N-Tree Distance Sampling vs. Fixed-Radius Plots methods for tree density estimation in central Zagros forests
N-tree Distance Sampling (NTDS) is a well-known distance sampling method which is considered as cost-and time effective compared to fixed-Radius Plots. This study was conducted across an area of 36.40 ha in Helen forest reserve in Chaharmahal and Bakhtiari Province. The study area mostly comprises o...
| Main Authors: | , , |
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| Format: | Article |
| Language: | fas |
| Published: |
Research Institute of Forests and Rangelands of Iran
2014-11-01
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| Series: | تحقیقات جنگل و صنوبر ایران |
| Subjects: | |
| Online Access: | http://ijfpr.areeo.ac.ir/article_12414_d9e98d05372560e2c17000bde50cba87.pdf |
| Summary: | N-tree Distance Sampling (NTDS) is a well-known distance sampling method which is considered as cost-and time effective compared to fixed-Radius Plots. This study was conducted across an area of 36.40 ha in Helen forest reserve in Chaharmahal and Bakhtiari Province. The study area mostly comprises of natural, old-growth Brant`s oak (Quercus brantii) stands. Here, the stands were first fully callipered. Two estimators of Moore and Kleinn-Vilcko sample plot methods were applied to derive the diagnostic measures of relative bias (RB) and relative root mean square error (RRMSE) for a number of 2 to 12 trees. For each estimator, 30 repeats with each encompassing 50 Sample points were selected. The results showed the fixed plot sampling (FPS) to be of higher performance in the clumpy-distributed trees within stands with 154.25 trees per ha. In addition, the Kleinn-Vilcko estimator was shown to be most efficient for N ≥ 5 trees. Due to its high error rate, the Moore estimator yet returned poor performances in density estimation across the study area. |
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| ISSN: | 1735-0883 2383-1146 |