Quantitative Comparison of Plant Community Hydrology Using Large-Extent, Long-Term Data

Abstract

Large-extent vegetation datasets that co-occur with long-term hydrology data provide new ways to develop biologically meaningful hydrologic variables and to determine plant community responses to hydrology. We analyzed the suitability of different hydrological variables to predict vegetation in two water conservation areas (WCAs) in the Florida Everglades, USA, and developed metrics to define realized hydrologic optima and tolerances.Using vegetation data spatially co-located with long-term hydrological records, we evaluated 7 variables describing water depth, hydroperiod length, and number of wet/dry events; each variable was tested for 2-, 4-and 10-year intervals for Julian annual averages and environmentally-defined hydrologic intervals. Maximum length and maximum water depth during the wet period calculated for environmentally-defined hydrologic intervals over a 4-year period were the best predictors of vegetation type. Proportional abundance of vegetation types along hydrological gradients indicated that communities had different realized optima and tolerances across WCAs. Although in both WCAs, the trees/shrubs class was on the drier/shallower end of hydrological gradients, while slough communities occupied the wetter/deeper end, the distribution of Cladium, Typha, wet prairie and Salix communities, which were intermediate for most hydrological variables, varied in proportional abundance along hydrologic gradients between WCAs, indicating that realized optima and tolerances are contextdependent.3

Hydrologic restoration in a dynamic subtropical mangrove‐to‐marsh ecotone

“…Although a macrocosm study indicated that C . jamaicense has broad inundation and water depth tolerances and grew best in areas with relatively deep water (maximum depth 94 cm; Serna et al ), field (Childers et al ), mesocosm (Miao & Zou ), and modeling (Gann & Richards ) studies have indicated that C . jamaicense growth and productivity declined with increased water depth and hydroperiod.…”

“…It is therefore probable that salinity at our brackish marsh sites was stressful to this species. Although a macrocosm study indicated that C. jamaicense has broad inundation and water depth tolerances and grew best in areas with relatively deep water (maximum depth 94 cm; Serna et al 2015), field (Childers et al 2006), mesocosm (Miao & Zou 2012), and modeling (Gann & Richards 2015) studies have indicated that C. jamaicense growth and productivity declined with increased water depth and hydroperiod. We were not able to assess the possible role of water depth and flooding duration as factors limiting C. jamaicense growth because we have just a single depth measurement per quadrat per sampling event.…”

The Effect of Disturbance and Freshwater Availability on Lower Florida Keys’ Coastal Forest Dynamics

“…Conditional densities for each community type along each gradient (elevation, distance to coast, May groundwater salinity, and November groundwater salinity) were derived using the package 'sm' in R v.3.1.2 (R core team, 2014). These plots provided information on the proportional abundance of each community compared to all other communities along each point of the environmental gradient (Gann and Richards, 2015).…”