Riparian zones possess an unusually diverse array of species and environmental processes. The ecological diversity is related to variable flood regimes, geographically unique channel processes, altitudinal climate shifts, and upland influences on the fluvial corridor. The resulting dynamic environment supports a variety of life-history strategies, biogeochemical cycles and rates, and organisms adapted to disturbance regimes over broad spatial and temporal scales. Innovations in riparian zone management have been effective in ameliorating many ecological issues related to land use and environmental quality. Riparian zones play essential roles in water and landscape planning, in restoration of aquatic systems, and in catalyzing institutional and societal cooperation for these efforts.

The Ecology of Interfaces: Riparian Zones

Multivariate statistical techniques for the evaluation of spatial and temporal variations in water quality of Gomti River (India)—a case study

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Hydrological functions of tropical forests: not seeing the soil for the trees?

Veterinary antibiotics in the aquatic and terrestrial environment

http://users.auth.gr/users/0/1/051310/public_html/Publications/19.pdf

Assessment of the surface water quality in Northern Greece.

Arainfall simulator was used to evaluate the effective-ness of vegetative filter strips (VFS) for the removal of sediment, nitrogen (N), and phosphorus (P) from cropland runoff. Simulated rainfall was applied to nine experimental field plots on an eroded Groseclose silt loam soil (clayey, mixed, mesic Typic Hapludalt) with a 5.5 by 18.3 m bare cropland source area and either a 0, 4.6, or 9.1 m VFS located at the lower end of each plot. Fertilizers were applied to the plots at rates of 222 kg/ha of liquid N and 112 kg/ha of P2O5 and K2O. Water samples were collected from the base of each plot and analyzed for sediment and nutrient content. One set of plots was constructed to encourage concentrated rather than shallow uniform flow. The 9.1 and 4.6 m VFS with shallow uniform flow removed an average of 84 and 70% of the incoming suspended solids, 79 and 61% of the incoming P, and 73 and 54% of the incoming N, respectively. Soluble nutrients in the filter effluent were sometimes greater than the incoming soluble nutrient load, presumably due to lower removal efficiencies for soluble nutrients and the release of nutrients previously trapped in the filters. Concentrations of soluble inorganic N and P in filter strip effluent were sufficient to cause eutrophic plant growth in aquatic ecosystems. Observation of existing VFS showed that on-farm VFS were not likely to be as effective as experimental VFS because of problems with flow concentrations.

Vegetative Filter Strips for Agricultural Nonpoint Source Pollution Control

Nonpoint sources of pollution that contribute fecal bacteria to surface waters have proven difficult to identify. Knowledge of pollution sources could aid in restoration of the water quality, reduce the amounts of nutrients leaving watersheds, and reduce the danger of infectious disease resulting from exposure to contaminated waters. Patterns of antibiotic resistance in fecal streptococci were analyzed by discriminant and cluster analysis and used to identify sources of fecal pollution in a rural Virginia watershed. A database consisting of patterns from 7,058 fecal streptococcus isolates was first established from known human, livestock, and wildlife sources in Montgomery County, Va. Correct fecal streptococcus source identification averaged 87% for the entire database and ranged from 84% for deer isolates to 93% for human isolates. To field test the method and the database, a watershed improvement project (Page Brook) in Clarke County, Va., was initiated in 1996. Comparison of 892 known-source isolates from that watershed against the database resulted in an average correct classification rate of 88%. Combining all animal isolates increased correct classification rates to > or = 95% for separations between animal and human sources. Stream samples from three collection sites were highly contaminated, and fecal streptococci from these sites were classified as being predominantly from cattle (>78% of isolates), with small proportions from waterfowl, deer, and unidentified sources ( approximately 7% each). Based on these results, cattle access to the stream was restricted by installation of fencing and in-pasture watering stations. Fecal coliforms were reduced at the three sites by an average of 94%, from prefencing average populations of 15,900 per 100 ml to postfencing average populations of 960 per 100 ml. After fencing, <45% of fecal streptococcus isolates were classified as being from cattle. These results demonstrate that antibiotic resistance profiles in fecal streptococci can be used to reliably determine sources of fecal pollution, and water quality improvements can occur when efforts to address the identified sources are made.

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Determining sources of fecal pollution in a rural Virginia watershed with antibiotic resistance patterns in fecal streptococci.

Nitrogen removal in constructed wetlands employed to treat domestic wastewater.

C  H A G E D O R N , J  B  C R O Z I E R , K  A  M E N T Z , A  M  B O O T H , A  K  G R A V E S , N  J  N E L S O N A N D R  B  R E N E A U J R  2003 Aims: Carbon source utilization profiles as a phenotypic fingerprinting methodology for determining sources of faecal pollution in water were evaluated Methods and Results: Three hundred and sixty-five Enterococcus isolates were collected from known faecal sources in four different geographical regions and were identified to species with the commercial Biolog system Discriminant analysis (DA) was used to identify the substrate-containing wells that best classified the 365 isolates by source By using 30 of the 95 wells for the analysis, the average rate of correct classification (ARCC) by source was 92AE7% for a human vs non-human two-way classification when isolates from all regions were combined into one library Corresponding ARCCs for other classification schemes were 81AE9% for a four-way classification of human vs livestock vs wildlife vs domestic pets, and 85AE7% for a three-way classification without human isolates When three individual libraries were made based on classification of sources within Enterococcus species, the ARCC was 95AE3% for the Ent faecalis library, 95AE8% for the Ent gallinarum library and 94AE7% for the Ent mundtii library Thirty Enterococcus isolates (unknown sources) were obtained from each of three stream sites where a specific source of pollution was apparent; 90AE0% of the isolates from a human-suspected source were classified as human, 86AE6% were classified as livestock from a livestock-suspected site, and 93AE3% were classified as wildlife from a wildlife-suspected site Conclusions: Phenotypic fingerprinting with carbon source utilization profiles provided levels of correct classification by sources from an Enterococcus library that were in the upper range of those reported in the literature ARCCs for three Enterococcus species-specific libraries were very high and may be the best approach for further developing this concept and methodology Significance and Impact of the Study: The results, based on a modest Enterococcus library and a preliminary field validation test, demonstrated the potential for carbon source utilization profiles to be employed as a phenotypic method for determining sources of faecal pollution in water

R. B. Reneau

Papers

Vegetative Filter Strips for Agricultural Nonpoint Source Pollution Control

Determining sources of fecal pollution in a rural Virginia watershed with antibiotic resistance patterns in fecal streptococci.

Nitrogen removal in constructed wetlands employed to treat domestic wastewater.

Carbon source utilization profiles as a method to identify sources of faecal pollution in water.

Nitrate removal in riparian wetland soils: Effects of flow rate, temperature, nitrate concentration and soil depth