Longitudinal Structure of an Agricultural Prairie River System and its Relationship to Current Stream Ecosystem Theory

Abstract

The largescale structure of an agriculturally developed prairie river system in central Illinois was examined and compared with predictions from current stream ecosystem theory. High rates of primary productivity (> 15 g carbon∙m−2∙d−1) were characteristic of the watershed, although longitudinal patterns in riparian vegetation, stream temperature, and primary productivity were inverted relative to typical streams in forested uplands. Empirical models of gross primary production and community respiration were developed. Light availability, mediated by both channel shading and turbidity, appeared to be the principal factor limiting primary productivity. Both nitrate and orthophosphorus were found in high concentrations throughout the watershed. Largescale patterns in nutrient availability suggest that landuse patterns, and particularly urbanization, strongly affected spatial and temporal distributions of both nutrients. Differences between prairie river systems and "prototype" structures envisioned by the River Continuum Concept (RCC) derive from the descriptive nature of the RCC, and its inability to incorporate nonstandard distributions of key driving variables. The use of empirical modelling in stream ecosystem studies is discussed.

Longitudinal patterns of metabolism in a southern Appalachian river

“…NPP at our upstream sites was lower than reported for other 4th-order streams, but several of those streams were in agricultural regions of the midwest where primary production was high because of high nutrients and light (Flemer 1970, Wiley et al 1990). Walker Camp Prong, in the Great Smoky Mountain National Park, Tennessee, had the lowest NPP of streams compared here (Mulholland et al 1986).…”

“…Walker Camp Prong, in the Great Smoky Mountain National Park, Tennessee, had the lowest NPP of streams compared here (Mulholland et al 1986). Although NPP at our upstream sites was low, our downstream sites had NPP values that were higher than other eastern US streams (Hoskin 1959, Hornberger et al 1977, Sumner and Fisher 1979, Hill and Webster 1982, Bott et al 1985 but lower than streams from the midwest (Bott et al 1985, Wiley et al 1990). NPP at our most downstream site was very similar to the New River, Virginia, another mid-sized southern Appalachian river (Hill and Webster 1982).…”

“…Despite the impact of humans on the LTR from impoundment and agriculture, the Raritan River, New Jersey (Flemer 1970) and Vermilion River, Illinois (Wiley et al 1990) had much higher R as a result of nutrient loading from agricultural or municipal sources. R in our downstream reaches was similar to other rivers in the Appalachians (Hornberger et al 1977) …”

Zooplankton of the Paraguay River : a comparison between sections and hydrological phases

“…The question of how the structure and function of communities change from headwaters to river mouths in relation to the abiotic environment remains a central issue in the study of the biology of running water systems ( Vannote et al 1980, Statzner & Higler 1985, Minshall et al 1985, Meyer & Edwards 1990, Wiley et al 1990, Petts & Calow 1996, Miranda & Raborn 2000, Maamri et al 2005. Several investigations of river zooplankton have shown that abundance and species richness increase downstream though the information available for large South American Rivers is limited (José de , Saunders & Lewis 1989, Vasquez & Rey 1989.…”

Influência de fatores ambientais na distribuição de famílias de insetos aquáticos em rios no sul do Brasil

“…The land use is strongly related to patterns of large-scale (geographic), but patterns in the levels of land use influence water chemistry and subsequently biotic assemblages (eg communities of invertebrates and fish) (WILEY et al, 1990;TOWNSEND et al, 1997). The community structure can be more sensitive to disturbances of local land use than the ecosystem processes that incorporate both biotic and abiotic components in spatial scales broader (SPONSELLER et al, 2001).…”