999 resultados para stream restoration


Relevância:

100.00% 100.00%

Publicador:

Resumo:

The long-term performance of infrastructure depends on reliable and sustainable designs. Many of Pennsylvania’s streams experience sediment transport problems that increase maintenance costs and lower structural integrity of bridge crossings. A stream restoration project is one common mitigation measure used to correct such problems at bridge crossings. Specifically, in an attempt to alleviate aggradation problems with the Old Route 15 Bridge crossing on White Deer Creek, in White Deer, PA, two in-stream structures (rock cross vanes) and several bank stabilization features were installed along with a complete channel redevelopment. The objectives of this research were to characterize the hydraulic and sediment transport processes occurring at the White Deer Creek site, and to investigate, through physical and mathematical modeling, the use of instream restoration structures. The goal is to be able to use the results of this study to prevent aggradation or other sediment related problems in the vicinity of bridges through improved design considerations. Monitoring and modeling indicate that the study site on White Deer Creek is currently unstable, experiencing general channel down-cutting, bank erosion, and several local areas of increased aggradation and degradation of the channel bed. An in-stream structure installed upstream of the Old Route 15 Bridge failed by sediment burial caused by the high sediment load that White Deer Creek is transporting as well as the backwater effects caused by the bridge crossing. The in-stream structure installed downstream of the Old Route 15 Bridge is beginning to fail because of the alignment of the structure with the approach direction of flow from upstream of the restoration structure.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

At a global scale, aquatic ecosystems are being altered by human activities at a greater rate than at any other time in history. In recent years, grassroots efforts have generated interest in the restoration of degraded or destroyed aquatic habitats, especially small wetlands and streams where such projects are feasible with local resources. We present ecological management lessons learned from 17 years of monitoring the fish community response to the channel relocation and reach-level restoration of Juday Creek, a 3rd-order tributary of the St. Joseph River in Indiana, USA. The project was designed to increase habitat complexity, reverse the effects of accumulated fine sediment (< 2 mm diameter), and mitigate for the impacts of a new golf course development. The 1997 restoration consisted of new channel construction within two reaches of a 1.2-km section of Juday Creek that also contained two control reaches. A primary social goal of the golf course development and stream restoration was to avoid harm to the non-native brown trout fishery, as symbolic of community concerns for the watershed. Our long-term monitoring effort revealed that, although fine sediment increased over time in the restored reaches, habitat conditions have promoted the resurgence of native fish species. Since restoration, the fish assemblage has shifted from non-native Salmonidae (brown trout, rainbow trout) to native Centrarchidae (rock bass, largemouth bass, smallmouth bass). In addition, native, nongame species have remained stable or have increased in population abundance (e.g., Johnny darter, mottled sculpin). The results of this study demonstrate the value of learning from a restoration project to adjust management decisions that enhance environmental quality.

Relevância:

70.00% 70.00%

Publicador:

Resumo:

Vam monitoritzar paràmetres físics i químics, macroinvertebrats bentònics, clorofil·la a, productors primaris i matèria orgànica durant un any (2001-2002) per examinar els efectes d'una font puntual sobre la composició taxonòmica, la estructura de la comunitat, l'organització funcional, la utilització de l'habitat i la estoquiometria al riu la Tordera (Catalunya). Aigües avall de la font puntual, concentració de nutrients, cabal i conductivitat eren majors que al tram d'aigües amunt, mentre que oxigen dissolt era menor. La densitat de macroinvertebrats era més elevada al tram d'aigües avall però la biomassa era similar als dos trams. La riquesa taxonòmica al tram de dalt era un 20% més alt que al tram de baix. Els anàlisis d'ordenació separen clarament els dos trams en el primer eix, mentre que els dos trams presentaven una pauta temporal similar en el segon eix. La similaritat entre els dos trams en composició taxonòmica, densitats i biomasses després de les crescudes d'abril i maig de 2002, indiquen que les pertorbacions del cabal poden actuar com a un mecanisme de reinici de la comunitat bentònica i jugar un paper important per a la restauració d'ecosistemes fluvials. Els dos trams presentaven una biomassa de perifiton, plantes vasculars, CPOM i FPOM similars, mentre que clorofil·la a, algues filamentoses, molses i SPOM eren majors al tram d'aigües avall. La densitat relativa de trituradors era menor sota la font puntual mentre que col·lectors i filtradors van ser afavorits. La biomassa relativa de trituradors també era menor sota la font puntual, però la biomassa de col·lectors i depredadors va augmentar. Les relacions entre densitat de grups tròfics i els seus recursos eren rarament significatives. La relació s'explicava millor amb la biomassa de macroinvertebrats. Els dos trams compartien la mateixa relació per raspadors, col·lectors i filtradors però no per trituradors i depredadors. La densitat i la biomassa de macroinvertebrats es trobaven positivament correlacionades amb la quantitat de recursos tròfics i la complexitat d'habitat, mentre que la riquesa taxonòmica es trobava negativament relacionada amb paràmetres hidràulics. La influència dels substrats inorgànics prenia menor rellevància per a la distribució dels macroinvertebrats. Els anàlisis d'ordenació mostren com les variables del microhabitat de major rellevància eren CPOM, clorofil·la a, algues filamentoses i velocitat. La cobertura de sorra només era significativa per al tram d'aigües amunt i les molses, al d'aigües avall. El número de correlacions significatives entre macroinvertebrats i les variables del microhabitat era més elevat per al tram de dalt que per al de baix, bàsicament per diferències en composició taxonòmica. La biomassa de macroinvertebrats va aportar una informació semblant a la obtinguda per la densitat. Perifiton i molses tenien uns continguts de nutrients similars en els dos trams. Els %C i %N d'algues filamentoses també eren similars en els dos trams però el %P sota la font puntual era el doble que al tram de dalt. Les relacions estoquiomètriques en CPOM, FPOM i SPOM eren considerablement menors sota la font puntual. Els continguts elementals i relacions van ser molt variables entre taxons de macroinvertebrats però no van resultar significativament diferents entre els dos trams. Dípters, tricòpters i efemeròpters presentaven una estoquiometria similar, mentre que el C i el N eren inferiors en moluscs i el P en coleòpters. Els depredadors presentaven un contingut en C i N més elevat que la resta de grups tròfics, mentre que el P era major en els filtradors. Els desequilibris elementals entre consumidors i recursos eren menors en el tram d'aigües avall. A la tardor i l'hivern la major font de nutrients va ser la BOM mentre que a la primavera i a l'estiu va ser el perifiton.

Relevância:

60.00% 60.00%

Publicador:

Resumo:

Catchment and riparian degradation has resulted in declining ecosystem health of streams worldwide. With restoration a priority in many regions, there is an increasing interest in the scale at which land use influences stream ecosystem health. Our goal was to use a substantial data set collected as part of a monitoring program (the Southeast Queensland, Australia, Ecological Health Monitoring Program data set, collected at 116 sites over six years) to identify the spatial scale of land use, or the combination of spatial scales, that most strongly influences overall ecosystem health. In addition, we aimed to determine whether the most influential scale differed for different aspects of ecosystem health. We used linear-mixed models and a Bayesian model-averaging approach to generate models for the overall aggregated ecosystem health score and for each of the five component indicators (fish, macroinvertebrates, water quality, nutrients, and ecosystem processes) that make up the score. Dense forest close to the survey site, mid-dense forest in the hydrologically active nearstream areas of the catchment, urbanization in the riparian buffer, and tree cover at the reach scale were all significant in explaining ecosystem health, suggesting an overriding influence of forest cover, particularly close to the stream. Season and antecedent rainfall were also important explanatory variables, with some land-use variables showing significant seasonal interactions. There were also differential influences of land use for each of the component indicators. Our approach is useful given that restoring general ecosystem health is the focus of many stream restoration projects; it allowed us to predict the scale and catchment position of restoration that would result in the greatest improvement of ecosystem health in the regions streams and rivers. The models we generated suggested that good ecosystem health can be maintained in catchments where 80% of hydrologically active areas in close proximity to the stream have mid-dense forest cover and moderate health can be obtained with 60% cover.

Relevância:

60.00% 60.00%

Publicador:

Resumo:

HIGHLIGHTS FOR FY 2006 1. Captured and tagged 475 Gulf sturgeons in five Florida rivers and one bay. 2. Documented Gulf sturgeon marine movement and habitat use in the Gulf of Mexico. 3. Assisted the National Oceanic and Atmospheric Administration (NOAA) with the collection of Gulf sturgeon, implantation of acoustic tags, and monitoring of fish in a study to examine movement patterns and habitat use in Pensacola and Choctawhatchee bays post-Hurricane Ivan. 4. Provided technical assistance to Jon “Bo” Sawyer in completing a study – Summer Resting Areas of the Gulf Sturgeon in the Conecuh/Escambia River System, Alabama-Florida – for acquiring a Degree of Master of Science at Troy University, Alabama. 5. Coordinated tagging and data collection with NOAA observers aboard trawlers while collecting Gulf sturgeon during dredging operations in the coastal Gulf of Mexico. 6. Hosted the 7th Annual Gulf Sturgeon Workshop. 7. Implemented Gulf Striped Bass Restoration Plan by coordinating the 23rd Annual Morone Workshop, leading the technical committee, transporting broodfish, coordinating the stocking on the Apalachicola-Chattahoochee-Flint (ACF) river system, and evaluating post-stocking success. 8. Continued updating and managing the Freshwater Mussel Survey Database, a Geographic Information System (GIS) database, for over 800 unique sites in the Northeast Gulf (NEG) drainages in Alabama (AL), Georgia (GA), and Florida (FL). 9. Formed a recovery implementation team for listed mussels in the ACF river basin and oversaw grant cooperative agreements for 14 listed and candidate freshwater mussels in the NEG watersheds. 10. Initiated a project in the Apalachicola River to relocate mussels stranded as a result of drought conditions, and calculate river flows at which mussels would be exposed. 11. Initiated a project in Sawhatchee Creek, Georgia to determine the status of threatened and endangered (T&E) freshwater mussels and target restoration projects, population assessments, and potential population augmentation to lead toward recovery of the listed species. 12. Initiated a study to determine the age and growth of the endangered fat threeridge mussel (Amblema neislerii). 13. Provided technical assistance to the Panama City Ecological Services office for a biological opinion on the operations of Jim Woodruff Lock and Dam and its effects on the listed species and designated and proposed critical habitat in the Apalachicola River, Florida. 14. Assisted with a multi-State, inter-agency team to develop a management plan to restore the Alabama shad in the ACF river system. 15. Conducted fishery surveys on Tyndall AFB, Florida and Ft. Benning, Georgia and completed a report with recommendations for future recreational fishery needs. 16. Provided fishery technical assistance to four National Wildlife Refuges (NWR) (i.e., Okefenokee NWR, Banks Lake NWR, St. Vincent NWR, and St. Marks NWR). 17. Initiated an Aquatic Resources and Recreation Fishing Survey on Department of Defense facilities located in Region 4. 18. Identified 130 road-stream crossings on Eglin AFB for rehabilitation and elimination of sediment imputs. 19. Continued the Aquatics Monitoring Program at Eglin AFB to assess techniques that determine current status and sustainability of aquatic habitat and develop a measure to determine quality or degradation of habitat. 20. Assisted Eglin AFB Natural Resource managers in revising the installation’s Integrated Natural Resources Management Plan (INRMP) and its associated component plans. 21. Coordinated recovery efforts for the endangered Okaloosa darter including population/life history surveys, stream restoration, and outreach activities. 22. Initiated a comprehensive status review of the Okaloosa darter with analyses performed to assess available habitat, preferred habitats, range expansions/reductions/fragmentations, population size, and probability of extinction. 23. Assisted the Gulf Coastal Plain Ecosystem Partnership and the Florida Fish and Wildlife Conservation Commission (FWC) under a Memorandum of Agreement to develop conservation strategies, implement monitoring and assessment programs, and secure funds for aquatic management programs in six watersheds in northwest Florida and southeast Alabama. 24. Entered into a cooperative agreement with the U.S. Air Force to encourage the conservation and rehabilitation of natural resources at Hurlburt Field, Florida. 25. Multiple outreach projects were completed to detail aquatic resources’ conservation needs and opportunities; including National Fishing Week, Earth Day, several festivals, and school outreach.

Relevância:

60.00% 60.00%

Publicador:

Resumo:

HIGHLIGHTS FOR FY 2005 1. Assisted with a study to assess hurricane impacts to Gulf sturgeon critical foraging habitat. 2. Documented Gulf sturgeon marine movement and habitat use in the Gulf of Mexico. 3. Documented Gulf sturgeon spawning with the collection of fertilized eggs in the Apalachicola River, Florida. 4. Documented Gulf sturgeon spawning with the collection of fertilized eggs in the Yellow River, Florida. 5. Assisted with benthic invertebrate survey at Gulf sturgeon marine foraging grounds. 6. Implemented Gulf Striped Bass Restoration Plan by coordinating the 22nd Annual Morone Workshop, leading the technical committee, transporting broodfish, and coordinating the stocking on the Apalachicola-Chattahoochee-Flint (ACF) river system. 7. Over 87,000 Phase II Gulf striped bass were marked with sequential coded wire tags and stocked in the Apalachicola River. Post-stocking evaluations were conducted at 45 sites in the fall and spring and 8 thermal refuges in the summer. 8. Completed fishery surveys on 4 ponds on Eglin AFB totaling 53 acres, and completed a report with recommendations for future recreational fishery needs. 9. Completed final report for aquatic monitoring at Eglin AFB from 1999 to 2004. 10. Completed a field collection of the endangered Okaloosa darter to be incorporated into a status review to be completed in FY06. 11. Provided technical assistance to the Region 4 National Wildlife Refuge (NWR) program on changes to the fishery conservation targets for the region. Also provided technical assistance to four NWRs (i.e., Okefenokee NWR, Banks Lake NWR, St. Vincent NWR, and St. Marks NWR) relative to hurricanes and recreational fishing. 12. A draft mussel sampling protocol was tested in wadeable streams in Northwest Florida and southwest Georgia, and an associated field guide, poster, and Freshwater Mussel Survey Protocol and Identification workshop were completed in FY05. 13. Implemented recovery plan and candidate conservation actions for 14 listed and candidate freshwater mussels in the Northeast Gulf Watersheds. 14. Initiated or completed multiple stream restoration and watershed management projects. A total of 7.5 stream miles were restored for stream fishes, and 11 miles of coastline were enhanced for sea turtle lighting. A total of 630 acres of wetlands and 2,401 acres of understory habitat were restored. 15. Conducted a watershed assessment to develop a threats analysis for prioritizing restoration, protection, and enhancement to natural resources of Spring Creek, Georgia and Canoe Creek, Florida. 16. Continued the formation of an Unpaved Road Interagency Team of Federal, State, and local agencies in Northwest Florida to promote stream protection and restoration from unpaved road sediment runoff. Began the development of a technical committee agreement. 17. Conducted Alabama Unpaved Road Inventory within the Northeast Gulf Ecosystem. Data collection will be completed during FY06. 18. Finalized the development of two North Florida hydrophysiographic regional curves for use by the Florida Department of Transportation (DOT) and others involved with stream restoration and protection. Initiated the development of the Alabama Coastal Plain Riparian Reference Reach and Regional Curves for use by the Alabama Department of Environmental Management (ADEM). 19. Provided technical assistance in collecting data, analysis, and thesis formulation with Troy University, Alabama, to identify the influence of large woody debris in southeastern coastal plain streams. 20. Completed pre- and post-restoration fish community monitoring at several restoration projects including Big Escambia Creek, Magnolia Creek, and Oyster Lake, Florida. 21. Established a watershed partnership for the Chipola River in Alabama and Florida and expanded development and participation in the Spring Creek Watershed Partnership, Georgia. 22. Continued to identify barriers which inhibit the movement of aquatic species within the Northeast Gulf Ecoregion. 23. Completed a report on road crossing structures in Okaloosa darter streams to guide the closure/repair/maintenance of roads to contribute to recovery of the endangered species. In cooperation with Three Rivers RC&D Council, fish passage sites identified in the report were prioritized for restoration. 24. Monitored Aquatic Nuisance Species in the Apalachicola River and tested the sterility of exotic grass carp. 25. Multiple outreach projects were completed to detail aquatic resources conservation needs and opportunities. Participated in National Fishing Week event, several festivals, and school outreach.

Relevância:

60.00% 60.00%

Publicador:

Resumo:

HIGHLIGHTS FOR FY 2004 1. Completed the second of a 3-year Gulf sturgeon population estimate on the Escambia River, Florida. 2. Completed the first of a 2-year Gulf sturgeon population estimate on the Apalachicola River, Florida. 3. Conducted Gulf sturgeon presence-absence surveys in three other Florida river systems. 4. Documented Gulf sturgeon marine habitat use in the near shore waters of the Gulf of Mexico. 5. Identified environmental threats to Gulf sturgeon spawning habitat in the Choctawhatchee River, Florida. 6. Initiated a study to document Gulf sturgeon spawning with the collection of fertilized eggs in the Yellow River, Florida. 7. Implemented Gulf Striped Bass Restoration Plan by coordinating the 21st Annual Morone Workshop, leading the technical committee, transporting broodfish, and coordinating the stocking on the Apalachicola-Chattahoochee-Flint (ACF) river system. 8. Over 86,000 Phase II Gulf striped bass were marked with sequential coded wire tags and stocked in Lake Seminole and the Apalachicola River. Post-stocking evaluations were conducted at 31 sites. 9. Drafted updates to Apalachicola-Chattahoochee-Flint Striped Bass Restoration and Evaluation Five-Year Plan with partners. 10. Fishery surveys were conducted on Tyndall Air Force Base and St. Marks and St. Vincent National Wildlife Refuges. 11. Habitat evaluations and population surveys were completed at 153 Okaloosa darter stream sites. 12. Aquatic insect biomonitoring and identification of over 39,000 individual aquatic macroinvertebrates was completed and provided to Eglin Air Force Base. 13. Ten years of fishery data from Okefenokee and Banks Lake National Wildlife Refuges was analyzed with recommendations incorporated into the refuge Comprehensive Conservation Plan. 14. A draft mussel sampling protocol was tested in wadeable streams in northwest Florida and southwest Georgia. 15. Implemented recovery plan and candidate conservation actions for 14 listed and candidate freshwater mussels in the Northeast Gulf Watersheds. 16. Worked with partners in developing the Spring Creek Watershed Partnership in the Flint River basin, Georgia. 17. Multiple stream restoration and watershed management projects were initiated or completed. A total of 6.8 stream miles were restored for stream fishes, along with 56.4 miles of coastline were enhanced for sea turtle lighting. A total of 135 acres of wetlands and 58 acres of understory habitat were restored. 18. Multiple outreach projects were completed to detail aquatic resources conservation needs and opportunities. Participated in National Fishing Week event, BASS ProShops event, several festivals, and school outreach.

Relevância:

60.00% 60.00%

Publicador:

Resumo:

HIGHLIGHTS FOR FY 2003 1. Continued a 3-year threatened Gulf sturgeon population estimate in the Escambia River, Florida and conducted presence-absence surveys in 4 other Florida river systems and 1 bay. 2. Five juvenile Gulf sturgeon collected, near the mouth of the Choctawhatchee River, Florida, were equipped with sonic tags and monitored while over-wintering in Choctawhatchee Bay. 3. Continued to examine Gulf sturgeon marine habitat use. 4. Implemented Gulf Striped Bass Restoration Plan by coordinating the 20th Annual Morone Workshop, leading the technical committee, transporting broodfish, and coordinating the stocking on the Apalachicola-Chattahoochee-Flint (ACF) river system. 5. Over 73,000 Phase II Gulf striped bass were marked with sequential coded wire tags and stocked in the Apalachicola River. Post-stocking evaluations were conducted at 31 sites. 6. Three stream fisheries assessment s were completed to evaluate the fish community at sites slated for habitat restoration by the Partners for Fish and Wildlife Program (PFW). 7. PFW program identified restoration needs and opportunities for 10 areas. 8. Developed an Unpaved Road Evaluation Handbook. 9. Completed restoration of Chipola River Greenway, Seibenhener Streambank Restoration, Blackwater River State Forest, and Anderson Property. 10. Assessments for fluvial geomorphic conditions for design criteria were completed for 3 projects. 11. Geomorphology in Florida streams initiated development of Rosgen regional curves for Northwest Florida for use by the Florida Department of Transportation. 12. Developed a Memorandum of Understanding between partners for enhancing, protecting, and restoring stream, wetland, and upland habitat in northwest Florida 13. Completed aquatic fauna and fish surveys with new emphasis on integration of data from reach level into watershed and landscape scale and keeping database current. 14. Compliance based sampling of impaired waterbodies on Eglin Air Force Base in conjunction with Florida Department of Environmental Protection for Total Maximum Daily Load development support. 15. Surveyed 20 sites for the federally endangered Okaloosa darter, provided habitat descriptions, worked with partners to implement key recovery tasks and set priorities for restoration. 16. Worked with partners to develop a freshwater mussel survey protocol to provide standard operating procedures for establishing the presence/absence of federally listed mussel species within a Federal project area. 17. GIS database was created to identify all known freshwater mussel records from the northeast Gulf ecosystem. 18. Completed recovery plan for seven freshwater mussels and drafted candidate elevation package for seven additional mussels. Developed proposals to implement recovery plan. 19. Worked with Corps of Engineers and State partners to develop improved reservoir operating policies to benefit both riverine and reservoir fisheries for the ACF river system. 20. Multiple outreach projects were completed to detail aquatic resources conservation opportunities. 21. Multiple stream restoration and watershed management projects initiated or completed (see Appendix A).

Relevância:

60.00% 60.00%

Publicador:

Resumo:

HIGHLIGHTS FOR FY 2002 1. United States Senator Bob Graham assisted with a Gulf sturgeon survey. 2. Completed 3-year Gulf sturgeon population study in the Choctawhatchee River drainage. 3. Completed Gulf sturgeon potential spawning habitat survey for Northwest Florida and Southeast Alabama river systems. 4. Initiated Gulf sturgeon marine habitat and food resources study. 5. Completed Gulf sturgeon sentinel fish study. 6. Coordinated and conducted tagging of over 110,000 Phase II striped bass at Welaka and Warm Springs National Fish Hatchery. 7. Completed Okefenokee National Wildlife Refuge fishery sampling. 8. Developed a manuscript regarding the fishery of Banks Lake NWR. 9. Initiated development of a fish Index of Biotic Integrity for Florida panhandle streams. 10. Coordinated Okaloosa darter workshop. 11. Continued examining insect communities on Eglin AFB. 12. Sponsored and coordinated stream restoration workshop. 13. Provided technical assistance via Partners for Fish and Wildlife for stream restoration within the Northeast Gulf Ecosystem. 14. Finalized regional curve development in the Northern Region of Florida and secured significant funds for FY03 to expand to other regions in Florida. 15. Initiated freshwater mussel conservation in the Northeastern Gulf Ecosystem.

Relevância:

60.00% 60.00%

Publicador:

Resumo:

Worldwide, the ecological condition of streams and rivers has been impaired by agricultural practices such as broadscale modification of catchments, high nutrient and sediment inputs, loss of riparian vegetation, and altered hydrology. Typical responses include channel incision, excessive sedimentation, declining water quality, and loss of in-stream habitat complexity and biodiversity. We review these impacts, focusing on the potential benefits and limitations of wood reintroduction as a transitional rehabilitation technique in these agricultural landscapes using Australian examples. In streams, wood plays key roles in shaping velocity and sedimentation profiles, forming pools, and strengthening banks. In the simplified channels typical of many agricultural streams, wood provides habitat for fauna, substrate for biofilms, and refuge from predators and flow extremes, and enhances in-stream diversity of fish and macroinvertebrates.

Most previous restoration studies involving wood reintroduction have been in forested landscapes, but some results might be extrapolated to agricultural streams. In these studies, wood enhanced diversity of fish and macroinvertebrates, increased storage of organic material and sediment, and improved bed and bank stability. Failure to meet restoration objectives appeared most likely where channel incision was severe and in highly degraded environments. Methods for wood reintroduction have logistical advantages over many other restoration techniques, being relatively low cost and low maintenance. Wood reintroduction is a viable transitional restoration technique for agricultural landscapes likely to rapidly improve stream condition if sources of colonists are viable and water quality is suitable.

Relevância:

60.00% 60.00%

Publicador:

Resumo:

Stream restoration often focuses on increasing habitat heterogeneity to reverse ecosystem degradation. However, the connection between heterogeneity and ecosystem structure and processes is poorly understood. We looked to investigate this interaction from both applied and basic science perspectives. For the applied study, we examined two culvert replacements designed to mimic natural stream channels, to see if they were better at maintaining ecosystem processes within as well as upstream and downstream of culverts compared to non-replaced culverts. We measured three ecosystem processes (nutrient uptake, hydrologic characteristics, and coarse particulate organic matter retention) and found that stream simulation culvert restoration improved organic matter retention within culverts, and that there were no differences in processes measured upstream and downstream of both restoration designs. Our results suggest that measurements of ecosystem processes are more likely to show a response to restoration if they match the scale of the restoration activity. For the basic science study, we quantified the longitudinal spatial heterogeneity of physical and biofilm characteristics at microhabitat to segment scales on streams with different streambed variability. We found that all physical characteristics and biofilm characteristics were spatially independent at the macro-habitat scale and greater. Together, these studies demonstrate the importance of scale in ecological interactions and the value of incorporating considerations of scale into restoration activities.

Relevância:

60.00% 60.00%

Publicador:

Resumo:

Automatic segmentation using univariate and multivariate techniques provides more objective and efficient segmentations of the river systems (Alber & Piégay, 2011) and can be complementary to the expert criteria traditionally used (Brenden et al., 2008) INTEREST: A powerful tool to objectively segment the continuity of rivers, which is required for diagnosing problems associated to human impacts OBJECTIVE: To evaluate the potentiality of univariate and multivariate methods in the assessment of river adjustments produced by flow regulation

Relevância:

60.00% 60.00%

Publicador:

Resumo:

From an extensive literature review and meta-analyses, this study has i) identified the most important hydromorphological process related to river degradation and rehabilitation, ii) conceptually linked it to evolutionary and functional response chains of aquatic biota, and iii) provided empirical evidence and ecological data for the respective hydromorphological requirements, preferences and limitations of aquatic plants, benthic invertebrates, lampreys, and freshwater fishes.

Relevância:

60.00% 60.00%

Publicador:

Resumo:

"PRT-3219183"--Colophon.

Relevância:

40.00% 40.00%

Publicador:

Resumo:

In-stream structures including cross-vanes, J-hooks, rock vanes, and W-weirs are widely used in river restoration to limit bank erosion, prevent changes in channel gradient, and improve aquatic habitat. During this investigation, a rapid assessment protocol was combined with post-project monitoring data to assess factors influencing the performance of more than 558 in-stream structures and rootwads in North Carolina. Cross-sectional survey data examined for 221 cross sections from 26 sites showed that channel adjustments were highly variable from site to site, but approximately 60 % of the sites underwent at least a 20 % net change in channel capacity. Evaluation of in-stream structures ranging from 1 to 8 years in age showed that about half of the structures were impaired at 10 of the 26 sites. Major structural damage was often associated with floods of low to moderate frequency and magnitude. Failure mechanisms varied between sites and structure types, but included: (1) erosion of the channel bed and banks (outflanking); (2) movement of rock materials during floods; and (3) burial of the structures in the channel bed. Sites with reconstructed channels that exhibited large changes in channel capacity possessed the highest rates of structural impairment, suggesting that channel adjustments between structures led to their degradation of function. The data question whether currently used in-stream structures are capable of stabilizing reconfigured channels for even short periods when applied to dynamic rivers.