REPLY 10.1002/2013WR015033 Reply to comment by John M. Juston et al. on ‘‘Spatial and temporal phosphorus distribution changes in a large wetland ecosystem’’ Xavier Zapata-Rios 1,2 , Rosanna G. Rivero 1,3 , Ghinwa M. Naja 1 , and Pierre Goovaerts 4 1 Science Department, Everglades Foundation, Palmetto Bay, Florida, USA, 2 Department of Hydrology and Water Resources, University of Arizona, Tucson, Arizona, USA, 3 College of Environment and Design, University of Georgia, Athens, Georgia, USA, 4 BioMedware, Inc., Ann Arbor, Michigan, USA 1. Introduction The authors thank Juston et al. [2014] for their contribution and comments discussing the analysis and methodologies used in Zapata-Rios et al. [2012] (referred to henceforth as ZR2012). The authors are listing below their responses to Juston et al. [2014] comments organized in sections that follow the original struc- ture of the comments. 2. Methodology Juston et al. [2014] pointed out that ZR2012 undermined their intentions with critical methodological faults, and followed up with outdated and potentially misleading conclusions. We beg to disagree with this statement since data interpolation of water and soil samples for spatial analysis is a well established and accepted methodology used in books and published scientific papers [Cressie, 1993; Goovaerts, 1997; Murphy et al., 2009]. The 49 stations mentioned in Juston et al. [2014] were only used for the analysis of long- and short-term changes in total phos- phorus (TP) concentrations during the period between 1995 and 2007 and only stations having complete data available during this time frame were included. However, the maps presented in Figure 2 of ZR2012 were devel- oped using more data points and the stations were listed and explained in Table 1 of ZR2012. We are also attaching here new maps showing the station locations for clarification per season and per year (Figure 1). More- over, data density considerations for the selected years were extensively discussed in ZR2012. In their comments, Juston et al. [2014] offered an alternative trend analysis that, according to the authors, sug- gested a more accurate and contemporary view of improving conditions in water TP concentrations through- out much of the Everglades Protection Area (EvPA). However, this alternative analysis did not account for the spatial distribution and geostatistical principles applied in ZR2012, methodology used in other studies addressing TP concentrations in the Everglades, and accounting for both, spatial and temporal variability [Bru- land et al., 2007; DeBusk et al., 2001; Grunwald et al., 2008; Rivero et al., 2007]. Those studies were developed to predict soil data exhibiting significant variability while addressing important parameters also considered in ZR2012, such as density of sampling, spatial distribution, cross validation, and many other factors, as exten- sively described in the original Methodology section of ZR2012. Moreover, in their investigation, Juston et al. [2014] failed to provide a spatiotemporal analysis of phosphorus concentrations in the Everglades and as a result, their spatial and temporal trends and change analyses in this ecosystem are not conclusive. Indeed, Fig- ures 3 and 4 of Juston et al. [2014] are not enough evidence of spatiotemporal changes in the Everglades. Aver- aging values from spatially widespread and diverse areas is not the best way to conduct a spatiotemporal analysis as this would not account for spatial variability and for the effect of spatial autocorrelation. 3. Data Availability and Outliers Juston et al. [2014] argued that: (a) ZR2012 omitted SFER (South Florida Environmental Report) data (SFWMD—South Florida Water Management District Water Resources Division), and (b) ZR2012 does not specifically address the temporal characteristics of EvPA data, or how their data treatment may have influ- enced map interpolation results (single grab sample (n 5 1) treated as being equally representative as sta- tion with multiple samples (e.g., n 5 6 or 8)). This article is a reply to Juston et al. [2014] doi: 10.1002/2013WR014462. Correspondence to: R. G. Rivero, rrivero@uga.edu Citation: Zapata-Rios, X., R. G. Rivero, G. M. Naja, and P. Goovaerts (2014), Reply to comment by John M. Juston et al. on ‘‘Spatial and temporal phosphorus distribution changes in a large wetland ecosystem,’’ Water Resour. Res., 50, 5367–5371, doi:10.1002/ 2013WR015033. Received 12 NOV 2013 Accepted 23 APR 2014 Accepted article online 29 APR 2014 Published online 5 JUN 2014 ZAPATA-RIOS ET AL. V C 2014. American Geophysical Union. All Rights Reserved. 5367 Water Resources Research PUBLICATIONS