Synergies and trade-offs in the management of lowland rural floodplains: an ecosystem services approach

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1 This article was downloaded by: [Jim Rouquette] On: 21 December 2011, At: 02:17 Publisher: Taylor & Francis Informa Ltd Registered in England and Wales Registered Number: Registered office: Mortimer House, Mortimer Street, London W1T 3JH, UK Hydrological Sciences Journal Publication details, including instructions for authors and subscription information: Synergies and trade-offs in the management of lowland rural floodplains: an ecosystem services approach J.R. Rouquette a b, H. Posthumus c d, J. Morris c, T.M. Hess c, Q.L. Dawson c & D.J.G. Gowing a a Department of Life Sciences, The Open University, Walton Hall, Milton Keynes, MK7 6AA, UK b Department of Animal and Plant Sciences, University of Sheffield, Sheffield, S10 2TN, UK c Department of Natural Resources, School of Applied Sciences, Cranfield University, Bedfordshire, MK43 0AL, UK d Natural Resources Institute, University of Greenwich, Chatham, ME4 4TB, UK Available online: 16 Dec 2011 To cite this article: J.R. Rouquette, H. Posthumus, J. Morris, T.M. Hess, Q.L. Dawson & D.J.G. Gowing (2011): Synergies and trade-offs in the management of lowland rural floodplains: an ecosystem services approach, Hydrological Sciences Journal, 56:8, To link to this article: PLEASE SCROLL DOWN FOR ARTICLE Full terms and conditions of use: This article may be used for research, teaching, and private study purposes. Any substantial or systematic reproduction, redistribution, reselling, loan, sub-licensing, systematic supply, or distribution in any form to anyone is expressly forbidden. The publisher does not give any warranty express or implied or make any representation that the contents will be complete or accurate or up to date. The accuracy of any instructions, formulae, and drug doses should be independently verified with primary sources. The publisher shall not be liable for any loss, actions, claims, proceedings, demand, or costs or damages whatsoever or howsoever caused arising directly or indirectly in connection with or arising out of the use of this material.

2 1566 Hydrological Sciences Journal Journal des Sciences Hydrologiques, 56(8) 2011 Special issue: Ecosystem Services of Wetlands Synergies and trade-offs in the management of lowland rural floodplains: an ecosystem services approach J.R. Rouquette 1,2, H. Posthumus 3,4,J.Morris 3,T.M.Hess 3,Q.L.Dawson 3 and D.J.G. Gowing 1 1 Department of Life Sciences, The Open University, Walton Hall, Milton Keynes MK7 6AA, UK 2 Department of Animal and Plant Sciences, University of Sheffield, Sheffield S10 2TN, UK j.r.rouquette@sheffield.ac.uk 3 Department of Natural Resources, School of Applied Sciences, Cranfield University, Bedfordshire MK43 0AL, UK 4 Natural Resources Institute, University of Greenwich, Chatham ME4 4TB, UK Received 30 July 2010; accepted 13 May 2011; open for discussion until 1 June 2012 Editor Z.W. Kundzewicz; Guest editor M.C. Acreman Citation Rouquette, J.R., Posthumus, H., Morris, J., Hess, T.M., Dawson, Q.L. and Gowing, D.J.G., Synergies and trade-offs in the management of lowland rural floodplains: an ecosystem services approach. Hydrological Sciences Journal 56 (8), Abstract Priorities for the management of lowland rural floodplains in many parts of Europe have changed from a focus on agricultural production towards multi-functional landscapes that provide a range of environmental, social and economic benefits to society. This paper uses an ecosystem services framework to explore alternative management scenarios with different objectives (production, biodiversity, floodwater storage, agri-environment and income) for two rural floodplains in England. Each scenario featured different types of land cover and hydrological management. The results revealed the key role of the hydrological regime in shaping ecosystem service provision in floodplains. Both conflicts and synergies were apparent. Scenarios with deep water tables and low flood frequencies had high scores for agricultural production and flood storage capacity, but low scores for environmental outcomes. Scenarios with shallow water tables and frequent flooding showed high scores for environmental and cultural outcomes, but at the cost of a reduced flood storage capacity and increased flood risk. The scope for multiple benefits has implications for the realignment of policies to realize extra value from floodplain ecosystems. Key words ecosystem services; floodplain; flood risk; land use; wetland Synergies et arbitrages dans la gestion des plaines d inondation rurales: une approche écosystémique des services Résumé Un peu partout en Europe, pour la gestion des plaines d inondation rurales, les priorités ont évolué d une focalisation sur la production agricole vers des approches multi-fonctionnelles qui offrent un éventail d avantages environnementaux, sociaux et économiques pour la société. Cette étude utilise le cadre des services écosystémiques pour explorer des scénarios alternatifs de gestion avec des objectifs différents (production, biodiversité, stockage des eaux de crue, agro-environnement et revenu) pour deux plaines d inondation rurales en Angleterre. Chaque scénario fait apparaître différents types de couverture terrestre et de gestion hydrologique. Les résultats ont révélé le rôle clé du régime hydrologique dans la fourniture de services écosystémiques dans les zones inondables. Conflits et synergies sont apparus. Des scénarios avec des nappes profondes et une faible fréquence des inondations ont des scores élevés pour la production agricole et la capacité de stockage d inondation, mais de faibles scores pour les résultats environnementaux. Les scénarios avec des nappes peu profondes et des inondations fréquentes réalisent des scores élevés pour les résultats environnementaux et culturels, mais au prix d une capacité de stockage d inondation réduite et d un risque accru d inondation. La portée des avantages multiples a des implications pour le réalignement des politiques visant à réaliser une valeur supplémentaire à partir des écosystèmes des plaines inondables. Mots clefs services écosystémiques; plaines inondables; risques d inondation; utilisation des terres; zones humides INTRODUCTION Lowland rural floodplains have the potential to provide a range of ecosystem goods and services to society (Tockner and Stanford 2002, Hale and Adams 2007). Their unique position in the landscape means that the ecosystem services that they ISSN print/issn online 2011 IAHS Press

3 Synergies and trade-offs in the management of lowland rural floodplains: an ecosystem services approach 1567 generate reflect the interaction between terrestrial and hydrological characteristics and processes, in many cases engineered to suit particular purposes. Floodplains are recognized for their potential importance for farming, flood management and biodiversity, but this can often lead to conflicting demands on land and water resources (Morris et al. 2009). In addition, they are able to provide a range of other environmental and cultural services. Until recently, agricultural production has been seen as the predominant service provided by these areas. It has been estimated that up to 90% of floodplains in Europe and North America have been cultivated and hydrologically modified for agriculture (Tockner and Stanford 2002). However, priorities are changing, with the focus now shifting towards providing multifunctional landscapes that deliver a range of environmental, social and economic benefits to society (Potter 2006, Otte et al. 2007). The ecosystem approach provides an appropriate framework by which society can evaluate and manage its relationship with the environment. Although the concept of ecosystem services has been around for many decades (e.g. Ehrlich and Ehrlich 1981, Costanza et al. 1997, Daily 1997), it was the publication of the Millennium Ecosystem Assessment (MEA 2005) that brought the approach to the fore. Frameworks for the evaluation of ecosystem services havebeendeveloped (e.g. Turner et al. 2000, de Groot et al. 2002, MEA 2005, de Groot 2006, Boyd and Banzhaf 2007), and the approach has been explored for both wetland ecosystems (Turner et al. 2000, Brauman et al. 2007) and for more heavily modified agricultural landscapes (Swinton et al. 2007, Zhang et al. 2007, Sandhu et al. 2008). In addition, research has examined ecosystem service provision under a range of alternative land-use scenarios (Santelmann et al. 2004, Lindborg et al. 2009, Nelson et al. 2009, Posthumus et al. 2010) in an attempt to understand trade-offs and synergies in land management and to inform more sustainable land management strategies. The ecosystem services delivered by floodplains are inextricably linked to hydrology (Tockner and Stanford 2002, Morris et al. 2009) with the hydrological regime determining vegetation and land cover under a natural or managed environment. Traditionally, high flood risk, elevated water tables and potentially saturated soils have limited landuse options available on floodplains. However, flood defence and land drainage investments have modified natural hydrological regimes, allowing a wider range of land-use options, from intensive arable farming to flood storage. Thus, the hydrological regimes of floodplains are now typically defined by human preference for types of land use and the services these provide. Where flood risk is low and the field water levels can be controlled to avoid waterlogging, intensive arable farming is possible delivering high agricultural productivity. Less intensive farming methods, such as grazing of wet grassland, can tolerate lower standards of flood protection and land drainage (Hess and Morris 1988, Wheeler et al. 2004) and are more closely associated with the provision of non-market goods, such as nature conservation and amenity. Each land-use type has the potential to deliver a specific set of ecosystem goods and services, and there are clear synergies and trade-offs between the different services provided. A key challenge for the management of floodplains, and for sustainable natural resource management in general, is to examine the ecosystem services provided by alternative land-use types and to explore ways in which different management priorities can be integrated more effectively. Here, we examine ecosystem service provision in relation to land use and hydrological regime under alternative management scenarios. In this paper, we answer the following research questions: (1) What land cover is likely to occur on lowland rural floodplains under a range of future land-management scenarios? (2) What hydrological regimes are required by the different land covers and, hence, the different scenarios? (3) What ecosystem services do alternative scenarios provide? Finally, (4) What are the relationships between hydrological regimes and ecosystem-service provision? METHODS This paper is based on a research project entitled Integrated Land and Water Management in Floodplains carried out under the UK Rural Economy and Land Use Programme (RELU, This project explored opportunities to integrate farming, nature conservation and flood management in eight lowland floodplain areas in England (see Fig. 1). These eight floodplains were previously engineered for agricultural flood defence purposes and studied to assess agricultural benefits by some of the authors in the 1980s. The eight sites were selected to cover a range of land uses, farming systems, soil types, hydrological and engineering features and geographical locations. For the purpose of this paper, two contrasting floodplain sites have been selected from the suite of eight study sites, to explore in more detail

4 1568 J. R. Rouquette et al. Fig. 1 Map showing location of all eight floodplain study sites. Results are presented for two contrasting sites; Beckingham Marshes (number 3 on map) and Kingsmoor / Witcombe Bottom (number 7). the provision of services under a range of scenarios: Beckingham Marshes a predominantly arable floodplain; and Kingsmoor / Witcombe Bottom a grassland floodplain. These sites are considered to be representative of agriculturally engineered floodplain areas found throughout Europe and North America. At each site, five alternative land-use scenarios were considered with differing goals. Each of these requires a different hydrological regime, in terms of frequency of flooding and seasonal water tables, which in turn determines the level of ecosystem service delivery under each scenario. The conflicts and synergies between ecosystem services can be evaluated by considering the level of ecosystem-service delivery under each scenario. arable farming. In the 1960s and 1970s, the drainage ditch network was improved and the pumping station upgraded to facilitate field underdrainage. This led to a further expansion of arable farming within the floodplain, and, by 1983, 82% of the area had been converted to arable farming and 74% of the land had new field drainage installed (Morris et al. 1984). By 2000, 90% of the area was used for arable farming, with wheat and oilseed rape as the main crops. Beckingham Marshes is now characterized by a fixed, controlled inflow of flood water (through overtopping or breaching of the river banks), and a controlled outflow of water (through gravity drainage and a pumped drainage system). About 5% of the area is susceptible to a 1 in 10-year flood event, and 22% of the area to a 1 in 20-year flood event. Study sites Beckingham Marshes Beckingham Marshes is an area of floodplain adjacent to the River Trent in the East Midlands of England, UK, covering an area of about 900 ha. Prior to 1945, the area was almost entirely grassland and marsh, and acted as a natural washland for the protection of Gainsborough, situated on the opposite side of the river. A wartime improvement scheme rebuilt the flood banks, cut new drains and installed a new pumping station. An appraisal of the flood probability in 1954 concluded that the whole marsh could expect to flood if the Trent catchment at this point experienced the 1 in 20-year event, but partial inundation might be expected if flood flows were in excess of the 1 in 10-year event. At this time, about one quarter of the area was converted to Kingsmoor / Witcombe Bottom The floodplains of Kingsmoor and Witcombe Bottom are situated, respectively, to the north and south of the River Yeo in the southwest of England. Together they cover an area of approximately 1400 ha. The Yeo s history of flooding has produced a raised channel, with the bed of the river standing above the lowest points of the surrounding moors. Whilst the natural levees of the Yeo historically afforded some degree of flood protection to the surrounding floodplains, it was inundated on average more frequently than once a year. The risk of the Yeo overtopping was often exacerbated by backing-up of water downstream. When flooding occurred, the natural topography facilitated movement of floodwaters to the lowest point in the floodplains. However, when levels in the Yeo were

5 Synergies and trade-offs in the management of lowland rural floodplains: an ecosystem services approach 1569 high, flaps on the drainage outfalls would close to prevent river water flowing into the floodplain, but at the same time preventing evacuation of drainage water until river levels dropped. Even when the Yeo did not breach its banks, seepage through the surrounding soils would occur when river levels were high. A drainage improvement scheme was implemented in the 1970s; the flood banks were strengthened, a pumping station was installed, and main drains were excavated to provide additional storage. By the 1980s it was estimated that 19% of the land had new field drainage installed, which allowed flood waters to recede within days of inundation, rather than standing for months, as was the case before the drainage improvement scheme. For those farmers who had not installed field drainage, however, the natural drainage conditions had not changed significantly (Silsoe College 1987). The land use has remained predominantly grassland, although the drainage improvement scheme resulted in an intensification of grass production. Kingsmoor and Witcombe Bottom are thus also characterized by a fixed controlled inflow of flood water (through overtopping of the river banks), and a controlled outflow of water (through gravity drainage and a pumped drainage system). It is estimated that annual flooding only occurs on 8% of the land whilst major floods are experienced, on average, once in every 3 years on 69% of the land. In the remainder of this paper Kingsmoor and Witcombe Bottom are referred to jointly as Kingsmoor. Land-use scenarios and hydrological regimes Farmer interviews were carried out during the winter and spring season in 2006/07 using structured questionnaires to collect data on current farming systems, land use, farm inputs and outputs, and field drainage. Ecological surveys were undertaken in summer 2007 to determine current habitats and biodiversity. Data obtained through the farmer interviews and ecological surveys are used for the baseline scenario in the analysis. Five alternative management scenarios were developed. Four single-objective scenarios sought to maximize the provision of one particular policy objective. These were designed to maximize agricultural production, biodiversity, flood water storage, and income derived from land-based activities respectively. In addition, a compromise scenario was developed; an agri-environment scenario that attempted to balance agricultural production and biodiversity. For each scenario, the type of land use most suited to the scenario s objective was determined by the project team based on a combination of historical and current evidence of land and water management, the views of local key informants including farmers, flood managers and conservationists, and a bio-physical assessment of what could practically be achieved on each site. Typical constraints taken into account were climate, soil type, and for some scenarios current farming systems. However, it was assumed that the hydrological regime is adjusted to suit land use by imposing required levels of control over drainage and flood probability. For each scenario, land use is thus determined by the interaction of site characteristics and the scenario objectives. This, in turn, determines the seasonal hydrological regime required to sustain that particular land use. Hydrological regimes are defined in terms of mean water-table depth, days with surface water and fluvial flood probability, and are based on expert knowledge and published sources (Wheeler et al. 2004, Barsoum et al. 2005). The objectives and constraints of each scenario are shown below: Production The production scenario comprises intensive agricultural land use for food production, which was the objective at each site when land drainage was improved in the 1960s and 1970s. Land use is defined by soil and climatic potential, and the main farming systems in the area. The hydrological regime is characterized by rapid drainage and controlled, low-frequency flooding. Biodiversity This scenario seeks to enhance biodiversity at the site, without imposed constraints regarding land use; that is, the biodiversity objective supersedes the objective of agricultural production in determining land use. Local soil conditions, topography and historical context, together with local and regional conservation priorities have been used to determine the specific habitat types that would be created. Given the floodplain setting of our study sites, wetland habitats are considered to be the most appropriate, and, hence, the hydrological regime is characterized by frequent flooding and natural drainage. Floodwater storage This seeks to maximize the attenuation of the flood hydrograph as part of a strategic flood risk management scheme. The floodplain

6 1570 J. R. Rouquette et al. is managed to maximize floodwater-storage potential when the river reaches design discharge, and to evacuate stored floodwater as quickly as possible after the event (in order to provide storage for subsequent events). This scenario thus requires a hydrological regime with controlled low flood frequency ( 1:10 year) and rapid drainage. A land-cover type with high transpiration rates (either improved grass or winter cereals) and a low field water-table position maximizes below ground storage. Agri-environment This scenario seeks to enhance biodiversity within the constraint that the dominant land use remains agricultural. Land-use options were selected that are promoted by current agri-environmental schemes, in particular the Higher Level Stewardship Scheme (Defra 2005). The same criteria are used for determining the habitat types as for the biodiversity scenario. The hydrological regime attempts to combine the requirements of agriculture and wildlife habitats, and typically consists of medium duration flooding and good surface drainage. Income The income scenario seeks to maximize the income derived from the land, based on 2006 prices for agricultural produce and payments received through Environmental Stewardship. The land use for this scenario is determined by the scenario with the highest estimated annual profitability per hectare (defined in terms of the difference between total revenues and total average costs, where the latter includes both variable and fixed costs). Ecosystem services and indicators The conceptual framework used in this study is described in greater detail in Posthumus et al. (2010). The major ecosystem services provided by lowland floodplains were identified (Table 1) by means of a literature review and a stakeholder workshop (unpublished data). Indicators were developed to assess the delivery of each ecosystem service under the current situation and under the different management scenarios (details of the methodology for each indicator are provided in Posthumus et al. 2010). The value of ecosystem services was determined by estimating economic gains (e.g. agricultural production), avoided damage costs (e.g. infrastructure or residential properties at risk of flooding), continued access to resources (e.g. maintenance of soil quality), or contribution to human well-being (e.g. landscape value or recreation). When calculating the indicators, it was assumed that the scenarios were under full establishment and differences in financial performance reflected differences in average annual benefits and costs. As many of the indictors were measured in different units, attributes were normalized in order to enable comparisons. This was achieved by dividing each indicator by the maximum score so that normalized scores ranged from 1 (best) to 0 (worst) for positive indicators (such as agricultural production or habitat provision) and from 0 (best) to 1 (worst) for negative indicators (such as greenhouse gas emissions, nutrient leaching, or flood risk to properties and infrastructure). Table 1 Indicators for ecosystem goods and services provided by lowland floodplains. (reprinted from Ecological Economics, Vol 69, Posthumus et al., A framework for the assessment of ecosystem goods and services; a case study on lowland floodplains in England, , Copyright 2010, with permission from Elsevier.). Function Good or service Indicator Unit Production Agricultural production Gross output ha -1 year -1 Financial return Net margin ha -1 year -1 Employment Labour man hours ha -1 year -1 Soil quality Soil carbon stock kg C ha -1 Regulation Floodwater storage Time to fill capacity days Water quality Nutrient leaching kg NO 3 ha -1 year -1 Greenhouse gas balance Global Warming Potential kg CO 2 equiv. ha -1 year -1 Habitat Habitat provision Habitat conservation value score Wildlife Species conservation value score Carrier Transport Risk exposure road infrastructure ha -1 year -1 Settlement Risk exposure residential properties ha -1 year -1 Space for water Proportion of area annually inundated by fluvial flood percentage Information Recreation Potential recreational use score Landscape Landscape value score

7 Synergies and trade-offs in the management of lowland rural floodplains: an ecosystem services approach 1571 RESULTS Land cover provided under alternative scenarios Land cover and habitats occuring under the existing (i.e. 2006) situation and projected to occur under the alternative scenarios are shown in Fig. 2 (see Table 2 for further explanation of the land-cover types). Land cover under the production and floodwater storage scenarios is projected to be similar, with both scenarios showing a marked increase in agricultural intensity compared to 2006, being dominated by cereals at Beckingham Marshes and temporary leys at Kingsmoor. Change from the 2006 situation is projected to be most dramatic under the biodiversity scenario, where fen, reedbed and woodland land covers dominate. The agri-environment scenario promotes low-intensity farming practices and, hence, land cover is dominated by wet grazing and low-input hay meadows at both sites. Under the income scenario, two divergent outcomes become apparent. At Kingsmoor a site with a tradition of dairy production intensive dairying provides the greatest farm income, so temporary leys and fodder crops are projected to become the predominant land cover. However, at Beckingham Marshes, although currently a cereal producing area, greater farm income could be achieved by operating an extensive beef system and entering the land for Higher Level Stewardship payments (assuming 2006 prices for wheat). Therefore wet grazing becomes the most important land use at this site. Hydrological regimes Hydrological regimes were defined in terms of watertable depth, days with surface water and fluvial flood probability for each season. Days with surface water is highly correlated with fluvial flood probability, so is not discussed further here. Figure 3 shows the mean annual hydrological regime for each of the land-cover types identified in the scenarios (see also Table 2). These are typical values for floodplain land-cover types in favourable condition, but hydrological conditions can vary to some degree. The hydrological regimes of the land covers (Fig. 3) can be used to predict the hydrological regimes of each site under the different management scenarios. Figure 4 presents the seasonal mean watertable depth and fluvial flood probability for the two floodplains for each scenario. Because the floodplains are engineered to control flooding and drainage, it is assumed that these hydrological conditions can be achieved using existing or adapted engineering works. In order to support the production scenario, the hydrological regimes at the study sites do not need to alter greatly from the 2006 situation, which Fig. 2 Mean percentage area of land-cover and habitat types provided under the existing (in 2006) situation and under five alternative management scenarios for two floodplain sites in England.

8 1572 J. R. Rouquette et al. Table 2 Main land-cover and habitat types and a brief description of their hydrological requirements, projected to occur under alternative management scenarios. NVC: UK National Vegetation Classification community type. Land cover NVC communities Summary of habitat and hydrological requirements Arable and horticulture: Root crops OV9,13,14 Unable to tolerate inundation and requires low water table. Cereal (incl. maize) OV7-11 Can tolerate occasional winter flooding only. Temporary leys MG7a,b Can tolerate occasional winter flooding only. Permanent grass MG6,7 Improved permanent pasture. Low risk of inundation and moderate to low water tables. Wet grazing: Improved wet grasslands typically managed by low intensity cattle grazing. Floodplain grazing marsh MG13 Subject to frequent inundation in winter and spring, with water table falling for remainder of year. Other rough grazing MG9,10 Subject to regular inundation, moderate to poor drainage. Lowland meadows: Semi-natural neutral grasslands with low artificial inputs. Traditionally managed for hay with aftermath grazing. Floodplain meadow MG4 Well drained and subject to periodic winter flooding. Old hay meadow MG5 Traditional dry hay meadow. Water meadow MG8 Subject to frequent winter inundation. Moderate to good drainage. Fen, marsh and swamp: Lowland Fen S24,25, M27 Species-rich. Water above ground level for most of year. Reedbed S4 Dominated by Phragmites australis (common reed). Water above ground level year-round. Woodland: Alluvial forest W5-7 Wet woodland on neutral soils. Variable hydrological regimes but generally subject to periodic winter flooding and moderate to high water tables. Fig. 3 Hydrological regimes, showing mean water-table depth and annual fluvial flood probability, for a variety of land-cover and habitat types that could potentially occur on lowland floodplains.

9 Synergies and trade-offs in the management of lowland rural floodplains: an ecosystem services approach 1573 Fig. 4 Hydrological regimes at Beckingham Marshes (BM) and Kingsmoor / Witcombe Bottom (K/WB), showing: (a) seasonal mean water table depth, and (b) seasonal fluvial flood probability for the existing (in 2006) situation and five alternative management scenarios. is expected as land drainage has been improved at both sites for the benefit of agriculture. A substantial alteration in the hydrological regimes, however, is required to meet the objectives of the biodiversity scenario. Under the floodwater storage scenario, both sites have a target flood probability of 10%. The sites are maintained with a mean water-table depth of 1.0 m and zero days of standing surface water, so that maximum flood storage capacity is available during periods of inundation. This scenario would require major changes to the hydrological regime for the Kingsmoor floodplain, but less so for Beckingham Marshes. Such a hydrological regime is ideal to support intensive agricultural production, but is incapable of supporting most of the semi-natural floodplain habitats (Table 2 and Fig. 3) that are needed to support higher levels of biodiversity. The agri-environment scenario requires a hydrological regime that is between those described for the biodiversity and production scenarios, reflecting its objectives as a compromise between those scenarios (Fig. 4). The income scenario is similar to the production scenario at Kingsmoor and similar

10 1574 J. R. Rouquette et al. to the agri-environment scenario at Beckingham Marshes. Hence the hydrological regime is similar to those respective scenarios. Ecosystem-service provision The level of ecosystem-service provision achieved by the two sites under the alternative scenarios is shown in Table 3. Figure 5 shows the total sum of normalized values for the indicators. Note that the scores shown in Fig. 5 are not weighted and thus all the ecosystem services listed are considered of equal importance. Under the 2006 situation, the Kingsmoor site, which is predominantly occupied by dairy farming, provides high levels of agricultural production and employment, but also high levels of adverse environmental impacts indicated by nutrient leaching Table 3 Indicator outcomes for ecosystem services under alternative management scenarios. Ecosystem goods and services (affecting water quality) and greenhouse gas emissions. This site also scores considerably less well for landscape value, as it is currently, at least in part, being managed in a way that is divergent from local countryside and landscape priorities. By comparison Beckingham Marshes has some elements that are in keeping. These differences are exacerbated under the production scenario (Table 3 and Fig. 5). Kingsmoor would be managed almost exclusively for dairy production with high values for agricultural production, financial return and employment, but also for nutrient leaching and greenhouse gas emissions. There is no history of dairy production in the Beckingham Marshes area, hence cereals dominate under the production scenario, with concomitant lower outputs for the above mentioned ecosystem services. Indicators 2006 Production Agri-env. Biodiversity Flood storage Income Beckingham Marshes: Agricultural production Gross output ( /ha) Financial return Net margin ( /ha) Employment Labour (h/ha) Soil quality Soil carbon (t C/ha) Floodwater storage Time to fill (d) Water quality Nitrate leaching (kg NO 3 /ha) Greenhouse gas GWP (kg CO 2 eq./ha) balance Habitat provision Score per ha Species Score per ha Transport Risk exposure ( /ha) Settlement Risk exposure ( /ha) Space for Water Annual area flooded (ha) Recreation Score Landscape Score Kingsmoor / Witcombe Bottom: Agricultural production Gross output ( /ha) Financial return Net margin ( /ha) Employment Labour (hours/ha) Soil quality Soil carbon (t C/ha) Floodwater storage Time to fill (d) Water quality Nitrate leaching (kg NO 3 /ha) Greenhouse gas GWP (kg CO 2 eq./ha) balance Habitat provision Score per ha Species Score per ha Transport Risk exposure ( /ha) N/A N/A N/A N/A N/A N/A Settlement Risk exposure ( /ha) Space for Water Annual area flooded (ha) Recreation Score Landscape Score Results for Beckingham Marshes have been published in Posthumus et al

11 Synergies and trade-offs in the management of lowland rural floodplains: an ecosystem services approach 1575 Fig. 5 Normalized scores for ecosystem services provided under the existing (in 2006) situation and under five alternative management scenarios for: (a) Beckingham Marshes (Posthumus et al. 2010), and (b) Kingsmoor / Witcombe Bottom. Scores are normalized across each individual site and range form 0 (worst) to 1 (best) for positive indicators and from 0 (best) to 1 (worst) for negative indicators. Under the biodiversity scenario, both sites provide a similar level of ecosystem services. If all ecosystem services are considered to be of equal importance, then this scenario considerably enhances total ecosystem-service provision. Agricultural production is very low, but some financial return is

12 1576 J. R. Rouquette et al. received due to agri-environment and woodland grant payments. This scenario scores particularly well for soil quality, habitat and species values, space for water, recreation and landscape values, and has low environmental impact indicated by low (i.e. good ) scores for water quality and greenhouse gas balance. Although the biodiversity scenario increases flood risk to properties at both sites and flood risk to infrastructure at Beckingham Marshes, the density of roads and residential houses is low. Therefore the average flood damage cost per hectare is relatively small. Both sites would achieve the lowest aggregated score for ecosystem service provision under the floodwater storage scenario. Due to the deep water table, relatively low fluvial flood risk and high transpiration rates required under this scenario, intensive agricultural production is the most suitable land use, with dairy at Kingsmoor and cereals at Beckingham Marshes. Hence this scenario is similar in land use and ecosystem service provision to the production scenario, and at odds with the biodiversity scenario. Flood water storage is highest, and flood risk to properties is lowest under this scenario, although as both sites are already defended against flooding there is only a slight improvement over the current situation. In this study, we have only considered on-site flood alleviation benefits. Both sites would need to be considered in the context of the wider catchments, as on-site flood storage may provide considerable flood damage cost savings downstream. Under the compromise agri-environment scenario, Kingsmoor would predominantly be managed under an extensive beef system on various types of wet grassland. Half of the Beckingham Marshes site would be managed in this way, with the other half managed as high biodiversity-value floodplain meadow (NVC community type MG4). The provision of ecosystem services under this scenario is similar to that provided under the biodiversity scenario, although levels of agricultural production and financial return are considerably higher. Indeed, financial return is higher under this scenario than under the 2006 situation at both sites due to agri-environment payments. Flood control structures would be retained under this scenario and so floodwater storage capacity is considerably higher, and flood risk to properties and infrastructure reduced, compared to the biodiversity scenario, and similar to the 2006 situation. The income scenario produces the greatest difference between the two sites (Fig. 5). At Kingsmoor, the greatest farm income (net return) can be achieved by managing the land for maximum agricultural production. Hence the land use and ecosystem services delivered are almost identical to those delivered under the production scenario. However, at Beckingham Marshes, greater farm income can be achieved by managing the land as floodplain grazing marsh under extensive beef. For this scenario farmers receive payments under the Higher Level Stewardship scheme of 335 per hectare per year for the maintenance of wet grassland for breeding waders. Thus for Beckingham Marshes, the income scenario is similar to the agri-environment scenario, with a similar provision of ecosystem services. Linking hydrological regime to ecosystem service provision Correlations between ecosystem services under alternative land-use scenarios (based on the indicator scores) for the two sites are shown in Table 4. The production and floodwater storage scenarios are highly correlated and these are both correlated with the income scenario at Kingsmoor. At Beckingham Marshes the income scenario is much more closely Table 4 Correlations between ecosystem services provision under alternative management scenarios, with Beckingham Marshes shown below the diagonal and Kingsmoor / Witcombe Bottom above the diagonal Production Biodiversity Flood storage Agri-env. Income Production Biodiversity Floodwater storage Agri-environment Income Correlations are Spearman s rank correlation coefficients (n = 14). The r s values and the associated P values ( P < 0.05, P < 0.01, P < 0.001) are shown.

13 Synergies and trade-offs in the management of lowland rural floodplains: an ecosystem services approach 1577 correlated with the agri-environment scenario. The biodiversity scenario is not significantly correlated with any other scenario at Beckingham Marshes, but is highly correlated with the agri-environment scenario at Kingsmoor. The 2006 situation is correlated with most scenarios at both sites (with biodiversity being the most different) as it appears to be an intermediate scenario between the two extremes of the biodiversity-agricultural production spectrum. If the mean hydrological regime and levels of ecosystem service provision across the range of scenarios is compared (t-tests, d.f. = 10), there are few significant differences between the two sites. Only the absolute values for employment and floodwater storage are significantly (P < 0.05) higher for Kingsmoor than Beckingham Marshes across the alternative scenarios. The higher value for employment is associated with dairy production in Kingsmoor. Dairy was not considered as a possible farming system in Beckingham Marshes, because there has been little dairy activity in the past and present and there is thus little local infrastructure to support it. The higher value for floodwater storage is explained by the sizes of the floodplains relative to their catchments. It thus seems that an originally arable site does not result in significantly different outcomes for ecosystem services than an originally grassland site. Both sites can be adapted under alternative scenarios to deliver a particular set of ecosystem services. Table 5 Correlations between hydrological characteristics and ecosystem services. Beckingham Marshes Mean annual water-table depth Annual flood probability When analysing correlations between hydrological characteristics and ecosystem services (Table 5), it appears that changes in fluvial flood probability (and days with surface water, which is closely correlated with flood probability) have a larger effect on ecosystem services than a changing water-table depth, in particular for Kingsmoor. For Beckingham Marshes, flood probability is negatively correlated (P < 0.05) with agricultural production, but positively correlated (P < 0.05) with eight other ecosystem services: with soil quality, habitat provision, space for water and recreation showing the strongest positive correlation (P < 0.01). In Kingsmoor, on the other hand, flood probability is negatively correlated (P < 0.05) with agricultural production, employment, floodwater storage and settlement; it shows a positive correlation with the other ecosystem services. Financial return is the only ecosystem indicator that is not significantly correlated with flood probability in Kingsmoor. Only a few ecosystem services are significantly correlated with water-table depth. In Beckingham Marshes, agricultural production is positively correlated because of its predominantly arable production. Soil quality, water quality, greenhouse gas emissions and landscape value are negatively correlated with water-table depth. A lowering of the water table (i.e. a higher value for the water-table depth) permits more intensive arable production, thus negatively affecting Days with surface water Kingsmoor / Witcombe Bottom Mean annual water-table depth Annual flood probability Days with surface water Agricultural production Financial return Employment Soil quality Floodwater storage Water quality Greenhouse gas emissions Habitat provision Species Transport N/A N/A N/A Settlement Space for water Recreation Landscape value Total score Correlations (n = 6) are significant at: : P < 0.05 and : P < 0.01.

14 1578 J. R. Rouquette et al. the other ecosystem services. However, when the water-table depth becomes too shallow, it is necessary to switch land use from arable to grassland, explaining the more pronounced effect of water-table depth on ecosystem services at this site. At Kingsmoor, water-table depth has a less pronounced effect on agricultural production and related ecosystem services given its land use is predominantly grassland under all scenarios. Only settlement and space for water show a respectively positive and negative significant correlation with water-table depth. DISCUSSION Hydrological regimes Hydrology plays a key role in determining the land use and habitat types that occur on lowland floodplains. Vegetation responds to the depth of the water table, the quality of the drainage and to the depth, duration and seasonality of flooding (Runhaar et al. 1997, Silvertown et al. 1999, Wheeler et al. 2004). Table 6 summarizes the main land-cover types and habitats that exist or can be created on floodplains in terms of their hydrological requirements. The breadth of the hydrological regime varies between habitats, with some able to tolerate a relatively wide range of conditions (so they appear in many cells of Table 6) and others having quite specific requirements. The impact of flooding on agriculture varies considerably according to crop type and the seasonality, duration and depth of the event. Agricultural crops are particularly susceptible to summer flooding (Drew 1983). A short-duration flood event in the summer (June August) can lead to a 100% loss of yield for root crops, % loss of cereals, and significant damage to hay and silage crops (Hess and Morris 1988), although damage to grazing is considerably less. Longer-duration summer flooding leads to even greater losses. For example, the summer 2007 floods in England were reported to have cost farmers an average of 1207 per hectare (Posthumus et al. 2009). In contrast, short-duration winter floods tend to have limited impact on agricultural crops (e.g. Trought and Drew 1980). Agricultural crops are also unable to tolerate high water tables or poor drainage conditions during critical growth periods, especially in summer, with a reduction in yield reported once water tables rise to within 50 cm of ground level (Dunderdale and Morris 1997). Hydrological regimes clearly have a controlling influence over the type of crop that can be grown, with greater control over hydrology enabling a greater intensity of agricultural production. Where floodplains have been engineered for hydrological control, flood probability and drainage can be adjusted to suit particular land-cover types. In the scenario modelling exercise presented in this paper, the hydrological regimes of the scenarios Table 6 The hydrological regimes of land cover and habitat types found on lowland floodplains (adapted from International Journal of River Basin Management, Vol 3, Morris et al., A framework for integrating flood defence and biodiversity in washlands in England., 1 11, Copyright 2005, with permission from Elsevier.). Surface water per annum Winter flooding only Flooding at any time of year Mean annual water table: >50 cm cm <30 cm >50 cm cm <30 cm 0 10 days Root crops Permanent grass Water meadow Rough grazing Rough grazing Water meadow Cereals Rough grazing Grazing marsh Alluvial forest Water meadow Grazing marsh Temporary leys Floodplain meadow Alluvial forest Grazing marsh Alluvial forest Permanent grass Alluvial forest Alluvial forest Old hay meadow Floodplain meadow days Permanent grass Rough grazing Water meadow Grazing marsh Water meadow Grazing marsh Rough grazing Floodplain meadow Grazing marsh Rough grazing Grazing marsh Lowland fen Floodplain meadow Water meadow Alluvial forest Alluvial forest Alluvial forest Alluvial forest Grazing marsh Alluvial forest >60 days Rough grazing Grazing marsh Grazing marsh Alluvial forest Lowland fen Lowland fen Alluvial forest Alluvial forest Lowland fen Reedbed Reedbed Reedbed

15 Synergies and trade-offs in the management of lowland rural floodplains: an ecosystem services approach 1579 thus reflect the land-cover types and habitats found within them. Habitats under the biodiversity and agri-environment scenarios require shallow water tables, periods with standing water and frequent flooding. It is assumed that existing flood defences could be altered to meet these requirements. However, as a consequence, the sites are no longer suitable for some of the more intensive agricultural land uses without incurring crop yield penalties. Conversely, under the production scenario, the hydrological regime is engineered to provide suitable conditions for cereals, root crops and grass leys, but these conditions are incompatible with many of the seminatural habitat types described here. As both of the sites discussed in this paper have already been engineered to reduce flood frequency, lower water tables and enhance drainage, the hydrological conditions required for the production scenario are largely already being met. The hydrological requirements of the floodwater storage scenario are, perhaps, of most interest here. It is often assumed that floodwater storage and biodiversity can be accommodated at the same sites (e.g. Jones 2010), and indeed there is much interest in utilizing sites for both aims. However, as our results show, if an area is to be managed to maximize flood storage capacity, the hydrological regime will necessarily be unsuitable for semi-natural and biodiversityrich habitats that depend on shallow water tables and frequent flooding. It can, however, be compatible with intensive agricultural land use, assuming that flooding occurs mainly in winter, and that flood waters are removed and field water levels are restored relatively quickly after an event. Linking hydrology to ecosystem-service provision in lowland floodplains Analysis of the ecosystem services delivered under the alternative management scenarios has highlighted the strong link between increasing agricultural production and decreasing environmental and cultural quality. Scenarios that require a hydrological regime with deep water tables and relatively low flood frequencies (e.g. production and floodwater storage scenarios) scored highly for agricultural production and flood-storage capacity but poorly for environmental indicators for both sites. Conversely, when shallow water tables and frequent flooding are required (e.g. biodiversity scenario), higher scores were obtained for most environmental and cultural goods and services, but at the cost of flood-storage capacity and flood risk to properties and infrastructure. The agri-environment scenario achieved the highest aggregated score for ecosystem services. This scenario was able to achieve consistently high scores for habitat and cultural indicators, with low environmental impacts and little effect on flood risk and flood storage capacity. Relatively high scores were also achieved for financial return due to agrienvironment payments. However, without these subsidies financial return would be very low or close to zero. The high aggregated score of this scenario is perhaps not surprising as the hydrological management under this scenario is a compromise between the other more extreme scenarios, and thus more likely to accommodate the greatest range of ecosystem services. Other scenarios are more extreme in their hydrological regimes and thus likely to score highly on some ecosystem services, but poorly on others. Although the alternative scenarios showed many similarities for the two floodplains, there are some interesting, detailed differences. For example, the difference in aggregated scores for ecosystem services between the compromise agri-environment scenario and the 2006 situation is much higher for Beckingham Marshes than Kingsmoor. This can be explained by the fact that the current management of Beckingham Marshes is characterized by a low flood frequency, supporting arable production. The compromise agrienvironment scenario assumes shallower water tables and more frequent flooding, causing a drastic land-use change from arable to grassland and, subsequently, major shifts in some ecosystem services. Land-use changes and impacts on ecosystem services are less drastic for Kingsmoor, which is a typical grassland area with a hydrological regime more similar to the agri-environment scenario. Analysis of correlations between hydrological indicators and ecosystem services revealed that most ecosystem services showed stronger correlations with flood probability than water-table depth. However, changes in water-table depth have a bigger impact on ecosystem services on an arable site than a grassland site, because shallow water tables cause a major shift in land use on the former site (i.e. from arable to grassland). Hence, delivery of multifunctional landscapes in floodplains, as defined in this paper, may be more difficult to achieve for arable areas than for grassland areas. There is, however, scope for arable floodplains to deliver flood storage services alongside arable production, though this may call for compensatory payments to farmers who provide this facility to alleviate flood risk in downstream urban areas (Morris et al. 2007, Posthumus et al. 2008).