Re-estimating the changes and ranges of forest biomass carbon in China during the past 40 years

Abstract Background In recent decades the future of global forests has been a matter of increasing concern, particularly in relation to the threat of forest ecosystem responses under potential climate change. To the future predictions of these responses, the current forest biomass carbon storage (FCS) should first be clarified as much as possible, especially at national scales. However, few studies have introduced how to verify an FCS estimate by delimiting the reasonable ranges. This paper addresses an estimation of national FCS and its verification using two-step process to narrow the uncertainty. Our study focuses on a methodology for reducing the uncertainty resulted by converting from growing stock volume to above- and below-ground biomass (AB biomass), so as to eliminate the significant bias in national scale estimations. Methods We recommend splitting the estimation into two parts, one part for stem and the other part for AB biomass to preclude possible significant bias. Our method estimates the stem biomass from volume and wood density (WD), and converts the AB biomass from stem biomass by using allometric relationships. Results Based on the presented two-step process, the estimation of China’s FCS is performed as an example to explicate how to infer the ranges of national FCS. The experimental results demonstrate a national FCS estimation within the reasonable ranges (relative errors: + 4.46% and − 4.44%), e.g., 5.6–6.1 PgC for China’s forest ecosystem at the beginning of the 2010s. These ranges are less than 0.52 PgC for confirming each FCS estimate of different periods during the last 40 years. In addition, our results suggest the upper-limits by specifying a highly impractical value of WD (0.7 t∙m− 3) on the national scale. As a control reference, this value decides what estimate is impossible to achieve for the FCS estimates. Conclusions Presented methodological analysis highlights the possibility to determine a range that the true value could be located in. The two-step process will help to verify national FCS and also to reduce uncertainty in related studies. While the true value of national FCS is immeasurable, our work should motivate future studies that explore new estimations to approach the true value by narrowing the uncertainty in FCS estimations on national and global scales.

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Correcting the overestimate of forest biomass carbon on the national scale

Methods in Ecology and Evolution ◽

10.1111/2041-210x.12505 ◽

2015 ◽

Vol 7 (4) ◽

pp. 447-455 ◽

Cited By ~ 5

Author(s):

Xiaolu Zhou ◽

Xiangdong Lei ◽

Changhui Peng ◽

Weifeng Wang ◽

Carl Zhou ◽

...

Keyword(s):

Forest Biomass ◽

Biomass Carbon ◽

National Scale

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Understanding the uncertainty in global forest carbon turnover

Biogeosciences ◽

10.5194/bg-17-3961-2020 ◽

2020 ◽

Vol 17 (15) ◽

pp. 3961-3989 ◽

Cited By ~ 1

Author(s):

Thomas A. M. Pugh ◽

Tim Rademacher ◽

Sarah L. Shafer ◽

Jörg Steinkamp ◽

Jonathan Barichivich ◽

...

Keyword(s):

Large Scale ◽

Tree Mortality ◽

Forest Biomass ◽

Turnover Time ◽

Biomass Carbon ◽

Carbon Turnover ◽

Turnover Rates ◽

Wide Range ◽

The Future ◽

Total Turnover

Abstract. The length of time that carbon remains in forest biomass is one of the largest uncertainties in the global carbon cycle, with both recent historical baselines and future responses to environmental change poorly constrained by available observations. In the absence of large-scale observations, models used for global assessments tend to fall back on simplified assumptions of the turnover rates of biomass and soil carbon pools. In this study, the biomass carbon turnover times calculated by an ensemble of contemporary terrestrial biosphere models (TBMs) are analysed to assess their current capability to accurately estimate biomass carbon turnover times in forests and how these times are anticipated to change in the future. Modelled baseline 1985–2014 global average forest biomass turnover times vary from 12.2 to 23.5 years between TBMs. TBM differences in phenological processes, which control allocation to, and turnover rate of, leaves and fine roots, are as important as tree mortality with regard to explaining the variation in total turnover among TBMs. The different governing mechanisms exhibited by each TBM result in a wide range of plausible turnover time projections for the end of the century. Based on these simulations, it is not possible to draw robust conclusions regarding likely future changes in turnover time, and thus biomass change, for different regions. Both spatial and temporal uncertainty in turnover time are strongly linked to model assumptions concerning plant functional type distributions and their controls. Thirteen model-based hypotheses of controls on turnover time are identified, along with recommendations for pragmatic steps to test them using existing and novel observations. Efforts to resolve uncertainty in turnover time, and thus its impacts on the future evolution of biomass carbon stocks across the world's forests, will need to address both mortality and establishment components of forest demography, as well as allocation of carbon to woody versus non-woody biomass growth.

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Separating Regressions for Model Fitting to Reduce the Uncertainty in Forest Volume-Biomass Relationship

Forests ◽

10.3390/f10080658 ◽

2019 ◽

Vol 10 (8) ◽

pp. 658

Author(s):

Caixia Liu ◽

Xiaolu Zhou ◽

Xiangdong Lei ◽

Huabing Huang ◽

Carl Zhou ◽

...

Keyword(s):

Field Data ◽

Forest Biomass ◽

Model Fitting ◽

Graphical Analysis ◽

Biomass Estimation ◽

Allometric Relationship ◽

Stem Biomass ◽

Intermediate Variable ◽

Growing Stock ◽

Pseudo Data

The method of forest biomass estimation based on a relationship between the volume and biomass has been applied conventionally for estimating stand above- and below-ground biomass (SABB, t ha−1) from mean growing stock volume (m3 ha−1). However, few studies have reported on the diagnosis of the volume-SABB equations fitted using field data. This paper addresses how to (i) check parameters of the volume-SABB equations, and (ii) reduce the bias while building these equations. In our analysis, all equations were applied based on the measurements of plots (biomass or volume per hectare) rather than individual trees. The volume-SABB equation is re-expressed by two Parametric Equations (PEs) for separating regressions. Stem biomass is an intermediate variable (parametric variable) in the PEs, of which one is established by regressing the relationship between stem biomass and volume, and the other is created by regressing the allometric relationship of stem biomass and SABB. A graphical analysis of the PEs proposes a concept of “restricted zone,” which helps to diagnose parameters of the volume-SABB equations in regression analyses of field data. The sampling simulations were performed using pseudo data (artificially generated in order to test a model) for the model test. Both analyses of the regression and simulation demonstrate that the wood density impacts the parameters more than the allometric relationship does. This paper presents an applicable method for testing the field data using reasonable wood densities, restricting the error in field data processing based on limited field plots, and achieving a better understanding of the uncertainty in building those equations.

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Forest biomass-carbon variation affected by the climatic and topographic factors in Pearl River Delta, South China

Journal of Environmental Management ◽

10.1016/j.jenvman.2018.11.130 ◽

2019 ◽

Vol 232 ◽

pp. 781-788 ◽

Cited By ~ 7

Author(s):

Gang Wang ◽

Dongsheng Guan ◽

Ling Xiao ◽

M.R. Peart

Keyword(s):

South China ◽

Pearl River Delta ◽

Forest Biomass ◽

River Delta ◽

Pearl River ◽

Biomass Carbon ◽

Topographic Factors

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Problems in the inventory of the belowground forest biomass carbon stocks

Forest - Rivista di Selvicoltura ed Ecologia Forestale ◽

10.3832/efor0415-0030542 ◽

2006 ◽

Vol 3 (4) ◽

pp. 542-554 ◽

Cited By ~ 3

Author(s):

B Lasserre ◽

M Marchetti ◽

R Tognetti

Keyword(s):

Forest Biomass ◽

Carbon Stocks ◽

Biomass Carbon

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The Circle of Societal Death

10.7591/cornell/9781501755903.003.0049 ◽

2021 ◽

pp. 172-200

Author(s):

Samuel Cohn

Keyword(s):

Economic Growth ◽

Large Scale ◽

Twelve Step ◽

Economic Decline ◽

Government Officials ◽

Education Society ◽

Step Process ◽

Self Defense ◽

The Future ◽

And Performance

This chapter illustrates the twelve-step process known as the Circle of Societal Death. Assume some externally caused source of economic decline. This will lower governmental functioning by lowering tax revenues. Low government revenues and performance demoralize government functionaries. When government officials are powerless and irrelevant, there is no reason for them not to become corrupt; corruption in the police and the judiciary leads to crime. Once people become genuinely worried about personal security, networks of social cooperation contract. This means they delegitimize everything outside the group, especially the state, and everything becomes defined in ethnic terms. As both crime and ethnic conflict escalate, young people are drawn into self-defense activity. The movement of youth from investment in the future to coercion in the present mortgages the economic growth of the future. As youth are pulled out of education, society becomes less intellectually capable. Fundamental engineering, business, and technological skills become lost, and projects of large-scale coordination suffer. As projects of large-scale coordination become nonviable, economic growth declines. This circle of death also works in reverse.

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What is the value of digital health?

European Journal of Public Health ◽

10.1093/eurpub/ckaa165.969 ◽

2020 ◽

Vol 30 (Supplement_5) ◽

Author(s):

A Jani

Keyword(s):

Digital Health ◽

Tertiary Prevention ◽

Resource Utilisation ◽

Market Place ◽

True Value ◽

The Future ◽

Care Systems ◽

Eu Commission ◽

The Eu

Abstract The panellist Anant Jani will discuss about: What is the value of digital health? There is much hope and hype surrounding the potentially transformative effect that digital health tools can have in health and care systems but it is very difficult to ascertain the true value that digital health tools currently deliver or could deliver in the future. Compounding this uncertainty is the diverse, large and ever-changing digital health landscape - there are currently over 300,000 health and care apps on the market place in comparison to the less than 2000 drugs health and care systems normally have to deal with. In this session, we highlight how the quadruple value framework, recently endorsed by the EU Commission, can be used to help rationalize the digital health ecosystem by promoting the interventions that have the greatest potential to promote primary, secondary or tertiary prevention while optimising resource utilisation.

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