UC Merced

The primary objective of this study is to create baseline soil salinity maps using an electromagnetic device, Geonics' EM-38. These soil salinity maps will be used to semi-quantitatively assess how the current soil salinity affects plant productivity and how micro-topography affects soil salinity. Based on these semi-quantitative analyses, recommendations on how to mitigate the high saline areas will be proposed to aid wetland managers in the management of these ponds. Given that the use of the EM-38 in wildland and wetland systems is novel and innovative, notes and suggestions of procedures will be summarized in order to aid in future mapping efforts. It is hypothesized that the highest concentrations of salts will be in isolated depressions and areas of the pond that have higher elevation, both of which experience minimal water flows. The lowest concentrations of salts will be in areas with high water flow such as the swales. Swamp timothy productivity will be negatively affected with increasing soil salinity. A secondary objective is to investigate the ability of spectral reflectance values and various vegetation indices to predict swamp timothy seed productivity within the wetland study sites. The high resolution imagery, as described in section 1.5.1, will be used to explore these principles.