Microbial Dynamics in the Stormwater Treatment Areas

Kanika S. Inglett

Soil and Water Sciences Department

University of Florida, Gainesville FL

Black Box of the microbial dynamics

Higher nutrient loads

Lower nutrient

loads

inflow outflow

Black Box of the microbial dynamics

Energy and nutrient flow is through the microbial loop

Organic Matter decomposition

Transformation of nutrients

Nutrient release

Nutrient uptake

Flux out

retention

inflowoutflow

microbial loop

Zones of the microbial activities

Anaerobic zone

Aerobic zone

Periphyton

Rhizosphere

Detritus/floc

Water column

Vegetation

aerobic to anaerobic algae and bacteriahigh C availability, higher biomass and activity

Phototrophic, heterotrophic, high C availability,

Facultative or obligate anaerobic bacteriaLow available C, alternate electron acceptors, lower biomass and activity

Aerobic bacteria High available C, root exudates vegetation specific higher biomass and activity

algal, fungal, bacterial biomass, high available C, Vegetation dependent lignin to cellulosic ratio

Nutrient availability and enzyme activities

Plant litter

3000:46:1

86:13:1

60:7:1

C:N:P

Soil organic matter

Microbial biomass • Microbial respiration

• Potential Mineralizable Phosphorus• Potential Mineralizable Nitrogen

• Microbial biomass C,N,P

Extracellular Enzyme activities

Organic Matter decomposition

Transformation of nutrients

C enzymesN enzymesP enzymes

Inorganic P

Ph

osp

hat

ase

Modified from Penton and Newman, 2007 Biogeochem 84,83

Phosphatase activity in ref sites (µmoles g-1 h-1)

LNWR WCA-2A WCA- 3A ENP-TS

refenr

85

23 21 18

TP (

10

3)

g kg

-

1

N substrates

Nit

roge

n e

nzy

me

s

Sinsabaugh et al 2008 Ecol Lett

Acetylglucosiminiodase

Vegetation in the STAs • Nutrient uptake- nutrient removal

• Source of C – litter, detritus, rhizosphere

• Allows microorganisms to colonize

Emergent aquatic vegetation

Submerged aquatic vegetation

RAS

PreSTA 1

PreSTA 2

Floc Litter

(APA

/APA

max

)*1

00

Effects on enzyme activitiesSoil depth

Wright and Reddy, 2001 SSSAJ 65:588

Enzy

me

Act

ivit

y (μ

mo

lg d

w-1

h-1

)

Percentage Distance from the Inflow

RASFloc

N enzymes

P enzymes

C enzymes

Rice et al. 2017

Vegetation type

Percentage Distance from the Inflow

Figure 8. Floc EAV and SAV display peaks of higher E at the inflow, while

E N:P

Floc RAS

E N:P

THURSDAY 8:00am–10:15am

SESSION 2 POSTER # 66

Vegetation Effects on Microbial Enzyme Activities in Soils of the StormwaterTreatment Areas (STAs) Rice et al.

Rice et al. 2017

Does flow affect the microbial nutrient availability?

• Flow can alter advective processes• Enhance exchanges between reactive zones• Upstream affects the downstream• River continuum concept

Inflow water

Outflow water

S N(1

0-5

ms-1

)

Ammonium uptake by algae with flow

Water velocity

S P(1

0-5

ms-1

) Phosphate uptake by algae with flow

Water velocity

6 cm depth

Overlying water

Cheng et al, 2017 Water 9,6

Flow effects

Larned and Atkinson, 1997, Mar Ecol Press Series 157,295

THURSDAY 8:00am–10:15am

SESSION 2 POSTER # 63

Effects of Flow on Enzyme Activity in the Everglades Stormwater

Treatment Areas (STAs)

Baker et al.

Baker et al. 2017

Future Directions

• Other components (periphyton, mats)• Diel variations in activity (day/light, dark)• Coupling with inorganic nutrients (e.g., P fractionation)• Greenhouse gas emissions

Acknowledgement and Collaboration

University of Florida

Dr. Patrick Inglett, Kaylee Rice (MS), Sara Baker (undergraduate student), Dr. Xiaolin Liao, Dr. Rupesh Bhomia, Brent Warner

South Florida Water Management District

Odi Villapando, Jill King, Kathy Pietro