Ecosystems are an assembly of a wide range of species that interact with one another, and with their environment, at relatively local scales. They exhibit self-organized patterns and maintain stability at much larger spatiotemporal scales. We are interested in understanding the patterns and dynamics of ecosystems, what causes them, how they are influenced by variations (seasonal/stochastic) in external drivers [1,2] and to device predictive tools [3,4]. We do this by employing/extending simple theoretical tools from statistical physics and applied mathematics, and by suitably testing those with empirical/laboratory data.
Ecosystems are naturally exposed to gradual changes in their external conditions and these typically results in a proportionate smooth response in their state. Occasionally, ecosystems can undergo abrupt and irreversible changes. Well studied examples include algal blooms in lakes or oceans, coral bleaching, or desertification in semi-arid forests. Many of these dramatic changes can happen by small changes in external drivers. Such abrupt changes, also referred to as catastrophic regime shifts/critical transitions, can lead to enormous loss of ecosystem services to humans. In this context, we are interested in devising early warning signals, or leading indicators, of abrupt transitions, using mathematical models [3,4,14,15], developing statistical methods [5,7,12], and testing in the real world [9,10,11].
Related publications:
[17] Nikunj Goel., Vishwesha Guttal, Simon A Levin and Carla Staver (2018). Dispersal increases the resilience of tropical savanna and forest distributions. bioRxiv, 476184.
[16] Sumithra Sankaran, Sabiha Majumder, Ashwin Viswanathan and Vishwesha Guttal, Clustering and correlations: Inferring resilience from spatial patterns in ecosystems, bioRxiv. Data and codes. In Review.
[15] Majumder, Sabiha, Krishnapriya Tamma, Sriram Ramaswamy, and Vishwesha Guttal. Inferring critical points of ecosystem transitions from spatial data. bioRxiv, Data and Codes. In Review.
[14] Alexandre Genin, Sabiha Majumder, Sumithra Sankaran, Alain Danet, Vishwesha Guttal, Florian Schneider, Sonia Kefi, 2018, Monitoring ecosystem degradation using spatial data and the R package spatialwarnings, Methods in Ecology and Evolution, 9: 2067-2075, DOI: https://doi.org/10.1111/2041-210X.13058
[13] Alexandre Génin*, Sabiha Majumder*, Sumithra Sankaran*, Florian D Schneider, Alain Danet, Miguel Berdugo, Vishwesha Guttal, Sonia Kefi, 2018, Indicators of regime shifts in ecological systems with spatially heterogeneous stressors, Ecological Indicators, 94:520-533 (*These authors contributed equally to this work).
[12] Sumithra Sankaran*, Sabiha Majumder*, Sonia Kefi, Vishwesha Guttal, 2018, Implications of being discrete and spatial for detecting early warning signals of regime shifts, Ecological Indicators, 94:503-511 (*These authors contributed equally to this work).
[11] Chen Ning, Kailiang Yu, C Jayaprakash, Vishwesha Guttal, 2018, Rising variability, not slowing down, as a leading indicator of a stochastically driven abrupt transition in a dryland ecosystem, The American Naturalist, 191: E1 E14, Data and Codes via Dryad. There is also a Lay summary.
Media coverage:
as being of special significance by Donald DeAngelis
Changes in dryland ecosystems, in Deccan Herald by Suma M of Gubbi Labs.
[10] Stephanie Eby*, Amit Agrawal*, Sabiha Majumder, Andew Dobson and Vishwesha Guttal, 2017, Alternative stable states and spatial indicators of critical slowing down along a spatial gradient in a savanna ecosystem, Global Ecology and Biogeography, 26: 638-649; Codes and Data are available on Github. PDF (*These authors contributed equally to this work).
[9] Vishwesha Guttal, Srinivas Raghavendran, Nikunj Goel, and Quentin Hoarau. Lack of Critical Slowing Down Suggests that Financial Meltdowns Are Not Critical Transitions, yet Rising Variability Could Signal Systemic Risk, PLoS ONE, 11(1): e0144198. PDF
[8] Amit Badhuri, Srinivas Raghavendra, Vishwesha Guttal, 2015, On the Systemic Fragility of Finance Led Growth, Metroeconomica, 66: 158-186. PDF
[7] Sonia Kefi*, Vishwesha Guttal*, William A Brock, Stephen R Carpenter, Aaron M Ellison, Valerie N Livina, David A Seekel, Marten Scheffer, Egbert H van Nes, Vasilis Dakos, 2014, Early warning signals of ecological transitions: Methods for spatial patterns, PLoS ONE 9(3): e92097. doi:10.1371/journal.pone.0092097 (*These authors contributed equally to this work).(*These authors contributed equally to this work).
[6] Vishwesha Guttal*, C. Jayaprakash*, Omar P. Tabbaa*, 2013, Robustness of early warning signals of regime shifts in time-delayed ecological models, Theoretical Ecology, Online Early (*All authors contributed equally to this manuscript and the names are listed in alphabetical order).
[5] Vasilis Dakos, Stephen R. Carpenter, William A. Brock, Aaron M. Ellison, Vishwesha Guttal, Anthony R. Ives, Sonia Kefi, Valerie Livina, David A. Seekell, Egbert H. van Nes, Marten Scheffer, 2012, Methods for detecting early warnings of critical transitions in time series: Illustrated using simulated ecological data. PLoS ONE. 7(7): e41010. PDF
[4] Vishwesha Guttal, C. Jayaprakash. 2009, Spatial variance and spatial skewness: Leading indicators of regime shifts in spatial ecological systems, Theoretical ecology, 2:3-12.PDF
[3] Vishwesha Guttal, C. Jayaprakash. 2008, Changing Skewness: An early warning signal of regime shifts in ecological systems, Ecology Letters 11:450-460.PDF
Highlight: Faculty of 1000 Biology
[2] Vishwesha Guttal, C Jayaprakash, 2007, “Self-organization and productivity in semi-arid ecosystems: Implications of seasonality in rainfall”, Journal of Theoretical Biology, 248: 490-500. PDF
[1] Vishwesha Guttal, C. Jayaprakash, 2007, “Impact of noise on bistable ecological systems”,Ecological Modelling, 201: 420-428. PDF
Theoretical Ecology and Evolution Laboratory 
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