Effects of stream restoration on denitrification in an urbanizing watershed

被引:210
作者
Kaushal, Sujay S. [1 ]
Groffman, Peter M. [2 ]
Mayer, Paul M. [3 ]
Striz, Elise [3 ]
Gold, Arthur J. [4 ]
机构
[1] Univ Maryland, Ctr Environm Sci, Appalachian Lab, Frostburg, MD 21532 USA
[2] Inst Ecosyst Studies, Millbrook, NY 12545 USA
[3] US EPA, Off Res & Dev, Natl Risk Res Management Lab, Ada, OK 74820 USA
[4] Univ Rhode Isl, Dept Nat Resources, Kingston, RI 02881 USA
关键词
Chesapeake Bay; USA; eutrophication; nitrogen; stream restoration; urbanization;
D O I
10.1890/07-1159.1
中图分类号
Q14 [生态学(生物生态学)];
学科分类号
071012 ; 0713 ;
摘要
Increased delivery of nitrogen due to urbanization and stream ecosystem degradation is contributing to eutrophication in coastal regions of the eastern United States. We tested whether geomorphic restoration involving hydrologic "reconnection'' of a stream to its floodplain could increase rates of denitrification at the riparian-zone-stream interface of an urban stream in Baltimore, Maryland. Rates of denitrification measured using in situ N-15 tracer additions were spatially variable across sites and years and ranged from undetectable to > 200 mu g N center dot( kg sediment)(-1) center dot d(-1). Mean rates of denitrification were significantly greater in the restored reach of the stream at 77.4 +/- 12.6 mu g N center dot kg(-1) center dot d(-1) ( mean 6 SE) as compared to the unrestored reach at 34.8 +/- 8.0 mu g N center dot kg(-1) center dot d(-1). Concentrations of nitrate-N in groundwater and stream water in the restored reach were also significantly lower than in the unrestored reach, but this may have also been associated with differences in sources and hydrologic flow paths. Riparian areas with low, hydrologically "connected'' streambanks designed to promote flooding and dissipation of erosive force for storm water management had substantially higher rates of denitrification than restored high "nonconnected'' banks and both unrestored low and high banks. Coupled measurements of hyporheic groundwater flow and in situ denitrification rates indicated that up to 1.16 mg NO3--N could be removed per liter of groundwater flow through one cubic meter of sediment at the riparian-zone-stream interface over a mean residence time of 4.97 d in the unrestored reach, and estimates of mass removal of nitrate-N in the restored reach were also considerable. Mass removal of nitrate-N appeared to be strongly influenced by hydrologic residence time in unrestored and restored reaches. Our results suggest that stream restoration designed to "reconnect'' stream channels with floodplains can increase denitrification rates, that there can be substantial variability in the efficacy of stream restoration designs, and that more work is necessary to elucidate which designs can be effective in conjunction with watershed strategies to reduce nitrate-N sources to streams.
引用
收藏
页码:789 / 804
页数:16
相关论文
共 79 条
[1]   Denitrification capacity in a subterranean estuary below a Rhode Island fringing salt marsh [J].
Addy, K ;
Gold, A ;
Nowicki, B ;
McKenna, J ;
Stolt, M ;
Groffman, P .
ESTUARIES, 2005, 28 (06) :896-908
[2]   In situ push-pull method to determine ground water denitrification in riparian zones [J].
Addy, K ;
Kellogg, DQ ;
Gold, AJ ;
Groffman, PM ;
Ferendo, G ;
Sawyer, C .
JOURNAL OF ENVIRONMENTAL QUALITY, 2002, 31 (03) :1017-1024
[3]   Effect of stream channel size on the delivery of nitrogen to the Gulf of Mexico [J].
Alexander, RB ;
Smith, RA ;
Schwarz, GE .
NATURE, 2000, 403 (6771) :758-761
[4]   Ecology - Synthesizing US river restoration efforts [J].
Bernhardt, ES ;
Palmer, MA ;
Allan, JD ;
Alexander, G ;
Barnas, K ;
Brooks, S ;
Carr, J ;
Clayton, S ;
Dahm, C ;
Follstad-Shah, J ;
Galat, D ;
Gloss, S ;
Goodwin, P ;
Hart, D ;
Hassett, B ;
Jenkinson, R ;
Katz, S ;
Kondolf, GM ;
Lake, PS ;
Lave, R ;
Meyer, JL ;
O'Donnell, TK ;
Pagano, L ;
Powell, B ;
Sudduth, E .
SCIENCE, 2005, 308 (5722) :636-637
[5]   Nitrogen retention, removal, and saturation in lotic ecosystems [J].
Bernot, MJ ;
Dodds, WK .
ECOSYSTEMS, 2005, 8 (04) :442-453
[6]   Chesapeake Bay eutrophication: Scientific understanding, ecosystem restoration, and challenges for agriculture [J].
Boesch, DF ;
Brinsfield, RB ;
Magnien, RE .
JOURNAL OF ENVIRONMENTAL QUALITY, 2001, 30 (02) :303-320
[7]   Ground water stratification and delivery of nitrate to an incised stream under varying flow conditions [J].
Bohlke, J. K. ;
O'Connell, Michael E. ;
Prestegaard, Karen L. .
JOURNAL OF ENVIRONMENTAL QUALITY, 2007, 36 (03) :664-680
[8]  
Böhlke JK, 2004, LIMNOL OCEANOGR, V49, P821
[9]   Hyporheic rehabilitation in rivers: restoring vertical connectivity [J].
Boulton, Andrew J. .
FRESHWATER BIOLOGY, 2007, 52 (04) :632-650
[10]   Anthropogenic nitrogen sources and relationships to riverine nitrogen export in the northeastern USA [J].
Boyer, EW ;
Goodale, CL ;
Jaworsk, NA ;
Howarth, RW .
BIOGEOCHEMISTRY, 2002, 57 (01) :137-169