Soil plays a major role in wetland effects on watershed transport of phosphorus and nitrogen which drive the formation of Harmful Algal Blooms. Determining soil chemical characteristics is important for estimating and predicting wetland performance and understanding how performance can be improved. Soil in wetlands is spatially heterogeneous and unlike water, is relatively stationary and doesn’t mix as water does. An important question for evaluating soil function in wetlands is where and how many samples must be collected to generate an estimate of soil chemical composition with the desired level of confidence and accuracy. To answer this question we applied geostatistical techniques to the analysis of high-density soil sampling of pools in five wetland projects with a variety of conditions, hydroperiods, vegetation, and soil characteristics. We will summarize the results and explain how they can be used to decide the minimum number of soil samples that should be collected to achieve different levels of accuracy. We will also explain the limitations and give examples of the variation and considerations for applying this to wetland monitoring.
