Graphical estimation of the quadratic mean diameter for fine woody debris in the Hyrcanian Beech forests of Kheiroodkenar, Nowshahr

Articles in Press

Document Type : Research Paper

Authors

1 Agricultural Research, education and extension organization (AREEO)

2 Prof., Department of Forestry, Faculty of Natural Resources, Sari Agricultural Sciences and Natural Resources University, Sari, Iran.

3 Postdoctoral researcher / Sari University of Agricultural Sciences and Natural Resources

10.22034/ijf.2023.360214.1888

Abstract

According to the intergovernmental panel on climate change (IPCC) report, fine woody debris (FWDs) is considered as one of the prominent carbon sinks in forest ecosystems Therefore, estimating the FWDs carbon stock with high accuracy and certainty is so necessary for management. The goal of this study was to introduce quadratic mean diameter (QMD) for the FWDs in order to increase accuracy of their carbon storage estimation. For plots with areas of 20 × 20 m2 were randomly taken within one hectare of pure beech and mixed beech stands in the Hyrcanian forests of Kheiroodkenar in Nowshahr. The diameter of woody debris intersecting with side of the square was measured. Three diameter classes including 1-2.5, 2.5-4.5, 4.5-7.5 cm were separated on the basis of diameter distribution in the stands. Through the graphical estimation (GE) the power function for diameter abundance in each stand was fitted on the basis of measured diameter in the fields. Midpoint areas under the curves were estimated for each diameter class in order to achieve the QMD for FWDs. The power function fitted for each stand was log-transformed and the logarithmic linear model goodness of fit was taken into account for clarifying the function slope. The slope was introduced as main parameter for estimation the under curve by Integral method. The results showed that the QMDs for each diameter class in each stand were slightly higher than values of arithmetic mean and midpoint (median) of each diameter class. Since product of the FWDs number and square of the QMD in each diameter class on the basis of the line-transect method is the main part of the FWDs carbon stock formulation, the values of carbon storage in larger scales would be considerably higher acquired in comparison with introducing other diameter means in the relation.

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Iranian Journal of Forest

Articles in Press, Accepted Manuscript
Available Online from 30 July 2023

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History

  • Receive Date: 06 September 2022
  • Revise Date: 01 April 2023
  • Accept Date: 20 February 2023

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