Tree functional types simplify forest carbon stock estimates induced by carbon concentration variations among species in a subtropical area

Huili Wu,Shuai Ouyang,Xiangwen Deng,Xi Fang,Wenhua Xiang,Pifeng Lei

doi:10.1038/s41598-017-05306-z

Huili Wu, Shuai Ouyang + Show 4 more

Open Access

https://doi.org/10.1038/s41598-017-05306-z

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Abstract

Forests contain one of the world’s largest carbon (C) pools and represent opportunities for cost-effective climate change mitigation through programmes such as the United Nations-led “Reducing Emissions from Deforestation and Forest Degradation” Programme (REDD). Generic estimates for the conversion of forest biomass into C stock are not sufficiently accurate for assessing the utility of harvesting forest to offset carbon dioxide emissions, currently under consideration by the REDD Programme. We examined the variation in C concentration among tree species and tree functional types (classified based on leaf morphological and phenological traits) in a subtropical forest and evaluated the effects of these variations on stand-level estimations of C stock. This study was conducted in the Paiyashan Forest State Farm and the Dashanchong Forest Park, Hunan Province, China. C concentrations differed significantly among tree species (P < 0.0001) and were significantly higher in gymnosperm than angiosperm species. Estimations of stand C stocks were similar using either functional types or species- and tissue-specific C concentrations. The use of functional type classification to estimate stand C stock is an effective tool for implementing C sequestration trade and C credit programmes and the UN-REDD Programme in subtropical forests.

Highlights

Forests are essential to the approximately 1.6 billion people who depend on them for food, water, fuel, medicines, tradition and livelihood[1]
We investigated the correlation between five functional traits (WD, mean annual increment of biomass (MAI), relative growth rate (RGR), specific leaf area (SLA) and leaf area (LA)) and C concentrations, while controlling for phylogeny, to test their predictive value in subtropical tree species
Average C concentration was highest in C. lanceolata (47.9 ± 2.5%, mean ± SD) and lowest in A. fortunei (42.3 ± 1.0%) (Table 1)

Summary

Introduction

Forests are essential to the approximately 1.6 billion people who depend on them for food, water, fuel, medicines, tradition and livelihood[1]. As part of UN-based forest C accounting protocols[6, 7], accurate measures of C concentrations for diverse tree species are needed to estimate the size of C stock in forest biomass. Generalizing C concentration based on tree phylogeny (e.g. gymnosperm and angiosperm species) and functional traits may provide a realistic alternative. This possibility is supported by research showing that C concentrations vary between functional types[10, 17, 18]. We investigated the correlation between five functional traits (WD, MAI, RGR, SLA and LA) and C concentrations, while controlling for phylogeny, to test their predictive value in subtropical tree species

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