1. Altered Hydrology & Vegetation: Effects on the Transport and Breakdown of Organic Matter in Urban Streams Kenneth T. Belt 1, Christopher Swan 2, Richard Pouyat 1, Sujay Kaushal 3, Peter Groffman 4, Istvan Turcsanyi 5, William Stack 6, and Gary Fisher 7 1 USDA Forest Service, 2 UMBC Dept. of Geography and Environmental Systems 3 UMCES Appalachian Lab, 4 Institute of Ecosystem Studies, 5, UMBC Center for Urban Environmental Research & Education, 6 Baltimore City DPW, 7 USGS BES Annual Meeting, Baltimore, UMBC, October 19, 2006 UMBC

2. Outline Urban Drainage Networks Leaf Breakdown DOC Export (preliminary) POM Export (preliminary) Ongoing Work

3. Support… Phyl (my wife)…arthritic bag making sessions, field work…putting up with me. Rich Pouyat (USFS)…Guidance, encouragement, bag making…field work (the infamous blind rainstorm drive) Chris Swan (UMBC GES)…guidance, encouragement, nutrient analysis, bug picking support Sujay Kaushal (UMCES)…guidance, encouragement, DOC analyses Peter Groffman/Dan Dillon, Gio et al. (IES)…sampling support, nutrient data; loan of an “ISCO” Claire Welty (CUERE)…facilities, guidance; loan of 2 “ISCOs” Istvan Turcsanyi (CUERE)…guidance and endless filtering and weighing UMBC GES interns: Bill Greenwood, Yaakov Birnbaum, Heather Modic All those technicians & colleagues…..

4. Motivation Leaves (and breakdown products & leachate) in streams are an important energy (food) source They also are habitat They are important in a variety of BGC reactions and pathways They also likely carry significant, not heretofore considered, elemental/pollutant loads

5. Urban Drainage Networks

6. Buried Urban Streams

7. Increased Effective Drainage Density in Urban Streams Curb & Gutter Network

8. “Upland Riparian” Streams…

9. ….Deliver Particulate & Dissolved Loads to Streams

10. Urban Landscapes & Organic Matter Transport

11. The Gutter Subsidy

12. Civil Infrastructure and Organic Matter POM Pollutants Outputs To Stream Outputs To Stream Forest StandUrban Landscape

13. Leaf Breakdown

14. How quickly do leaves breakdown in the stream benthic environment?

15. Mass Loss from Leaf Bags

16. Breakdown Rates: Mass Loss Coefficients Exponential decay model: W t W 0 -1 = e -kt W 0 = the initial leaf mass (g) W t is the mass (g) remaining on day t k is the rate of breakdown (day -1 )

17. Leaf Breakdown: Basic Questions…Streams, Sources & Landscape Position 1.Do leaves breakdown faster in suburban than in forested streams? 2.Do leaves from upland portions of the urban landscape breakdown faster than riparian leaves? 3.Do leaves from gutter sources break down faster than leaves from higher points in the landscape and riparian leaves? 4.Do riparian leaves from different locations along the urban- rural gradient differ in their breakdown rates?

18. Stream Study Sites Baismans Run (Forested) Gwynns Falls At Gwynnbrook (Suburban) 10 kilometers Leaf Litter Breakdown Study Streams

19. Baltimore City Gwynns Falls at Gwynnbrook (Suburban) Baismans Run (Forested) Baismans Run Gwynns Falls at Gwynnbrook Study Stream Catchments

20. Riparian Source Sites (Sycamore) Distal Riparian (rural) Suburban Riparian Urban, Riparian Proximal Riparian (rural)

21. Suburban Landscape Urban Landscape Urban, Gutter Suburban, Gutter Lawn (“Landscape”) & Gutter Source Sites (Planetree)

22. Study Streams: Light Green- Forested, Dark Green- Suburban Suburban Stream Forested Stream Leaf Mass Loss Rates (Sycamore) (Planetree) Litter Sources

23. Urban Streams… Faster Mass Loss: Urban vs. Suburban Streams Leaf Mass Loss Rates

24. Riparian sources Slower Mass Loss Rates: Upland vs. Riparian Leaf Mass Loss Rates

25. “Gutter”… about the same as “Landscape” Litter Sources: Gutter vs. Landscape Leaf Mass Loss Rates Urban… Much faster than Suburban

26. No Effect for Riparian Leaves? The Riparian Urban-Rural Gradient Leaf Mass Loss Rates

27. DOC Export

28. DOC Export in Urban Streams 1.How do urban DOC concentrations and export rates compare to “natural” systems ? 2.How much does DOC transport vary temporally (seasonal); how important is hydrology (storms)? 3.Is drainage density (and its attendant features) important?

29. Preliminary DOC & Flow Data 8 of 13 sites 15 to 20 samples at each site July to November 2005 Grab sampling…every few weeks Mostly dry weather Some with recent storm runoff activity (within days)

33. More ISC… More Runoff

34. More ISC… Higher DOC Conc

35. More ISC… Higher Catchment DOC Exports

36. Urban catchments… High DOC exports at higher flows

37. Urban catchments produce large DOC loads…including at elevated flows And these loads may be related to to impervious area cover & infrastructure…?

38. POM Export

39. POM Export in Urban Streams 1.How do urban POM concentrations and export rates compare to “natural” systems ? 2.How much does POM transport vary temporally (seasonal); how important is hydrology (storms)? 3.Is drainage density (and its attendant features) important?

40. AFDM & TSS at 3 Sites Baismans R, GFalls at Gwynnbrook, Dead R; Apr to Sep 2006 % Organic Matter Forested: 31 % Suburban: 39 % Urban: 52% % Organic Matter Apr-MayJun-Sep Forested: 40 %29 % Suburban: 50 %37 % Urban: 42 %54% TSS AFDM Forested Suburban Urban

41. AFDM & TSS at 11 Sites Spg-Sum 2006

42. Ongoing/Future Work

43. Organic Matter…the Urban Dilemma Urban streams: faster particle breakdown …greater export rates from the benthic ecosystem…carbon poor benthos But…. Higher urban imports (gutter subsidy)? Smaller particles? Leached loads (DOC)?

44. Organic Matter in Streams: Types of OM DOC- dissolved OM FPOM- fine particulate OM CPOM- coarse particulate OM

45. Organic Matter in Streams: Basic Transport Pathways DOC CPOM FPOM Groundwater Surface & Shallow Groundwater Leaching Surface Waters DOC Riparian & Upland Litterfall

46. 13 gauged BES catchments…an urban-rural gradient Storm and dry weather sampling Intensive sampling with auto samplers at 3 catchments Particulate and dissolved organic matter Urban hydrology approach Sediment exports (% organic matter) Basic Approach

47. Bridge Dry Weather Flow Storm Flow Discrete Storm FPOM Samples Discrete Storm CPOM Samples 24 hr CPOM Sampler (Dry Weather Flow) Whole Storm CPOM Sampler Peak Storm Flow CPOM Sampler (stationary) Intensive Site Sampling Conceptual Scheme Automated Sampler FPOM Grab (Dry Weather Flow) USGS Stage Recorder

48. Gwynns Falls Main Channel Stream Sites Small Headwater Stream Sites Subcatchment Stream Sites Baismans Run Gwynns Falls BES Stream Sites: Routine & Intensive GFGB GFVN GFCP BARN POBR DRKR 3 Intensive Monitoring Sites 13 Routine Sampling Sites:

49. Gwynns Falls Main Channel Stream Sites Small Headwater Stream Sites Subcatchment Stream Sites Baismans Run Gwynns Falls BES Stream Sites: Auto Storm Composites GFGB GFVN RGHT BALT & LANV 7 Auto Sampler Storm Composite Samplers (including the 3 OM intensive Sites) 13 Routine Sampling Sites:

50. A Multidisciplinary, Cooperative Effort… US Forest Service UMBC Geography & Environmental Systems UMCES Appalachian Lab Center for Urban Environmental Research and Education Baltimore Ecosystem Study/Institute of Ecosystem Studies City of Baltimore DPW US Geological Survey …and more partners to come