September 24, 2021

Online Workshop on the 12th European Conference on Ecological Restoration

The team of project ALNUS (Patricia María Rodríguez González, Inês Gomes Marques, Cristina Vieites Blanco) and the ALNUS consultant Simon Dufour organized the online workshop “Socio-ecological restoration of riparian vegetation by integrating biotic and abiotic pressures” on September 9th 2021, during the 12th European Conference on Ecological Restoration. The event was introduced by Dr. Patricia Rodríguez González, followed by four invited speakers: Dr. Roland Jansson (Umeå University, Sweden), Dr. Jonàs Oliva (University of Lleida, Spain), Dr. Eduardo González (Colorado State University, USA) and Dr. Simon Dufour (University of Rennes 2, France). Afterwards, the interactive part ‘Disentangling interacting pressures that affect the recovery of riparian forests’ was guided by Dr. Cristina Vieites Blanco and MSc Inês Gomes Marques.

This workshop highlighted the importance of considering interacting biotic and abiotic pressures, and to properly frame these multiple pressures in their socio-economic context to improve ecological restoration success. The main take-home messages from invited presentations were:

•          River regulation – a major driver of species richness and area reduction of riparian vegetation – can be tackled through the introduction of environmental flows (mimicking the natural flow regime) or structural rehabilitation (e.g. boulders to protect shorelines). A cost-benefit analysis is needed to decide the rehabilitation actions of the affected riparian zones.

•          Alder decline caused by Phytophthora xalni and P. uniformis is hard to control and so it requires to be detected early. In infected areas, resistance was found for P. uniformis (the least pathogenic, but the most resistant to frost), leading to some P. xalni resistance. Restoration may be achieved favouring healthy trees and removing diseased alders.

•          Depending on objectives, different methods for invasive plants removal are possible: mechanically, chemically, or through burn or biocontrol; although subsequent active restoration may be needed to recover native vegetation. Tamarix invasion in North America was firstly promoted for streambanks stabilization, then controlled with biocontrol, and now only removed when an active restoration ensures the preservation of its ecological functions.

•          Riparian landscapes have biophysical and social dimensions, both complex and neither should be overlooked. The cultural, social and political characteristics have been often neglected in riparian studies, despite their crucial role in restoration success. To improve management success, various stakeholders should be included in the decision-making process, increasing the number of collaborators and information sources and the relative importance of plant-related goals

Conclusions from interactive activities:

•          Participants’ perceptions on interacting pressures that affect riparian forest recovery were discussed. Alteration of water flow regime and agriculture were perceived as the most important pressures. The interactions of water flow regime with invasive species (plants and pathogens) and with agriculture, were generally perceived as synergistic, whilst the interaction agriculture and invasive species was mostly perceived as additive. This participatory activity highlighted the complexity of anticipating the interaction of two pressures as the type of interaction is context specific.

•          With all their complexity, pressures are only the tip of the iceberg. The DPSIR (Drivers – Pressures- State-Impacts-Responses) framework, which tries to simplify the chain of causal links on a system, can be a useful tool in a global approach that takes into consideration all these dimensions. This is particularly important for a successful ecological restoration.

We specially thank the participation of the invited speakers and the contributions of the public.

You can download the Conclusions Report HERE