Location: Dale Bumpers Small Farms Research CenterTitle: Identification of potential carbon sinks by combining remote sensing, soil data and digital soil mapping of wetlands
|LIBOHOVA, ZAMIR - Natural Resources Conservation Service (NRCS, USDA)|
Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 12/18/2017
Publication Date: N/A
Technical Abstract: Wetlands are a major component of natural system that perform functions like water cleaning and carbon storage. There are three features present in wetland definitions: (i) shallow water/saturated conditions – topographic wetness index (TWI), (ii) unique soils – poorly and very poorly drained soils (PD&VPD), and (iii) vegetation adapted to wet conditions – Hyperion reflectance. The objective of this study was to use remote sensing in combination with soil information in a Digital Soil Mapping (DSM) platform to (i) identify potential wetlands in the glaciated landscapes of northern Indiana; and (ii) asses their contribution as potential C sink. In this study potential wetlands must meet the first two criteria regardless of their current land use. The study area size was 47 km2 located in Tippecanoe county, Indiana. Based on TWI and PD&VPD, 25% of the area was identified as potential wetlands, while 10% based on Hyperion spectral signature only. The intersection of Hyperion reflectance with TWI and PD&VPD decreased potential wetlands to 2.8 %. According to the National Wetland Inventory (NWI), 9.9% of the area is wetland of which 4.1 % fresh water forest shrubs/emergent vegetation and 0.5% lakes and ponds. Since the objective of our study was identification of potential wetlands, existing lakes, ponds and streams were excluded from the analysis. The spectral reflectance from the vegetation on the edges of these water bodies was included. The addition of Hyperspectral signature was very restrictive. However, its use as a criteria combined with DSM and soil information is promising. The PD&VPD soils (Mollisols) stored 67 Mg ha-1 SOC for the 0-25 cm soil thickness, compared with 32 Mg ha-1 SOC for the surrounding upland (Alfisols). Depressions dominated by Histosols stored 188 Mg ha-1 SOC or 83% and 64% more compared to Alfisols and Mollisols. This represents the potential increase in soil C storage.