Flow impacts on P and OM Cycling in the Ridge and Slough:

Transcription

1 Flow impacts on P and OM Cycling in the Ridge and Slough: Lessons from landscape budgets in the Decomp Physical Model and Shark Slough, ENP Colin Saunders South Florida Water Management District Greater Everglades Ecosystem Restoration Coral Springs, FL. April, 2017

2 DPM co-authors S. Newman E. Tate-Boldt E. Cline C. Zweig M. Manna C. Hansen F. Sklar L. Larsen R. Jaffe P. Regier D. Ho B. Rosen J. Harvey J. Choi J. Lewis

3 Outline 1. Introduction and DPM findings 2. Objectives 3. Approach: Phosphorus Mass Balance 4. Results 5. Summary and Next Steps

4 Restoring Connectivity to the Everglades Landscape South Flow direction North Modified from McVoy et al. 2011

5 Restoring Connectivity to the Everglades Landscape S. Hagerthey et al Multiple regime shifts in a subtropical peatland: community-specific thresholds to eutrophication. Ecol Mon J. Sirota et al Organic-matter loading determines regime shifts and alternative states in an aquatic ecosystem. PNAS Modified from McVoy et al. 2011

6 What is the Decomp Physical Model (DPM)? WCA3A S-152 RS1 L67-A WCA3B S1 Uncertainty 1: Do high velocities (>2 cm/s) generate sediment movement needed to restore the ridge and slough topography? Uncertainty 2: To what extent does sheetflow alter P and OM cycling and ultimately foodwebs RS2 DPM Flow-way UB3 UB2 DB3 UB1 DB2 DB1 5

7 DPM Hydrologic Flow Fields w,, Nov-Jan : Travel Distance per per 3-hr (1-km max) S-152 Flows did not follow the ecologically preferred (north-south) pattern Velocities ranged from cm s -1 High flows (2-5 cm s -1 ) were limited to ~500-m CANAL BACKFILL 6

8 Tracking Floc Movement and Deposition Tracking particle movement: slough to ridge S-152 Velocity 2-5 cm s -1 RS1 Slough Center Ridge-Edge Slough-Edge Velocity 1-2 cm s -1

9 Flow alters slough structure Mechanisms by which flow alters landscape Periphyton/Utricularia collapses / slough clearing (periphyton disappears) Velocities increase with sustained flow Floc disappears 8

10 Other flow observations Velocity, sediment transport increase with flow duration Sediment traps, Flowtracker ADVs (C. Saunders) Aquatic primary production & respiration reduced Metabolism studies (Tate-Boldt et al., GEER) Floc more erodible, more labile(?) with flow Benthic flume (S. Newman, M. Manna) Molecular biomarkers (R. Jaffe, P. Regier) Algal taxonomy (B. Rosen) 9

11 2. Objectives for DPM data synthesis: Phosphorus mass balance model S-152 High Flow (0-500 m) Medium Flow ( m) Low-Flow ( m) Which flow-mediated mechanisms are needed to explain observed changes in ecosystem P stocks (mainly water TP and floc P)? Using a linked mass balance, to what extent does flow impact P cycling beyond 500-m? How fast do changes migrate downstream? 10

12 3. Approach P budgets of Landscape Ribbons Phosphorus budget: SRS-2 slough inflow floc atmos. dep water outflow peri/sav ` Noe & Childers (2007) summarized P stocks, fluxes for ridge & slough habitats, Everglades-wide FCE LTER data to generate ridge, slough budgets for conceptual landscape ribbons in ENP: near-canal, interior, coastal ecotone soil deadag cons Highlights most important fluxes, discrepancies among data, data gaps, & uncertainties roots liveag 11

13 3. Approach P budgets of Landscape Ribbons Phosphorus budget: SRS-2 slough Noe & Childers (2007) summarized P stocks, fluxes for ridge & slough habitats, Everglades-wide Periphyton P Uptake (gp m -2 yr -1 ) ** Uptake max * K TP Water TP (ug L -1 ) ** Noe et al., 2002 & FCE LTER data * Hwang et al., 1998 FCE LTER data to generate ridge, slough budgets for conceptual landscape ribbons in ENP: near-canal, interior, coastal ecotone Highlights most important fluxes, discrepancies among data, data gaps, & uncertainties Dynamic budget models in STELLA to compare observed & predicted time series of P stocks & fluxes 12

14 Application to DPM landscape S-152 High Flow 2-5 cm/s RS1 Z5-3 Z4-1 RS2 Medium Flow 1-2 cm/s Low-Flow <1 cm/s Slough habitats in three 500-m landscape ribbons High-, Medium-, Low-Flow Simulation period Baseline Years 3 Flow Events Drivers: Daily water depth & velocity Upstream TP (S152 inflow TP) Observed vs predicted time series Periphyton P (g P m -2 ) Floc P (g P m -2 ) Water TP, TPP (ug/l) Sediment transport (g cm -2 FA d -1 ) 13

15 Application to the DPM study High Flow Slough S-152 High Flow 2-5 cm/s Control atmos. dep inflow outflow Water Medium Flow 1-2 cm/s Low-Flow <1 cm/s floc soil peri cons deadag roots liveag 14

16 Application High Flow Conditions inflow floc atmos. dep outflow Diss-P Partic-P Peri/SAV soil cons deadag roots liveag 15

17 Application High Flow Conditions Flow-mediated Mechanisms Peri/SAV sinking inflow atmos. dep outflow Diss-P Partic-P floc Peri/SAV soil cons deadag roots liveag 15b

18 Application High Flow Conditions Flow-mediated Mechanisms Peri/SAV sinking Peri/SAV stays low (-uptake, +turnover) inflow floc atmos. dep outflow Diss-P Partic-P Peri/SAV soil cons deadag roots liveag 15c

19 Application High Flow Conditions Flow-mediated Mechanisms Peri/SAV sinking Peri/SAV stays low (-uptake, +turnover) Floc more erodible (+turnover) inflow floc soil atmos. dep outflow Diss-P Partic-P Peri/SAV cons deadag roots liveag 15d

20 Application High Flow Conditions Floc more erodible (+turnover) floc soil atmos. dep Flow-mediated Mechanisms inflow outflow Peri/SAV sinking Peri/SAV stays low (-uptake, +turnover) Partic-P into ridge Diss-P Partic-P deadag Peri/SAV cons roots liveag 15e

21 Application High Flow Conditions floc soil atmos. dep Flow-mediated Mechanisms inflow outflow Peri/SAV sinking Peri/SAV stays low (-uptake, +turnover) Floc more erodible (+turnover) Partic-P into ridge? Diss-P Partic-P Peri/SAV cons Partic-P settling reduced deadag roots liveag 15f

22 4. Results Baseline (no-flow) depth (cm) or P stocks (g m-2) Depth & Peri-P Floc-P P stocks (g m-2) Model Model Obs (RS1) Obs (C1) (RS1) Obs (C1) Water TP & TPP Sediment Transport 20 Model TP Model TPP g L g cm-2 FA d-1 0 1/1/12 1/1/13 1/1/14 1/1/15 1/1/16 1/1/12 1/1/13 1/1/14 1/1/15 1/1/

23 depth (cm) or P stocks (g m-2) Results All Flow Mechanisms (what we expected to see) Depth & Peri-P Water TP & TPP Model TP Model TPP Floc-P Sediment Transport P stocks (g m-2) Model Model Obs (RS1) Obs (C1) (RS1) Flow Obs (C1) event g L g cm-2 FA d-1 0 1/1/12 1/1/13 1/1/14 1/1/15 1/1/16 1/1/12 1/1/13 1/1/14 1/1/15 1/1/

24 4. Results All Flow Mechanisms depth (cm) or P stocks (g m-2) Depth & Peri-P Floc-P P stocks (g m-2) Model Model Obs (RS1) Obs (C1) (RS1) Flow Obs (C1) event Water TP & TPP Sediment Transport 20 Model TP Model TPP g L g cm-2 FA d-1 0 1/1/12 1/1/13 1/1/14 1/1/15 1/1/16 1/1/12 1/1/13 1/1/14 1/1/15 1/1/

25 4. Results Fitted Model depth (cm) or P stocks (g m-2) Depth & Peri-P Floc-P P stocks (g m-2) Model Model Obs (RS1) Obs (C1) (RS1) Flow Obs (C1) event Water TP & TPP Sediment Transport 20 Model TP Model TPP g L g cm-2 FA d-1 0 1/1/12 1/1/13 1/1/14 1/1/15 1/1/16 1/1/12 1/1/13 1/1/14 1/1/15 1/1/

26 4. Results What mechanisms are needed to fit to the data? Flow-mediated Mechanisms atmos. dep ++uptake, ++turnover Post-flow: uptake, turnover remain high Peri/SAV collapses Peri/SAV reduced (-uptake, +turnover) Floc more erodible, potentially more labile floc Dissolv-P Partic-P Peri/SAV Capture Partic-P into ridge soil cons Partic-P Settling reduced Partic-P capture (veg) deadag roots liveag 19

27 Objective 2 Linked P Budgets S-152 High Flow 2-5 cm/s Medium Flow 1-2 cm/s High Flow Slough atmos. dep Dissolv-P Partic-P Moderate Flow Slough atmos. dep Water Low-Flow <1 cm/s floc Peri/SAV Capture floc peri/sav soil cons soil cons deadag deadag roots liveag roots liveag 20

28 Summary and Next Steps Mass balance provides a common currency to integrate physical and biological responses to flow Although flow clears out sloughs, floc-p stocks doubled ** Preliminary ** model suggests 2-20x increase in periphyton uptake and turnover (including post-flow) contrary to aquatic metabolism modeing (Tate-Boldt et al.) and periphyton incubations (Newman et al.) consistent with increases in periphyton TP on periphytometers, including post-flow effects (Newman et al.) synthesis with other DPM data still in progress 22

29 DPM Science Team F. Sklar C. Saunders S. Newman C. Coronado C. Zweig S. Hagerthey L. Larsen D. Watts J. Harvey B. Rosen M. Dickman J. Choi J. Lewis E. Tate-Boldt M. Manna E. Cline C. Hansen M. Blaha F. Santarmaria J. Trexler M. Bush S. Bornhoeft M. Ross P. Ruiz A. Swartz J. Gomez K. Skalak L. Soderqvist R. Jaffe D. He P. Regier B. Jara J. Sah S. Baisden S. Wilcox N. Garratt D. Crawford T. Kinsey D. George D. Ho D. Hickman

30 4. Results Baseline (no-flow) depth (cm) or P stocks (g m-2) Depth & Peri-P Floc-P P stocks (g m-2) Model Model Obs (RS1) Obs (RS1) (C1) Obs (C1) Water TP & TPP Sediment Transport 20 Model TP Model TPP g L g cm-2 FA d-1 0 1/1/12 1/1/13 1/1/14 1/1/15 1/1/16 1/1/12 1/1/13 1/1/14 1/1/15 1/1/ b

31 Linked Moderate Flow Floc P P stocks (g m-2) Linked Baseline-Flow Model Model Obs (RS1) Obs (RS1) (C1) Obs (C1) Linked High-Flow P stocks (g m-2) 0.0 1/1/12 1/1/13 1/1/14 1/1/15 1/1/16 1/1/12 1/1/13 1/1/14 1/1/15 1/1/