Estimating the volume of coarse woody debris of forest floor using sampling with probability proportional methods

A variety of new methods have been proposed by ecologists and biologists for data collection on different attributes of coarse woody debris (CWD). Amongst others methods based on probability proportional to size are the newest techniques. These approaches are based on selecting individual logs into...

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Main Authors: Somayyeh Izadi, Hormoz Sohrabi
Format: Article
Language:fas
Published: Research Institute of Forests and Rangelands of Iran 2015-06-01
Series:تحقیقات جنگل و صنوبر ایران
Subjects:
Online Access:http://ijfpr.areeo.ac.ir/article_103006_51af754afefa7b24bd0928b6ca6b1e12.pdf
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author Somayyeh Izadi
Hormoz Sohrabi
author_facet Somayyeh Izadi
Hormoz Sohrabi
author_sort Somayyeh Izadi
collection DOAJ
description A variety of new methods have been proposed by ecologists and biologists for data collection on different attributes of coarse woody debris (CWD). Amongst others methods based on probability proportional to size are the newest techniques. These approaches are based on selecting individual logs into the sample unite using some forms of unequal probability sampling. In the present study, we aimed to introduce “Distance Limited Sampling” (DLS) and “Sausage protocol” of “Fixed Area Method” as well as assessing their precision and accuracy for estimating volume of CWD. These methods select individual logs into the samples using probability proportional to length of the logs. To collect the data, a set of attributes including location, top and bottom diameter and length of all logs in a 250×250 m plot in an un-harvested temperate forest were fully inventoried, and the location of logs were mapped. Then different methods with different sample unit sizes were simulated in R programming language environment using SampSurf package. Results indicated that both methods are unbiased. Considering precision of the estimates, Sausage protocol of fixed area sampling led to more precise estimates of volume of the loges than those estimated by DLS. Consequently, Sausage protocol is concluded for further usage as a promising method in the field due to its unbiasedness and production of highly-precise estimates.
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spelling doaj.art-e90f0af6bc114abe9ab049ef3a335bed2022-12-22T00:10:32ZfasResearch Institute of Forests and Rangelands of Iranتحقیقات جنگل و صنوبر ایران1735-08832383-11462015-06-0123222223310.22092/ijfpr.2015.103006103006Estimating the volume of coarse woody debris of forest floor using sampling with probability proportional methodsSomayyeh Izadi0Hormoz Sohrabi1M. Sc. Forestry, Natural Resources and Marine Science Faculty, Tarbiat Modares University, Noor, IranAssistant Prof., Natural Resources and Marine Science Faculty, Tarbiat Modares University, Noor, IranA variety of new methods have been proposed by ecologists and biologists for data collection on different attributes of coarse woody debris (CWD). Amongst others methods based on probability proportional to size are the newest techniques. These approaches are based on selecting individual logs into the sample unite using some forms of unequal probability sampling. In the present study, we aimed to introduce “Distance Limited Sampling” (DLS) and “Sausage protocol” of “Fixed Area Method” as well as assessing their precision and accuracy for estimating volume of CWD. These methods select individual logs into the samples using probability proportional to length of the logs. To collect the data, a set of attributes including location, top and bottom diameter and length of all logs in a 250×250 m plot in an un-harvested temperate forest were fully inventoried, and the location of logs were mapped. Then different methods with different sample unit sizes were simulated in R programming language environment using SampSurf package. Results indicated that both methods are unbiased. Considering precision of the estimates, Sausage protocol of fixed area sampling led to more precise estimates of volume of the loges than those estimated by DLS. Consequently, Sausage protocol is concluded for further usage as a promising method in the field due to its unbiasedness and production of highly-precise estimates.http://ijfpr.areeo.ac.ir/article_103006_51af754afefa7b24bd0928b6ca6b1e12.pdfBiasSausage protocolfixed area samplingdistance limited sampling
spellingShingle Somayyeh Izadi
Hormoz Sohrabi
Estimating the volume of coarse woody debris of forest floor using sampling with probability proportional methods
تحقیقات جنگل و صنوبر ایران
Bias
Sausage protocol
fixed area sampling
distance limited sampling
title Estimating the volume of coarse woody debris of forest floor using sampling with probability proportional methods
title_full Estimating the volume of coarse woody debris of forest floor using sampling with probability proportional methods
title_fullStr Estimating the volume of coarse woody debris of forest floor using sampling with probability proportional methods
title_full_unstemmed Estimating the volume of coarse woody debris of forest floor using sampling with probability proportional methods
title_short Estimating the volume of coarse woody debris of forest floor using sampling with probability proportional methods
title_sort estimating the volume of coarse woody debris of forest floor using sampling with probability proportional methods
topic Bias
Sausage protocol
fixed area sampling
distance limited sampling
url http://ijfpr.areeo.ac.ir/article_103006_51af754afefa7b24bd0928b6ca6b1e12.pdf
work_keys_str_mv AT somayyehizadi estimatingthevolumeofcoarsewoodydebrisofforestfloorusingsamplingwithprobabilityproportionalmethods
AT hormozsohrabi estimatingthevolumeofcoarsewoodydebrisofforestfloorusingsamplingwithprobabilityproportionalmethods