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Flow regulation reduces native plant cover and facilitates exotic invasion in riparian wetlands / Jane A Catford in Journal of applied ecology, 48 ([01/01/2011]) 

Public Citation [article]  inJournal of applied ecology > 48 [01/01/2011] . - 432-442 Titre : Flow regulation reduces native plant cover and facilitates exotic invasion in riparian wetlands Type de document : Électronique Auteurs : Jane A Catford ; Barbara J Downes ; Christopher J Gippel ; Peter A Vesk Année de publication : 2011 Article en page(s) : 432-442 Langues : Anglais (eng) Catégories : [CBNPMP-Thématique] Plantes subspontanées, naturalisées, envahissantes Résumé : 1. River regulation and exotic plant invasion threaten riverine ecosystems, and the two often co-occur. By altering water regimes, flow regulation can facilitate plant invasion by providing conditions that directly benefit invading species, or by reducing competition from native species unsuited to the modified conditions. Integrating water and weed management has the potential to limit riparian plant invasion and maximize the ecological benefit of environmental flows. 2. We surveyed plant communities and modelled flood histories of 24 riparian wetlands along the regulated River Murray, south-eastern Australia. There were no suitable control rivers, so we compared modelled pre- and post-regulation hydrological data to quantify hydrological change in the study wetlands. Regression analyses revealed relationships between hydrological modification and cover of native non-weed, native weed and exotic weed groups and 10 individual species. 3. Exotic cover was highest and native non-weed cover lowest in wetlands that had experienced the greatest change in hydrology – a reduction in peak flow. Native weeds did not respond to hydrological modification indicating that exotic species’ success was not reliant on their generalist characteristics. 4. By altering habitat filters, hydrological modification caused a decline in amphibious native non-weed species cover and simultaneously provided drier conditions that directly favoured the exotic species group dominated by terrestrial species. Exotic species were potentially further assisted by human-mediated dispersal. 5. Species and functional diversity was inversely related to exotic cover. By shifting the balance between native and exotic taxa and changing community functional composition, flow regulation may disrupt the ecological function and ecosystem services of floodplain wetlands. 6. Synthesis and applications. Worldwide, flow regulation has led to riverine ecosystems becoming more terrestrial. The success of most introduced plants relies on minimal inundation. In this study, flood magnitude was more important than frequency, timing, or duration for wetland flora because it reflects spatial extent and depth of flooding. Augmenting natural spring floods with environmental flows will kill terrestrial weeds and facilitate native macrophyte growth. Combined with strategies for managing particular amphibious weeds, we recommend flows of 117 000–147 000 ML day−1 for at least 2 days every 10 years for River Murray wetland weed management. Lien pérenne : DOI : 10.1111/j.1365-2664.2010.01945.x Permalink : https://biblio.cbnpmp.fr/index.php?lvl=notice_display&id=142753 Catford, Jane A, Downes, Barbara J, Gippel, Christopher J, Vesk, Peter A 2011 Flow regulation reduces native plant cover and facilitates exotic invasion in riparian wetlands. Journal of applied ecology, 48: 432-442.

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Consultable Article (2011) URL

Seed supply for broadscale restoration: maximizing evolutionary potential / Linda M. Broadhurst in Evolutionary applications, 1 (4) (2008) 

Public Citation [article]  inEvolutionary applications > 1 (4) (2008) . - 587–597 Titre : Seed supply for broadscale restoration: maximizing evolutionary potential Type de document : Imprimé Auteurs : Linda M. Broadhurst ; Andrew J. Lowe ; David J. Coates ; Saul A. Cunningham ; Maurice McDonald ; Peter A Vesk ; Colin Yates Année de publication : 2008 Article en page(s) : 587–597 Langues : Anglais (eng) Catégories : [CBNPMP-Thématique] Restauration des écosystèmes [CBNPMP-Thématique] Diversité génétique Résumé : Restoring degraded land to combat environmental degradation requires the collection of vast quantities of germplasm (seed). Sourcing this material raises questions related to provenance selection, seed quality and harvest sustainability. Restoration guidelines strongly recommend using local sources to maximize local adaptation and prevent outbreeding depression, but in highly modified landscapes this restricts collection to small remnants where limited, poor quality seed is available, and where harvesting impacts may be high. We review three principles guiding the sourcing of restoration germplasm: (i) the appropriateness of using ‘local’ seed, (ii) sample sizes and population characteristics required to capture sufficient genetic diversity to establish self-sustaining populations and (iii) the impact of over-harvesting source populations. We review these topics by examining current collection guidelines and the evidence supporting these, then we consider if the guidelines can be improved and the consequences of not doing so. We find that the emphasis on local seed sourcing will, in many cases, lead to poor restoration outcomes, particularly at broad geographic scales. We suggest that seed sourcing should concentrate less on local collection and more on capturing high quality and genetically diverse seed to maximize the adaptive potential of restoration efforts to current and future environmental change. Lien pérenne : DOI : 10.1111/j.1752-4571.2008.00045.x Permalink : https://biblio.cbnpmp.fr/index.php?lvl=notice_display&id=149232 Broadhurst, Linda M., Lowe, Andrew J., Coates, David J., Cunningham, Saul A., McDonald, Maurice, Vesk, Peter A, Yates, Colin 2008 Seed supply for broadscale restoration: maximizing evolutionary potential. Evolutionary applications, 1(4): 587–597.

Documents numériques

Consultable Article (2008) URL