Biogeochemistry of Wetlands Institute of Food and Agricultural Sciences (IFAS) Biogeochemistry of Wetlands Science and Applications Biogeochemical Indicators Wetland Biogeochemistry Laboratory Soil and Water Science Department University of Florida Instructor K. Ramesh Reddy krr@ufl.edu 9/17/2018 9/17/2018 9/17/2018 WBL WBL 1 1

Biogeochemical Indicators Topic Outline Introduction Concept of indicators Guidelines for Indicator Development Levels of Indicators Sampling protocol an design Data analysis 9/17/2018 WBL 2

Biogeochemical Indicators- Nutrient Impacts/Recovery What physical, chemical, and biological properties are affected by nutrient impacts? What biogeochemical processes are affected by nutrient loading to wetlands? What biogeochemical indicators or endpoints can be measured to determine nutrient impacts/recovery of wetlands? Is there a sufficient range of values for biogeochemical indicators so that they may serve as sensitive indicators of nutrient impact/recovery? Does the distribution and central tendency of biogeochemical indicators discriminate between natural spatial variability and anthropogenic impact in wetlands? 9/17/2018 WBL

Guidelines for Indicator Development Conceptual Relevance: Is the indicator relevant to the assessment question (management concern) and to the ecological resource or function at risk? Feasibility of Implementation: Are the methods for sampling and measuring the environmental variables technically feasible, appropriate, and efficient for use in a monitoring program? Response Variability: Are human errors of measurements and natural variability over time and space sufficiently understood and documented? Interpretation and Utility: Will the indicator convey information on ecological conditions that is meaningful to environmental decision-making? (Jackson et al., 2000, USEPA). 9/17/2018 WBL

Nutrient Cycling in Soil and Water Column Emergent macrophyte Submerged macrophyte Periphyton Water Soil C N P Bioavailable nutrients S 9/17/2018 WBL

Nutrient Impacts on Detritus, Soil, and Water Impacted Unimpacted Hours to Days Water Hours to Days < 2 years < 2 years Detritus < 50-100 years < 10-15 years 0-10 cm > 50-100 years >10- 15 years 10-30 cm 9/17/2018 WBL

Nutrient Impacts in Wetlands External Nutrient Load Periphyton Vegetation Water Internal Nutrient Load Detritus 0-10 cm Microbial/Chemical Processes 10-30 cm 9/17/2018 WBL

Biogeochemical Indicators Spatial Resolution Sensitivity Cost Response Time Micro Macro Scale of measurement of a Process or an Indicator, and it’s influence on cost and response time 9/17/2018 WBL

Biogeochemical Processes/Indicators Nutrient load Hydrology Sediment load Soil-Water Column Biogeochemical Process Spatial/ Stressors/ Temporal Regulators Patterns Biogeochemical Indicator [Endpoint] Ecological Function Algae/ Vegetation Microbial Fish Diversity Diversity 9/17/2018 WBL

Biogeochemical Indicators The indicators can be measured at three levels: Level I - low cost, easily measurable, and less sensitive. Level II - medium cost, moderate complexity, and moderately sensitive. Level III - high cost, very complex, and highly sensitive. 9/17/2018 WBL

Biogeochemical Indicators Level I - Indicators Water column: Causal variable Detritus/Soil: Response and Causal variables Level II – Indicators Water, detritus, and Soil: Response variables Level III – Indicators 9/17/2018 WBL

Level - I Water Column pH Suspended solids Dissolved oxygen Conductivity Salinity Turbidity Alkalinity Color Biochemical oxygen demand Water depth Hardness Conservative tracers Dissolved oxygen Bioavailable nutrients Ammonium N; nitrate N; dissolved reactive P; dissolved total P Total phosphorus and nitrogen Chemical composition of periphyton Total organic carbon and dissolved organic carbon Carbon-nitrogen ratios Carbon-phosphorus ratio 9/17/2018 WBL

Level - I Soil and Detrital/floc Layers Floc depth Bulk density Soil pH Soil redox potential Extractable nutrients (HCl and Mehlich III) Extractable ammonium Loss on ignition (LOI) Total P, N, and S C:N:P:S ratios Extractable metals 9/17/2018 WBL

Level - II Water Column Primary productivity Heterotrophic respiration Extracellular enzyme activity Species composition of periphyton Diel pH and dissolved oxygen Biological nitrogen fixation 9/17/2018 WBL

Level - II Soil and Detrital/floc Layers Microbial biomass C,N,P, and S Enzyme activities Soil porewater nutrients Soil phosphorus forms Organic nitrogen Organic and inorganic sulfur Single point phosphate isotherm Extractable metals Total mercury Pesticides Soil mineralogical composition 9/17/2018 WBL

Level - II Soil and Detrital/floc Layers Soil oxygen demand Soil-water nutrient exchange rates Organic matter accretion rates Equilibrium P concentration (EPCo) Phosphorus partition coefficients Detrital decomposition rates Potentially mineralizable P, N, and S Nitrification, and denitrification Iron and sulfate reduction Methyl mercury Methanogenesis Microbial respiration 9/17/2018 WBL

Level - III Water Column Microbial diversity Cellular fatty acids rRNA sequence analysis 9/17/2018 WBL

Level - III Soil and detrital layer Substrate Induced: Microbial respiration Organic nitrogen mineralization Organic phosphorus mineralization Microbial diversity Cellular fatty acids rRNA sequence analysis Phosphate sorption isotherms Equilibrium phosphorus concentration (EPCo) Phosphorus sorption coefficients Mineralogical composition Stability of phosphate precipitates and minerals Stable isotopes Organic P and C characterization (NMR) 9/17/2018 WBL

Linkage between Level – I Indicators and Nutrient Load Level - I Response Variable Nutrient Load Causal Variable 9/17/2018 WBL

Level - II Level - I Linkage between Level – I and Level – II Indicators Level - II Response Variable Level - I Causal Variable 9/17/2018 WBL

Level - III Level - II Linkage between Level – II and Level – III Indicators Level - III Response Variable Level - II Causal Variable 9/17/2018 WBL

Data Analysis Level I Level II Analyze Data Identify Indicators Monitor STA Performance Evaluation Primary Data Model Parameters Hydro - Biogeochemical/ Statistical Models 9/17/2018 WBL

Indicator Evaluation ? Complementary Indicators Ratio of impacted site relative to reference site Comparison of sensitivity, time and effort 9/17/2018 WBL

Nutrient Impact Index Impact Index: log [IS/RS] Distance from inflow 2 -1 -2 1 2 Impacted Site [IS] Reference Site [RS] Impact Index: log [IS/RS] Background level Distance from inflow 9/17/2018 WBL

Impact Index Impact Index: log [IS/RS] 1 Severe impact 0.5 0.5 1 -0.5 -1 No Impact- background condition Moderate impact Severe impact Impact Index: log [IS/RS] Impact Index 9/17/2018 WBL

Total Phosphorus in WCA-2A soils (0-10 cm) 1990 1998 9/17/2018 WBL

Extracellular Enzymes [Water Conservation Area-2A] Impact Index = log [IS/RS] Enzymes Detrital Soil layer 0-10 cm] B-D-Glucosidase 0.56 0.40 Protease 0.16 0.07 Alkaline Phosphatase -0.70 -0.37 Arylsulfatase -0.10 -0.12 Phenol Oxidase 0.19 0.16 9/17/2018 WBL

Organic Matter Decomposition [Water Conservation Area-2A] Impact Index = log [IS/RS] Process/ Detrital Soil Indicator layer [0-10 cm] Respiration Aerobic 0.21 0.23 Anaerobic 0.41 0.28 MBC 0.33 0.11 MBC/TOC 0.30 0.15 MBC = Microbial biomass carbon 9/17/2018 WBL

Nitrogen Transformations [Water Conservation Area-2A] Impact Index = log [IS/RS] Process/ Detrital Soil Indicator layer [0-10 cm] PMN 0.40 0.25 SINM (Alanine) 0.62 0.45 MBN 0.23 0.12 SINM/MBN 0.39 0.33 Nitrification 0.17 0.20 Denitrification 0.31 0.31 N2 fixation 1.0 SINM = Substrate induced nitrogen mineralization MBN = Microbial biomass nitrogen 9/17/2018 WBL

Phosphorus Transformations [Site: WCA-2A] Impact Index = log [IS/RS] Process/ Detrital Soil Indicator layer [0-10 cm] PMP 0.85 -0.03 SIPM (G-6-P) 0.08 -0.41 MBP 0.33 0.17 SIPM/MBP -0.28 -0.48 C/P ratio -0.51 -0.51 Labile Pi 1.07 0.52 PMP = Potentially mineralizable P; SIPM = substrate induced P mineralization MBP = microbial biomass P 9/17/2018 WBL

Microbial Biomass N and PMN Floc- Total N and P Ratios 5000 200 MBN PMN 4000 150 3000 MBN (mg kg-1) 2000 PMN (mg kg-1 d-1) 100 1000 50 100 200 300 400 100 200 300 400 Molar N:P ratio Molar N:P ratio 9/17/2018 WBL

Microbial Biomass P and PMP Floc- Total N and P Ratios MBP (mg kg-1) 100 200 300 400 500 Molar N:P ratio 10 20 30 PMP (mg kg-1 d-1) MBP PMP 9/17/2018 WBL

Impact Index – Detritus/Floc- WCA-2a 1 Microbial Populations [ 1.7 -2.1] N2 fixation, PMP, Labile Pi High impact B-D-Glucosidase 0.5 Microbial Respiration, MBC, MBP, PMN, SINM, TP, and TPi Moderate impact Protease, MBN, Phenol Oxidase, nitrification, Denitrification Impact Index: log [IS/RS] Arylsulfatase, TC, TN No Impact- background condition Moderate impact -0.5 Alkaline Phosphatase Activity, C/P ratio, N/P Ratio High impact -1 9/17/2018 WBL

Data Analysis and Synthesis Descriptive statistics to define frequency distribution and central tendency of biogeochemical indicators Multivariate analyses to evaluate relationships between biogeochemical indicators and ecological condition Geostatistical analyses to evaluate spatial patterns and spatial structure of biogeochemical indicators Predictive modeling to forecast evolution of biogeochemical indicators and ecological integrity 9/17/2018 WBL

Stepwise Canonical Discriminant Analysis: Abiotic Indicators: Everglades –WCA-2a 10 8 F1 F4 U3 Site 6 4 2 Canonicla Variate 1 (u1) -2 -4 -6 -4 -3 -2 -1 1 2 3 4 5 Canonical Variate 2 (u2) 9/17/2018 WBL

Stepwise Canonical Discriminant Analysis: Biotic Indicators: Everglades –WCA-2a 4 F1 F4 U3 Site 3 2 1 Canonical Variate 1 (u1) -1 -2 -3 -4 -3 -2 -1 1 2 3 4 5 Canonical Variate 2 (u2) 9/17/2018 WBL

Biogeochemical Indicators Paradigm Key Challenges Simultaneous measurements of “processes” and ‘indicators” at various spatial and temporal scales Integration of these measurements across scales using statistical and process models 9/17/2018 WBL

Minimum Data – Level I Water column: Detritus/Floc: Soil: Detrital Water depth Total Nitrogen Total Phosphorus Detritus/Floc: Total carbon, Total nitrogen Total phosphorus Soil: Bulk density Organic matter content, Total nitrogen, Total phosphorus, Extractable nitrogen, Extractable phosphorus (Mehlich –1 and 3) Extractable Fe, Al, Ca, Mg, and K 00- cm Detrital Floc 0- cm Soil 10 cm 9/17/2018 WBL

Soil Sampling in 2003 Stratified random sampling design Total number of sampling sites (n): 1,349 (+~10% replicates) Floc/detritus 0-10 cm 10-20 cm Area ~ 8,250 km2 Average sampling density: 9/17/2018 WBL

Biogeochemical Indicators Summary Indicators may reflect biological, chemical, or physical attributes that can be used to characterize current status or to predict impact or change. Such indicators of wetland ecosystem integrity should be sensitive, reliable, accurate, rapid, and inexpensive. Indicators should be clearly understood and accepted by scientists, environmental managers, and policy makers. Indicator levels in accessing impact to wetland ecosystem may be based on the ease of measurement and the ability to respond to change. Level I indicators are easily measurable whereas level II and III indicators provide more scientifi c rigor and are used to support easily measurable indicators 9/17/2018 WBL

Biogeochemical Indicators Summary Wetland can exhibit a high degree of spatial heterogeneity; thus, the sampling protocol should aim to capture the underlying spatial variability of wetland indicators. The selection of indicator variable, sampling design, data collection, and statistical/geostatistical methods to analyze dataset is linked. Before using any selected biogeochemical indicator, a sampling design must be established that represents unimpacted and impacted portions of the wetland to assess early warning signals of decline in ecosystem health. Each sampling protocol, if possible, should compare environmental conditions to a reference or control site. 9/17/2018 WBL