Nature-based solutions knowledge gaps

Explore the nature-based knowledge gap analysis below to help identify future avenues for research.

The knowledge gap database compiles an evidence base for nature-based solutions, to support defining research and innovation avenues, bolster policy and practitioners’ knowledge and knowledge-implementation. The database gathers 'gaps' collected through desk study and online consultations from August to October 2021 (see the NetworkNature report on practical, research and innovation needs for more information). 171 knowledge gaps were collected and categorized into 30 broad gap topics. This database will be updated during the course of the NetworkNature.

Displaying 81 - 100 of 169

Broad topic

Gap Description	Origin of source	Source	Resource	Broad topic
knowledge gaps surround-ing applications and their effectiveness; insufficient understanding of costs and benefits; diverse stakeholder values and perceptions; and limited policy and economic instruments (and/or the will to apply them)	Desk Study	Academic literature	Nelson, D.R., Bledsoe, B.P., Ferreira, S., Nibbelink, N.P., 2020. Challenges to realizing the potential of nature-based solutions. Current Opinion in Environmental Sustainability 45, 49–55. https://doi.org/10.1016/j.cosust.2020.09.001	Cost/benefit evaluations
Knowledge on problem solving of different pollution sources with NbS exists and can be adapted to number of cases in our physical environment. However, when adopting spatial plans, deciding on future investments, municipalities/regions rarely expand their quest for solutions for NbS and their circular, multipurpose benefits. General practice and regulation does not stimulate or remind to search for optimal solutions in NbS.	Online public consulation	Private company (SME) sector		Awareness and capacity building
Lack of data regarding the quantification of benefits and co-benefits of NbS ecosystem services, including their economic valuation. Municipalities have difficulty reaching NbS concepts and approaches since they are already overloaded with knowledge regarding other related concepts (e.g., green infrastructure or ecosystem services). Decision-makers and practitioners often lack the know-how to address trade-offs and make good use of the available technical solutions.	Online public consulation	University / Higher Education / Public research institute sector	Toxopeus, H., Polzin, F., 2021. Reviewing financing barriers and strategies for urban nature-based solutions. Journal of Environmental Management 289, 112371. https://doi.org/10.1016/j.jenvman.2021.112371 Somarakis, G., Stagakis, S., Chrysoulakis, N., n.d. ThinkNature / Nature-Based Solutions Handbook. https://doi.org/10.26225/JERV-W202 Egusquiza, A., Cortese, M., Perfido, D., 2019. Mapping of innovative governance models to overcome barriers for nature based urban regeneration. IOP Conf. Ser.: Earth Environ. Sci. 323, 012081. https://doi.org/10.1088/1755-1315/323/1/012081	Cost/benefit evaluations Awareness and capacity building
Lack of deep understanding among multidisciplinary key actors	Desk Study	Grey literature	Somarakis, G., Stagakis, S., Chrysoulakis, N., n.d. ThinkNature / Nature-Based Solutions Handbook. https://doi.org/10.26225/JERV-W206	Awareness and capacity building
Lack of detailed understanding, in particular as regards the cost structure of NbS and the need to budget for long term maintenance costs.	Desk Study	Grey literature	McQuaid, Siobhán, Rhodes, Mary-Lee, Andersson, Thomas, Croci, Edoardo, Feichtinger-Hofer, Marianne, Grosjean, Matthieu, Lueck, Alina, Kooijman, Esmee, Lucchitta, Benedetta, Rizzi, Daniela, Reil, Alice, Schante, Joanne, 2021. From Nature-based Solutions to the Nature-based Economy - Delivering the Green Deal for Europe. Draft White Paper for consultation. Nature-based Economy Working Group of EC Task Force III on Nature-based Solutions. https://doi.org/10.5281/ZENODO.5055605	Effectivennes at different time scales Cost/benefit evaluations
Lack of evidence regarding long-term effects of nature-based solutions	Desk Study	Academic literature	Dumitru, A., Frantzeskaki, N., Collier, M., 2020. Identifying principles for the design of robust impact evaluation frameworks for nature-based solutions in cities. Environmental Science & Policy 112, 107–116. https://doi.org/10.1016/j.envsci.2020.05.029	Effectivennes at different time scales
Lack of knowledge regarding the impacts of NbS on health and wellbeing	Desk Study	Grey literature	Somarakis, G., Stagakis, S., Chrysoulakis, N., n.d. ThinkNature / Nature-Based Solutions Handbook. https://doi.org/10.26225/JERV-W207	Impacts for health and well-being
Lack of longer-term evaluations to assess effects over time and guaranteeing continuity of monitoring measurements: often models of monitoring impacts lack the continuity of measurement from the pregreeningto the long-term effects in the post-greening phase, they are also influenced by the complexity and feasibility of the monitoring itself.	Desk Study	Institutional publication	European Commission, Directorate-General for Research and Innovation, 2021. Evaluating the impact of nature-based solutions: a handbook for practitioners.	Effectivennes at different time scales Monitoring tools
Lack of standardized and harmonized techniques for measuring carbon sequestration across habitats that allow for evaluating wider environment management or large-scale monitoring and surveys: While there are well-established techniques to measure carbon sequestration within habitats, these techniques differ largely among habitats. According to Stafford et al. (2021), “woodland sequestration rates are calculated using biomass estimates as a large percentage of the final value” while “aquatic habitats tend to focus more on carbon buried in sediments”. These differences require a standardization of the measurement protocols across habitats to better compare the efficiency of carbon sequestration across these habitats. Further harmonized larger scale monitoring schemes are required which are embedded in the national emission inventory efforts.	Online public consulation	International or European research organisation/initiative sector	Stafford, R., Chamberlain, B., Clavey, L., Gillingham, P.K., McKain, S., Morecroft, M.D., Morrison-Bell, C. and Watts, O. (Eds.) (2021). Nature-based Solutions for Climate Change in the UK: A Report by the British Ecological Society. London, UK	Direct and indirect benefits for climate mitigation
Long-time horizons: Adaptation is a long-term issue and any success will only be noticeable after long time horizons. It is, therefore, challenging to monitor success and especially beyond project timelines. This is especially relevant for EbA as ecosystem management and restoration require longer periods to be assessed	Desk Study	Institutional publication	UNEP-IEMP, 2019. Research on Ecosystem-based Adaptation (EbA): A reference guide.	Effectivennes at different time scales
Many of these observations are increasingly backed up by research, although there remains a lack of scientific synthesis and there are several knowledge gaps, in particular around how the cost-effectiveness of NbS compares to alternatives.	Desk Study	Academic literature	Seddon, N., Chausson, A., Berry, P., Girardin, C.A.J., Smith, A., Turner, B., 2020. Understanding the value and limits of nature-based solutions to climate change and other global challenges. Phil. Trans. R. Soc. B 375, 20190120. https://doi.org/10.1098/rstb.2019.0120	Effectiveness compared to conventional approaches
Measurability of intangible impacts (e.g., aesthetic enjoyment) and spillovers (impact of NbS intervention may spread beyond the treated area or group) as well as accounting for trade-offs is challenging, particularly because of the diverse perspectives of stakeholder valuing NbS, the multiple time scales of assessment and influence of other programs and factor.	Desk Study	Institutional publication	European Commission, Directorate-General for Research and Innovation, 2021. Evaluating the impact of nature-based solutions: a handbook for practitioners.	Synergies and trade-offs between goals
Methods of creating and maintaining the protected green areas (e.g. the River Parks) to balance their ability to be used by citizens and their effective protection, without losing biodiversity. The rules of making them available and using them.	Desk Study	Grey literature	De Vreese, R., 2021. Reviewing the knowledge on the importance of UF-NbS for resilient cities (D1.2).	Protected area management
Methods of precise evaluation and determination of ecological continuity; taking into account and balancing all types of continuity (needs of various species of plants and animals, hydrological, city ventilation, alternative forms of transport, etc.).	Desk Study	Grey literature	De Vreese, R., 2021. Reviewing the knowledge on the importance of UF-NbS for resilient cities (D1.2).
Metrics: There are no universal metrics for adaptation in general or specifically for EbA. Often it is a challenge to define what exactly needs to be monitored (risk reduction, ecosystem service provision, food security, etc.) and at what level (national, regional and local).	Desk Study	Institutional publication	UNEP-IEMP, 2019. Research on Ecosystem-based Adaptation (EbA): A reference guide.	Monitoring tools
More effective long-term strategies that address the risks of slow-onset events, such as increasing temperature and biodiversity loss, and their interaction with multiple drivers (e.g. land use change) and cascading tipping points related to ecosystem degradation is needed (e.g. in relation to public health, food and water security, ecosystem resilience).	Desk Study	Institutional publication	European Environment Agency., 2021. Nature-based solutions in Europe policy, knowledge and practice for climate change adaptation and disaster risk reduction. Publications Office, LU.	Risks from slow-onset events
More information is needed on the synergies and trade‑offs of combining NbS with grey infrastructure (i.e. hybrid measures).	Desk Study	Institutional publication	European Environment Agency., 2021. Nature-based solutions in Europe policy, knowledge and practice for climate change adaptation and disaster risk reduction. Publications Office, LU.	Effectiveness of hybrid solutions
More specifically, urban administrations may lack information on legal instruments and requirements for implementing NbS.	Desk Study	Academic literature	Kabisch, N., Frantzeskaki, N., Pauleit, S., Naumann, S., Davis, M., Artmann, M., Haase, D., Knapp, S., Korn, H., Stadler, J., Zaunberger, K., Bonn, A., 2016. Nature-based solutions to climate change mitigation and adaptation in urban areas: perspectives on indicators, knowledge gaps, barriers, and opportunities for action. E&S 21, art39. https://doi.org/10.5751/ES-08373-210241	Awareness and capacity building
More work appears to be needed on the relative costs and benefits of NbS in different settings, or more accurately, on who bears the costs or enjoys the benefits of these investments.This in itself presents a challenge for research and innovation into NbS and their co-benefits, highlighting the need for contextualised and place-specific cases. Cooperative research and innovation is required across Europe to develop new ways of understanding how multiple often individually small NbS can combine to deliver collectively significant strategies	Desk Study	Institutional publication	European Commission. Directorate General for Research and Innovation., 2020. Nature-based solutions: state of the art in EU funded projects. Publications Office, LU.	Effectiveness across socio-ecological contexts Social cohesion and environmental justice NbS interaction at the landscape scale
Much of the research on the role of NbS for sustainable communities has been conducted in an urban environment, with the result that we have more limited understanding of how such interventions might support the development of rural sustainability or the generation of sustainable communities at the landscape level across both urban and rural domains.	Desk Study	Institutional publication	European Commission. Directorate General for Research and Innovation., 2020. Nature-based solutions: state of the art in EU funded projects. Publications Office, LU.	Effectiveness across socio-ecological contexts