Environmental Management DOI 10.1007/s00267-013-0217-3

Climate Change Adaptation: Putting Principles into Practice Malcolm Ausden

Received: 28 March 2013 / Accepted: 10 December 2013 Ó Springer Science+Business Media New York 2013

Abstract Carrying out wildlife conservation in a changing climate requires planning on long timescales at both a site and network level, while also having the flexibility to adapt actions at sites over short timescales in response to changing conditions and new information. The Royal Society for the Protection of Birds (RSPB), a land-owning wildlife conservation charity in the UK, achieves this on its nature reserves through its system of management planning. This involves setting network-wide objectives which inform the 25-year vision and 5-year conservation objectives for each site. Progress toward achieving each site’s conservation objectives is reviewed annually, to identify any adjustments which might be needed to the site’s management. The conservation objectives and 25-year vision of each site are reviewed every 5 years. Significant long-term impacts of climate change most frequently identified at RSPB reserves are: loss of intertidal habitat through coastal squeeze, loss of low-lying islands due to higher sea levels and coastal erosion, loss of coastal freshwater and brackish wetlands due to increased coastal flooding, and changes in the hydrology of wetlands. The main types of adaptation measures in place on RSPB reserves to address climate change-related impacts are: recreation of intertidal habitat, re-creation and restoration of freshwater wetlands away from vulnerable coastal areas, blocking artificial drainage on peatlands, and addressing pressures on freshwater supply for lowland wet grasslands in eastern and southeastern England. Developing

M. Ausden (&) RSPB, The Lodge, Sandy, Bedfordshire SG19 2DL, UK e-mail: [email protected]

partnerships between organizations has been crucial in delivering large-scale adaptation projects. Keywords Climate change adaptation
Nature reserves
Protected areas
Management planning
Adaptive management

Introduction There are now many papers in the scientific literature providing recommendations for how to promote adaptation of wildlife to climate change (Heller and Zavaleta 2009), and these recommendations have been translated into national guidance on adaptation principles (e.g., Hopkins et al. 2007; Smithers et al. 2008; Scottish Natural Heritage 2012). Despite this, there are still few examples in the scientific literature of adaptation measures already in place. In this paper, I describe how the Royal Society for the Protection of Birds (RSPB), a land-owning wildlife conservation charity, has been taking climate change into account in the management of its network of 213 nature reserves in the UK. Nature reserves and other protected areas are expected to remain a crucial tool for biodiversity conservation under a changing climate (Thomas et al. 2012; Hiley et al. 2013). I first describe how the predicted long-term impacts of climate change are taken into account at both a site and network level on RSPB reserves, and how the RSPB plans, reviews, and adapts actions on its reserves through its management planning (adaptive management) system. I then describe the main types of predicted impacts of climate change on reserves, and adaption actions which have been put in place since the mid-1990s, when the impacts of

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climate change on RSPB reserves were first recognized as an important issue (Hossell 1994).

Planning, Implementing, and Reviewing Adaptation Measures Planning and implementing conservation measures in a changing climate is more difficult than in a stable climate, because of the uncertainty of future climatic conditions and how species will respond to these. For measures which have short-term implications (e.g., short-term management of grazing and water levels) measures can be adapted in response to observed changes in climatic conditions and species distributions, within the context of longer-term goals. For measures which take a long time to deliver their full benefits (particularly many types of habitat creation and restoration), actions need to be initiated a long time before they are expected to deliver their full benefits. The system which the RSPB uses to plan, review, and adapt actions on its reserves (i.e., carry out adaptive management) on these different timescales is described in the following section. An important influence on the management of the RSPB’s nature reserves is the European Union’s (EU’s) Nature Directives. These aim to secure favorable condition of priority species, including through the protection and management of sites classified as Special Protection Areas (SPAs) in accordance with Article 4 of the EC Birds Directive, and designated as Special Areas of Conservation

(SACs) under the EC Habitats Directive. Member States are required to take action to avoid site deterioration and to compensate for the impacts of plans or projects which pass the tests set out in the Directives. Climate change is clearly able to cause site deterioration, as are projects aimed at facilitating climate change adaptation, such as measures to reduce flood risk (see later). RSPB’s Management Planning System The system which the RSPB uses to plan, review, and adapt actions on its reserves is summarized in Fig. 1. Conservation objectives for the entire reserve network are set out in the RSPB’s Reserves Strategy. This has been developed to support the delivery of favorable condition of statutory designated sites in the UK, and delivery of the UK Biodiversity Action Plan. The Reserves Strategy takes into account a range of factors, including the predicted impacts of climate change. This Strategy informs the priorities and objectives of individual reserves, which are described in each reserve’s management plan. Each reserve management plan has a long-term vision and this, together with information elsewhere in the management plan (see later), informs the site’s 5-year conservation objectives. Each site produces an annual report each year. This describes the management carried out during the previous year, and reports on progress toward achieving the main objectives in its management plan. Each annual report is audited by a headquarters-based team of ecologists, to identify any important issues which need addressing. An

Fig. 1 The Royal Society for the Protection of Birds’ management planning system

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annual review meeting is also held at some sites. Both processes identify any adjustments needed to the reserve’s management prescriptions to help achieve the reserve’s conservation objectives. Each reserve management plan is reviewed every 5 years. This process reviews whether any adjustments are required to the site’s long-term vision, and re-sets the sites conservation objectives and the actions intended to achieve them. The revised management plan is agreed at both regional and headquarters levels. The process of discussion and agreement at headquarters level aims to resolve any remaining issues, and ensures that the site’s objectives contribute to the RSPB’s wider objectives. It also helps influence policy development, identify research needs, and identify any interventions required by statutory bodies to address any external factors affecting the reserve’s conservation interest. At reserves which contain statutory protected areas, the contents of the management plan are also consented by the relevant statutory agency. The final part of the adaptive management process involves collating information from reserve annual reports and audits to assess progress toward achieving the networkwide objectives contained in the RSPB’s Reserve Strategy. This process can trigger actions if the organization proves to be under-performing against its own objectives. This overall system of having a 25-year vision, objectives which are reviewed every 5 years, and actions which are reviewed annually, is ideally suited for taking into account the predicted impacts of climate change. It allows actions to be initiated now, which are aimed at delivering their full benefits in the more distant future. It also enables actions to be reviewed and adapted on a short timescale within the context of longer-term and network-wide goals. Format of RSPB Management Plans All RSPB reserve management plans are written to the same format. Section 1 of the plan contains information about the site. Section 2 evaluates the importance of different features (species, assemblages of species, and habitats) at the site and provides the rationale for management. Section 3 contains a long-term vision for the site, and 5-year, quantified conservation objectives. This section also summarizes the management intended to achieve these objectives, and the monitoring required to determine progress toward achieving these objectives. Section 4 contains the site’s work program. Section 1 also contains information on projected changes in key climate, and climate-related, variables at the site based on data from the UK Climate Impacts Program projections (http://ukclimateprojections.defra.gov.uk). This information comprises graphs of projected changes in monthly maximum temperature, number of growing days

per month, and monthly potential soil moisture deficit. Management plans for coastal sites also contain information on projected rises in sea level. For all of these parameters, data are provided on current values, and projected values for 2030 under the high emissions scenario. Section 2 also includes a table summarizing the predicted impacts of climate change on key features at the site in the absence of adaptation measures, together with possible adaptation actions. This table can also include species predicted to colonize the site. The long-term vision for each RSPB reserve is for 25 years. This is a compromise between being a long enough period of time over which to consider important processes and changes (including those related to climate change), without being too long a period to be irrelevant to people currently managing the reserve. However, for sites dominated by habitats whose condition can change very slowly, such as woodland and blanket bog, the management planning guidance recommends including an additional vision over a longer time period. For example, a reserve where large-scale expansion of native Scots pine (Pinus sylvestris) woodland is taking place also has a 200-year vision.

Climate Change Adaptation Measures on the RSPB’s Nature Reserves Table 1 shows the frequency of different types of predicted climate change impacts on habitats, which are referred to in reserve 25-year visions i.e., impacts which are considered important enough to significantly affect the extent or quality of the habitat at the site during the following 25 years. Table 2 summarizes the main actions which have been undertaken, or are in place, on RSPB reserves which have been partly, or wholly, driven by consideration of the predicted impacts of climate change. It does not include measures expected to facilitate adaptation of wildlife to climate change would also be carried out to benefit conservation in the absence of climate change. Examples of these include maintaining existing areas of high quality natural and semi-natural habitat (including reducing nonclimate change-related pressures on wildlife), and increasing the total area, and size of patches, of high quality semi-natural habitat (e.g., Hodgson et al. 2009, 2011). It is worth noting, that consideration of climate change impacts has particularly influenced the location of where the RSPB has re-created lowland heathland. This is a rare and fragmented habitat in the UK, and the RSPB has re-created lowland heathland to the north of the current core range of the majority of its characteristic species, to help facilitate their northward range expansion.

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Environmental Management Table 1 Predicted impacts of climate change on habitats, which are referred to in 25-year visions for Royal Society for the Protection of Birds’ nature reserves Habitats

Number of sites containing the habitata

Predicted impact referred to in 25-year vision

Intertidal

48

Loss of habitat through coastal squeeze

48

Loss of habitat due to higher sea levels/increased coastal erosion

100

Low-lying coastal islands used by nesting terns

6

Percent of sites containing the habitat which refer to the impact

Sand dunes

13

Loss of habitat through coastal erosion

8

Coastal freshwater/brackish wetlands (excluding saline lagoons)

51

Increased frequency of coastal flooding and eventual loss of habitat

24

Saline lagoons

12

Loss through coastal change

50

All freshwater and brackish wetlands

88

Increased/unpredictable freshwater flooding

5

Lowland wet grassland

44

Reduction in water availability in late spring and summer

14

Peatlands

25

Increased summer drying

8

Upland heath and upland grassland

39

None

–

Lowland heathland

12

None

–

Broad-leaved woodland

66

Increased summer drying

5

a

Sites containing[5 ha of the habitat, apart from for low-lying coastal islands used by nesting terns, for which all sites are included, because all of these islands are \5 ha

The measures carried out on RSPB reserves are dominated by those which aim to address: (1) loss of intertidal habitat through coastal squeeze, (2) loss of coastal freshwater and brackish wetlands (mainly freshwater reedbeds) through coastal flooding, and (3) drying out of peatlands in summer. It should be noted that actions to address drying out of peatlands in summer are most commonly viewed as measures to restore high quality habitat and reduce current greenhouse gas emissions. These measures have been included, though, because they are also expected to reduce the vulnerability of these peatlands to projected increases in summer drying (see later). A fourth important category of impact, increased pressure on freshwater supply for lowland wet grassland, is a particular issue in eastern and southeastern England. For example, of the seven water storage reservoirs constructed to address water supply issues at the 44 RSPB lowland wet grassland reserves, six have been constructed at the 21 lowland wet grassland reserves in eastern and southeastern England. The adaptation measures implemented on RSPB reserves span the range of potential adaptation responses described in the literature (e.g., Heller and Zavaleta 2009; Morecroft et al. 2012). They include measures principally aimed at: increasing resistance to change (for example using water storage to help maintain a similar hydrological regime to at present), building resilience to help species and habitats withstand change or recover from perturbations (for example by reducing non-climate change-related pressures on them), and, facilitating change, often referred

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to as accommodation and transformation (for example facilitating the development of intertidal habitat through managed realignment). Details of measures to address these four categories of impacts, and the lengths of time it takes some types of action to realize their conservation benefits, are described in the following sections.

Examples of Adaption Actions Put in Place on RSPB Reserves Re-creating Intertidal Habitat to Help Offset Losses of Intertidal Habitat Through Coastal Squeeze Intertidal habitat in the UK is of high conservation importance, principally for the internationally important numbers of wintering and passage waterbirds that it supports. The results of bioclimate modeling suggest that the UK’s estuaries will remain climatically suitable for supporting large numbers of wintering waterbirds for at least the next few decades, even though the species composition of waterbird assemblages at individual estuaries is expected to significantly change (Johnston et al. 2013). The importance of the UK’s intertidal habitat for waterbirds is reflected in a high proportion of its area being classified as SPAs, with some areas of intertidal habitat designated as SACs. Importantly, as described earlier, SPA and SAC habitat which is lost as a consequence of measures to reduce flood risk (including measures carried out in response to increases in flood risk

Environmental Management Table 2 Actions carried out on Royal Society for the Protection of Birds’ nature reserves between 1994 and 2013 which are expected to facilitate adaptation of wildlife to climate change Habitats

Intertidal

Low-lying coastal islands used by nesting terns

Coastal freshwater/brackish wetlands (other than saline lagoons)

Predicted climate change impact

Loss of habitat through coastal squeeze

Increased inundation/increased erosion/complete loss of island

Increased coastal flooding and eventual loss of habitat

Response

Area of land (and number of sites) affected by works Major works completed

Under construction

Re-creation of intertidal habitat on arable land or improved grassland through managed realignmenta

450 ha (5 sites)b

ca 400 ha (1 site)

Re-creation of intertidal habitat on arable land or improved grassland through regulated tidal exchange

16 ha (2 sites)

54 ha (1 site)

Re-alignment of coastal defences to allow coastal freshwater/brackish habitat to become intertidal habitatc

21 ha (2 sites)

–

Raising of island using shingle dredgings

1,000 m2 (1 site)

–

Creation of new islands in managed realignment areas

(1 site)

(1 site)

Protection of habitat from coastal flooding through improvement of sea defencesd

249 ha (2 sites)e

–

Creation of replacement reedbed (and associated fen and open water) away from areas vulnerable to coastal flooding

732 ha (12 sites)

433–448 ha (2 sites)

Restoration of freshwater reedbeds to offset the effects of loss of coastal freshwater reedbeds

423 ha (10 sites)f

–

Creation of coastal grazing marsh away from areas vulnerable to coastal flooding, to replace coastal grazing marsh predicted to be lostg

248 ha (2 sites)

120 ha (1 site)

Saline lagoons

Loss through coastal change

Creation of replacement saline lagoons

14 ha (1 site)

27 ha (1 site)

Lowland wet grassland

Reduction in water availability in late spring and summerh

Storage of winter water in reservoirs for use in spring and summer

602 hai (7 reservoirs at 5 sites)

–

Provision for rotational hydrological management of flooded areas

21 ha (1 site)

–

Increase in frequency/duration of drought and extreme rainfall eventsh

Creation of unflooded lowland wet grassland for birds to nest on when the main area of habitat is flooded in spring/summer

74 ha (1 site)

–

Increased summer drying

Blocking of artificial drainage

7,660 ha (9 sites)

–

Stabilisation of eroding peat

250 ha (1 site)j

–

Removal of non-native conifer plantation on deep peat, with some blocking of artificial drainage

2,033 ha (2 sites)

–

Blocking of artificial drainage

12 ha (1 site)

–

Peatlands

Broad-leaved woodland a

Increased summer drying

Does not include intertidal habitat created to directly compensate for loss of habitat through port development

b

Includes one site where the scheme was implemented before the land was transferred to RSPB, but the RSPB was involved in the design of the site

c

Changes resulting from the same works undertaken as for note d

d

Changes resulting from the same works undertaken as for note c

e

The area of land which has increased protected from coastal flooding as a result of the works

f

The total area of reedbed at the sites where restoration measures were undertaken

g

Only includes sites where habitat has been created as part of Environment Agency’s Regional Habitat Creation Program to compensate for expected losses of coastal grazing marsh, or as part of intertidal habitat creation schemes

h

Measures put in place principally to address current hydrological issues, which are likely to be exacerbated by climate change

i

The area of habitat to which the reservoirs supply water

j

Most work carried out before the land became an RSPB reserve, but the RSPB was a partner in this work

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caused by climate change) needs to be replaced by compensatory habitat. Intertidal habitat in the UK is predicted to be lost through coastal squeeze. This occurs where the rate of relative sea level rise is greater than that of accretion, but new intertidal habitat is prevented from developing further inland by fixed sea defenses. The projected rate of sea level rise is greater in southern England than in the north of the UK, because glacial isostatic adjustment is causing land levels in southern England to sink, and land levels in the north of the UK to rise (http://ukclimateprojections.defra. gov.uk). In England, an estimated 72 % of the area of intertidal habitats lies to the seaward side of artificial defenses, and is, therefore, at potential risk from coastal squeeze (Committee on Climate Change 2013). The principal drivers for intertidal habitat re-creation in the UK have been to re-create habitat for wildlife (in more than half of cases to compensate for intertidal habitat lost through development) and to provide cost-effective coastal defenses (Rupp-Armstrong et al. 2008). However, it is important to recognize that re-creation of intertidal habitat also provides other benefits. In particular, intertidal areas store large quantities of carbon, and provide nursery areas for commercially important fish species (Chmura et al. 2003; Colclough et al. 2005; Shepherd et al. 2007; Fonseca et al. 2011). Large areas of intertidal habitat are likely to be required to offset predicted losses of intertidal habitat, as well as to provide compensatory habitat for any development of ports or tidal barrages on SPAs or SACs. There are, though, limited opportunities for re-creating large areas of intertidal habitat along many stretches of the coast, because of the scarcity of large blocks of low-lying coastal land which are free of roads and other infrastructure. Because of these limited opportunities, it is, therefore, important that new coastal wetlands are designed to maximize their conservation and other benefits. The value of re-created intertidal habitat for wildlife can be increased by creating creeks, pools, and islands in areas at high elevation within the tidal frame. Creeks and pools provide important habitat for feeding birds and for fish (discussion in Colclough et al. 2005; Lourenc¸o et al. 2005), but do not usually develop in flatter areas at higher elevation within the tidal frame following the introduction of tidal flooding (Wallace et al. 2005). Increasing topographic variation in higher areas is also expected to increase plant species richness (Wolters et al. 2005), and will provide nesting areas for common redshank (Tringa totanus), which are safe from tidal flooding. It is also valuable, where possible, to create coastal islands for nesting and roosting birds as part of intertidal habitat re-creation schemes. In particular, shingle-covered islands can provide valuable nesting habitat for little terns

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(Sternula albifrons), common terns (Sterna hirundo), and common ringed plovers (Charadrius hiaticula), which is free of ground predators and human disturbance. Little terns and common ringed plovers nesting elsewhere on beaches often breed at reduced densities and suffer low breeding productivity, because of human disturbance and the impacts of ground predators (Pickerill 2004; Fasola et al. 2002; Liley and Sutherland 2007), while existing low-lying islands are vulnerable to loss through sea level rise and increased coastal erosion (Table 1). Although rising sea levels will inevitably result in the formation of low-lying islands, these features are so rare along the coastline of the UK that it seems sensible to take opportunities to create them. Creating saline lagoons and other coastal wetland habitats as part of intertidal habitat re-creation projects will help offset predicted losses of existing examples of these features (Tables 1, 2; Spencer and Brooks 2012) and, for some bird species, might provide important additional feeding areas at high tide and when estuarine food supplies have been depleted in late winter (Velasquez and Hockey 1992; Masero et al. 2000; Gill et al. 2007). Creating transitions between intertidal and freshwater habitat, and between intertidal and terrestrial habitat, is also valuable. These transitions support many rare species, but are rare along much of the UK’s coastline and at many intertidal habitat re-creation sites, where sea walls create an abrupt transition between intertidal habitat and the grassland of the sea wall (Rees et al. 2010). Shallow freshwater flows across intertidal mudflats are an important feature for wetland birds (Ravenscroft and Beardall 2003). The following case study describes the range of features which have been incorporated into the design of intertidal and associated wetland habitats at Wallasea Island Wild Coast. The large scale of this project, together with the ability to land form large areas, means that it has been possible to incorporate a wider range of wetland features into its design than has been possible at many other intertidal habitat re-creation sites. Other partners in the Wallasea Island Wild Coast project are Crossrail Ltd., Defra and the Environment Agency. Case Study: Wallasea Island Wild Coast Project Wallasea Island lies on the coast of Essex, England. It is connected to the mainland by a ca. 200 m length of road, but is otherwise surrounded by intertidal habitat. The island had two particular advantages as a site for re-creating intertidal habitat. First, most of the island was owned by one farm and contained no buildings or public roads. Second, most of the island’s sea walls were of a low flood defense standard. The farmland on Wallasea Island was relatively flat and low-lying, with an average elevation of 0.85 m below the

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lowest level at which salt marsh is expected to develop. If there was an unplanned breach of the sea wall, then tidal flooding of the island would increase the tidal prism (the difference in volume of water between high tide and low tide) of the adjoining Roach and Crouch Estuaries by an estimated 11 million m3 over a mean Spring tide. This increase in tidal prism was predicted to cause significant adverse impacts on the rest of the estuary (higher water levels, increased flow speeds and widening and deepening of the channel to the seaward side of the breach), and increase stress on the estuaries’ coastal defenses. The results of modeling suggested that to avoid adverse impacts on the adjacent estuaries, any increase in the tidal prism needed to be less than 2–3 million m3 over a mean Spring tide. Two approaches to intertidal habitat re-creation were considered: managed realignment and regulated tidal exchange (RTE). Managed realignment involves deliberate breaching or removal of sea walls, embankments, or dikes to allow tidal flooding of the area to their landward side. RTE involves installing a water control structure in a sea wall, embankment, or dike, to allow controlled tidal flooding of the area inland of it. RTE was initially investigated as a way of re-creating intertidal habitat on Wallasea Island, because it could be used to reduce the flow of tidal water onto and off the island, and thereby limits any increase in the estuary’s tidal prism. As accretion increased the height of the substrate within the RTE area, so the maximum level of water within the RTE area could be increased accordingly, without any further increase in the estuary’s tidal prism. This RTE option was proving to be expensive, because it required improving the flood defense standard of long sections of the existing sea wall, and the installation of large tide gates to regulate the flow of water into and out of the RTE areas. An alternative managed realignment design was then developed. This involved raising the level of the land at Wallasea Island prior to the introduction of tidal flooding, to limit the increase in the adjacent estuaries’ tidal prism to 2 million m3 over a mean Spring tide following breaching of the sea walls at Wallasea Island. The managed realignment areas were to be in three separate cells, so that the site can be developed in stages. This was to minimize risk, and because the material used to raise land levels would be from different sources and arrive at different times. The final design for the site comprises ca. 400 ha of intertidal habitat (including transitional salt marsh up to 1 m above the level of the Highest Astronomical Tide) created through managed realignment following raising of land levels, and 54 ha of RTE. Land in the first 160-ha managed realignment cell is being raised using inert material excavated during the construction of a new railway tunnel under London by Crossrail Ltd., which is being

transported to the site by ship. Creeks and pools are being created during land forming in the managed realignment areas prior to breaching. These have been designed to mimic, as far as possible, the network of larger creeks present before the land was claimed for agriculture. Different designs of islands are being created in intertidal areas and saline lagoons to provide suitable nesting habitat for common redshank, terns, and Eurasian spoonbills (Platalea leucorodia). The area of RTE has been retained to provide an area in which the frequency and duration of flooding can be controlled, to manipulate habitat conditions to benefit breeding, passage, and wintering birds. Most of the new sea walls and counter walls at Wallasea will have an especially shallow gradient (1 in 40) between the level of the Highest Astronomical Tide and 1 m above this, to ensure that a wide transitional zone between salt marsh and non-tidal grassland exists under a range of possible future sea levels. The design of Wallasea also includes a variety of transitional brackish/freshwater wetland habitats to enhance its value for wildlife, and to mitigate the effects of the loss of freshwater and brackish ditches at the site. These habitats comprise a 27 ha saline lagoon, and 120 ha of freshwater coastal grazing marsh/brackish marsh. These are designed to provide additional feeding, nesting, and roosting habitat for birds. The coastal grazing marsh/brackish marsh includes a 6 ha area containing a dense network of ditches and pools designed to optimize conditions for water voles (Arvicola amphibious). There will also be improved visitor access at the site, with 15 km of new and improved access routes, and eventually a range of other visitor facilities. The wetland as a whole will accommodate substantial additional quantities of water during a storm surge, which should reduce pressures on other parts of the surrounding estuary. Large-scale habitat re-creation projects such as Wallasea Island Wild Coast can take a long time to implement. The RSPB identified Wallasea Island as a potential site for recreation of intertidal habitat in the late 1990s, and began talking to the island’s major landowner in 2000 about the possibility of acquiring land. Design of the proposed new wetland began in 2006, and the planning application for recreating wetland habitat was submitted in 2008. Construction of facilities to receive excavated material by barge began in 2009, and land forming of the first intertidal area started in 2012. The first 160-ha area of managed realignment at Wallasea is planned to be breached in 2016. Following the introduction of tidal flooding, densities of wading birds, and biomass densities of their main benthic invertebrate prey, probably usually take three or more years to reach comparable levels to those on adjacent mudflats (Evans et al. 1998; Atkinson et al. 2004; Mander et al. 2007). Salt marsh plants are quick to establish in new areas

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of intertidal habitat of suitable elevation, although it may take a long time for plant assemblages to fully resemble those found on ancient, naturally-developed salt marsh, if they ever resemble these at all (Wolters et al. 2005, 2008; Garbutt and Wolters 2008; Mossmann et al. 2012). Thus, it is expected that the first areas of intertidal habitat at Wallasea will be capable of supporting comparable densities of waterbirds to those on adjacent mudflats 19 or more years after initial contact with the former landowners at the site, and 13 or more years after the site started to be designed. Re-creating and Restoring Freshwater Wetlands to Compensate for Loss of Freshwater and Brackish Wetlands Through Coastal Flooding This risk of coastal flooding in the UK is expected to increase due to rising sea levels and a possible increase in the frequency and severity of storms (Ramsbottom et al. 2012; Committee on Climate Change 2013). In England, an estimated 32,000 ha of sites designated for wildlife are vulnerable to coastal flooding (Defra 2006). Coastal flooding is a particularly important issue for the UK’s freshwater reedbed and its associated species. Freshwater reedbed is a rare habitat in the UK, with a total estimated area of 5,000 ha (UK Biodiversity Action Plan Priority Habitat Descriptions. Reedbeds), and many of the few large ([ca. 100 ha) freshwater reedbeds in the UK are in coastal areas of eastern England, which are at risk from coastal flooding. Coastal flooding of freshwater reedbeds is a particular issue for the small UK breeding population of Eurasian bitterns (Botaurus stellaris) (hereafter ‘bittern’). This had declined to just 15–20 booming (‘‘singing’’) males in the UK during the first half of the 1990s, and reached a low point of just 11 booming males in 1997. During this period, the majority of the UK’s breeding bitterns were in freshwater reedbeds at risk from coastal flooding (Gilbert et al. 2010). Flooding of freshwater reedbeds with saline water kills freshwater fish, which are an important prey of bitterns in the UK (Gilbert et al. 2003). Although tidal reedbeds can be used to some extent by bitterns for feeding, they are unsuitable for nesting bitterns because of their widely fluctuating water levels. Case Study: Recreation and Restoration of Freshwater Reedbeds Away from Vulnerable Coastal Areas Conservation work began in the mid-1990s to create and restore freshwater reedbeds to benefit bitterns. This work was targeted and coordinated through the development of a Species Action Plan for bitterns (Williams et al. 1995). Much of the work was funded by two EU LIFE-Nature

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projects which were led by the RSPB and Natural England and involved a range of organizations. The first project (from 1996 to 2000) carried out ‘‘emergency action’’ for bitterns, and the second project (from 2002 to 2006) aimed to create a network of reedbeds suitable for bitterns away from vulnerable areas of the coast. Approximately 700 ha of reedbed was restored during these two EU LIFE-Nature projects, and 300 ha of reedbed created during the second EU LIFE-Nature project (Brown et al. 2012). Work carried out on RSPB reserves as part of these and other reedbed creation and restoration projects is summarized in Table 2. Details of the creation of reedbed at one of these sites, Lakenheath Fen RSPB reserve, are provided by Sills and Hirons (2011). Restoration and creation of reedbeds have been accompanied by a large increase in numbers of booming bitterns on RSPB reserves. Significantly, there has been an increase in the proportion of booming bitterns in reedbeds which are at no or low risk of coastal flooding, due mainly to the development of bittern populations in reedbeds created away from vulnerable coastal areas since the mid1990s (Fig. 2). The results of population modeling suggest that recovery of the UK bittern population was fueled mainly by productivity at three coastal reedbeds in Suffolk, England, all of which are threatened by coastal flooding (Gilbert et al. 2010). Despite this success, the status of the UK bittern population remains vulnerable. It is thought that in many years only half, or less than half, of sites occupied by booming bitterns support nesting females (Gilbert et al. 2010), and a large proportion of the UK bittern population is still confined to a small number of large reedbeds. The reedbeds created through this strategy already provide habitat for a wide range of other wetland species, with reedbed created at Lakenheath Fen and Ham Wall RSPB reserves taking approximately 15 years to develop breeding populations of the full range of bird species typical of this habitat in their respective regions (Fig. 3). Reedbed which started to be created 11 years previously has been found to support a similar species richness of reedbed-specialist moths to ‘‘long-established’’ reedbeds in close proximity to it, but a lower species richness of reedbed-specialist Diptera (Hardman et al. 2012). We do not know how quickly newly created reedbeds have been colonized by other taxa. There are a number of bird species associated with reedbeds whose current European breeding distribution lies largely to the south of the UK, and which have the potential to establish (or re-establish) regular breeding populations in the UK. These comprise two groups. First, species for which climate envelope modeling (Huntley et al. 2007), based on a 3 °C rise in global temperatures above those of pre-industrial times, predicts that the UK will have a suitable climate: little bittern (Ixobrychus minutus), blackcrowned night-heron (Nycticorax nycticorax), purple heron

Environmental Management Fig. 2 Numbers of booming (‘‘singing’’ male) Eurasian bitterns at Royal Society for the Protection of Birds’ reserves which are at different risks of coastal flooding. Flood risk is taken from the UK Environment Agency’s interactive flood risk map

(Ardea purpurea), great reed warbler (Acrocephalus arundinaceus), and white-spotted bluethroat (Luscinia svecica cyanecula). Second, species whose numbers are increasing in the UK and elsewhere in Western Europe (Balmer et al. 2013): great egret (Ardea alba) and Eurasian spoonbill. Although the colonially-breeding species among these (black-crowned night-heron, great egret, purple heron, and Eurasian spoonbill) will nest in wet reedbed or wet scrub and wet woodland associated with reedbed, they also require large areas of non-reedbed wetland foraging habitat within commuting distance of their nesting colony (Cramp 1977, 1988, 1992; Hafner and Fasola 1991; Barbraud et al. 2002; van der Hut et al. 2008; Platteeuw et al. 2010). Three of the potential colonists listed, purple heron, little bittern, and great egret, have already nested in the UK since 2010, in all cases in recently created reedbed. These comprise the first recorded breeding in the UK by purple heron and great egret, and the first recorded regular breeding in the UK by little bittern (Holt 2013; Holling and The Rare Breeding Birds Panel 2012). Thus, measures which were carried out primarily to benefit bitterns and other reedbed species whose UK populations were at risk through coastal flooding, are also facilitating large-scale range expansion of additional species. Blocking Artificial Drainage on Peatlands to Reduce Summer Drying Blanket bog and associated upland habitats in the UK are of high conservation importance for their assemblage of

breeding birds (Thompson et al. 1995). The UK contains an estimated 10–15 % of the world’s blanket peat habitats, and the UK’s peatlands are estimated to contain approximately 3,200 million tonnes of carbon (Tallis 1998; Worrall et al. 2010). Upland peat catchments provide a large proportion of the UK’s drinking water. However, much of the UK’s blanket bog has been degraded through over-grazing, burning, deposition of atmospheric pollutants, and artificial drainage (Committee on Climate Change 2013), while large areas of blanket bog have also been planted with non-native conifers. Artificial drainage of peatlands causes the surface layers of peat to dry out and releases CO2 (see review by Bain et al. 2011). Projected changes in climate are expected to increase summer drying of peatlands in the UK, with climatic conditions projected to become less suitable for the growth of blanket peat in the UK under a range of future climate scenarios, especially in eastern regions of the UK (Worrall et al. 2007; Clark et al. 2010). The aims of management of degraded upland peatlands managed by the RSPB have been to begin restoring seminatural blanket bog habitats, reduce CO2 emissions, and in the longer-term re-commence carbon sequestration through peat accumulation. Two RSPB reserves, Lake Vyrnwy in Powys, Wales and Dove Stone in Greater Manchester, England, are in catchments for reservoirs which supply drinking water. At these two sites, an additional important aim of large-scale peatland restoration has been to reduce discoloration of drinking water. Peatland restoration at Lake Vyrnwy has been part-funded by an EU LIFE-Nature project (LIFE Active Blanket Bog in Wales). Peatland

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(a)

(b)

(c)

Peatland restoration has involved blocking artificial drainage ditches [in most cases using small peat or piling dams, or heather (Calluna vulgaris) bales], stabilizing any eroding peat, excluding burning and where necessary reducing levels of, or excluding, grazing. At Forsinard Flows RSPB reserve in Highland, Scotland, restoration work has involved extensive drain blocking to raise and stabilize water levels, and felling large areas of non-native conifers planted on deep peat and blocking artificial drainage in these areas. Much of the initial restoration work and land purchase at Forsinard was part-funded by two EU LIFE-Nature projects. Restoring a more natural hydrology to blanket bog is predicted to increase food supply for European golden plovers (Pluvialis apricaria) and some other birds breeding in upland areas, by reducing the negative impacts of climate-induced drying on the abundance of crane flies (Tipulidae) (Pearce-Higgins 2010, 2011; Pearce-Higgins et al. 2010). A feature of the work at Lake Vyrnwy is that it has involved a replicated experiment to investigate the effects of drain blocking on hydrology, greenhouse gas emissions, and wildlife. At this site, four paired river sub-catchments were identified, and drains were blocked in one of each pair of these sub-catchments. The effects of drain blocking on hydrology have been fairly rapid. During the first 3 years following drain blocking, there has been an increase in water storage within the peatland, an increase in stability of the water table, lower discharge rates, a reduction in peak flows of water, and less water discoloration, compared to the period before drains were blocked (Wilson et al. 2010, 2011a, b). Abundance of crane flies has also increased in line with changes in soil moisture during the first few years following drain blocking (Carroll et al. 2011). We do not know how long it will take to restore artificially drained blanket bog, or peatlands from which forestry plantation has been removed, to a similar state to before they were drained or afforested. Addressing Pressures on Freshwater Supply for Lowland Wet Grasslands in eastern and southeastern England

Fig. 3 Development of breeding populations of selected bird species at newly created reedbeds

restoration at Dove Stone has taken place through a partnership between the RSPB and United Utilities (a water company) through the Sustainable Catchment Management Project before the area became an RSPB reserve.

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Lowland wet grassland is a cultural landscape, whose hydrology is manipulated for agriculture, and sometimes to benefit wildlife and for flood risk management. In the UK, key conservation features of lowland wet grassland include its characteristic assemblage of breeding waders, mainly northern lapwing (Vanellus vanellus), common redshank and common snipe (Gallinago gallinago (Wilson et al. 2005; Ausden and Bolton 2012), and its wintering waterbirds. Habitat quality for both of these groups, as well as for lowland wet grassland’s other characteristic wetland wildlife, is strongly affected by hydrology. The ability to

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achieve the desired hydrological conditions for most species associated with lowland wet grassland, will, therefore, be affected by changes in climate, flood risk management, and other pressures on water availability in the site’s catchment. The most important impact of climate change on habitat quality for breeding waders at many sites is likely to be the effect of lower rainfall and higher temperatures in late spring and summer (http://ukclimateprojections.defra.gov. uk) increasing the rate of drawdown of water levels during the wader breeding season. This is because hydrological management to provide optimal feeding conditions for waders during their breeding season (shallow pools and moist surface soil) involves having only a slow rate of drawdown of water levels, ideally without extensive and prolonged surface flooding in the preceding winter and early spring (Ausden et al. 2001; Ausden and Bolton 2012). Within the UK, reductions in water availability are projected to be greatest in southeast England, with reductions due to changes in climate likely to be exacerbated by increased demand for water for agriculture, industry, and services (Environment Agency 2011; Rance et al. 2012; Sanderson et al. 2012). There are already significant pressures on water supply for many wetlands in this region. In the far south-east of England, at some sites which do not receive significant inputs of river water, the duration and extent of winter flooding is also predicted to decline despite an increase in winter rainfall, because water levels are predicted to be far lower in late summer and autumn (Thompson et al. 2009). Reduction in the duration and extent of shallow winter flooding would reduce the suitability of these sites for wintering wildfowl, which use shallow water for feeding and roosting. A range of measures have been used on RSPB reserves to improve conditions for breeding waders at sites which already lack sufficient water in dry springs. The approach has been to try to increase water supply in spring and early summer, and to make best use of the water available (i.e., actions aimed at building resilience/increasing resistance). Measures for increasing water availability in spring and early summer have included securing additional inputs of water, and using reservoirs to store water abstracted from rivers in winter (when river flows are high) for use in spring and early summer (Table 2). These reservoirs have typically been designed with sufficient capacity (and water supply) to achieve optimum water levels in 75 % of years under current climatic conditions, but with additional capacity to take account of projected future reductions in water availability. Measures to make best use of the available water include reducing leaks from sluices and bunds, excavating shallow ‘‘foot drains’’ to maintain wet areas when the rest of the field surface has dried out (Eglington et al. 2008), and rotationally flooding different

areas of grassland instead of trying to keep a larger area of grassland flooded every year. It has also been important to ensure that there is a suitable infrastructure (e.g., pump capacity) to move sufficient quantities of water to areas which require it, and to remove excess water during extreme flood events. Winter rainfall is also projected to increase in the UK, and there is projected to be an increase in the frequency of extreme rainfall events all year round (http://ukclimatepro jections.defra.gov.uk). Extreme rainfall events can also cause spring and summer flooding of washlands and river floodplains, which reduces breeding productivity of waders (Green et al. 1987; Ratcliffe et al. 2005). At the Ouse Washes, Cambridgeshire, England, unflooded grassland has been created for waders to nest on in years when the adjacent washland is flooded in spring (Table 2). This has been carried out to address current hydrological issues, but should also help mitigate the impacts of any increase in the frequency and duration of spring and summer flooding. At some sites in southeastern England, increases in the rate of drawdown of water levels in spring and summer might eventually make it impractical to maintain very similar hydrological conditions to at present. An alternative response to that described earlier, would be to accept an increased rate of drawdown in water levels in spring and summer and, where practical, encourage (or just allow) deeper and more extensive flooding in winter. This would mean that, in the case of breeding waders, areas might still remain wet enough during the breeding season despite this greater rate of drawdown. This approach would aim to accommodate (rather than resist) changes in hydrology that occur as a result of climate change, and might result in the hydrology of these sites becoming increasingly similar to the current hydrology of wetlands further south in Europe, which have high water levels in winter and a large drawdown of water levels through spring and summer (Hoffmann 1958; Valverde 1958). Pursuing this accommodation approach might result in these sites becoming more suitable for species which currently occur in wetlands in southern Europe, but which are presently rare in, or absent from, the UK. We have been investigating the habitat requirements of wetland birds which could potentially extend their breeding range north to the UK in the future, and are starting to take these species’ requirements, and predicted longer-term changes in hydrological conditions, into account when considering the design of new wetland habitat.

Discussion An important point to note is that much of the activity carried out by the RSPB to facilitate adaptation is highly consistent with current best conservation practice, rather

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than (yet) requiring a step-change in the types of actions undertaken. The actions already in place on RSPB reserves are dominated by measures to address the loss of coastal wetlands, and the impacts of changes in water availability on habitats whose hydrology has been highly modified by human activity. These measures, together with the RSPB’s creation and restoration of high quality habitat, and ongoing management of existing high quality habitat, are expected to provide conservation benefits in the absence of climate change, and under a wide range of future climatic conditions. Measures which might be used more widely at RSPB reserves in the near-future are: (1) enhancing small-scale heterogeneity in local microclimates through land forming to increase the resilience of invertebrate populations to climatic variation (Oliver et al. 2010), and (2) using dredgings to provide coastal nesting areas for terns and waders (Krogh and Schweitzer 1999; Scarton 2008), and to re-charge eroding areas of coastline where natural longshore drift of sediment has been disrupted by human activity. Many of the types of habitat re-creation and restoration described take many years to realize their full conservation benefits, meaning that it is important to initiate these projects as soon as possible if they are to deliver high adaptation benefits in the next few decades. This is particularly important when aiming to provide replacement habitat. The example of the recovery of the UK breeding population of bitterns also illustrates the importance of ongoing good conservation management of sites to provide a source of emigrants to colonize new areas, even if the source of these emigrants eventually becomes unsuitable for that particular species. The EU Nature Directives stand to play a particularly important role in securing good conservation management of important wildlife sites and reducing other pressures on wildlife (Dodd et al. 2010). Funding from the EU LIFE-Nature Program has also been important in delivering many of the large-scale adaptation projects described in this paper. The system of adaptive management used by the RSPB has been valuable in enabling informed adjustments to be made at a site level, particularly in response to the impacts of recent extreme weather events affecting water availability. It is important to re-emphasize, though, that many large-scale adaptation initiatives need to be driven by a long-term, network-wide strategy, rather than by just local considerations (Lawton et al. 2010). A network-wide strategy is needed to ensure that the reserve network as a whole continues to benefit key species and habitats, even though the abundance of species at individual sites within the network will inevitably change. In addition, even though the need to provide replacement habitat might be identified at a site level, in many cases the delivery of this replacement habitat will take place elsewhere, often outside of the current protected area network.

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Finally, all of the very large-scale actions described in this paper have only been possible to deliver through developing partnerships, many of them highly innovative, between organizations. These include partnerships between conservation organizations to achieve shared conservation goals (the large-scale projects to create and restore freshwater reedbeds), and between conservation organizations and other service providers to deliver both biodiversity and other ecosystem service benefits (re-wetting peatlands and re-creating intertidal habitat). We also recognize that reserve management needs to sit within the context of planning and management of the wider landscape. The principles which have been described are now being embraced in the RSPB’s Futurescapes program of landscape-scale conservation initiatives in the UK. Acknowledgments I would like to thank the following people who provided information for, or commented on, an earlier draft of this paper: Richard Bradbury, Neil Cowie, Jim Densham, Gillian Gilbert, Graham Hirons, Daniella Klein, Dave O’Hara, Katherine Puttick, Dave Rogers, Norrie Russell, Pat Thompson, Chris Tyas, Mike Walker, Gwyn Williams, Simon Wotton and Olly Watts. Many people have been involved in the design and development of Wallasea Island Wild Coast, in particular Mark Dixon, Stephen Hare, Dave Hedges, Graham Hirons, Hilary Hunter, Jeff Kew, Phil McLoughlin, Susanne Armstrong, Colin Scott, John Sharpe and Chris Tyas. I would also like to thank four anonymous referees for their helpful comments. We are grateful for funding for projects through the EU LIFENature Program, and for funding of restoration and ongoing of management of sites through agri-environment schemes payments from the Rural Development Program.

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