Dynamics of stand density and self-thinning in Chinese fir plantations: theoretical insights and empirical validation

IntroductionStand density management is essential for adaptive silviculture, thinning decisions, growth modeling, and yield prediction in forestry, particularly for plantations. Despite extensive research on self-thinning rules and the maximum size-density law, significant gaps remain in the biophys...

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Main Authors: Shisheng Long, Siqi Zeng, Guangxing Wang
Format: Article
Language:English
Published: Frontiers Media S.A. 2024-11-01
Series:Frontiers in Plant Science
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Online Access:https://www.frontiersin.org/articles/10.3389/fpls.2024.1444807/full
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author Shisheng Long
Siqi Zeng
Guangxing Wang
author_facet Shisheng Long
Siqi Zeng
Guangxing Wang
author_sort Shisheng Long
collection DOAJ
description IntroductionStand density management is essential for adaptive silviculture, thinning decisions, growth modeling, and yield prediction in forestry, particularly for plantations. Despite extensive research on self-thinning rules and the maximum size-density law, significant gaps remain in the biophysical understanding and validation of the relationships among key stand variables and parameters.MethodsThis study theoretically explored and validated the relationship between maximum size-density and two key metrics: average diameter at breast height (D) and tree height (H). We used time-series data from a 30-year clear-cut, fully stocked Chinese fir plantation, a fast-growing commercial species in China, for validation.ResultsA growth balance status for fully stocked stands was proposed, wherein prior to self-thinning, the growth rate of the stand basal area (G) aligns with that of the average tree height (H), expressed as G'/(G−b0)=H'/H and approaching a constant slope, b1. Generalized maximum size-density and stand density index (SDI) equations were developed: N1.0=A×D−2 and SDI=A⋅D−2 with A=4×(b0+b1H)/π, differing from traditional equations. Additionally, a generalized self-thinning equation, v=kHqN1.0−1 or w=c1HqN1.0−1, was introduced, indicating that in fully stocked stands, tree volume or biomass depends on both tree height and tree count.DiscussionThese findings advance understanding of the maximum size-density law and self-thinning boundary, providing refined tools for managing stand density in Chinese fir plantations.
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spelling doaj-art-e26226a62fae4e09bcffb031d44b86422024-11-15T04:50:02ZengFrontiers Media S.A.Frontiers in Plant Science1664-462X2024-11-011510.3389/fpls.2024.14448071444807Dynamics of stand density and self-thinning in Chinese fir plantations: theoretical insights and empirical validationShisheng Long0Siqi Zeng1Guangxing Wang2Faculty of Forestry, Central South University of Forestry and Technology, Changsha, Hunan, ChinaFaculty of Forestry, Central South University of Forestry and Technology, Changsha, Hunan, ChinaDepartment of Geography and Environmental Resources, Southern Illinois University, Carbondale, IL, United StatesIntroductionStand density management is essential for adaptive silviculture, thinning decisions, growth modeling, and yield prediction in forestry, particularly for plantations. Despite extensive research on self-thinning rules and the maximum size-density law, significant gaps remain in the biophysical understanding and validation of the relationships among key stand variables and parameters.MethodsThis study theoretically explored and validated the relationship between maximum size-density and two key metrics: average diameter at breast height (D) and tree height (H). We used time-series data from a 30-year clear-cut, fully stocked Chinese fir plantation, a fast-growing commercial species in China, for validation.ResultsA growth balance status for fully stocked stands was proposed, wherein prior to self-thinning, the growth rate of the stand basal area (G) aligns with that of the average tree height (H), expressed as G'/(G−b0)=H'/H and approaching a constant slope, b1. Generalized maximum size-density and stand density index (SDI) equations were developed: N1.0=A×D−2 and SDI=A⋅D−2 with A=4×(b0+b1H)/π, differing from traditional equations. Additionally, a generalized self-thinning equation, v=kHqN1.0−1 or w=c1HqN1.0−1, was introduced, indicating that in fully stocked stands, tree volume or biomass depends on both tree height and tree count.DiscussionThese findings advance understanding of the maximum size-density law and self-thinning boundary, providing refined tools for managing stand density in Chinese fir plantations.https://www.frontiersin.org/articles/10.3389/fpls.2024.1444807/fullself-thinning rulestand densitytree heightstand density indexChinese fir plantation
spellingShingle Shisheng Long
Siqi Zeng
Guangxing Wang
Dynamics of stand density and self-thinning in Chinese fir plantations: theoretical insights and empirical validation
Frontiers in Plant Science
self-thinning rule
stand density
tree height
stand density index
Chinese fir plantation
title Dynamics of stand density and self-thinning in Chinese fir plantations: theoretical insights and empirical validation
title_full Dynamics of stand density and self-thinning in Chinese fir plantations: theoretical insights and empirical validation
title_fullStr Dynamics of stand density and self-thinning in Chinese fir plantations: theoretical insights and empirical validation
title_full_unstemmed Dynamics of stand density and self-thinning in Chinese fir plantations: theoretical insights and empirical validation
title_short Dynamics of stand density and self-thinning in Chinese fir plantations: theoretical insights and empirical validation
title_sort dynamics of stand density and self thinning in chinese fir plantations theoretical insights and empirical validation
topic self-thinning rule
stand density
tree height
stand density index
Chinese fir plantation
url https://www.frontiersin.org/articles/10.3389/fpls.2024.1444807/full
work_keys_str_mv AT shishenglong dynamicsofstanddensityandselfthinninginchinesefirplantationstheoreticalinsightsandempiricalvalidation
AT siqizeng dynamicsofstanddensityandselfthinninginchinesefirplantationstheoreticalinsightsandempiricalvalidation
AT guangxingwang dynamicsofstanddensityandselfthinninginchinesefirplantationstheoreticalinsightsandempiricalvalidation