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Riparian Restoration (riparian + restoration)
Selected AbstractsAllogenic and autogenic influences upon riparian vegetation dynamicsAREA, Issue 4 2006Robert A Francis Riparian vegetation dynamics are regarded as being driven by allogenic hydrogeomorphological factors, with autogenic (plant-induced) influences becoming more important as landform stability is achieved. Autogenic processes, however, may have a substantial influence on both plant dynamics and the river environment from the earliest stages of plant establishment. Various aspects of both allogenic and autogenic processes in riparian vegetation dynamics are discussed here; in particular how plants may promote bank stability and sedimentation, and river island development. Riparian restoration often fails to incorporate autogenic processes, thereby restricting the re-establishment of natural functioning, and further interdisciplinary work is needed to address this. [source] MARSH DEVELOPMENT AT RESTORATION SITES ON THE WHITE MOUNTAIN APACHE RESERVATION, ARIZONA,JOURNAL OF THE AMERICAN WATER RESOURCES ASSOCIATION, Issue 6 2003Jonathan W. Long ABSTRACT: To prioritize sites for riparian restoration, resource managers need to understand how recovery processes vary within landscapes. Complex relationships between watershed conditions and riparian development make it difficult to predict the outcomes of restoration treatments in the semiarid Southwest. Large floods in 1993 scoured riparian areas in the Carrizo watershed on the White Mountain Apache Reservation in east-central Arizona. We evaluated recovery at three of these sites using repeated photographs and measurements of channel cross sections and stream-side vegetation along permanent transects. The sites were mapped as lying on the same soil type, had similar streamside vegetative communities, and were similarly treated through livestock exclusion and supplemental seeding. However, the sites and individual reaches within the sites followed strikingly different development paths. Dramatic recovery occurred at a perennial reach where cover of emergent wetland plants increased from 4.7 percent (standard error = 0.8 percent) in October 1995 to 55.5 percent (standard error = 2.7 percent) in September 2001. At several other reaches, geologic and hydro geomorphic characteristics of the sites limited inputs of fine sediment or surface water, resulting in modest or negligible increases in emergent cover. Recovery efforts for highly valued marshlands in this region should prioritize perennial reaches in low gradient valleys where salty sediments are abundant. [source] Riparian Forest Restoration: Increasing Success by Reducing Plant Competition and HerbivoryRESTORATION ECOLOGY, Issue 2 2002Bernard W. Sweeney Abstract The reestablishment of riparian forest is often viewed as "best management practice" for restoring stream ecosystems to a quasi-natural state and preventing non-point source contaminants from entering them. We experimentally assessed seedling survivorship and growth of Quercus palustris (pin oak), Q. rubra (red oak), Q. alba (white oak), Betula nigra (river birch), and Acer rubrum (red maple) in response to root-stock type (bare root vs. containerized), herbivore protection (tree shelters), and weed control (herbicide, mowing, tree mats) over a 4-year period at two riparian sites near the Chester River in Maryland, U.S.A. We started with tree-stocking densities of 988/ha (400/ac) in the experimental plots and considered 50% survivorship (i.e., a density of 494/ha [200/ac] at crown closure) to be an "acceptable or minimum" target for riparian restoration. Results after four growing seasons show no significant difference in survivorship and growth between bare-root and containerized seedlings when averaged across all species and treatments. Overall survivorship and growth was significantly higher for sheltered versus unsheltered seedlings (49% and 77.6 cm vs. 12.1% and 3.6 cm, respectively) when averaged across all species and weed control treatments. Each of the five test species exhibited significantly higher 4-year growth with shelter protection when averaged across all other treatments, and all species but river birch had significantly higher survivorship in shelters during the period. Seedlings protected from weeds by herbicide exhibited significantly higher survivorship and growth than seedlings in all other weed-control treatments when averaged across all species and shelter treatments. The highest 4-year levels of survivorship/growth, when averaged across all species, was associated with seedlings protected by shelters and herbicide (88.8%/125.7cm) and by shelters and weed mats (57.5%/73.5 cm). Thus, only plots where seedlings were assisted by a combination of tree shelters and either herbicide or tree mats exhibited an "acceptable or minimum" rate of survivorship (i.e.,>50%) for riparian forest restoration in the region. Moreover, the combined growth and survivorship data suggest that crown closure over most small streams in need of restoration in the region can be achieved most rapidly (i.e., 15 years or less) by protecting seedlings with tree shelters and controlling competing vegetation with herbicides. [source] Evaluating the effects of riparian restoration on a temperate river-system using standardized habitat surveyAQUATIC CONSERVATION: MARINE AND FRESHWATER ECOSYSTEMS, Issue S1 2010E. Clews Abstract 1.The restoration of degraded riparian zones to improve a range of functions is attracting increasing interest, but there are still questions about (i) how effectively restoration changes riparian or channel conditions; (ii) whether riparian management offsets the effects of wider catchment pressures; and (iii) whether these effects can be detected quantitatively. 2.A catchment-scale experiment was used to assess the effects of riparian restoration on riparian and channel conditions in the Welsh River Wye. In a hierarchically designed survey, variations in river habitat character were assessed among tributaries where riparian zones were recently managed for restoration (n=9 streams), unmanaged controls (n=12), intensively grazed pastures (n=3) and coniferous plantation (n=3). Management between 1997 and 2003, largely involving coppicing, was designed to exclude grazing through fencing in order to enable vegetation development while creating salmonid refuges. River habitat character was assessed using the UK ,River Habitat Survey' (RHS) method, with habitat variation quantified using Principal Components Analysis. 3.Stream habitats varied significantly among treatment categories. Streams draining plantation conifer had ,harder' channel features, while those draining intensively grazed pasture were characterized by finer substrata and more active channels than elsewhere. Riparian management reduced livestock trampling (= poaching) and increased algal cover relative to controls. Coppicing and riparian fencing successfully excluded grazing on banks while increasing in-stream vegetation cover, but did not affect substrata, flow-types and channel features. 4.These data show that RHS can detect habitat variation among streams in contrasting riparian land-use, revealing some apparently significant effects of recent restoration. We advocate longer-term investigations at reach to catchment scales to assess longer-term effects on channel and flow character, and to appraise fully the extent to which local riparian management can offset impairments at a catchment or larger scale, such as altered run-off regimes, sediment delivery and climate change. Copyright © 2010 John Wiley & Sons, Ltd. [source] | ||||||||||