Search USGS⌕ Search

USGS · 5224587

Reach-scale effects of riparian forest cover on urban stream ecosystems

Abstract

We compared habitat and biota between paired open and forested reaches within five small streams (basin area 10?20 km2) in suburban catchments (9%?49% urban land cover) in the Piedmont of Georgia, USA. Stream reaches with open canopies were narrower than forested reaches (4.1 versus 5.0 m, respectively). There were no differences in habitat diversity (variation in velocity, depth, or bed particle size) between open and forested reaches. However, absence of local forest cover corresponded to decreased large wood and increased algal chlorophyll a standing crop biomass. These differences in basal food resources translated into higher densities of fishes in open (9.0 individuals?m?2) versus forested (4.9 individuals?m?2) reaches, primarily attributed to higher densities of the herbivore Campostoma oligolepis. Densities of terrestrial invertebrate inputs were higher in open reaches; however, trends suggested higher biomass of terrestrial inputs in forested reaches and a corresponding higher density of terrestrial prey consumed by water column feeding fishes. Reach-scale biotic integrity (macroinvertebrates, salamanders, and fishes) was largely unaffected by differences in canopy cover. In urbanizing areas where catchment land cover drives habitat and biotic quality, management practices that rely exclusively on forested riparian areas for stream protection are unlikely to be effective at maintaining ecosystem integrity.

Explore related subjects

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

A.H. Roy, C.L. Faust, Mary C. Freeman, J.L. Meyer. 2005. Reach-scale effects of riparian forest cover on urban stream ecosystems. https://pubs.usgs.gov/publication/5224587

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related USGS reports

Effects of turbulence-inducing baffles on passage performance of brook trout, white sucker, and sea lamprey: Implications for conservation and control

Invasive sea lamprey ( Petromyzon marinus ) control in the Great Lakes is ongoing. Installing passive selective passage structures could reduce costs, yet there is a need to evaluate such methods under realistic hydraulic conditions to inform designs. In this study, we evaluated the swimming performance of brook trout ( Salvelinus fontinalis ), white sucker ( Catostomus commersonii ), and sea lamprey under manipulated flows and baffle configurations in a 35 m flume lined with substrate preventing attachment. Using accelerated failure time models, we examined ascent distance (Dmax) under two slopes (1% and 3%) and velocities from 0.25–3.0 m s⁻¹. Responses varied by species: white sucker had the greatest Dmax, especially at 1% slope, whereas sea lamprey, despite lacking paired fins/rays, occasionally exceeded white sucker at 3% with small spoiler baffles and bare substrate. Contrary to common perception, brook trout, the only salmonid in this study, performed less well than the other two species. Across species, higher velocities impaired performance, with declines linked to energy dissipation (EDF). Findings show how hydraulic structures shape species-specific passage.

Great Lakes↗

A framework for estimating age and growth using sibship relationships inferred from genomic data

Pedigree reconstruction based on genomic data offers a novel approach for estimating age and growth in wild populations. However, frameworks that use reconstructed pedigrees to parameterize growth models have not been available. We developed a sibship age and growth framework and evaluated the approach using simulation and an empirical application to Sea Lamprey ( Petromyzon marinus ) age and growth analysis. Simulation research revealed that the framework may be widely applicable to semelparous fishes. Applicability to iteroparous fishes was constrained to scenarios in which the percentage of multi-age sibling groups was low. Age assignment using the framework was unbiased for sibling groups first captured at younger ages. Age assignment for sibling groups first captured at older ages (after growth rate had substantially slowed) was biased low due to the hierarchal approach that we adopted to estimate sibling group age-at-first capture. However, this did not result in biased growth parameter estimates. Model output allowed for identification of unreliable age assignments. Finally, the empirical application provided evidence that the framework could address knowledge gaps that have been challenging to address with established age and growth methods.

Canadian Journal of Fisheries and Aquatic Sciences↗

Identifying overlap between native fish movements and a possible seasonal Grass Carp deterrent in the Sandusky River, Ohio, USA

Riverine fishes are vulnerable to habitat fragmentation caused by interrupted access to vital habitats. Fragmentation using artificial structures can be used to limit the spread of invasive fishes by inhibiting movement between critical habitats. Thus, tradeoffs exist between maintaining connectivity for native species and restricting movement of invasive fishes. A nonphysical deterrent has been proposed to prevent invasive Grass Carp ( Ctenopharyngodon idella ) from reaching spawning habitats in the Sandusky River, a tributary to Lake Erie, during late spring–summer. However, this timing overlaps with spawning periods of a suite of native fishes. We used acoustic telemetry and ichthyoplankton surveys to examine movement and spawning activity of multiple native species and to assess potential impacts of deterrent operation on reproduction. All species used the proposed deterrent location during the Grass Carp spawning period, and their movements corresponded with larval fish collections, indicating upstream spawning. These findings suggest the deterrent could unintentionally restrict native species’ access to essential habitats. Balancing habitat connectivity and invasive species control will likely depend on species-specific responses and careful timing of deterrent operation.

Ohio↗