Gabor, Rachel听1听;听Russell, Nina听2听;听Blum, Alex听3听;听Eilers, Katie听4听;听McKnight, Diane听5
1听INSTAAR and Environmental Studies Program, University of Colorado, Boulder, CO, 80302, USA
2听INSTAAR and Environmental Studies Program, University of Colorado, Boulder, CO, 80302, USA
3听United States Geological Survey, Boulder,80303 CO, USA
4听Department of Ecology and Evolutionary Biology, University of Colorado, Boulder, CO, 80302, USA
5听INSTAAR and Department of Civil, Environmental, and Architectural Engineering, University of Colorado, Boulder, CO, 80302, USA
As worldwide trends of increasing DOM concentrations continue to be reported, and their source investigated (Monteith et al., 2007), it is becoming more important to elucidate the link between soluble organic matter in a catchment and dissolved organic matter in the corresponding aquatic system. Within the Boulder Creek Critical Zone Observatory, soil samples were collected along transects and from several deep pits on both south- and north-facing slopes in Boulder Canyon, Colorado. The extractable DOM from each sample was leached with 0.5 M potassium sulfate (Jones and Willett, 2006) and both whole water and fulvic acid fractions were analyzed with UV-VIS and fluorescence spectroscopy. Parallel factor analysis (PARAFAC) was then used to model the fluorescence excitation-emission matrices to characterize the chemical properties of the DOM (Cory and McKnight, 2005). While available soluble organic matter was significantly higher at the surface and tended to steadily decrease with depth, amount and chemical character did vary with soil horizon. These results were compared to the chemical signature of the DOM from the stream the catchment feeds. Organic matter from the surface was much more similar to the stream DOM than matter near bedrock. The soil samples from both pits and transects were also analyzed for mineralogical content and microbe population and this data will be used to develop a clear picture of the source, transport, and role of organic matter within both terrestrial and aquatic sections of the catchment.
Monteith D, Stoddard J, Evans C, de Wit H, Forsius M, Hogasen T, Wilander A, Skjelkvale B, Jeffries D, Vuorenmaa J, Keller B, Kopacek J, Vesely J. Nature, 2007; 450: 537-540.
Jones DL, Willett VB. Soil Biology & Biochemistry, 2006; 38: 991-999.
Cory RM, McKnight DM. Environ. Sci. Tehcnol., 2005; 39: 8142-8149.