From sink to source: Tipping points of blue carbon storage in Mediterranean seagrass ecosystemsInternal

BlueTipS

Activity Overview

Type: Foresight Workshop
Start Date: October 1, 2019
End Date: October 3, 2019
Host: CNRS
Venue: Montpellier, France
Contact: Vasilis Dakos
E-mail: vasilis.dakos [at] umontpellier.fr
Funding Call: EuroMarine 2018 call for FWS and WG proposals
Total Budget: €7,500
Funds Granted: €7,500

Seagrasses are declining at alarming rates due to climate change and human activities near the coasts, with the risk of experiencing abrupt and irreversible collapses. It is estimated that present rates of seagrass loss could result in the release of up to 299Tg carbon per year, eventually shifting from sinks to sources of carbon. What is lacking is a mechanistic understanding of how the potential collapse of seagrass meadows could have cascading effects on the dynamics of carbon sequestration in order to quantify the risk of coastal ecosystems shifting from carbon sinks to carbon sources.

The goal of this Foresight Workshop is therefore to bring together experts on tipping point dynamics with experts on seagrass ecology in order to connect theoretical insights of ecosystem tipping responses to stress with the dynamics of carbon sequestration and release in coastal Mediterranean seagrass ecosystems (Posidonia oceanica meadows). Ultimately, this workshop aims to help provide a methodological framework to conserve and manage seagrass ecosystems using tipping point science and eventually optimize blue carbon storage in the region.

KEY OBJECTIVES

The workshop will cover three key topics:

  • Conceptually integrating a tipping point perspective in the ecosystem functioning of P. oceanica meadows across the Mediterranean basin
  • Developing a modeling framework for studying these questions in seagrass ecosystems across the Mediterranean basin
  • Designing experimental work to assess the risk of collapse in seagrass meadows and their fragility to shifting from sink to carbon sources at the Mediterranean scale

In order to address these topics, the workshop will be:

  • Conducting a review/perspective of patterns of P. oceanica degradation and the links of seagrasses to blue carbon dynamics
  • Developing models that will describe the spatial dynamics of growth and degradation of P. oceanica (inspired from terrestrial ecosystem models) and how to connect these models to ecosystem functioning in terms of carbon sequestration and release in the sea sediment
  • Designing field experiments and protocols for the assessment of the risk of collapse in P. oceanica using ecosystem scale proxies that could reflect the system’s fragility to shifting from carbon sink to source

EXPECTED OUTCOMES

  1. A perspective paper
  2. A Project Proposal (in national, bilateral or European calls)
  3. Networking opportunities for student and researcher exchange

EXPECTED IMPACT

This workshop will provide insights on how to improve management practices of sensitive seagrass habitats, ensuring provision of key ecosystem services from seagrass meadows and contributing in mitigation of climate change.

Summary

Over the course of the three day workshop, the gathered group of experts on tipping point dynamics and seagrass ecology discussed the theoretical insights of ecosystem tipping responses to stress with the dynamics of carbon sequestration and release in coastal Mediterranean Seagrass ecosystems. The overarching goal of those in attendance was to provide a framework for conserving and managing these ecosystems using tipping point science, eventually leading to optimised blue carbon storage in the region.

The participants discussed in detail the conceptual integration of a tipping point perspective with regards to the functioning of P. oceanica meadows in the Mediterranean basin. They then evaluated how to develop this perspective into a modelling framework and the design of experimental work to study the risk of ecosystem collapse due to their shift from carbon sink to source.

Outputs

Over the two and a half day meeting, the researchers mapped the links of stressors and disturbances to blue carbon dynamics, an exercise that is being developed into a perspective paper. Another paper will capture their development of a mathematical model linking seagrass stress responses to ecosystem functioning in terms of carbon sequestration and release in sediment. Finally, the group designed a slate of field experiments and surveys that were consolidated into a project proposal.