The Long-term Ecological Research Network research infrastructure can help scaling up ecological restoration: Insights from a questionnaire

Ecological restoration is considered fundamental to counteract anthropogenic ecosystem degradation, fragmentation, biodiversity loss, and climate change. Recognizing this need, many initiatives have been launched to promote ecological restoration globally, e.g. UN Decade on Ecosystem Restoration 2021-2030, post-2020 global biodiversity framework of UN Convention on Biological Diversity. At the European Union level, as part of the Biodiversity Strategy for 2030 and the European Green Deal, the European Parliament has recently approved the proposal on Nature Restoration Law that sets the ambitious goal to restore “at least 20% of the EU’s land and sea areas by 2030”. Achieving such massive global restoration targets poses challenges including the need for long-term research and effective monitoring of success, ensuring the availability of suitable reference ecosystems, fostering collaborations across diverse fields and actors, and securing sustained funding.

Research infrastructures, especially those that provide long-term ecological knowledge on ecosystem health, functioning and services in response to different environmental impacts and environmental change can help upscale restoration efforts. The International Long-term Ecological Research Network (ILTER) conducts site-base whole ecosystem research globally. The HUN-REN Centre for Ecological Research is among the founders of its pan-European regional network of ILTER (eLTER) where a European research infrastructure is currently being developed, possibly comprising 500 formally accredited ecosystem research sites across 26 countries and encompassing all European regions.

An international research team led by Melinda Halassy (Restoration Ecology Group) from two research centres, the HUN-REN Centre for Ecological Research and the Portuguese Centre for Ecology, Evolution and Environmental Changes both affiliated to eLTER and the Society for Ecological Restoration Europe (SERE), reviewed the knowledge and practice of ecological restoration in the pan-European region of the Long-Term Ecological Research Network to demonstrate its importance and potential contribution to the implementation of the EU Nature Restoration Law. The review was developed using an online questionnaire between November 2021 and March 2022 to gather information on eLTER restoration experts and details of recovery projects, including the use of eLTER contributions.

Based on 62 restoration experts and 42 restoration projects identified from 18 countries, eLTER restoration expertise covers most of the European habitats, diverse degradation states and restoration techniques. Restoration projects cover mainly biological degradation, particularly those related to habitat change (e.g. infrastructure development, industrial activities, lack of management), overexploitation (e.g. intensive agriculture, overgrazing), and to some extent climate change (which may have caused natural disturbances such as extreme rainfall or drought). A significant majority of the projects (78%) were monitored beyond the average project lifecycle (5 years). No generic protocol was used for monitoring, but most projects used a high number and a diverse array of indicators, and assessed the progress of recovery several times, based on a pre-implementation status, an untreated control or a reference ecosystem. Most projects achieved restoration success on the long term providing five ecosystem services on average as benefits, mainly supporting services such as biodiversity or habitat, but also cultural and regulating services. The survey shows that current financial commitments from the EU are below national and private funding for at least eLTER restoration project.

The study demonstrates that cooperation with eLTER network could be beneficial for achieving restoration targets through multiple contributions. eLTER provides long-term, standardized, and open-access data on natural and semi-natural ecosystems that allow understanding natural fluctuations over time that could reduce the restoration costs associated with reference sites or the collection of background data. The conceptual framework and guidelines for the long-term monitoring of eLTER could potentially be used to develop a harmonised monitoring and evaluation framework for the different European ecosystems and research traditions, allowing comparability between sites and EU-wide evaluation. In addition, research networks such as eLTER can facilitate multidisciplinary discussions and dialogues between different stakeholders, especially when conflicting stakeholder interests are involved in restoration.