Peatlands of the madre de dios river of peru: Distribution, geomorphology, and habitat diversity

Abstract

We present results of research concerning the distribution, depth, volume, geomorphology, and habitat diversity of peatlands in the southern Peruvian Amazon. We identified 295 peatlands covering 294 km2 and ranging in size from 10 to 3,500 ha. Individual peatlands were mostly restricted to the meander belt of the Madre de Dios River. Mean peat depth was 2.54±1.84 m (n0429), however we encountered depths to 9 m and 10% of the measurements exceeded 5 m.We developed a calibration factor to calculate peat volume across the study area, estimating total peat volume within 295 peatlands at 657±119 Mm3. An interpolated depth map of subsurface morphology of a single peatland showed that fluvial features were well-conserved beneath several meters of peat and three distinct subsurface geomophological units defined by peat depth could be identified: the Primary Basin, Secondary Basin, and Intrabasin flats. Subsurface geomorphology resulted in increased within-habitat heterogeneity and explained 35% of the variation of pixel values extracted from Landsat™ imagery. Representing a hydrological link from elevated uplands to the lower floodplains, peatlands in Madre de Dios are especially threatened on local scales by habitat alteration in the uplands and gold mining in the floodplains. © Society of Wetland Scientists 2012.