Characterizing peatland carbon balance estimates using freely available Landsat ETM+ data

Abstract

International audienceWe demonstrate the potential of using freely available satellite data from the Landsat ETM+ sensor for generating carbon balance estimates for lowland peatlands. We used a lowland ombrotrophic peatland in the UK as our test site representing a range of peatland conditions. A literature survey was undertaken to identify the simplest classification schema that could be used to distinguish ecohydrological classes for carbon sequestration on the peatland surface. These were defined as: active raised bog, Eriophorum-dominated bog, milled unvegetated peat and drained or degraded bog, with bracken and Carr woodland to define the bog edges. A maximum likelihood classifier (MLC) was used to map the spatial distribution of the six classes on the peatland surface. A Landsat ETM+ band-5 derived brightness-texture layer created using geostatistical methods greatly improved classification accuracies. The results showed the best accuracy of the MLC, when compared to finer scale methods, with Landsat ETM+ bands alone was 74%, which increased to 93% when including the brightness-texture layer. An estimate of carbon sequestration status of the site was performed that showed good agreement with the results of a finer-scale-based estimate. The coarse-scale map estimating −12 000 kg carbon and fine scale map estimating +23 000 kg carbon per annum. We conclude that with further development of our tool, if textural measures are used alongside optical data in MLC, it is possible to achieve good quality estimates of carbon balance status for peatland landscapes. This represents a potentially powerful operational toolkit for land managers and policy makers who require spatially distributed information on carbon storage and release for carbon pricing and effective land management. Copyright © 2014 John Wiley & Sons, Ltd

Long-Term Peatland Condition Assessment via Surface Motion Monitoring Using the ISBAS DInSAR Technique over the Flow Country, Scotland

“…Globally, peatlands store approximately one third of global soil carbon, whilst covering only approximately 3% of the land and freshwater surface [3]. They contribute to the global atmospheric balance of greenhouse gases (GHGs) [4]: intact peatlands are typically net sinks for carbon [5][6][7][8], whereas degraded or disturbed peatlands are known to be carbon sources [9]. They also provide maintenance of biodiversity and protection of water resources [10,11].…”

“…Various methods of surveying peatland surface motion, such as site surveys (PVC tubes, Levelling and Differential Global Positioning system (DGPS), terrestrial LiDAR) and remote sensing via airborne platforms, are limited [9]. Indeed, systematic field measurement of surface motion over large areas is difficult and prohibitively expensive, so few field studies have gathered surface motion data.…”

Estimating Peatland Water Table Depth and Net Ecosystem Exchange: A Comparison between Satellite and Airborne Imagery

“…Eddy covariance towers are also commonly used in the assessment of NEE in peatland ecosystems, with the advantage that these provide a larger footprint than chambers and can provide near-continuous long-term data [19,20]. For large-scale studies, MODIS-derived products have been used to assess NEE [21,22], however, the large spatial resolution (e.g., 0.5-1 km) is inadequate to capture the small-scale heterogeneity of peatlands, along with other known limitations for peatlands such as the errors in the vapor pressure deficit determined from land cover (for GPP estimation) [23,24]. More recently, the potential of Landsat 7 ETM+ data (30 m resolution) was shown for determining peatland classes with high accuracy [23], from which to estimate the C balance.…”

“…For large-scale studies, MODIS-derived products have been used to assess NEE [21,22], however, the large spatial resolution (e.g., 0.5-1 km) is inadequate to capture the small-scale heterogeneity of peatlands, along with other known limitations for peatlands such as the errors in the vapor pressure deficit determined from land cover (for GPP estimation) [23,24]. More recently, the potential of Landsat 7 ETM+ data (30 m resolution) was shown for determining peatland classes with high accuracy [23], from which to estimate the C balance. Given the long history of the Landsat program, a less explored aspect is the development of C models (e.g., NEE) taking advantage of these multitemporal data.…”

Assessing the Land and Vegetation Cover of Abandoned Fire Hazardous and Rewetted Peatlands: Comparing Different Multispectral Satellite Data

“…These specific features are related to human-disturbed rewetted and restored peatlands. However, few studies have addressed this use of data [30][31][32].…”