Abstract
Disruption of longitudinal connectivity is a major concern in most of the world´s rivers. Approaches based on graph theory have proven to be a suitable tool for analysing functional connectivity. However, previous applications of graph-based connectivity methods to river systems have been oversimplified in that they have treated potential barriers as binary features and rivers as symmetric networks. We here apply a network analytical approach in which (a) upstream and downstream connectivity are considered so that fish passability values across dams are asymmetrical, and (b) it is possible to consider a continuous range of passability values for every dam. We build on previous and widely used connectivity metrics (Probability of Connectivity, PC), which here are generalised and adapted toward that end. We compare the results of our approach with those that would be obtained under the more simplified assumptions of symmetric movement and of barriers as binary features. We want to prove if there are substantial differences between considering or not the asymmetry in river networks. The application of symmetrical and asymmetrical PC highlights major differences between the upstream connectivity versus the downstream connectivity. We provide our methods in a free software package so that they can be used in any other application to riverscapes. We expect to provide a better graph-based approach for the prioritisation of the removal or permeabilization of artificial obstacles as well as for the preservation of target river segments for connectivity conservation and restoration.
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Baranyi G, Saura S, Podani J, Jordán F (2011) Contribution of habitat patches to network connectivity: redundancy and uniqueness of topological indices. Ecol Indic 11:1301–1310
Bednarek AT (2001) Undamming rivers: a review of the ecological impacts of dam removal. Environ Manage 27(6):803–814
Bjornn TC, Peery CA (1992) A review of literature related to movements of adult salmon and steelhead past dams and through reservoirs in the Lower Snake River. Technical Report 92–1, US Fish and Wildlife Service, Idaho Cooperative Fish and Wildlife Research Unit, University of Idaho, Moscow
Bodin Ö (2009) Ecological topology and networks. In: Meyers S. (ed) Encyclopedia of complexity and system Science. Springer, New York, pp 2728–2744
Bodin Ö, Saura S (2010) Ranking individual patches as connectivity providers: integrating network analysis and patch removal experiments. Ecol Modell 221:2393–2405
Bourne CM, Kehler DG, Wiersma YF, Cote D (2011) Barriers to fish passage and barriers to fish passage assessments: the impact of assessment methods and assumptions on barrier identification and quantification of watershed connectivity. Aquat Ecol 45:389–403
Branco P, Segurado P, Santos JM, Pinheiro P, Ferreirs MT (2012) Does longitudinal connectivity loss affect the distribution of freshwater fish? Ecol Eng 48:70–78
Calabrese JM, Fagan WF (2004) A comparison shoppers´ guide to connectivity metrics: trading of between data requirement and information content. Front Ecol Environ 2:529–536
Carranza ML, D’Alessandro E, Saura S, Loy A (2012) Connectivity providers for semi-aquatic vertebrates: the case of the endangered otter in Italy. Landscape Ecol 27:281–290
CHD (2009) Plan hidrológico del Duero. Plan hidrológico de la parte española de la demarcación hidrográfica del Duero propuesta de proyecto de plan hidrológico de cuenca. España
Cote D, Kehler DG, Bourne C, Wiersma YF (2009) A new measure of longitudinal connectivity for stream networks. Landscape Ecol 24:101–113
Erös T, Schmera D, Schick RS (2011) Network thinking in riverscape conservation—a graph-based approach. Biol Conserv 144:184–192
Erös T, Olden JD, Schick RS, Schmera D, Fortin M-J (2012) Characterizing connectivity relationships in freshwaters using patch-based graphs. Landscape Ecol 27:303–317
Erős T, Grant, EHC (2015) Unifying research on the fragmentation of terrestrial and aquatic habitats: patches, connectivity and the matrix in riverscapes. Freshw Biol 60(8):1487–1501
González Fernández G, Pérez Cardenal D, Miguelez Carbajo D, Gallego García R, Fernández Suárez R, Álvarez Durango E, Canal Rubio P, Roa Álvarez I, Rosa Cubo E, Seisdedos Fidalgo P (2010) Diagnóstico de la conectividad longitudinal en la Cuenca del Duero. Ministerio de Medio Ambiente, Medio Rural y Marino. Available on http://www.chduero.es/acciona5/metodologia/ic.pdf
Gough P, Philipsen P, Schollema PP, Wanningen H (2012) From sea to source: International guidance for the restoration of fish migration highways. Regional Water Authority Hunze en Aa´s. The Netherlands
Grant EHC (2011) Structural complexity, movement bias, and metapopulation extinction risk in dendritic ecological networks. J N Am Benthol Soc 30(1):252–258
Grant EHC, Lowe WH, Fagan WF (2007) Living in the branches: population dynamics and ecological processes in dendritic networks. Ecol Lett 10(2):165–175
Hilty JA, Lidicker WZ Jr, Merenlender A (2012). Corridor ecology: the science and practice of linking landscapes for biodiversity conservation. Island Press
Januchowski-Hartley SR, McIntyre PB, Diebel M, Doran PJ, Infante DM, Joseph C, Allan JD (2013) Restoring aquatic ecosystem connectivity requires expanding inventories of both dams and road crossings. Front Ecol Environ 11(4):211–217
Junta de Castilla y León (1997) Estudio de las poblaciones piscícolas del río Cega (Segovia). Technical Report: Estudios Biológicos, Madrid
Kondolf GM, Boulton AJ, O’Daniel S, Poole GC, Rahel FJ, Stanley EH, Whol E, Bång A, Carlstrom J, Cristoni C, Huber H, Koljonen S, Louhi P, Nakamura K (2006) Process-based ecological river restoration: visualizing three-dimensional connectivity and dynamic vectors to recover lost linkages. Ecol Soc 11(2):5
Lucas MC, Baras E, Thom TJ, Duncan A, Slavík O (2001) Migration of freshwater fishes, vol 47. Blackwell Science, Oxford
Minor ES, Urban DL (2007) Graph theory as a proxy for spatially explicit population models in conservation planning. Ecol Appl 17:1771–1782
Minor ES, Urban DL (2008) A graph-theory framework for evaluating landscape connectivity and conservation planning. Conserv Biol 22:297–307
Nicola GG, Elvira B, Almodovar A (1996) Dams and fish passage facilities in the large rivers of Spain: effects on migratory species. Large Rivers 10:375–379
O’Hanley JR (2011) Open rivers: barrier removal planning and the restoration of free-flowing rivers. J Environ Manage 92(12):3112–3120
O’Hanley JR, Tomberlin D (2005) Optimizing the removal of small fish passage barriers. Environ Model Assess 10(2):85–98
Oki T, Kanae S (2006) Global hydrological cycles and world water resources. Science 313(5790):1068–1072
Padgham M, Webb JA (2010) Multiple structural modifications to dendritic ecological networks produce simple responses. Ecol Modell 221(21):2537–2545
Pascual-Hortal L, Saura S (2006) Comparison and development of new graph-based landscape connectivity indices: towards the priorization of habitat patches and corridors for conservation. Landscape Ecol 21:959–967
Rahel FJ, Olden JD (2008) Assessing the effects of climate change on aquatic invasive species. Conserv Biol 22:521–533
Rivers-Moore N, Mantel S, Ramulifo P, Dallas H (2016) A disconnectivity index for improving choices in managing protected areas for rivers. Aquatic Conservation: Marine Freshwater Ecosystems 26(S1):29–38
Santiago JM, García de Jalón D, Alonso C, Solana J, Ribalaygua J, Pórtoles J, Monjo R (2015) Brown trout thermal niche and climate change: expected changes in the distribution of cold-water fish in central Spain. Ecohydrol
Saura S, Pascual-Hortal L (2007) A new habitat availability index to integrate connectivity in landscape conservation planning: comparison with existing indices and application to a case study. Landscape Urban Plan 83:91–103
Saura S, Rubio L (2010) A common currency for the different ways in which patches and links can contribute to habitat availability and connectivity in the landscape. Ecography 33:523–537
Saura S, Torné J (2009) Conefor Sensinode 2.2: a software package for quantifying the importance of habitat patches for landscape connectivity. Environmental Modelling & Software 24: 135–139.
Saura S, Torné J (2012) Conefor 2.6 user manual (April 2012). Universidad Politécnica de Madrid. Available at http://www.conefor.org.
Schick RS, Lindley ST (2007) Directed connectivity among fish populations in a riverine network. J Appl Ecol 44:1116–1126
Segurado P, Branco P, Ferreira MT (2013) Prioritizing restoration of structural connectivity in rivers: a graph based approach. Landscape Ecol 28:1231–1238
Segurado P, Branco P, Avelar AP, Ferreira MT (2014) Historical changes in the functional connectivity of river based on spatial networks analysis and the past occurrences of diadromous species in Portugal. Aquatic Sci
Tockner K, Schiemer F, Ward JV (1998) Conservation by restoration: the management concept for a river-floodplain system on the Danube River in Austria. Aquat Conserv 8:71–86
Ward JV (1989) The four-dimensional nature of the lotic ecosystem. J N Am Benthol Soc 8:2–8
Wiens JA (2002) Riverine landscapes: taking landscape ecology into the water. Freshw Biol 47(4):501–515
Acknowledgements
Part of this study has been supported by 7th Framework Programme of the European Union (DURERO Project C1 3913442). We thank Gustavo González and his team for the valuable information about connectivity and barrier passability in the Duero River Basin. We would like to express our thanks to Pablo Moreno and Vanesa Martínez-Fernández for their comments which improved the quality of the paper. Two anonymous reviewers are thanked for their helpful comments and insights.
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Rincón, G., Solana-Gutiérrez, J., Alonso, C. et al. Longitudinal connectivity loss in a riverine network: accounting for the likelihood of upstream and downstream movement across dams. Aquat Sci 79, 573–585 (2017). https://doi.org/10.1007/s00027-017-0518-3
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DOI: https://doi.org/10.1007/s00027-017-0518-3