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NIMBioS Working Group:

Long Transients and Ecological Forecasting

Working group photo.
Meeting 1 participants (L to R): Gabriel Gellner, Mary Lou Zeeman, Ying-Cheng Lai, Alan Hastings, Kim Cuddington, Tessa Francis, Andrew Morozov, Katherine Scranton, Karen Abbott, Sergei Petrovskii.

Topic: Long living transients as a bugbear of ecological forecasting: Concepts, models and data

Meeting dates: March 1-3, 2017, October 26-28, 2017

Alan Hastings, Environmental Science and Policy, Univ. of California, Davis
Kim Cuddington, Biology, Univ. of Waterloo, Canada
Andrew Morozov, Mathematics, Univ. of Leicester, UK
Sergei Petrovskii, Mathematics, Univ. of Leicester, UK

Objectives: Predicting sudden changes in ecosystems - "regime shifts" - that often result in population collapse and biodiversity loss is a major issue for ecology and nature conservation. Analysis of population dynamics has traditionally focused on their long-term, asymptotic behavior, while largely disregarding transient dynamics. However, there is a growing understanding that in ecosystems the asymptotic behavior is rarely seen. In particular, a big new challenge for theoretical and empirical ecology is to understand the implications of long-living transients (LLT). The presence of LLT can be an explanation of regimes shifts alternative to "tipping points," so understanding of LLT would substantially improve the quality of long-term forecasting and crisis anticipation. At present, this research area seems to be in its infancy; systematic studies are lacking. Here we seek to make substantial progress in better understanding the role of LLT in ecology and in developing appropriate research techniques for long-term ecosystem management. The overall goal is to construct a unifying theory of LLT by combining the existing empirical facts, mathematical models, computational approaches and appropriate methods of data analysis. First, we will systematize the existing empirical data and models exhibiting LLT and classify the main scenarios of LLT based on the mechanisms that cause them. Second, we will revisit the mathematical techniques of description of LLT in models and set up milestones for necessary future advances. Finally, we will revisit the methods of data analysis in order to increase the reliability of revealing LLT from empirical data.


Meeting Summaries for NIMBioS Working Group:
Long Transients and Ecological Forecasting

Meeting 1, March 1-3, 2017 Agenda (PDF) Participants

Meeting 1 summary. Existence of long living transients (LLTs) is a phenomenon that can have serious implications for the understanding of ecological dynamics. The meeting brought together ten scientists with complementary expertise with the purpose to work on this problem. The meeting started with short presentations by the group members on various aspects of transient ecological dynamics. Presentations were followed by several intense brainstorming discussion sessions. The group has identified the main challenges in dealing with LLTs and agreed on the list of principal mechanisms resulting in LLTs, such as the existence of different time scales and the existence of ghost attractors. A particular attention was paid to emphasizing the difference between the regime shift scenarios due to graduate change in the environment conditions and the regime shifts due to the effect of LLTs. In particular, it has been discovered that the two alternatives require essentially different management strategies. The group then agreed on the plan of future actions, which includes preparation of a review or viewpoint paper and a more specific research paper with clear task division between the group members and specific deadlines for each stage of the work and the dates and a preliminary agenda for the next meeting.


NIMBioS Working Groups are chosen to focus on major scientific questions at the interface between biology and mathematics. NIMBioS is particularly interested in questions that integrate diverse fields, require synthesis at multiple scales, and/or make use of or require development of new mathematical/computational approaches. NIMBioS Working Groups are relatively small (up to 10 participants), focus on a well-defined topic, and have well-defined goals and metrics of success. Working Groups will meet up to 3 times over a two-year period, with each meeting lasting up to 2.5 days.

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