Improving estimates of tropical peatland area, carbon storage, and greenhouse gas fluxes

I T Lawson,J Wheeler,J Kaduk,B M M Wedeux,J Hoyos-Santillan,F C H Draper,K H Roucoux,D Large,S Sjögersten,P N Z B P Hassan,S E Page,A Boom,M Waldram,T J Kelly,K Tansey,P Aplin,W Murphy,G Dargie

doi:10.1007/s11273-014-9402-2

Abstract

Our limited knowledge of the size of the carbon pool and exchange fluxes in forested lowland tropical peatlands represents a major gap in our understanding of the global carbon cycle. Peat deposits in several regions (e.g. the Congo Basin, much of Amazonia) are only just beginning to be mapped and characterised. Here we consider the extent to which methodological improvements and improved coordination between researchers could help to fill this gap. We review the literature on measurement of the key parameters required to calculate carbon pools and fluxes, including peatland area, peat bulk density, carbon concentration, above-ground carbon stocks, litter inputs to the peat, gaseous carbon exchange, and waterborne carbon fluxes. We identify areas where further research and better coordination are particularly needed in order to reduce the uncertainties in estimates of tropical peatland carbon pools and fluxes, thereby facilitating better-informed management of these exceptionally carbon-rich ecosystems.

Highlights

Most peat in the tropics is located in the lowland humid forests of Southeast Asia, Amazonia, Central
In part 1, we focus on emerging remote sensing technologies which, alongside appropriate measurements on the ground, can improve our ability to map peatland extent
The overarching need is for a more coordinated approach to data collection and sharing. This is necessary to allow us to address the most fundamental, large-scale questions about how much peat exists in the tropics, and where it is; and about the role of tropical peatlands in the global carbon cycle, today and in the future

Summary

Introduction

Most peat in the tropics is located in the lowland humid forests of Southeast Asia, Amazonia, CentralAmerica and equatorial Africa (Figure 1). Page et al (2011b) estimated the extent of tropical peatlands at 441,000 km and their carbon (C) pool at 81.7–91.9 Gt C. Page et al (2011b) estimated the extent of tropical peatlands at 441,000 km and their carbon (C) pool at 81.7–91.9 Gt C. Accidental burning, due mainly to small-scale land clearance fires getting out of control, can lead to very large peat losses over weeks or months (e.g. in the exceptional El Niño year of 1997, CO2 emissions from Southeast Asian peatland fires were equivalent to 13–40% of total global fossil fuel emissions: Page et al 2002). Whilst a large proportion of lost tropical forest biomass can be recovered within decades in secondarygrowth forest (Letcher and Chazdon 2009), restoration of peatland carbon stocks to pre-disturbance levels would take thousands of years

Objectives

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Conclusion