RECOVER MAP 3.1.3.2 Regional Diatribution of Soil Nutrients

Mapping soil quality (nutrients, carbon quality, process dynamics) has recently been undertaken as part of an effort to characterize baseline conditions for performance assessment of Everglades recovery activities. While large scale maps are useful for characterization of spatial pattern, several layers of uncertainty limit use as measures of performance and restoration progress. In particular, large scale maps (Greater Everglades) make specific assumptions about short range variability that are not well quantified. Nugget variance (variability in space over short separation distances) directly confounds use of baseline map products because future spatial sampling will not, in practicality, be at identical locations. If nugget variability is high, then significant uncertainty about ecosystem change arises from not knowing if observed differences arise from intrinsic ecosystem processes or from responses to human management. Our primary objective is to determine the extent to which spatial variability and sampling uncertainty confound ecological change detection. We will use hierarchically nested sampling of soils to establish nugget variability so that change through time can be assigned as observational uncertainty or management response.
A related issue for mapping soil nutrients is greatly improving our understanding of the role of ecosystems in regulating nutrient conditions. Previous mapping efforts regarded space as the primary co-variate with soil nutrients, when there are numerous reasons to expect that ecological type and status are more important descriptors (with spatial autocorrelation playing a secondary, though still significant role). Our second objective is to partition variability in soil nutrient conditions in space and time, by ecosystem type, ecological status, and proximity to canals. We anticipate sampling of soils on a fine scale which traverse ecological transitions will help develop predictive models of the role of ecosystem type, geographic setting and, eventually, spatial structuring in regulating soil processes.