01821nas a2200181   4500008004100000245005100041210005000092300001500142490000800157520128700165100001901452700001701471700001801488700001801506700001601524700001701540856008201557       2006                        eng d00aModular experimental riffle-pool stream system0 aModular experimental rifflepool stream system  a1559 -15660 v1353 aWe describe a modular method for building a large, outdoor experimental stream system that has great flexibility for research projects in fish ecology, behavior, conservation, or management. The system has been in use for more than a decade at the University of Oklahoma Biological Station (Kingston, Oklahoma) and has been used with modification at four other research facilities in the Midwest. Here, we document the system in detail, including specifications for construction of the original system and modifications or improvements at other sites. The system uses commercially available, customized fiberglass round tank and trough units that can be configured in many different ways to create flowing pool and riffle habitats. The system appears to be a good mimic of small natural streams based on system flow rates, establishment of natural substrates and cover, stream chemistry relative to that of a natural creek, and fish behaviors. At least 39 fish species have been used successfully in 1–14-month experiments in these systems and approximately half have reproduced. The system offers great flexibility of design to experimenters, is cost effective, and may be of interest at other facilities that research basic biology, conservation, or management of stream fishes.1 aMatthews, W.J.1 aGido, K., B.1 aGarrett, G.P.1 aGelwick, F.P.1 aStewart, J.1 aSchaefer, J.  uhttp://knz.lternet.edu/content/modular-experimental-riffle-pool-stream-system01524nas a2200169   4500008004100000245006600041210006500107300001300172490000700185520099300192100001801185700001701203700001701220700001601237700001901253856008201272       2004                        eng d00aLife on the edge: the ecology of Great Plains prairie streams0 aLife on the edge the ecology of Great Plains prairie streams  a207 -2810 v543 aGreat Plains streams are highly endangered and can serve as model systems for studying disturbance ecology and related issues of resistance and resilience in temperate freshwaters. These streams exist in a precarious balance between flood and drying. In general, microbial activity recovers in days to weeks after drying or flooding, and invertebrate and fish species are quick to follow. In lower forested reaches, floods may be more intense but drying less common. Upstream reaches of prairie streams are characterized by frequent drying, little canopy cover, and limited leaf input. Life history and adaptations alter the ways in which stream organisms respond to these linear patterns. Human modification has altered these patterns, leading to large-scale loss of native grassland streams. The future for Great Plains streams is bleak, given the land-use changes and water-use patterns in the region and the large areas required to preserve intact, ecologically functional watersheds.1 aDodds, W., K.1 aGido, K., B.1 aWhiles, M.R.1 aFritz, K.M.1 aMatthews, W.J.  uhttp://knz.lternet.edu/content/life-edge-ecology-great-plains-prairie-streams02309nas a2200253   4500008004100000245010500041210006900146300001300215490000700228520150300235653001501738653001301753653001401766653001101780653002301791653001401814653001801828100001801846700001701864700001701881700001601898700001901914856012201933       2004                        eng d00aQuality and quantity of suspended particles in rivers: Continent-scale patterns in the United States0 aQuality and quantity of suspended particles in rivers Continents  a355 -3670 v333 aSuspended solids or sediments can be pollutants in rivers, but they are also an important component of lotic food webs. Suspended sediment data for rivers were obtained from a United States–wide water quality database for 622 stations. Data for particulate nitrogen, suspended carbon, discharge, watershed area, land use, and population were also used. Stations were classified by United States Environmental Protection Agency ecoregions to assess relationships between terrestrial habitats and the quality and quantity of total suspended solids (TSS). Results indicate that nephelometric determinations of mean turbidity can be used to estimate mean suspended sediment values to within an order of magnitude (r2 = 0.89). Water quality is often considered impaired above 80 mg TSS L−1, and 35% of the stations examined during this study had mean values exceeding this level. Forested systems had substantially lower TSS and somewhat higher carbon-to-nitrogen ratios of suspended materials. The correlation between TSS and discharge was moderately well described by an exponential relationship, with the power of the exponent indicating potential acute sediment events in rivers. Mean sediment values and power of the exponent varied significantly with ecoregion, but TSS values were also influenced by land use practices and geomorphological characteristics. Results confirm that, based on current water quality standards, excessive suspended solids impair numerous rivers in the United States.10aEcoregions10aLand use10apollution10aSeston10aSuspended sediment10aTurbidity10awater quality1 aDodds, W., K.1 aGido, K., B.1 aWhiles, M.R.1 aFritz, K.M.1 aMatthews, W.J.  uhttp://knz.lternet.edu/content/quality-and-quantity-suspended-particles-rivers-continent-scale-patterns-united-states