1. NBS Knowledge Databases

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 141 - 160 of 169
Gap Description Origin of source Source Resource Broad topic

Third, changes in the provision of ecosystem services over time, for example, under climate change and other stressors, are rarely considered, and there are major questions about how to balance future benefits with current costs

 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.2019.0123
  • Risks from slow-onset events

Third, engineered systems (e.g. bioretention, green roofs) need to be studied over long term to better understand the decline in performance and maintenance requirements.

 Desk Study Academic literature

Hamel, P., Tan, L., 2021. Blue–Green Infrastructure for Flood and Water Quality Management in Southeast Asia: Evidence and Knowledge Gaps. Environmental Management. https://doi.org/10.1007/s00267-021-01467-w
  • Monitoring tools

This lack of comparison between EbA-relevant inter- ventions and other non ecosystem-based options is a key knowledge gap that needs to be addressed.

 Desk Study Academic literature

Doswald, N., Munroe, R., Roe, D., Giuliani, A., Castelli, I., Stephens, J., Möller, I., Spencer, T., Vira, B., Reid, H., 2014. Effectiveness of ecosystem-based approaches for adaptation: review of the evidence-base. Climate and Development 6, 185–201. https://doi.org/10.1080/17565529.2013.867250
  • Effectiveness compared to conventional approaches

To date a lack of knowledge and skills on how to measure the effectiveness of NbS has been a major challenge increasing the perception of higher risks related to NbS and hampering larger scale implementation.

 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.5055608
  • Methodologies and tools for systematic evaluation

To deliver on this potential we need to consider how to secure active and ongoing participation from stakeholders across all sectors of the economy in an approach where parties have a full understanding of the value of nature as both an input and output in economic processes. 

 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.5055610
  • Stakeholder engagement

To increase participatory space and promote ownership of these decision-making processes, researchers argue for a focus on understanding risk perceptions before conducting vulnerability outcome assessments, and provide examples for how to do so.

 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.2020.09.003
  • Stakeholder engagement

To propose implementation or improve NbS it is highly valuable to map what you have known. Some info already exists, but for example distribution of habitat types at regional scale, some of which are important for improvement of e.g. carbon storage, is not mapped. To propose landscape adaption and improve its capacity to store more carbon we need to know where and how much of carbon sink habitats we have, what is their condition and health, and where to plan their extension....

 Online public consulation University / Higher Education / Public research institute sector
  • Knowledge base

Transformation of systems by human management lead to completely new environmental conditions, with non-analogue conditions to known systems, so-called novel ecosystems. Many of these new conditions are too extreme to be suitable for native species, e.g., mining areas on tertiary substrates (lignite mining) or central urban soils and climates. In such conditions, specific NbS (e.g., carbon sequestration, air purification, water storage) can only be delivered by non-native species. These, though, pose the danger of becoming invasive and harming native biodiversity and ecosystems. Clear guidelines are missing to determine under which conditions one might use non-native species for NbS, how to select species that provide the NbS without harming native systems, how to implement such novel ecosystems, and how to prevent negative trade-offs.

 Online public consulation International or European research organisation/initiative sector

Hobbs, R.J., Higgs, E., Harris, J.A., 2009. Novel ecosystems: implications for conservation and restoration. Trends in Ecology & Evolution 24, 599–605. https://doi.org/10.1016/j.tree.2009.05.012
  • Biodiversity benefits

User-friendly valuation tools for the evaluation of risk reduction by using urban NbS should be developed.

 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.
  • Valuation tools

Valuation of costs and benefits: EbA measures have the advantage to simultaneously generate multiple adaptation benefits and co-benefits, deliver cost-effective long-term solutions in an equitable manner.

 Desk Study Institutional publication

UNEP-IEMP, 2019. Research on Ecosystem-based Adaptation (EbA): A reference guide.
  • Cost/benefit evaluations

We do not know how offshore windfarms can be constructed so they benefit the marine environment. Thousands of offshore wind turbine foundations will be constructed soon. This will impact the marine environment, but we do not know if and how a windfarm can be constructed such that it benefits the marine environment. We do not know how to complete offshore windfarm decommissioning to benefit the marine environment.

 Online public consulation University / Higher Education / Public research institute sector
  • Biodiversity benefits

We need a better understanding of nature-based solutions for coastal protection. In other words, how can we enhance the ability of nature to protect our shore lines? Beach nourishment is the typical method for coastal protection, but it's rather destructive for the marine environment. We need better Nature-based solutions for coastal protection. Can we get seagrass, seaweed, geogenic reefs, biogenic reefs etc. to advance in such a way that coastal protection is improved? At the moment, we do not know if and how such goals may be achieved.

 Online public consulation University / Higher Education / Public research institute sector
  • Knowledge base

We therefore argue that evaluation plans of nature-based solutions should define and focus on both positive and negative effects and consider the magnitude of these effects for different demographic and ethnic groups.

 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.2020.05.028
  • Negative impacts

What are the costs and multiple benefits generated by different types and scales of NbS and hybrid solutions ?

 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 of hybrid solutions

What are the costs of maintenance for green infrastructure spaces in the long term?

 Desk Study Academic literature

Grace, M., Balzan, M., Collier, M., Geneletti, D., Tomaskinova, J., Abela, R., Borg, D., Buhagiar, G., Camilleri, L., Cardona, M., Cassar, N., Cassar, R., Cattafi, I., Cauchi, D., Galea, C., La Rosa, D., Malekkidou, E., Masini, M., Portelli, P., Pungetti, G., Spagnol, M., Zahra, J., Zammit, A., Dicks, L.V., 2021. Priority knowledge needs for implementing nature-based solutions in the Mediterranean islands. Environmental Science & Policy 116, 56–68. https://doi.org/10.1016/j.envsci.2020.10.010
  • Effectivennes at different time scales
  • Cost/benefit evaluations

What are the disservices, disadvantages and limitations of NbS?

 Desk Study Academic literature

Grace, M., Balzan, M., Collier, M., Geneletti, D., Tomaskinova, J., Abela, R., Borg, D., Buhagiar, G., Camilleri, L., Cardona, M., Cassar, N., Cassar, R., Cattafi, I., Cauchi, D., Galea, C., La Rosa, D., Malekkidou, E., Masini, M., Portelli, P., Pungetti, G., Spagnol, M., Zahra, J., Zammit, A., Dicks, L.V., 2021. Priority knowledge needs for implementing nature-based solutions in the Mediterranean islands. Environmental Science & Policy 116, 56–68. https://doi.org/10.1016/j.envsci.2020.10.014
  • Negative impacts

What crops or plants might be suitable for phytoremediation of wastewater including saltwater?

 Desk Study Academic literature

Grace, M., Balzan, M., Collier, M., Geneletti, D., Tomaskinova, J., Abela, R., Borg, D., Buhagiar, G., Camilleri, L., Cardona, M., Cassar, N., Cassar, R., Cattafi, I., Cauchi, D., Galea, C., La Rosa, D., Malekkidou, E., Masini, M., Portelli, P., Pungetti, G., Spagnol, M., Zahra, J., Zammit, A., Dicks, L.V., 2021. Priority knowledge needs for implementing nature-based solutions in the Mediterranean islands. Environmental Science & Policy 116, 56–68. https://doi.org/10.1016/j.envsci.2020.10.012
  • Performance and characteristics of plants

What innovative management approaches can be applied in protected areas to help overcome key current challenges, e.g. a lack of viability or sustainability due to lack of cost-effectiveness, value for money, societal acceptance or other issues; failure to deliver expected outcomes in terms of biodiversity protection?

 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.
  • Protected area management

What NbS are available for use in agriculture and pastoralism?

 Desk Study Academic literature

Grace, M., Balzan, M., Collier, M., Geneletti, D., Tomaskinova, J., Abela, R., Borg, D., Buhagiar, G., Camilleri, L., Cardona, M., Cassar, N., Cassar, R., Cattafi, I., Cauchi, D., Galea, C., La Rosa, D., Malekkidou, E., Masini, M., Portelli, P., Pungetti, G., Spagnol, M., Zahra, J., Zammit, A., Dicks, L.V., 2021. Priority knowledge needs for implementing nature-based solutions in the Mediterranean islands. Environmental Science & Policy 116, 56–68. https://doi.org/10.1016/j.envsci.2020.10.013
  • Effectiveness across socio-ecological contexts

What role can NbS play in the development and implementation of no net loss approaches addressing urban and rural biodiversity?

 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.
  • Biodiversity benefits