Review Perspectives on the potential for reconciliation ecology in urban riverscapes Robert A. Francis* Address: Department of Geography, King’s College London, Strand, London WC2R 2LS, UK. *Correspondence: Email: robert.francis@kcl.ac.uk Received: 9 August 2009 Accepted: 14 October 2009 doi: 10.1079/PAVSNNR20094073 The electronic version of this article is the definitive one. It is located here: http://www.cabi.org/cabreviews g CAB International 2009 (Online ISSN 1749-8848) Abstract Urban riverscapes represent some of the most heavily engineered and degraded freshwater eco- systems in the world, and offer limited opportunities for restoration or rehabilitation because of continued anthropogenic use. The future of maintaining biodiversity and ecological quality in anthropogenic ecosystems may rest with the incorporation of novel techniques for habitat creation and improvement into the management of such systems, to reconcile the ecological requirements of the ecosystem with anthropogenic resource use. This emerging field is termed ‘reconciliation ecology’ and its principles may be particularly relevant to urban riverscapes. This review firstly draws a distinction between river restoration and rehabilitation on the one hand and reconciliation ecology on the other, before reviewing key factors relating to possible habitat creation and improvement methods for heavily engineered urban riverscapes, within the context of reconciliation ecology. Examples are mainly drawn from the UK, but can have international applications. Although such methods are relatively unexplored at the present time, this represents a useful research area that may engender collaborations between restoration researchers and practitioners in urban regions. Keywords: Urban, River, Restoration, Rehabilitation, Reconciliation, Ecology, Riverscape Review Methodology: The ISI Web of Knowledge database and Google Scholar were searched for variations on the following keywords: River restoration, river rehabilitation, reconciliation ecology, riverscape, restoration objectives, restoration evaluation, river basin management, habitat creation, large woody debris, river walls, artificial islands, urban rivers, connectivity, resilience, complexity and heterogeneity. Based on this initial assessment, the references found within relevant articles, and established textbooks in the area, further more specific searches took place, incorporating relevant grey literature and articles in press that were noted as useful by colleagues or which were known to the author previously. Introduction Attempts to return degraded river systems to their pre- degradation states have taken place globally since the early 1980s, following increasing recognition of the severity and scale of anthropogenic impacts to freshwater ecosystems, and that the potential to improve compromised biological, geomorphological and hydrological characteristics of rivers exists [1]. With the quantity and quality of fresh- water resources becoming of increasing global, regional and local importance due to population growth and in- tensification of land use [2–4], there is increasing pressure to both preserve and restore freshwater ecosystems. Rivers provide a range of ecosystem services that are dependent on good ecological quality and functional inte- grity, the preservation or restoration of which requires generally holistic and broad (catchment to landscape) scale management, given the high connectivity and nested hier- archies of interrelated structure and process within rivers [5, 6]. Notable success has been recorded for some river rehabilitation efforts that have reinstated semi-natural river form and function to individual sites, but so far, rela- tively limited success at restoration of ecological quality and functional integrity has been recorded at broad spatial scales, and there is a need to identify techniques that might be used to achieve this both for freshwater ecosystems in general and for specific river typologies [7–10]. This has become particularly pressing because of the adoption of http://www.cabi.org/cabreviews CAB Reviews: Perspectives in Agriculture, Veterinary Science, Nutrition and Natural Resources 2009 4, No. 073