Complementary Approaches to Planning a Restored Coastal Wetland and Assessing the Role of Agriculture and Biodiversity: An Applied Case Study in Southern Italy

By inergency On Dec 30, 2023

[ad_1]

1. Introduction

The 12th of July 2023 should be considered a historic date for the European Union (EU), as the Parliament passed the “Nature Recovery” Law [1]. This is a fundamental, continent-wide, and comprehensive piece of legislation as part of the EU’s Biodiversity Strategy 2030 [2] and the even broader EU Green Deal [3]. It calls for binding targets to restore degraded ecosystems, especially those with the greatest potential for carbon sequestration and storage, and to prevent and mitigate the impacts of anthropogenic “natural” disasters. Europe’s nature is in alarming decline, with more than 80% of habitats in poor condition [1]. Restoring natural or semi-natural ecosystems and the species they support will help to increase biodiversity and secure the wide range of ecosystem services that nature can provide [1].

In this respect, wetlands are an essential reference ecosystem in the implementation of this new EU regulation and must be the target areas of extensive and significant restoration processes to be carried out in the coming years according to guidelines based on knowledge, experience, and adequate preparation in planning and design. Wetland planning and design is therefore the specific focus of this work.

In very simple terms, wetlands are natural or semi-natural areas periodically flooded or permanently covered by shallow water. However, this apparently simple definition covers an extremely large number of possible conditions [4]. The hydrology and morphology of the land, together with the variety of associated water sources and vegetation, have shaped different types of wetlands, although the common feature of all wetlands is that they always represent a “transition zone” between dry land and deep water [5]. Transitional environmental conditions create the synergistic result known as the “edge effect”. This means that wetlands can sustain a broad range of species which move between permanently flooded and dry areas, thus offering ecosystems with a very high biodiversity level [6]. Today, wetland ecosystems are marginal, fragile, vulnerable, and subject to intense anthropogenic impacts. Although many of the world’s most important wetlands are protected nature reserves, they still face a range of pressure. Intense water abstraction, up to overexploitation, and water pollution have caused severe degradation of several important wetland ecosystems. In addition to these local threats, climate change is widely expected to increase the stress on remaining wetlands [7]. Infrastructure development, land-use conversion, and difficult-to-manage tourist flows are other important influencing factors [8,9,10]. As a result, the ecological problems of wetlands have intensified, including water eutrophication together with biodiversity loss [11,12,13,14,15,16,17]. Excessive and inappropriate use of fertilizers and pesticides, the leaching of livestock slurry and poultry manure, and excessive agricultural non-point source pollution have led to severe eutrophication of downstream wetlands [18,19].

For a long time, until just a few decades ago, wetlands were considered dangerous, inhospitable, and unhealthy, sources of diseases such as malaria, or at least useless areas that had to be reclaimed for some productive purpose despite severe limitations. For these reasons, wetlands have been progressively reduced with a marked acceleration in the last century to make way for agricultural activities as well as human settlements [20]. Most wetlands have been destroyed or degraded since 1900 [20], and those that remain are among the most threatened ecosystems in the world [21]. Both agriculture and urban sprawl have transformed the landscape, converting natural land to crops and pastures or creating artificial land cover, while altering previous hydrological conditions, degrading water quality and threatening biodiversity [22]. Between 1780 and 1992, 45% of U.S. wetlands were converted to other land uses, primarily agriculture [23], and by the 1980s, 60–70% of wetlands had been lost in Europe, with the main losses resulting from agriculture [24]. In total, 3.4 million km² of inland wetlands have been lost since 1700, primarily for conversion to croplands [25,26]. Although wetlands are among the most valuable ecosystems and have been internationally declared areas to be protected and preserved, the extent of wetlands is still declining worldwide, and their functional condition are threatened to the detriment of the ecosystem services they can deliver [21]. It has been recently estimated that the global total wetland area is a minimum of 1.5–1.6 billion hectares [27], but more relevant is that the ecological status of the ecosystem components, and the complex of benefits/services that characterize wetlands, is deteriorating over time [28]. Apart from the Convention of the Parties in the frame of the Ramsar Treatise, no centralized database or maps of restored wetlands exist [29]. Furthermore, wetlands are often small and therefore difficult to map [30]. Even when wetlands can be detected, for example, by high-resolution, multispectral imagery, distinguishing restored versus intact wetlands may not be feasible [30].

Wetlands can provide a wide range of important ecosystem services that benefit people [31,32,33,34]. Assigning an economic value to these ecological services is a very difficult issue and has been much debated in the literature, starting with the seminal work of Costanza and co-workers [31,35]. In the case of wetlands, estimates also vary widely between different wetland types, ecological structure and function, climates, and environments. In many cases wetlands provide multifunctional benefits that should be integrated according to some specified criteria. A very rough estimate, or rather a range of estimates, allows the following assessment: wetlands 14,785 $ ha⁻¹ yr⁻¹; swamps/floodplains: 19,580 $ ha⁻¹ yr⁻¹; estuaries 22,832 $ ha⁻¹ yr⁻¹ [31,35]. Considering that wetlands can be coastal or inland, and that they can be estuarine, riverine, lacustrine, or palustrine, the economic value of their ecosystem services can be roughly in a range around the previous values. In Italy, for example, the value of wetland ecosystem services was estimated to be around 11,500 EUR ha⁻¹ yr⁻¹, a value not so different from previous estimates [36]. These services are the result of the full range of ecological functions that take place in this rich and diverse ecosystem. The combination of shallow water, high nutrient levels and high primary productivity creates a very complex ecosystem. Biodiversity conservation should therefore be considered the first and probably the most important service provided by wetlands [4,37,38,39,40]. Other categories of services include support, regulatory, provision, and cultural and recreational services. Wetlands have been described as the “kidneys” of the landscape because they act as downstream recipients of water and waste from both natural and human sources [6]. Wetlands have also been called nature’s “supermarkets” because of the extensive food chain and rich biodiversity they support [6].

In the context of climate change, losses from degraded and flooded wetlands are significant sources of greenhouse gas emissions, but wetland rewetting has an overall positive effect on reducing total emissions to the extent that the radiative forcing caused by CH₄ and N₂O is fully offset by CO₂ uptake [41].

According to the Millennium Ecosystem Assessment [42], the conversion and consequent loss of wetlands is expected to increase, and the global area of wetlands will decrease, particularly in coastal areas, as agricultural land expands. Long-term land conversion to agriculture use is projected towards 2050, driven by the need to increase food production and ensure food security for a still growing world population. Key policy decisions over the next 20–30 years will need to address several potential trade-offs. Particularly important trade-offs are those between agricultural production vs. water quality and use, natural and semi-natural land cover, and biodiversity [42]. In regions where agricultural expansion remains a major threat to wetlands, the development and diffusion of technological innovations that could sustainably increase food production per unit area without harmful trade-offs in terms of excessive water, nutrient, or pesticide use would significantly reduce the pressure on wetlands. This is considered sustainable intensification of agricultural systems, defined as a technology-driven process in which agricultural yields are increased without adverse environmental impacts, efficient use of natural resources and avoidance of further conversion of non-agricultural land [43,44,45,46]. This approach of saving agricultural land for nature conservation is also known as “land sparing”. An alternative approach is that of spatially integrating agricultural activity with nature conservation through a strategy known as “land sharing”, focusing on an agricultural model that is closely linked and conducive to the conservation of wild biodiversity. This is also known as the ecological intensification of agriculture [45,47,48,49,50,51,52]. Given the local conditions considered, this second approach has been proposed for use in our wetland planning process.

Today, with wetlands so limited and rare, their conservation, restoration and even reconstruction is seen as a vital and essential strategy, but also as a very demanding issue that requires coordinated action between managers, policy makers, stakeholders, and scientists [53,54,55,56,57,58,59]. A wetland conservation strategy should include understanding and addressing the interacting ecological and socioeconomic processes to manage the system and improve conditions for persistence and resilience in the face of pressures and impacts [54,60,61]. It requires a systemic planning and design process that performs complex analyses, supports transdisciplinary applications, translates qualitative considerations into a well-structured strategy, and develops sound background knowledge within a governance/policy framework [4,18,22,62,63,64,65,66,67]. The research idea we developed was to outline an integrated, possibly comprehensive, and well-structured planning framework for wetland systems. This has been carried out as a work in progress by applying the intended framework to a specific case study to guide planning, help define strategic aims for wetlands, and outline orderly, effective, and sustainable management actions. Theoretical or conceptual planning backgrounds were drawn from the previous literature on environmental engineering and biodiversity conservation [5,6,60,68,69,70,71,72,73,74].

With regard to the methodological approach developed in this study and proposed for more general application, we believe that the most innovative aspect is the attempt to integrate a longer-term strategy plan with a shorter-term action plan. In a nutshell, the aim is to develop an action plan to progressively achieve the final aims according to a well-defined order of priorities indicated by a strategic plan. Two different methodological tools have been used to support the development of this wetland planning process: the Yeomans scale of permanence (SoP) and the Driver–Pressure–State–Impact–Response (DPSIR) model. The useful harmonization of these two approaches has, to our knowledge, never been attempted before and should be seen as the most innovative outcome of our work in terms of a methodological legacy that can guide further wetland planning in the future.

3. Results

3.1. “The King’s Lagoon”: The Case Study

The planning process has been applied to a specific case study represented by the Laguna del Re (i.e., “King’s Lagoon”, translated from the Italian) in Siponto (Manfredonia, Province of Foggia, South Italy). It is a coastal wetland directly connected to the Adriatic Sea, located at the mouth of the Candelaro stream, with an extension of 40 hectares, part of the whole reclamation system of the Siponto polder (Figure 7).

The reclamation began a long time ago, but was decisively carried out just before the Second World War and completed in the 1950s. It involved a radical alteration of the natural hydrological regime in order to reclaim land for agriculture and human settlement. The remaining wetlands that still exist are one of the cornerstones of the Apulian coastal landscape. Today, the King’s Lagoon plays an important naturalistic role, it is included in the European Natura 2000 network and designated both a Zones of Special Conservation (ZSC), called the “Capitanata wetlands”, and a Special Protected Area (SPA), called the “Marshes of the Gulf of Manfredonia”. It is characterized by two priority habitats: 1150* “Coastal lagoons” and 1510* “Mediterranean salt steppes” according to the EU Habitats Directive (please note that the asterisk conventionally indicates the “priority” status of the habitat).

An important EU environmental LIFE project [97] was developed in the Siponto area; as a result, the new wetland, i.e., the King’s Lagoon, was created on the site of a previously reclaimed wetland. The project was completed in 2019 after 5 years of activities. It consisted of a wetland restoration project, which was carried out by replacing agricultural and illegally built areas with a natural-looking wetland system, redesigning new and reopening old canals that had silted up, digging “valleys” (i.e., stretches of water), installing weirs to regulate water inflow and outflow, and creating sluices in order to recreate the typical transitional coastal environment, characterized by the alternation of flooded areas and dry land.

A number of illegal buildings have been demolished, due to the previous subdivision of agricultural land into small plots, resulting in a noticeable and disturbing road network. The new wetland has also been equipped with wildlife observation structures (towers, boardwalks, and hides) to promote the naturalistic practice of birdwatching, as well as footpaths, huts, and terraces for visitors to encourage them to visit the natural oasis. It should be noted that the EU project also had an important social impact in terms of restoring legality, since after the demolition of the unauthorized buildings and the restoration of the natural environment, the former inhabitants were given small plots of land to grow fruit and vegetables under legal contracts. Today, agriculture is only allowed in certain areas of the entire wetland system.

3.2. Vision and Mission Definition

At a preliminary stage, the definition of the vision and mission has been entrusted to the research team in collaboration with the partners involved in the EU LIFE project [96]. Both the “Vision” and the “Mission” will be submitted to a wider stakeholder representation for approval and validation.

Vision statement: To achieve a harmonious conservation model that combines the effective protection of all wetland organisms with the sound restoration of natural resources. To change people’s cultural perspective on nature and develop societies capable of living in peace with nature rather than fighting it. To develop innovations in science and technology, particularly in the agricultural sector and in the provision of goods and services by protecting biodiversity, conserving natural capital, and enhancing the full functioning of ecosystems, thus contributing to an effective transition to sustainability.

Mission statement: To direct and guide all possible actions useful for the achievement of the objectives of nature restoration, and thus to produce a relaunch of the territory in a new guise; that of a natural area restored for the conservation of biodiversity within an agricultural context that supports this purpose and promotes the development of the land, including the economic growth of the resident population, by activating a tourism aware of this natural wealth and respectful and sensitive.

3.3. Goal Setting: Both Aims and Objectives

The ultimate aim of wetland planning is to ensure the restoration, maintenance, and, hopefully, the expansion of existing habitats, and to promote the favorable status of wetland habitats, an important condition for the conservation of key plant and animal species. This goal must also be achieved by placing the wetland in question within an extended network of natural or semi-natural ecosystems that provide the necessary connective functional roles in the system as a whole.

The conservation of biodiversity should be closely linked to the provision of sustainable human livelihoods (such as agriculture and fisheries) and the contribution of cultural values, together with recreational activities. In our view, these are considered to be the three main pillars of a well-managed wetland such as this case study.

A long-term strategy plan has been coupled with a short-term action plan with the ultimate aim of harmonizing these three wetland pillars or dimensions: the first relates to nature, the second to human livelihoods (i.e., provision of goods), and the third to culture and knowledge (i.e., sense of place).

A number of other general objectives are linked to these three pillars; for example, rich plant biodiversity enables the activation of ecological functions related to hydrological protection, water quality, soil conservation, and many other important environmental conditions that wetlands can ensure; the maintenance of traditional human livelihoods requires the adoption of systems that are not harmful to the environment and, at the same time, promote biodiversity; finally, cultural services cannot be maintained without taking into account the traditional knowledge derived from centuries of human settlement dependent on natural resources. The three objectives are therefore closely interlinked.

3.4. Strategic Lines of Wetland Development

As anticipated, the King’s Lagoon Strategy Plan is developed around three main pillars:

−: First pillar: Biodiversity conservation. Identifying a set of measures to protect and conserve the biodiversity of the King’s Lagoon, to promote the creation of a mixed mosaic of wetland and agricultural habitats, to maintain the ecological functionality of natural and agricultural ecosystems, and to preserve their natural capital in terms of ecosystem services.
−: Second pillar: Provision of sustainable goods and services. Regenerative agriculture. This can be divided into several cultivation models, each using more than one technique. One of the most inspiring is “permaculture”, a set of agricultural practices based on the natural maintenance of soil fertility, where the term itself emphasizes the concept of culture, thus a unified approach to all aspects of human society and its relationship with nature. The “regenerative agriculture” interventions planned for the King’s Lagoon are therefore designed to promote crop diversity by applying a multifunctional approach to build stable, productive agroecosystems, according to a model that reconciles economic growth with nature conservation.
−: Third pillar: Knowledge, education, recreation and governance. Visitors’ enjoyment of the natural heritage. Since the King’s Lagoon is included in the territory of the Gargano National Park and as one of the EU Natura 2000 sites, it is of paramount importance that visitor’s expectations regarding the naturalistic importance of the area are confirmed. Therefore, it is essential to support and improve the response capacity to the users’ needs in order to guide wetland development towards sustainable forms of natural and cultural fruition. In this regard, reference is made to the “European Charter for Sustainable Tourism in Protected Areas” [98]. The following principles should govern how tourism is developed and managed in protected areas: (1) giving priority to protection; (2) contributing to sustainable development; (3) engaging all stakeholders; (4) planning sustainable tourism effectively; (5) pursuing continuous improvement.

The previous pillars were then translated into strategic lines for wetland development (Table 1).

Strategy 1: Protecting the environment and biodiversity in the context of climate change. The conservation of nature (i.e., biodiversity) and of environmental systems, including natural and semi-natural landscapes, can no longer ignore climate change processes at local and planetary scales. The climatic context of the Siponto wetland system is that of the “European Mediterranean biogeographical region” and is changing rapidly. Adapting to and mitigating climate change is undoubtedly a new and considerable challenge that requires updating and integrating the usual management tools of natural protected areas. This new synthesis of management and protection tools is considered a prerequisite for the activation of integrated management strategies that take into account both nature conservation and sustainable local development.

Strategy 2: Wise use of natural spaces, agroecosystem heritage, and ecosystem services. The quality of the environment is affirmed both by specific excellence and by the overall quality of the landscape, considering natural open spaces and environmental infrastructures as optimal for living and enjoying life. Environmental protection should become a real asset for the development of the territory. This will be achieved through forms of cooperation and collaboration with landowners, individually or collectively, and by integrating them into a well-organized system. One issue that needs to be addressed is the concept of ecosystem services that protected natural areas can provide to society. These ecological functions are particularly important for mitigating the effects of climate change and the damage caused by pollution from large urban centers, and in preserving basic natural resources such as water and soil.

Strategy 3: Developing regenerative agriculture through environmental quality, together with safe, healthy, and fair agri-food products. The quality of a land should also be synonymous with the quality and genuineness of its agri-food products and, consequently, its gastronomy. In an increasingly globalized market, where commercial food products do not always guarantee quality and authenticity, typical products with a strong and direct link to the quality of the land of origin can make the difference. Consumers are much more likely to trust a product that is associated with a specific and well-known land, whose quality and healthiness they recognize, and are therefore willing to pay more for it.

Strategy 4: Enhancing the natural environment to boost the development of the area and its touristic attractiveness. The King’s Lagoon, if properly managed, should be seen as a major asset in promoting the viability of the area, whose attractiveness and competitiveness is increasingly measured by its environmental quality and the virtuous balance between socioeconomic development and nature/environment conservation.

Strategy 5: Communication and awareness-raising to develop environmental knowledge, a sense of place and respect for nature. Conservation of natural resources and biodiversity should be seen as a relevant issue and efforts to conserve species and habitats as a relevant activity for humanity. Raising public awareness is a fundamental step in creating an environment open to change and can contribute to the development of a well-informed and environmentally aware culture and knowledge. To be effective, it is essential to create an emotional connection with the public by informing them about the development lines of the wetland project and the results achieved. An even more direct involvement could be through “citizen science” initiatives, which are useful in multiplying the possibilities of collecting environmental data, but above all, in stimulating public involvement and participation. In this way, a process of consensus building is generated, creating a virtuous circle in which civil society, understanding the value of what has been achieved, becomes the carrier of a positive message within the various “social networks”.

Strategy 6: Education for sustainability. This issue is particularly aimed at young people of school age. The choice of the area on which to focus the environmental education program is based to the importance of the ecological network developed at a local level, with the wetlands of the Gulf of Manfredonia as the main environmental systems. The aim of this educational program is to make a large part of the population living in the same area aware of the value of the land in which they live. Involving the educational community would break the cultural isolation of protected natural areas, especially wetlands, which are often of interest only to insiders and researchers. Education on sustainability, biodiversity, and landscape conservation, aimed at citizens and teachers, is mainly carried out through joint projects with universities, research institutes, third sector associations and other organizations.

Strategy 7: Creating new synergies and strengthening cooperation: collaboration with associations and institutional bodies. The King’s Lagoon is an important reference area for environmental education and conservation actions in the province of Foggia, with particular attention to the Gargano National Park, of which the wetland is a part. The local cooperation network with all stakeholders aims to exchange experiences, coordinate actions, and share available resources. The aim is to consolidate the cooperation network, in particular with the municipal, provincial and regional departments for the environment, culture and public education, the regional education office, and other voluntary environmental and cultural associations, universities, the Provincial Natural History Museum of Foggia, and other visitor centers in the area. The creation of a local network seems strategic for the full development of the above activities, while respecting the specificity of each institution and association.

3.5. The DPSIR Components: Identification and Relationships

The expert meetings first allowed for the identification of “Pressures” and “Impacts”, as described in the previous section. Soon after, each “Pressure” and “Impact” was assigned to a “State”, again as a result of a participatory discussion among panelists. It was decided that “States” should broadly refer to the different environmental compartments, according to the following list: (1) water; (2) atmosphere; (3) soil quality; (4) biodiversity; (5) landscape, environmental health and human well-being (the latter being more heterogeneous than the formers). The following double entry matrix was therefore created (Table 2).

Finally, seven main drivers were identified by the panelists: (D1) industrial installations; (D2) proximity of urban areas; (D3) road traffic; (D4) tourist and visitor flows; (D5) poaching or illegal fishing and hunting; (D6) water regimes and management (including management by the Irrigation and Land Reclamation Consortium); (D7) agriculture. Drivers 1, 2, and 3 can only affect the wetland from the outside (they are only external drivers), while drivers 4, 5, 6, and 7 can affect the wetland from both the inside and the outside. Internal drivers are under the direct control of the wetland management authority and can therefore be regulated by a local design or action plan (i.e., bottom-up and short-term planning). In contrast, the regulation of external drivers is entrusted to a much broader territorial plan, which is more policy oriented (i.e., top-down and long-term planning). Each driver (from D1 to D7), linked to the set of “Pressures” and the set of “Impacts”, was cross-referenced with each of the “States” to form a comprehensive scoring matrix as described in the previous section.

The scoring process carried out by the experts made it possible to obtain priorities to be taken into account in the preparation of the strategy/action plan. The results obtained are reported as follows and can be observed in Table 3.

Looking at the “States”, the experts judged that, on average, biodiversity (S4) and landscape (S5) were the most important, while atmosphere (S2) and soil quality (S3) were given the least priority. Water bodies (S1) was placed in the middle of the ranking. In terms of “Drivers”, agriculture (D7) was judged the most influential, followed by water management (D6), while industrial installations (D1) was considered the least important.

Rather than looking at the average values of “States” or “Drivers”, it is much more important to focus on the score assigned to each “State x Driver” combination, which reflects the real priorities that need to be included in an action plan that takes into account the most critical issues identified by the experts. As reported in Appendix A—Table A1, a score ≥ 8 defines an essential SxD combination, having the highest importance. There are eight combinations considered to be essential, of which the Driver agriculture (D7) appears four times (i.e., in 50% of the cases), while the biodiversity State (S5) appears three times. The combination of water bodies x water management (S1xD6), together with the combination of soil quality x agriculture (S3xD7), received the highest score (9.87) and are in fact the most critical factors to be taken into account when considering wetland management. Poaching (and particularly illegal fishing) is considered a strong limitation to biodiversity (S4xD5) and received a score of 8,71. Agriculture is considered a possible threat not only with respect to soil quality, but also biodiversity (S4xD7, score 8.71), water bodies (S1xD7, score 8.43), and landscape (S5xD7, score 8.00). The Driver water management (D6) can greatly affect biodiversity (S4xD6, score 8.29), while the Driver road traffic (D3) may significantly affect the States landscape, environmental health and human well-being (S5xD3, score 8.00).

3.6. The Yeomans Scale of Permanence and the Associated “Responses” Identified in the DPSIR Model

As formerly reported, the DPSIR model was developed through a structured discussion and an exchange of views between the panelists (i.e., experts) and allowed for the identification of a wide range of “Responses” (i.e., actions, measures, and interventions to be taken in wetland management), as a logical combination of both “Pressures” and “Impacts”. The corresponding combinations of “State” and “Drivers” were submitted for scoring by the panelists (as reported in a double-entry matrix shown in Appendix A—Table A1) to select those “Responses” with the highest relevance or influence.

The same “Responses” were also ranked in terms of “permanence”, i.e., according to the ordered categories defined by the Yeomans SoP (and formerly shown in Figure 3).

We have therefore attempted to classify all the “Responses” selected and discussed by the convening experts according to the ranked categories of the Yeomans SoP. Appendix A—Table A2 shows the ordered list of all of them.

Some brief considerations about the landscape components introduced in the Yeomans SoP are the following.

P0. Climate. To be taken as it is. Only adaptation measures can be applied. The most permanent component is climate, including climate change. The overall climate produced the natural vegetation and gave the land its final shape, making it the first component on the scale.

P1. Land Shape and Waterflows. Land shape and waterflows are closely linked to climate. These components, together with climate, form the environment into which planning should fit. Although potentially modifiable, land shape and water flows, at both farm and catchment scale, would require the use of large earth moving machinery. This can be carried out at the very beginning of the wetland reconstruction or restoration process. Water infrastructure and management is of paramount importance as it has a direct impact on the wetland environment and, therefore, on the species within the ecosystem. Maintaining appropriate water levels is a key management objective; this can be achieved by properly regulating both inputs and outputs from watercourses flowing into and out of the wetland, whether these flows are natural or artificial.

P2. Access, Circulation, Building and Ecological Infrastructures. Traditionally, the term “infrastructure” has included only man-made assets and artefacts of economic interest. However, ecosystems should also be considered as a type of infrastructure that should not only be conserved but can also benefit human activities. Ecological infrastructure can therefore be defined as natural or naturally functioning ecological systems or networks that provide multiple services to people while allowing biodiversity to persist. Access, on the other hand, relates to mobility, allowing the movement of visitors, workers such as farmers, as well as machinery, and the need to avoid inappropriate concentrations of people and mass flows that may disturb wildlife or threaten habitat conservation. Buildings relates to the appropriate location of service facilities, including offices, visitor centers, storage, machine and tool sheds, and other necessary structures built according to ecological criteria.

P3. Vegetation, Habitats and Wildlife. As repeatedly emphasized, the conservation of biodiversity (at all levels: genetic, species, and landscape) is the priority objective. This is achieved through a species-specific approach (i.e., the protection of the most endangered species), but also through the conservation of the habitats and ecological niches of each species, as well as through the restoration of a complete local biocenosis.

P4. Zoning. Zoning encourages the assessment and design of activities in the wetland in terms of energy and resource requirements to reduce unnecessary travel time between different areas. Zones address the level of human activity, the efficiency of movement and the human effort required to manage the wetland. Of course, natural constraints must be taken into account, as well as the presence of areas of biodiversity that should be preserved. Usually, and as a general rule, landscape elements (individual plots, parcels, fields, and other vegetation patches) should be placed in the landscape according to their frequency of use (i.e., closer for the most used, farther away for the least used). Different types of agroecological structures (agroforestry, food forest, orchard, wild garden, wild marsh vegetation, etc.) should be placed differently according to their management needs.

P5. Soil Fertility/Soil Quality. Maintaining and continually improving the fertility and agronomic qualities of the soil is an important objective underlying the agroecological and regenerative techniques that must be applied in cultivation. The initial conditions of the soil were very unfavorable and represent a strong limitation on productivity. This suggests the use of specific techniques which, in addition to increasing the organic matter content of the soil, can mitigate the effects of very clayey soil with a high concentration of salts, particularly sodium. Crop rotation, soil organic amendments, cover crops, conservation agriculture, compost and biofertilizer applications, etc., are a diverse set of tools for applying consistent agroecological farming management.

P6. Sense of Place, Aesthetic, Cultural, Social, and Economic Values. Social and economic factors can strongly influence wetland management, both in terms of biodiversity and agriculture. National and regional regulations and laws can also influence a wide range of decisions. Wetland management should be a strong magnet for cultural initiatives, training, environmental education, and a tireless center for the promotion of environmental and natural values. This should encourage continuous cultural development, broad participation of people, and the development of a sense of belonging and attachment to the place.

3.7. The Making of the Wetland Action Plan

Taking into account both the key DPSIR “Responses” resulting from the combination and scoring of “State” and “Driver” (shown in Appendix A—Table A1) and the same “Responses”, this time ranked according to the Yeomans scale of permanence (shown in Appendix A—Table A2), a final “Wetland Action Plan” was developed. Table 4 summarizes the structural framework of the action plan.

The “Driver x State” pairs are clearly indicated in the same table, together with the corresponding score. Only the “essential” DxS combinations (i.e., score ≥ 8) have been considered in the development of the Wetland Action Plan, ordered according to the SoP ranking. For the sake of synthesis, and in order not to exceed the length of the text, the authors decided to present the action plan as a collection of factsheets reporting the full list of responses with a more detailed operational focus. For an in-depth examination of each of these factsheets, the reader is referred to Appendix B.

4. Discussion

4.1. Discussion of the Wetland Planning Outcomes

Expert scoring allowed the resulting DPSIR “Responses” to be ranked in terms of their relevance and influence on the development of the Wetland Strategy and Action Plan, while a priority order for their implementation was assessed according to the Yeomans scale of permanence.

Agriculture was the highest rated “Driver”, while biodiversity (habitats and species) the highest rated “State”. As a result, agriculture in general is seen as detrimental to the quality of the environment and therefore requires a complete rethink of farming concepts and practices, for example, through an agroecological transition. On the other hand, biodiversity has been identified as the most fragile and damaging of the environmental components and should be protected with great care. Their combination (agriculture and biodiversity) should be regarded as the strategic cornerstone of the whole planning framework. This means designing and implementing a system in which agriculture and nature (in our case a wetland) are allied ecological systems in mutual compensation, according to the way natural elements are embedded in the agricultural system.

Furthermore, agriculture as a “Driver” relates to each individual level of the Yeomans scale of permanence. At the first level of permanence, agriculture interacts with the water bodies through the regulation and management of the water supply (i.e., water pumping, floodgates, and sluices) and the monitoring of water quality. At the second level of permanence, it interacts with biodiversity through the creation of natural elements for ecosystem diversification and vegetation infrastructure (buffer zones, hedges, natural stepping stones, and other structures with an ecological function), thus promoting ecological connectivity for wildlife within and between the agricultural matrix. Similarly, at the third level of permanence, agriculture is again called upon by biodiversity, considering the need to maintain or even expand the wetland and increase wetland vegetation, to prevent the spread of allochthonous plant species and to monitor the quality of the habitats and the presence of wildlife species. Agriculture and biodiversity are a persistent combination also at the fourth level of permanence where recovery, restoration, and the protection of undisturbed “priority” habitats should be defined through zoning, together with farmland within the wetland, thus preventing its drainage. At the fifth level of permanence, agriculture is linked to soil quality and, at this level, low-input/low-impact farming practices should be planned, including permaculture, agroforestry, regenerative agriculture, and the cultivation of traditional crops and ancient varieties. Finally, at the sixth level of permanence, social, economic, and cultural values are involved in shaping the landscape, as well protecting the environment and human health through information, dissemination, education, and research with particular reference to sustainable agricultural training, both concepts and practices.

4.2. Discussion of the Wetland Planning Methodologies

The DPSIR model has been widely used in the assessment of coastal areas, wetlands, and lagoons; conversely, the approach proposed by Yeomans is of little or no use in general and has never been applied to these types of ecosystems in particular. It was therefore of great interest to examine its application compared to other approaches that also aim to prioritize actions and interventions to be undertaken. In this respect, the DPSIR model was often closely associated with some multi-criteria decision analysis (MCDA) techniques [62]. One of the most commonly used MCDA tools in participatory planning is the analytic hierarchy process (AHP), originally developed by Saaty [99]. This method, or similar methods in the same MCDA family, has been applied to the strategic and operational assessment of wetlands with encouraging results [54,55]. While the AHP method has been used in our previous research activities (e.g., recently in forest planning [100]), this time we wanted to turn to different prioritization methods belonging to another type of methodological approach referred to as expert group techniques for program planning, with specific reference to the Nominal Group Technique [71]. However, we would like to emphasize the significant difference between the prioritization methods already mentioned (the MCDA and NGT tool families), all of which aim to highlight the most relevant and critical actions, and Yeoamans’ approach, which identifies a scale of priorities in terms of a sequence, considering factors of a more permanent nature (to be addressed first) as opposed to others that are easier to change (to be addressed later). This second approach is not at all documented in the literature and, in our opinion, needs to be considered instead.

The Nominal Group Technique (NGT), when applied, proved to be effective in reaching a general agreement among the participating experts. The application of this method did not force a complete overlap of judgements, nor a perfect convergence of opinions. This is frequently a critical point of the technique and one that is widely debated [71]: how much to push for greater uniformity in the judgments of experts, or to preserve their differences of opinion. In our study, a double run of the NGT procedure was considered sufficient to achieve an approximate level of expert agreement, but this is not always the case. Differences in scoring were detected by calculating the Std Dev, which ranged between 0 and 1.92; in 12 out of 35 cases the Std Dev was less than 1.0, while in 6 cases it ranged between 1.5 and 1.92. This observed variability was considered reasonable and fully justifiable given the different technical backgrounds of the experts.

The combination of the DPSIR model and Yeomans’ scale of permanence proved to be of considerable methodological value, as it was able to effectively discriminate and group together the various interventions and actions developed in response to the planning process of the King’s Lagoon. On the one hand, through the convergence of the opinions of a composite panel of experts, the DPSIR model made it possible to define a ranking of the importance of stressors (i.e., both impacts and pressures) considered critical in relation to different drivers and status conditions, and to properly identify actions that adequately respond to the real needs of the wetland. On the other hand, the scale of permanence made it possible to establish an order of priority, based on the fact that certain interventions must be carried out before others, because they are necessarily preparatory and indispensable for the success of subsequent ones. The guidance provided by the Yeomans’ scale (and subsequent modifications by other authors) has been very helpful in this definition. We therefore believe that the integration of these two approaches, although unprecedented, has made the planning process particularly effective and has greatly enhanced its ability to interpret and guide interventions, actions, and transformations in dealing with the reconstruction, restoration, recovery, and management of wetlands [61,63,64,65,76,101,102,103].

In preparing this planning framework, it was particularly useful to distinguish between exclusively external (D1, D2 and D3) and predominantly internal drivers (D4, D5, D6 and D7). This made it possible to highlight the responses that are inevitably linked to large-scale territorial policies, which are superimposed on instruments and interventions at the local level. It is precisely on the basis of this distinction (exogenous vs. endogenous drivers) that the planning process has been divided into a strategic plan, which is more time-relaxed and relates to the more stable and permanent landscape components, and an action plan, which relates to the landscape components that are more dynamic over time and more easily changed. Indeed, a considerable number of laws and regulations operate at the international, European, and national levels, with particular reference to international agreements (e.g., the Ramsar Convention), the European Biodiversity Strategy, the Natura 2000 network, the Water Framework Directive, as well as the Italian legislative framework for environmental protection. These policies also have an impact at the local scale and at the level of the wetland system, such as that of the study area.

Considering the possible limitations of the methodological approach used, this refers to the exclusive, albeit preliminary, involvement of experts. We wanted to create a panel with different technical and scientific backgrounds, while keeping the total number of experts within reasonable limits. As a result, only the opinions of the experts were taken into account in the development of the wetland planning procedure at this stage. This means that the process is only partial and will inevitably involve a subsequent phase of wider discussion, possible further elaboration and, more generally, an exchange of views between stakeholders both within and outside the King’s Lagoon site. This phase of plan sharing and co-planning was not included in this study and will be concerned with the progress of ongoing initiatives at King’s Lagoon. In fact, we believe that the participation of residents and visitors, administrators and citizens, farmers and naturalists in the decision-making process regarding the development of the wetland is of great importance and a tool to achieve wide-ranging stakeholder involvement.

One potential constraint on the implementation of the wetland plan is a limiting aspect of a cultural nature. A barrier to be overcome in order to meet the expectations of good wetland management is the fact that the wetland itself should not be considered as a separate, independent tile in the territorial mosaic, unrelated to the context in which it is embedded. This limitation is shared with several other planning process reported in the literature [54,55,104]. Unfortunately, the services and products that a wetland can provide are still little appreciated by both residents and local authorities, whereas the full development of the wetland can only be activated by promoting awareness and appreciation of a wide range of tangible and intangible products, direct and indirect services, and ecological functions that stabilize the environment and renew its quality and livability.

Wetland restoration can promote the recovery of ecosystem services, and as the recovery of biodiversity within the wetland gradually increases, a wide range of ecosystem services can also increase significantly, thus generating a mutually supportive circle. The greater the biodiversity, the more intense the flow of ecosystem services, which reinforce and consolidate the increasing level of biodiversity. Our trust, at this early stage of the King’s Lagoon’s recovery, is the startup of these positive feedback loops, supported by experimental evidence from meta-analysis studies by other authors [98,105]. It follows that another limitation of the study relates to the uncertainty regarding trends in biodiversity development, which were not ascertained but only assumed. While wetland restoration can increase biodiversity to levels that are quantitatively similar to natural wetlands, it is not yet certain that this improvement will have a real impact on ecosystem functionality and thus on the restored ecosystem services to be provided. Unfortunately, greater diversity by itself do not ensure a high level of ecosystem functioning [106]. These considerations open the way for further research and future developments. It follows that the recovery dynamics of the numbers and categories of species recolonizing the restored wetland must be carefully monitored in order to identify (quantitatively and qualitatively) the effects of restoration, also in terms of species associations, relative species proportions, and ecological functionality, taking into account the design of the area’s management and the applied conservation programs.

Considering other limitations, this work has focused on the wetland planning methodology, but inevitably neglects a more quantitative treatment of the numerous environmental indicators that are nevertheless necessary and must be progressively implemented in future research developments in order to establish a rigorous data-centered approach. Therefore, monitoring should also include the chemical and physical characteristics of the wetland’s environmental compartments, in order to develop a thorough and integrated database of information that can be used to track the restoration process. Further research applications will include wetland management tools to be used in conjunction with simple and rapid assessment methods [107]. All the information obtained should be fed into assessment support systems, both in terms of valuing the reactivated ecosystem services [108] and estimating the health of the wetland; taking into account its achieved ecological status [109].

We are aware that our present analysis and consequent methodological proposal has been made at a general, still highly hierarchical level and at an early stage of wetland restoration. Further development will consist of a more detailed and explicit assessment in terms of scientific data analysis, which can be developed as information becomes available during the ongoing restoration process. Well-calibrated, comprehensive, and high-resolution interpretation models can generate scenarios of great interest, but obviously require a lot of data, which is not yet available. The importance of this work is therefore to properly frame and guide the planning in its early stages, so that serious and irreversible mistakes are not made and the restoration process is properly implemented and directed in the most appropriate direction.

5. Conclusions

Systematic and comprehensive wetland planning is needed to govern the wetland in the long term and to manage it in the short term, according to three important strategic pillars: (1) biodiversity conservation; (2) provision of sustainable goods and services (including regenerative forms of agriculture); (3) knowledge, education, and recreational values. This aim can be particularly difficult to achieve without a rigorous and effective methodology that takes into account all of the various but specific characteristics of a wetland and the several planning dimensions to be considered (i.e., nature and biodiversity, agriculture and other socioeconomic activities, tourism and recreation, scientific research, education and training, cultural heritage and traditions, etc.). Therefore, a unified framework has been defined to identify the drivers, pressures, states, and impacts, their complex interrelationships, and the set of responses to be implemented, according to well-defined relevance ranking and priority hierarchy, and to be achieved progressively in order to guide the full development of the wetland over time. In this respect, the combination of two different approaches has been proposed: the Yeomans scale of permanence and the DPSIR model. A specific study case (the King’s Lagoon) was considered to evaluate and validate the methodology. The Nominal Group Technique was used as a consensus method to achieve general agreement and convergence of opinion among the seven experts involved, who formed a composite panel. The DPSIR model allowed the identification of a wide range of “Responses“, after first identifying their influencing “Pressures“ and “Impacts“, and taking into account the “State“ that each “Response“ affects and the “Driver“ that it can counteract. Each “Response” was ranked according to the average score of importance assigned by the panelists and then projected onto the appropriate level of the permanence scale to determine its priority order. In this way, the wetland strategy and action plan was prepared and ready for implementation, subject to approval by a wider stakeholder representation.

The performance of the proposed methodology was found to be useful and effective, with considerable potential to assist land planners, decision makers, administrative managers of public government bodies, nature conservation agencies, and NGO representatives. For this reason, we encourage the adoption of the methodology developed here and its wider evaluation under different wetland conditions for ecological, naturalistic, land use and land cover, anthropogenic pressures, and many other factors that could affect their management and development.

[ad_2]