Recent Cattail Expansion and Possible Relationships to Water Management: Changes in Upper Taylor Slough (Everglades National Park, Florida, USA)

Abstract

Recent appearance of cattail (Typha domingensis) within a southern Everglades slough-Upper Taylor Slough (Everglades National Park)-suggests ecosystem eutrophication. We analyze water quality, nutrient enrichment, and water management operations as potential drivers of eutrophication in Upper Taylor Slough. Further, we attempt to determine why surface water phosphorus, a parameter used commonly to monitor ecosystem health in the Everglades, did not serve as an early warning for eutrophication, which has broader implication for other restoration efforts. We found that surface water total phosphorus concentrations generally were below a 0.01 mg L(-1) threshold determined to cause imbalances in flora and fauna, suggesting no ecosystem eutrophication. However, assessment of nutrient loads and loading rates suggest Upper Taylor Slough has experienced eutrophication and that continued total phosphorus loading through a point-source discharge was a major driver. These nutrient loads, combined with increases in hydroperiods, led to the expansion of cattail in Upper Taylor Slough. We recommend other metrics, such as nutrient loads, periphyton and arthropod community shifts, and sediment core analyses, for assessing ecosystem health. Monitoring surface water alone is not enough to indicate ecosystem stress.

Episodic disturbances drive nutrient dynamics along freshwater‐to‐estuary gradients in a subtropical wetland

“…Anthropogenic sources are often the driver of elevated TP concentrations in the Everglades (Surratt et al. , Osborne et al. ).…”

“…Direct discharges into upper TS (UTS) ceased in 1999, coincident with modifications in the headwater that promote surface and subsurface water movement into the slough, which was linked to downward trends in total phosphorus in UTS (Surratt et al. , Kotun and Renshaw ). Presently, the L31W canal and associated retention ponds convey water from more northern portions of the Everglades into the headwater of UTS, and it is part of a canal network supporting a hydrologic barrier on the eastern boundary of the Park with the objective of preventing eastward seepage of water out of the marsh.…”

Long-term (11 years) study of water balance, flushing times and water chemistry of a coastal wetland undergoing restoration, Everglades, Florida, USA

“…Demands for flood control in areas east of ENP have created a difference in water levels between canals bordering the park and lands east of the park resulting in water seeping out of the Everglades (Harvey and McCormick, 2009;Sullivan et al, 2013). Several restoration projects were completed in 2001 with the aim of increasing surface water flows into Taylor Slough, and include raising and lengthening of Taylor Slough Bridge (TSB) and the completion of the S332 detention basins with additional pump stations (Surratt et al, 2012;Sullivan et al, 2013) in the northern portion of Taylor Slough (Fig. 1).…”

“…Earlier studies have determined that the dominant sources of phosphorus into Taylor Slough were from atmospheric deposition (Sutula et al, 2001), and marine sources (Childers et al, 2006) including brackish groundwater discharge Koch et al, 2012). However, ecosystem level changes in northern Taylor Slough, such as the emergence of cattail (Typha domingensis; Surratt et al, 2012) and loss of periphyton biomass suggest nutrient enrichment has been taking place in response to restoration efforts .…”

Wetland Ecosystem Response to Hydrologic Restoration and Management: The Everglades and its Urban-Agricultural Boundary (FL, USA)

“…The goal of these basins is create a hydrologic buffer zone along the Everglades-urban-agricultural boundary by generating diffuse subsurface flow back toward the park. These projects not only have significantly influenced the hydrology of the ENP eastern boundary and the central portion of Taylor Slough, but also affected nutrient loading (Surratt et al 2012) and non-native and invasive species population introductions. The prospect of successfully restoring both water quantity and quality in Taylor Slough is contingent on understanding the ramification of current and past projects in order to inform and adapt future plans.…”