método de área variável Ponto de Bitterlich foi mais preciso e eficiente. As duas estruturas do método de área fixa, utilizando-se o Conglomerado em Cruz (CC) e o Conglomerado em Linha (CL) apresentaram resultados precisos e eficientes, entretanto, o CL foi superior ao CC.Palavras-chave: Eficiência relativa; precisão; reflorestamento.

scholarly journals Perbedaan cash holding pada perusahaan Dengan leverage tinggi dan rendah

2011 ◽  
Vol 1 (1) ◽  
pp. 57
Author(s):  
Anggita Langgeng Wijaya
Keyword(s):  
Sampling Method ◽  
Sampling Methods ◽  
Stock Exchange ◽  
Hypothesis Test ◽  
Cash Holdings ◽  
Cash Holding ◽  
Purposive Sampling ◽  
Manufacturing Company ◽  
The Difference ◽  
Test Use

This research tests the difference of cash holdings based on high and low corporate leverage for a sample of manufacturing company enlisted in Indonesian Stock Exchange over the pe- riod 2005-2007. Population of this research is all of manufacturing company at Indonesian Stock Exchange. Sampling methods use purposive sampling method. Hypothesis test use Mann- Whitney analysis. The results show that there are significance difference of cash holding among high leverage and low leverage firm. Firm with high leverage hold lower level of corpo- rate cash holdings. Keyword: cash holding, dummy, leverage.

scholarly journals Biomass and Carbon Stock Variation along slopes in Tropical Forest of Nepal: A case of Depard Community Forest, Makwanpur, Nepal

2021 ◽  
Vol 1 (2) ◽  
pp. 89-99
Author(s):  
Birendra Bohara ◽  
Mahamad Sayab Miya ◽  
Sachin Timilsina ◽  
Deepak Gautam ◽  
Siddhartha Regmi
Keyword(s):  
Carbon Stock ◽  
Sampling Method ◽  
Secondary Data ◽  
Total Biomass ◽  
Tree Biomass ◽  
Community Forest ◽  
Circular Area ◽  
Spss Software ◽  
The Difference ◽  
Non Destructive

This study was conducted to assess biomass and carbon stock along slopes in Depard community forest, Manahari-6, Makwanpur district of Nepal. In Nepal, carbon stock estimation has been less practiced in community forest. A random sampling method was applied in this study to collect biophysical data i.e. DBH and height by non-destructive method to estimate the quantity of tree biomass and carbon stock. 21 sample plots with 1% sampling intensity were established within the study area. The circular area of 250 m2 was predetermined with the radius of 8.92 m for this study. Secondary data were collected through published and unpublished literature. Data were pooled and analyzed with SPSS software. The total biomass and carbon stock were calculated to be 1381.30 t/ha and 649.21 t/ha, respectively. The biomass and carbon stock were highest (563.12 t/ha and 242.42 t/ha) in 0-5% slope, and lowest in >20% of slope (334.75 t/ha and 143.60 t/ha). The difference of biomass and carbon in slopes may be due to the accumulation of more organic matter and other minerals in the less sloped areas through rainfall, landslide.

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