ESA 2018 – New Orleans (Sabiha Majumder)

In August I attended the 103rd annual meeting of New Orleans Ecological Society of America … ‘Ecosystem resilience, extreme events and human well-being’. A theme I am fascinated by. In fact, I studied the effect of external drivers on ecosystem resilience and its stability during my PhD, so I was really enthused by the theme of this year’s conference!

I reached New Orleans on 5th August and was delighted to experience such a charming city! On the second day of the conference I was invited to speak at a session organized by a team from the University of Utah (including the Crowther Lab’s own Kailiang Yu!). I wanted to share the approach and findings gathered from my PhD. So in my presentation (“Inferring critical thresholds of ecosystem transition from spatial data”) I set out how can we estimate the threshold parameters of external drivers at which an ecosystem can shift to a qualitatively new state. In this work, we used concepts from the theory of phase transitions in Physics to develop a method to estimate the transition points in ecosystems. Based on these theories, we suggested that by looking at very simple spatial metrics like variance and autocorrelation of spatial images, we can calculate the threshold conditions at which the system will shift to another state. We also demonstrated our method using remotely sensed data. My talk led to very interesting discussion at the end and many people were interested in reading the paper. It is available on bioRxiv with the following link .The organisers have decided to write a review paper based on the whole session and it will be fun contributing to the paper which addresses ecosystem ecology from diverse angles!

I was so nervous before the talk, but after I had done it, I could enjoy the rest of the conference stress-free. It is always an advantage if your talk is scheduled early in the conference! The next two days passed attending various talks, arranging for meetings, running between sessions to find the venues and looking for coffee!

I, together with my former colleagues Krishnapriya Tamma and Sumithra Sankaran ( from Indian Institute of Science, Bangalore) organised our own session on the final day. Priya and I moderated the session with ten fantastic speakers to present their work in our session “Multistability and Spatio-Temporal Dynamics of Abrupt Transitions in Terrestrial Ecosystems: Theory, Application and Management”. The presenters ranged from theoreticians (using mathematical modelling to understand the multistabiltiy in ecosystems), to empiricists (using remotely-sensed and ground-truthed data to further enhance the models and test their applicability).

Each and every scientist delivered great presentations on how they are using diverse approaches to understand the abrupt transitions in a range of ecosystems. The session led to long and active discussions – the furious scribbling on white boards is always a good sign! The feedback was fantastic and there was a general feeling that we managed to stitch together the missing links between theory, application and management. A big thanks to all of presenters who I’ve acknowledged below!

Despite a mad rush to the airport following the conclusion of our session, we have managed to keep many of the great conversations going! Hopefully this leads to even more projects and great research papers!

The list of speakers in our session included:

The list of speakers in our session:

  1. Ehud Meron, Ben Gurion University, Israel.
    What does pattern-formation theory tell us about regime shifts
  2. Beniamino Abis, Max-Planck-Institut für Meteorologie, Germany.
    Shift happens: Observations and modelling of alternative tree cover states of the boreal ecosystem
  3. Haimm Weismann, Bar Ilan University, Israel.                                                  Empirical analysis of vegetation dynamics and the possibility of a catastrophic desertification transition
  4. Kathryn Fair, University of Guelph, Canada  
    “Spatial and social aspects of bistability in mosaic ecosystems”.
  5. Kristie Maciejewski, University of Stellenbosch, South Africa.  
    Dryland degradation as a social-ecological regime shift: A sub-Saharan case study
  6. Juan Carlos Rocha, Stockholm Resilience centre, Sweden.   @juanrocha    “Cascading effects of regime shifts: how terrestrial shifts can be interconnected?”
  7. Juan Bonachela, University of Strathclyde, Scotland  @Bonachela5       Catastrophic ecological transitions and management possibilities
  8. Thomas Bury, University of Waterloo, Canada  @bury182                                      Early warning indicators of ecological tipping points: Do they predict critical transitions in multi-stable systems, or something else?
  9. Vasilis Dakos, University of Montpellier, France.  @vdakos                                     Slow recovery from local disturbances as an indicator for loss of ecosystem resilience”
  10. Sumithra Sankaran, Indian Institute of Science, Bangalore, India .           Facilitation and ecosystem resilience: Clustering patterns and spatial correlations

Krishnapriya Tamma : @priya_tamma