Improving River Ecosystems with Nature-Based Solutions: New Insights, Methodological Advancements and Opportunities

Dear Colleagues,

River ecosystems have been severely damaged worldwide by a multitude of human pressures, such as pollution, nutrient enrichment, damming or overexploitation, and this has become more intense over the past five decades. For example, the fragmentation of river connectivity by dams and weirs has interrupted the migratory routes of many freshwater species, resulting in dramatic species decline and/or extinction. Forest cutting in river catchments, particularly of riparian vegetation, has contributed to the depletion of important ecosystem services by the loss of water purification ability and by the increase in risks of flooding, while several water management schemes (e.g., river straightening and prevention of lateral movements of river channels) have interrupted natural flooding regimes and floodplain processes. Point-source pollution and diffuse pollution, such as pesticides, fertilizers, industrial and household wastes, have also greatly impacted rivers as a result of increasing urbanization and agricultural production. More recently, the threats caused by non-native species invasion place rivers at a higher risk, reducing their biodiversity. Altogether, these pressures have caused severe effects on the biota, on the ecosystem services and on the economy as well and are likely to be exacerbated in the near future by additional pressures such as climate change.

Consequently, new approaches founded on the “working with nature” method have been sought in recent years and directed to support i) conservation and restoration of river ecosystems, ii) reduction in water-related risks, iii) climate change adaptation and iv) provision of ecosystems services and sustainable environment. This includes the so-called Nature-based Solutions (NbS), defined by the IUCN as “actions to protect, sustainably manage and restore natural or modified ecosystems that address societal challenges effectively and adaptively, simultaneously providing human well-being and biodiversity benefits”. NbS are therefore fundamental for reaching the EU Green Deal objectives (including the target of reconnecting at least 25,000 km of rivers in Europe by 2030); delivering socio-economic benefits including biodiversity conservation and climate change adaptation; and engaging economic sectors in restoration. Such solutions (e.g., rewetting, floodplain reconnection, reforestation to store carbon, natural water retention measures, riparian restoration, dam removal and reopening of old canals or rivers to increase resilience to heatwaves) should, therefore, be cost-effective while providing environmental, social and economic benefits, helping to build resilience and, at the same time, making use of multiple ecosystem services that they can bring.

Despite their increasing prominence, NbS could be further mainstreamed, and a promising avenue remains to be explored concerning their function relative to different river typologies and climate scenarios, as well as on technical standards, quantitative targets, measurable indicators, evaluation tools and trade-offs for evaluating their performance in providing multiple benefits and ecosystems services while being economically viable on the long-term.

This Special Issue of Hydrobiology aims to compile new information on a wide range of research and applications regarding the implementation of Nature-based Solutions (NbS), particularly on with respect to their design, assessment and evaluation, in order to improve river ecosystems. Multidisciplinary approaches that involve collaborative governance and/or economically viable models rendering NbS attractive and investable are also welcome. The papers selected for this Special Issue will be subject to a rigorous peer-review procedure with the aim of rapid and wide dissemination of results.

Dr. José Maria Santos
Dr. Patricia María Rodríguez González
Dr. Paulo Branco
Guest Editors

Manuscript Submission Information

Manuscripts should be submitted online at www.mdpi.com by registering and logging in to this website. Once you are registered, click here to go to the submission form. Manuscripts can be submitted until the deadline. All submissions that pass pre-check are peer-reviewed. Accepted papers will be published continuously in the journal (as soon as accepted) and will be listed together on the special issue website. Research articles, review articles as well as short communications are invited. For planned papers, a title and short abstract (about 100 words) can be sent to the Editorial Office for announcement on this website.

Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are thoroughly refereed through a single-blind peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Hydrobiology is an international peer-reviewed open access quarterly journal published by MDPI.

Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this open access journal is 1000 CHF (Swiss Francs). Submitted papers should be well formatted and use good English. Authors may use MDPI's English editing service prior to publication or during author revisions.

• NbS design, assessment and performance
• NbS links with restoration ecology and conservation biology
• NbS benefits and trade-offs
• ecosystem services provided by NbS
• NbS collaborative governance and economic-viable models
• NbS upscaling for climate change adaptation
• implementation of NbS in policy frameworks
• citizen and stakeholder engagement in NbS