Nitrate removal in stream riparian zones

Journal of Environmental Quality

Volumn 25, Issue 4, 1996, Pages 743-755

  Hill, Alan R ^a  

^a YORK UNIVERSITY   (Canada)

Author keywords

[No Author keywords available]

Indexed keywords

BIOMASS; CHEMISTRY; DENITRIFICATION; FLOW PATTERNS; GROUNDWATER FLOW; HYDROLOGY; LANDFORMS; NITRATES; SEDIMENTS; SURFACE WATERS; WATER LEVELS;

HYDROGEOLOGY; LANDSCAPES; NITRATE REMOVAL; STREAM RIPARIAN ZONES; VEGETATION; WATER TABLE;

CHEMICALS REMOVAL (WATER TREATMENT);

GROUND WATER; LAKE WATER; NITRATE; SURFACE WATER;

DENITRIFICATION; NONHUMAN; POLLUTION; REVIEW; WATER CONTAMINATION; WATER FLOW; WATER QUALITY;

EID: 0030199785     PISSN: 00472425     EISSN: None     Source Type: Journal    
DOI: 10.2134/jeq1996.00472425002500040014x     Document Type: Review

References (129)

1. Alley, W.M. 1993. Establishing a conceptual framework. p. 23-60. In W.M. Alley (ed.) Regional groundwater quality. Van Nostrand Reinhold, New York.
2. Altman, S.J., and R.R. Parizek. 1995. Dilution of nonpoint-source nitrate in groundwater. J. Environ. Qual. 26:707-718.
3. Ambus, P., and R. Lowrance. 1991. Comparison of denitrification in two riparian soils. Soil Sci. Soc. Am. J. 55: 994-997.
4. 15N and microsensor techniques. Appl. Environ. Microbiol. 58:303-313.
5. Bohlke, J.K., and J.M. Denver. 1995. Combined use of groundwater dating, chemical, and isotopic analyses to resolve the history and fate of nitrate contamination in two agricultural watersheds, Atlantic coastal plain, Maryland. Water Resour. Res. 31:2319-2339.
6. Bowden, W.B., W.H. McDowell, C.E. Ashbury, and A.M. Finley. 1992. Riparian nitrogen dynamics in two geomorphologically distinct tropical rain forest watersheds: Nitrous oxide fluxes. Biogeochemistry 18:77-99.
7. Brakenridge, G.R. 1988. River flood regimes and floodplain stratigraphy. p. 139-156. In V.R. Baker et al. (ed.) Flood geomorphology. John Wiley and Sons, New York.
8. Brinson, M.M. 1993. Changes in the functioning of wetlands along environmental gradients. Wetlands 13:65-74.
9. Brusch, W., and B. Nilsson. 1993. Nitrate transformation and water movement in a wetland area. Hydrobiologia 251:103-111.
10. Buresh, R.J., and W.H. Patrick. 1978. Nitrate reduction to ammonium in anaerobic soil. Soil Sci. Soc. Am. J. 42:913-917.
11. Carter, V. 1986. An overview of the hydrologic concerns related to wetlands in the United States. Can. J. Bot. 64:364-374.
12. Castelle, A.J., A.W. Johnson, and C. Conolly. 1994. Wetland and stream buffer size requirements - A review. J. Environ. Qual. 23: 878-882.
13. Cooper, A.B. 1990. Nitrate depletion in the riparian zone and stream channel of a small headwater catchment. Hydrobiologia 202:13-26.
14. Cooper, J.R., J.W. Gilliam, and T.C. Jacobs. 1986. Riparian areas as a control of nonpoint pollutants. p. 166-192. In D.L. Correll (ed.) Watershed research perspectives. Smithsonian Press, Washington, DC.
15. Correll, D.L. 1991. Human impact on the functioning of landscape boundaries. p. 90-109. In M.M. Holland and R.J. Naiman (ed.) Ecotones - The role of landscape boundaries in the management and restoration of changing environments. Chapman and Hall, New York.
16. Correll, D.L., T.E. Jordan, and D.E. Weller. 1994. Coastal plain riparian forests: Their role in filtering agricultural drainage. p. 67-72. In J.A. Kusler and C. Lassonde (ed.) Altered, artificial and managed wetlands focus: Agriculture and forestry. New York Assoc. of State Wetland Managers.
17. Correll, D.L., and D.E. Weller. 1989. Factors limiting processes in freshwater wetlands: An agricultural primary stream riparian forest. p. 9-23. In R.R. Sharitz and J.W. Gibbons (ed.) Freshwater wetlands and wildlife. Conf. 8603101. DOE Symp. Sur. U.S. Dep. of Energy, Washington, DC.
18. Crumpton, W.G., T.M. Isenhart, and S.W. Fisher. 1993. Fate of non-point nitrate loads in freshwater wetlands: Results from experimental wetland mesocosms. p. 283-291. In G.A. Moshiri (ed.) Constructed wetlands for water quality improvement. Lewis Publ., Boca Raton.
19. Davidson, E.A., S.C. Hart, and M.K. Firestone. 1992. Internal cycling of nitrate in soils of a mature coniferous forest. Ecology 73:1148-1156.
20. Dawson, T.E., and J.R. Ehleringer. 1991. Streamside trees that do not use stream water. Nature (London) 350:335-337.
21. Denver, J.M. 1991. Groundwater-sampling network to study agrochemicals effects on water quality in the unconfined aquifer. p. 139-149. In R.G. Nash and A.R. Leslie (ed.) Groundwater residue sampling design. ACS Symp. Ser. 465. Am. Chem. Soc., Washington, DC.
22. Devito, K.J. 1995. Sulphate mass balances in headwater wetlands of the Canadian Shield: Influence of catchment hydrogeology. Can. J. Fish. Aquat. Sci.52:1750-1760.
23. Devito, K.J., and P.J. Dillon. 1993. The influence of hydrologic condition and peat oxia on the phosphorus and nitrogen dynamics of a conifer swamp. Water Resour. Res. 29:2675-2685.
24. Devito, K.J., P.J. Dillon, and B.D. Lazerte. 1989. Phosphorus and nitrogen retention in five Precambrian shield wetlands. Biogeochemistry 8:185-204.
25. Devito, K.J., A.R. Hill, and N.T. Roulet. 1996. Groundwater-surface water interactions in headwater forested wetlands of the Canadian Shield. J. Hydrol. (In press.)
26. Dillaha, T.A., R.B. Reneau, S. Mostaghimi, and D. Lee. 1989. Vegetative filter strips for agricultural nonpoint source pollution control. Trans. Am. Soc. Agric. Eng. 32:513-519.
27. Duff, J.H., and F.J. Triska. 1990. Denitrification in sediments from the hyporheic zone adjacent to a small forested stream. Can. J. Fish. Aquat. Sci. 47:1140-1147.
28. Emmett, B.A., B. Reynolds, P.A. Stevens, D.A. Norris, S. Hughes, J. Gorres, and I. Lubrecht. 1993. Nitrate leaching from afforested Welsh catchments - Interactions between stand age and nitrogen deposition. Ambio 22:386-394.
29. Emmett, B.A., J.A. Hudson, P.A. Coward, and B. Reynolds. 1994. The impact of a riparian wetland on streamwater quality in a recently afforested upland catchment. J. Hydrol. 162:337-353.
30. Fail, J.L., M.N. Hamzah, B.L. Haines, and R.L. Todd. 1986. Above and below ground biomass, production and element accumulation in riparian forests of an agricultural watershed. p. 193-223. In D.L. Correll (ed.) Watershed research perspectives. Smithsonian Press, Washington, DC.
31. Fustec, E., A. Mariotti, X. Grillo, and J. Sajus. 1991. Nitrate removal by denitrification in alluvial groundwater: Role of a former channel. J. Hydrol. 123:337-354.
32. Gilliam, J.W. 1994. Riparian wetlands and water quality. J. Environ. Qual. 23:896-900.
33. Gordon, A.S., W.J. Cooper, and D.J. Scheidt. 1986. Denitrification in marl and peat sediments in the Florida Everglades. Appl. Environ. Microbiol. 52:987-991.
34. Gregory, S.V., F.J. Swanson, W.A. McKee, and K.W. Cummins. 1991. An ecosystem perspective of riparian zones. Bioscience 41: 540-551.
35. Grimm, N.B., and S.G. Fisher. 1984. Exchange between interstitial and surface water: Implications for stream metabolism and nutrient cycling. Hydrobiologia 111:219-228.
36. Groffman, P.M., E.A. Axelrod, J.L. Lemunyon, and W.M. Sullivan. 1991. Denitrification in grass and forested vegetated filter strips. J. Environ. Qual. 20:671-674.
37. Groffman, P.M., A.J. Gold, and R.C. Simmons. 1992. Nitrate dynamics in riparian forests: Microbial studies. J. Environ. Qual. 21: 666-671.
38. Hamzah, M.N. 1983. Root biomass, production, and decomposition in the riparian forests of an agricultural watershed. Ph.D. diss. Univ. of Georgia, Athens (Diss. Abstr. 83-20090).
39. Hanson, G.G., P.M. Groffman, and A.J. Gold. 1994a. Denitrification in riparian wetlands receiving high and low groundwater nitrate inputs. J. Environ. Qual. 23:917-922.
40. Hanson, G.G., P.M. Groffman, and A.J. Gold. 1994b. Symptoms of nitrogen saturation in a riparian wetland. Ecol. Appl. 4:750-756.
41. Haycock, N.E., and T.P. Burt. 1993a. Role of floodplain sediments in reducing the nitrate concentration of subsurface run-off: A case study in the Cotswolds, UK. Hydrol. Processes 7:287-295.
42. Haycock, N.E., and T.P. Burt. 1993b. The sensitivity of rivers to nitrate leaching: The effectiveness of near-stream land as a nutrient retention zone. p. 261-272. In D.S.G. Thomas and R.J. Allison (ed.) Landscape sensitivity. John Wiley and Sons, New York.
43. Haycock, N.E., and G. Pinay. 1993. Groundwater nitrate dynamics in grass and poplar vegetated riparian buffer strips during the winter. J. Environ. Qual. 22:273-278.
44. Haycock, N.E., G. Pinay, and C. Walker. 1993. Nitrogen retention in river corridors: European perspectives. Ambio 22:340-346.
45. Hedin, L.O., J.J. Armesto, and A.H. Johnson. 1995. Patterns of nutrient loss from unpolluted, old-growth temperate forests:Evaluation of biogeochemical theory. Ecology 76:493-509.
46. Hendricks, J.J., K.J. Nadelhoffer, and J.D. Aber. 1993. Assessing the role of fine roots in carbon and nutrient cycling. Trends Ecol. Evol. 8:174-178.
47. Hill, A.R. 1988. Factors influencing nitrate depletion in a rural stream. Hydrobiologia 160:111-122.
48. Hill, A.R. 1990. Groundwater flow paths in relation to nitrogen chemistry in the near-stream zone. Hydrobiologia 206:39-52.
49. Hill, A.R. 1991. A groundwater nitrogen budget for a headwater swamp in an area of permanent groundwater discharge. Biogeochemistry 14:209-224.
50. Hill, A.R., and K.J. Devito. 1996. Hydrologic - Chemical interactions in headwater forest wetlands. In C.C. Trettin et al. (ed.) Northern forested wetlands: Ecology and management. CRC/Lewis Publ., Boca Raton, FL.
51. Hinton, M.J., S.L. Schiff, and M.C. English. 1993. Physical properties governing groundwater flow in a glacial till catchment. J. Hydrol. 142:229-249.
52. Howard-Williams, C. 1985. Cycling and retention of nitrogen and phosphorus in wetlands: A theoretical and applied perspective. Freshwater Biol. 15:391-431.
53. Jacks, G., A. Joelsson, and S. Fleischer. 1994. Nitrogen retention in forested wetlands. Ambio 23:358-362.
54. Jacobs, T.C., and J.W. Gilliam. 1985. Riparian losses of nitrate from agricultural drainage waters. J. Environ. Qual. 14:472-478.
55. Jansson, M., R. Andersson, H. Berggren, and L. Leonardson. 1994. Wetlands and lakes as nitrogen traps. Ambio 23:320-325.
56. Johnson, D.W. 1992. Nitrogen retention in forest soils. J. Environ. Qual. 21:1-12.
57. Jordan, T.E., D.L. Correll, and D.E. Weller. 1993. Nutrient interception by a riparian forest receiving inputs from adjacent cropland. J. Environ. Qual. 22:467-473.
58. Koerselman, W. 1989. Groundwater and surface water hydrology of a small groundwaler-fed fen. Wetlands Ecol. Manage. 1:31-43.
59. Koike, I., and A. Hattori. 1978. Denitrification and ammonia formation in anaerobic coastal sediments. Appl. Environ. Microbiol. 35: 278-282.
60. Koike, I., and J. Sorensen. 1988. Nitrate reduction and denitrification in marine sediments. p. 251-273. In T.H. Blackburn and J. Sorensen (ed.). Nitrogen cycling in coastal marine environments. John Wiley and Sons, New York.
61. Lawrence, J.R., and M.J. Hendry. 1995. Mesocosms for subsurface research. Water Qual. Res. J. Canada 30:493-512.
62. Lee, D.R., and J.A. Cherry. 1978. A field exercise on groundwater flow using seepage meters and mini-piezometers. J. Geol. Educ. 27:6-10.
63. Lowrance, R.R. 1992. Groundwater nitrate and denitrification in a coastal riparian forest. J. Environ. Qual. 21:401-405.
64. Lowrance, R.R., R. Leonard, and J. Sheridan. 1985. Managing riparian ecosystems to control nonpoint pollution. J. Soil Water Conserv. 40:87-91.
65. Lowrance, R.R., J.K. Sharpe, and J.M. Sheridan. 1986. Long-term sediment deposition in the riparian zone of a coastal plain watershed. J. Soil Water Conserv. 41:266-271.
66. Lowrance, R.R., R.L. Todd, and L.E. Asmussen. 1984a. Nutrient cycling in an agricultural watershed: 1. Phreatic movement. J. Environ. Qual. 13:22-27.
67. Lowrance, R.R., R. Todd, J. Fail, O. Hendrickson, R. Leonard, and L. Asmussen. 1984b. Riparian forests as nutrient filters in agricultural watersheds. Bioscience 34:374-377.
68. McClain, M.E., J.E. Richey, and T.P. Pimental. 1994. Groundwater nitrogen dynamics at the terrestrial-lotic interface of a small catchment in the Central Amazon Basin. Biogeochemistry 27:113-127.
69. McDowell, W.H., W.B. Bowden, and C.E. Asbury. 1992. Riparian nitrogen dynamics in two geomorphologically distinct tropical rain forest watersheds: Subsurface solute patterns. Biogeochemistry 18: 53-75.
70. Mitsch, W.J., G.L. Dorge, and J.R. Wiemhoff. 1979. Ecosystem dynamics and a phosphorus budget of an alluvial swamp in southern Illinois. Ecology 60:1116-1124.
71. Morris, J.T., G.J. Whiting, and F.H. Chapelle. 1988. Potential denitrification rates in deep sediments from the southeastern coastal plain. Environ. Sci. Technol. 22:832-836.
72. Murray, R.E., Y.S. Feig, and J.M. Tiedje. 1995. Spatial heterogeneity in the distribution of denitrifying bacteria associated with denitrification activity zones. Appl. Environ. Microbiol. 61:2791-2793.
73. Muscutt, A.D., G.L. Harris, S.W. Bailey, and D.B. Davies. 1993. Buffer zones to improve water quality: A review of their potential use in UK agriculture. Agric. Ecosyst. Environ. 45:59-77.
74. Nash, R.G., and A.R. Leslie (ed.) 1991. Groundwater residue sampling design. Am. Chem. Soc., Washington, DC.
75. Nielsen, D.M. (ed.). 1991. Practical handbook of groundwater monitoring. Lewis Publ., Chelsea, MI.
76. Nielsen, L.P., P.B. Christensen, N.P. Revsbech, and J. Sorensen. 1990. Denitrification and photosynthesis in stream sediment studied with microsensor and whole-core techniques. Limnol. Oceanogr. 35:1135-1144.
77. O'Neill, G.J., and A.M. Gordon. 1994. The nitrogen filtering capability of Carolina poplar in an artificial riparian zone. J. Environ. Qual. 23:1218-1223.
78. Oremland, R.S., C. Umberger, C.W. Culbertson, and R.L. Smith. 1984. Denitrification in San Francisco Bay sediments. Appl. Environ. Microbiol. 47:1106-1112.
79. Osborne, L.L., and D.A. Kovacic. 1993. Riparian vegetated buffer strips in water-quality restoration and stream management. Freshwater Biol. 29:243-258.
80. Parkin, T.B. 1987. Soil microsites as a source of denitrification variability. Soil Sci. Soc. Am. J. 51:1196-1199.
81. Payne, W.J. 1973. Reduction of nitrogenous oxides by microorganisms. Bacteriol. Rev. 37:409-452.
82. Peterjohn, W.T., and D.L. Correll. 1984. Nutrient dynamics in an agricultural watershed: Observations on the role of a riparian forest. Ecology 65:1466-1475.
83. Peterjohn, W.T., and D.L. Correll. 1986. The effect of riparian forest on the volume and chemical composition of baseflow in an agricultural watershed. p. 244-262. In D.L. Correll (ed.) Watershed research perspectives. Smithsonian Press, Washington, DC.
84. Petersen, R.C., B.L. Madsen, M.A. Wilzbach, C.H.D. Magadza, A. Paarlberg, A. Kullberg, and K.W. Cummins. 1987. Stream management: Emerging global similarities. Ambio 16:166-179.
85. Petersen, R.C., L.B-M. Petersen, and J. Lacoursiére. 1992. A building-block model for stream restoration. p. 293-309. In P.J. Boon et al. (ed.) River conservation and management. John Wiley and Sons, New York.
86. Phillips, P.J., J.M. Denver, R.J. Shedlock, and P.A. Hamilton. 1993. Effect of forested wetlands on nitrate concentrations in ground water and surface water on the Delmarva peninsula. Wetlands 13: 75-83.
87. Pinay, G., and H. Decamps. 1988. The role of riparian woods in regulating nitrogen fluxes between the alluvial aquifer and surface water: A conceptual model. Reg. Rivers Res. Manage. 2:507-516.
88. Pinay, G., N.E. Haycock, C. Ruffinoini, and R.M. Holmes. 1994. The role of denitrification in nitrogen removal in river corridors. p. 107-116. In W.J. Mitsch (ed.) Global wetlands: Old world and new. Elsevier Science, Amsterdam, the Netherlands.
89. Pinay, G., L. Rogues, and A. Fabre. 1993. Spatial and temporal patterns of denitrification in a riparian forest. J. Appl. Ecol. 30: 581-591.
90. Pionke, H.B., and R.R. Lowrance. 1991. Fate of nitrate in subsurface drainage waters. p. 237-257. In R.F. Follett et al. (ed.) Managing nitrogen for groundwater quality and farm profitability. SSSA, Madison.
91. Postma, D., C. Boesen, H. Kristiansen, and F. Larsen. 1991. Nitrate reduction in an unconfined sandy aquifer: Water chemistry, reduction processes, and geochemical modeling. Water Resour. Res. 27:2027-2045.
92. Rice, C.W., and J.M. Tiedje. 1989. Regulation of nitrate assimilation by ammonium in soils and in isolated soil microorganisms. Soil Biol. Biochem. 21:597-602.
93. Risser, P.G. 1990. The ecological importance of land-water ecotones. p. 7-21. In R.J. Naiman and H. Décamps (ed.) The ecology and management of aquatic-terrestrial ecotones. Man and the Biosphere Ser. UNESCO, The Partheon Publ. Group, Paris.
94. Robertson, W.D., J.A. Cherry, and E.A. Sudicky. 1991. Ground water contamination from two small septic systems on sand aquifers. Ground Water 29:82-92.
95. Roulet, N.T. 1990. Hydrology of a headwater basin wetland: Groundwater discharge and wetland maintenance. Hydrol. Proc. 4:387-400.
96. Schipper, L.A., A.B. Cooper, and W.J. Dyck. 1991. Mitigating nonpoint-source nitrate pollution by riparian zone denitrification. p. 401-413. In I. Bogárdi and R.D. Kuzelka (ed.) Nitrate contamination. NATO ASI Ser. Vol. G30. Springer-Verlag, Berlin.
97. Schipper, L.A., A.B. Cooper, C.G. Harfoot, and W.J. Dyck. 1993. Regulators of denitrification in an organic soil. Soil. Biol. Biochem. 25:925-933.
98. Schipper, L.A., C.G. Harfoot, P.N. McFarlane, and A.B. Cooper. 1994. Anaerobic decomposition and denitrification during plant decomposition in an organic soil. J. Environ. Qual. 23:923-928.
99. Schnabel, R.R. 1986. Nitrate concentrations in a small stream as affected by chemical and hydrologic interactions in the riparian zone. p. 263-281. In D.L. Correll (ed.) Watershed research perspectives. Smithsonian Press, Washington, DC.
100. Schuller, R.M., J.P. Gibb, and R.A. Griffin. 1981. Recommended sampling protocols for monitoring wells. Ground Water Monit. Rev. 1:42-46.
101. Seitzinger, S.P., L.P. Nielsen, J. Caffrey, and P.B. Christensen. 1993. Denitrification measurements in aquatic sediments: A comparison of three methods. Biogeochemistry 23:147-167.
102. Simmons, R.C., A.J. Gold, and P.M. Groffman. 1992. Nitrate dynamics in riparian forests: Groundwater studies. J. Environ. Qual. 21: 659-665.
103. Sklash, M.G., and R.N. Farvolden. 1979. The role of groundwater in storm runoff. J. Hydrol. 43:45-65.
104. Smith, R.L., and J.H. Duff. 1988. Denitrification in a sand and gravel aquifer. Appl. Environ. Microbiol. 54:1071-1078.
105. Smith, R.L., R.W. Harvey, and D.R. LeBlanc. 1991. Importance of closely spaced vertical sampling in delineating chemical and microbiological gradients in groundwater studies. J. Contam. Hydrol. 7:285-300.
106. Smith, C.J., R.D. DeLaune, and W.H. Patrick. 1982. Nitrate reduction in Spartina alterniflora marsh soil. Soil Sci. Soc. Am. J. 46: 748-750.
107. Sorensen, J. 1978. Capacity for denitrification and reduction of nitrate to ammonia in a coastal marine sediment. Appl. Environ. Microbiol. 35:301-305.
108. Starr, R.C., and R.W. Gillham. 1989. Controls on denitrification in shallow unconfined aquifers. p. 51-56. In C. Kobus and M. Kinzelbach (ed.) Contaminant transport in groundwater. Balkema, Rotterdam.
109. Starr, R.C., and R.W. Gillham. 1993. Denitrification and organic carbon availability in two aquifers. Ground Water 31:934-947.
110. Swanson, F.J., S.V. Gregory, J.R. Sedell, and A.G. Campbell. 1982. Land-water interactions: The riparian zone. p. 267-291. In R.L. Edmonds (ed.) Analysis of coniferous forest ecosystems in the western United States. US/IBP Synthesis Ser. 14. Hutchinson Ross Publ. Co., Stroudsburg, PA.
111. Tiedje, J.M. 1982. Denitrification. p. 1011-1026. In A.L. Page et al. (ed.) Methods of soil analysis. Part 2. 2nd ed. Agron. Monogr. 9. ASA and SSSA. Madison, WI.
112. Tiedje, J.M., S. Simkins, and P.M. Groffman. 1989. Perspectives on measurement of denitrification in the field including recommended protocols for acetylene based methods. Plant Soil 115:261-284.
113. Tiedje, J.M., J. Sorensen, and Y.-Y.L. Chang. 1981. Assimilatory and dissimilatory nitrate reduction: Perspectives and methodology for simultaneous measurement of several nitrogen cycle processes. p. 331-342. In F.E. Clark and T. Rosswall (ed.) Terrestrial nitrogen cycles. Ecol. Bull. (Stockholm) 33. FRN Stockholm.
114. Toth, J. 1963. A theoretical analysis of groundwater flow in small drainage basins. J. Geophys. Res. 68:4795-4812.
115. Triska, F.J., J.H. Duff, and J. Avanzino. 1993. The role of water exchange between a stream channel and its hyporheic zone in nitrogen cycling at the terrestrial-aquatic interface. Hydrobiologia 251:167-184.
116. Triska, F.J., V.C. Kennedy, R.J. Avanzino, G.W. Zellweyer, and K.E. Bencala. 1989. Retention and transport of nutrients in a third order stream in northwestern California: Hyporheic processes. Ecology 70:1893-1905.
117. Trudell, M.R., R.W. Gillham, and J.A. Cherry. 1986. An in-situ study of the occurrence and rate of denitrification in a shallow unconfined sand aquifer. J. Hydrol. 83:251-268.
118. Vitousek, P.M., and W.A. Reiners. 1975. Ecosystem succession and nutrient retention: A hypothesis. Bioscience 25:376-381.
119. Vought, L.B-M., J. Dahl, C.L. Pedersen, and J.O. Lacoursière. 1994. Nutrient retention in riparian zones. Ambio 23:342-348.
120. Waddington, J.M., N.T. Roulet, and A.R. Hill. 1993. Runoff mechanism in a forested groundwater discharge swamp. J. Hydrol. 147: 37-60.
121. Walter, H.M., D.R. Keeney, and I.R. Fillary. 1979. Inhibition of nitrification by acetylene. Soil Sci. Soc. Am. J. 43:709-716.
122. Warwick, J., and A.R. Hill. 1988. Nitrate depletion in the riparian zone of a small woodland stream. Hydrobiologia 157:231-240.
123. Weller, D.E., D.L. Correll, and T.E. Jordan. 1994. Denitrification in riparian forests receiving agricultural discharges. p. 117-131. In W.J. Mitsch (ed.) Global wetlands: Old world and new. Elsevier Science, Amsterdam, the Netherlands.
124. White, J.W.C., E.R. Cook, J.R. Lawrence, and W.S. Broecker. 1985. The D/H ratios of sap in trees: Implications for water sources and tree ring D/H ratios. Geochim. Cosmochim. Acta 49:237-246.
125. Winter, T.C. 1988. Conceptual framework for assessment of cumulative impacts on the hydrology on non-tidal wetlands. Environ. Manag. 12:605-620.
126. Winter, T.C. 1992. A physiographic and climatic framework for hydrologic studies of wetlands. p. 127-148. In R.D. Robarts and M.L. Bothwell (ed.) Aquatic ecosystems in semi-arid regions: Implications for resource management. NHRI Symp. Ser. 7. Environment Canada, Saskatoon.
127. Winter, T.C., and M.R. Llamas. 1993. Introduction to the 28th international geological congress symposium on the hydrogeology of wetlands. J. Hydrol. 141:1-3.
128. Young, R.A., T. Huntrods, and W. Anderson. 1980. Effectiveness of vegetated buffer strips in controlling pollution from feedlot runoff. J. Environ. Qual. 9:483-487.
129. Zak, D.R., and D.G. Grigal. 1991. Nitrogen mineralization, nitrification and denitrification in upland and wetland ecosystems. Oecologia 88:189-196.