Key insights from the policy analysis are that there is general policy support for nature-based solutions but there are also many limitations and they often lack legal backing. Our study also showed that conservation status can help in implementing pond/pondscape nature-based solutions and that local leadership may be more important than policies. We identified 22 financing instruments for pond and pondscape nature-based solutions, which can be applied to different contexts.
The analyses of pond biodiversity identified two major underlying gradients at a European spatial scale. The first differentiates ponds based on hydroperiod, while the second gradient captures variation in eutrophication-associated variables. The analyses also reveal that cropland in close proximity to ponds enhances eutrophication, which impacts community composition and reduces richness of multiple aquatic organism groups.
Obtained results also suggest that effective pond biodiversity conservation can promote pond ecosystem multifunctionality, whereas ecosystem deterioration as a result of land use intensification and its associated eutrophication detrimentally affect several pond ecosystem functions. In addition, the number of ponds, their spatial distribution, and connections with other freshwater environments need to be considered for preserving pond diversity, resilience and associated ecosystem services.
The analyses on pond greenhouse gas (GHG) dynamics reveal that increases in nutrient and to a some extent temperature are likely to increase GHG emission from ponds. The results also indicate that reduction of nutrient loads in ponds would maximize net carbon sequestration, and that the presence of abundant submerged plants can provide some buffer against increased temperatures and/or nutrient enrichment. PONDERFUL analysis also revealed that temporary ponds act as sources of CO2 during the dry phase, with sediment moisture and temperature identified as the primary drivers of CO2 emissions. We also provided evidence that pond restoration significantly reduces GHG emissions. Our findings also suggest that climate-change induced drought will be a threat to pollinator communities at ponds because dry ponds have less complex and resilient plant-pollinator networks compared to ponds with water.
We analysed pondscapes’ efficiency and effectiveness in delivering ecosystem services and developed an approach for measuring their performance. Our surveys conducted with people living near pondscapes showed that these habitats greatly enhance quality of life. PONDERFUL also interacted with stakeholders across multiple workshop sessions to gather insights on their interactions with their pondscapes, their perspectives on conservation efforts, their knowledge about the potential impacts of climate change as well as to apply stakeholder input to land-use scenario development and modelling. With the extensive pond data collected through fieldwork and the information obtained from workshops, an integrative modelling framework was developed to predict the impact of climate and land use change on multiple indicators of biodiversity and ecosystem services. We also produced maps that identify high-priority areas at the European level where interventions are likely to have the greatest impact under different land use and climate scenarios.
Using the knowledge generated, we finally provided stakeholders and policy-makers with a set of new science-based tools for implementing pond-pondscapes nature-based solutions for addressing societal challenges. The tools are:
• An inventory of 183 nature-based solutions in Europe, coupled to eight PONDERFUL DEMO-sites, with success stories demonstrating the efficiency of pond/pondscapes for providing ecosystem services and Nature’s Contributions to People. These success stories are now included in a series of DEMO-site leaflets.
• CLIMA-Pond designs presenting a prototype of a pond as a nature-based solution for addressing climate change challenges in natural, rural and urban landscapes.
• A technical handbook on restoring, managing and creating ponds and pondscapes as nature-based solutions.
• A guidance document for policy makers, including a step-by-step guide to producing a national plan for ponds and pondscapes.
• A multi-criteria decision making tool that helps in the implementation of pond and pondscapes as nature-based solutions, by forecasting the potential Nature’s Contributions to People/ecosystem services and biodiversity benefits delivered under various scenarios of climate change and under different management actions.
Project results were disseminated through the PONDERFUL website, newsletters, technical webinars, animation videos, the PONDERFUL Information System, social networks, traditional media, conferences, scientific journals, workshops and external websites such as OPPLA and Horizon Result Platform.
