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Majumder A, Adak D, Bairagi N. Persistence and extinction of species in a disease-induced ecological system under environmental stochasticity. Phys Rev E 2021; 103:032412. [PMID: 33862731 DOI: 10.1103/physreve.103.032412] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2020] [Accepted: 03/02/2021] [Indexed: 01/17/2023]
Abstract
Population extinction is a serious issue both from the theoretical and practical points of view. We explore here how environmental noise influences persistence and extinction of interacting species in presence of a pathogen even when the populations remain stable in its deterministic counterpart. Multiplicative white noise is introduced in a deterministic predator-prey-parasite system by randomly perturbing three biologically important parameters. It is revealed that the extinction criterion of species may be satisfied in multiple ways, indicating various routes to extinction, and disease eradication may be possible with the right environmental noise. Predator population cannot survive, even when its focal prey strongly persists if its growth rate is lower than some critical value, measured by half of the corresponding noise intensity. It is shown that the average extinction time of population decreases with increasing noise intensity and the probability distribution of the extinction time follows the log-normal density curve. A case study on red grouse (prey) and fox (predator) interaction in presence of the parasites trichostrongylus tenuis of grouse is presented to demonstrate that the model well fits the field data.
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Affiliation(s)
- Abhijit Majumder
- Centre for Mathematical Biology and Ecology, Department of Mathematics, Jadavpur University, Kolkata 700032, India
| | - Debadatta Adak
- Department of Applied Mathematics, Maharaja Bir Bikram University, Agartala, Tripura 799004, India
| | - Nandadulal Bairagi
- Centre for Mathematical Biology and Ecology, Department of Mathematics, Jadavpur University, Kolkata 700032, India
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2
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Exploring resilience with agent-based models: State of the art, knowledge gaps and recommendations for coping with multidimensionality. ECOLOGICAL COMPLEXITY 2019. [DOI: 10.1016/j.ecocom.2018.06.008] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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3
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Tung S, Rajamani M, Joshi A, Dey S. Complex interaction of resource availability, life-history and demography determines the dynamics and stability of stage-structured populations. J Theor Biol 2018; 460:1-12. [PMID: 30300650 DOI: 10.1016/j.jtbi.2018.10.019] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2018] [Revised: 10/04/2018] [Accepted: 10/05/2018] [Indexed: 12/15/2022]
Abstract
The dynamics of stage-structured populations facing stage-specific variability in resource availability and/or demographic factors like unequal sex-ratios, remains poorly understood. We addressed these issues using a stage-structured individual-based model that incorporates life-history parameters common to many holometabolous insects. The model was calibrated using time series data from a 49-generation experiment on laboratory populations of Drosophila melanogaster, subjected to four different combinations of larval and adult nutritional levels. The model was able to capture multiple qualitative and quantitative aspects of the empirical time series across three independent studies. We then simulated the model to explore the interaction of various life-history parameters and nutritional levels in determining population stability. In all nutritional regimes, constancy stability of the populations was reduced upon increasing egg-hatchability, critical mass, and proportion of body resource allocated to female fecundity. However, the effects of increasing sensitivity of female-fecundity to adult density on constancy stability varied across nutrition regimes. The effects of unequal sex-ratio and sex-specific culling were greatly influenced by fecundity but not by levels of juvenile nutrition. Finally, we investigated the implications of some of these insights on the efficiency of the widely-used pest control method, the Sterile Insect Technique (SIT). We show that increasing the amount of juvenile food had no effects on SIT efficiency when the density-independent fecundity is low, but reduces SIT efficiency when the density-independent fecundity is high.
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Affiliation(s)
- Sudipta Tung
- Population Biology Laboratory, Biology Division, Indian Institute of Science Education and Research (IISER), Dr. Homi Bhabha Road, Pune 411 008, India
| | - M Rajamani
- Evolutionary Biology Laboratory, Evolutionary and Organismal Biology Unit, Jawaharlal Nehru Centre for Advanced Scientific Research, Jakkur P.O., Bengaluru 560 064, India
| | - Amitabh Joshi
- Evolutionary Biology Laboratory, Evolutionary and Organismal Biology Unit, Jawaharlal Nehru Centre for Advanced Scientific Research, Jakkur P.O., Bengaluru 560 064, India
| | - Sutirth Dey
- Population Biology Laboratory, Biology Division, Indian Institute of Science Education and Research (IISER), Dr. Homi Bhabha Road, Pune 411 008, India.
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Ovaskainen O. The Interplay between Immigration and Local Population Dynamics in Metapopulations. ANN ZOOL FENN 2017. [DOI: 10.5735/086.054.0111] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Affiliation(s)
- Otso Ovaskainen
- Department of Biosciences, P.O. Box 65, FI-00014 University of Helsinki, Finland (otso. ); and Centre for Biodiversity Dynamics, Department of Biology, Norwegian University of Science and Technology, N-7491 Trondheim, Norway
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Singer A, Frank K. Viability of cyclic populations. Ecology 2016; 97:3143-3153. [PMID: 27870022 DOI: 10.1002/ecy.1564] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/22/2016] [Revised: 06/13/2016] [Accepted: 08/05/2016] [Indexed: 11/05/2022]
Abstract
Theory on viability of small populations is well developed and has led to the standard methodology of population viability analysis (PVA) to assess vulnerability of single species. However, more complex situations involving community dynamics or environmental change violate theoretical assumptions. Synthesizing concepts from population, community, and conservation ecology, we develop a generic theory on the viability of cyclic populations. The interplay of periodic population decline and demography causes varying risk patterns that aggregate during cycles and modify the temporal structure of viability. This variability is visualized and quantitatively assessed. For two standard viability metrics that summarize immediate extinction risk and the general long-term conditions of populations, we mathematically describe the impact of population cycles. Finally, we suggest and demonstrate PVA for cyclic populations that respond to, e.g., seasonality, interannual variation, or trophic interactions. Our theoretical and methodological advancement opens a route to viability analysis in food webs and trophic meta-communities and equips biodiversity conservation with a long-missing tool.
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Affiliation(s)
- Alexander Singer
- Department of Ecological Modelling, Helmholtz-Centre for Environmental Research-UFZ, Permoserstrasse 15, D-04318, Leipzig, Germany.,German Centre for Integrative Biodiversity Research (iDiv) Halle-Jena-Leipzig, Deutscher Platz 5e, D-04103, Leipzig, Germany
| | - Karin Frank
- Department of Ecological Modelling, Helmholtz-Centre for Environmental Research-UFZ, Permoserstrasse 15, D-04318, Leipzig, Germany.,German Centre for Integrative Biodiversity Research (iDiv) Halle-Jena-Leipzig, Deutscher Platz 5e, D-04103, Leipzig, Germany.,Institute for Environmental Systems Research, University of Osnabrück, Barbarastrasse 12, D-49076, Osnabrück, Germany
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Tung S, Mishra A, Dey S. Simultaneous enhancement of multiple stability properties using two-parameter control methods in Drosophila melanogaster. ECOLOGICAL COMPLEXITY 2016. [DOI: 10.1016/j.ecocom.2016.05.001] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Be'er S, Assaf M, Meerson B. Colonization of a territory by a stochastic population under a strong Allee effect and a low immigration pressure. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2015; 91:062126. [PMID: 26172680 DOI: 10.1103/physreve.91.062126] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/01/2015] [Indexed: 06/04/2023]
Abstract
We study the dynamics of colonization of a territory by a stochastic population at low immigration pressure. We assume a sufficiently strong Allee effect that introduces, in deterministic theory, a large critical population size for colonization. At low immigration rates, the average precolonization population size is small, thus invalidating the WKB approximation to the master equation. We circumvent this difficulty by deriving an exact zero-flux solution of the master equation and matching it with an approximate nonzero-flux solution of the pertinent Fokker-Planck equation in a small region around the critical population size. This procedure provides an accurate evaluation of the quasistationary probability distribution of population sizes in the precolonization state and of the mean time to colonization, for a wide range of immigration rates. At sufficiently high immigration rates our results agree with WKB results obtained previously. At low immigration rates the results can be very different.
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Affiliation(s)
- Shay Be'er
- Racah Institute of Physics, Hebrew University of Jerusalem, Jerusalem 91904, Israel
| | - Michael Assaf
- Racah Institute of Physics, Hebrew University of Jerusalem, Jerusalem 91904, Israel
| | - Baruch Meerson
- Racah Institute of Physics, Hebrew University of Jerusalem, Jerusalem 91904, Israel
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Tung S, Mishra A, Dey S. A comparison of six methods for stabilizing population dynamics. J Theor Biol 2014; 356:163-73. [PMID: 24801858 DOI: 10.1016/j.jtbi.2014.04.036] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2013] [Revised: 04/25/2014] [Accepted: 04/28/2014] [Indexed: 11/17/2022]
Abstract
Over the last two decades, several methods have been proposed for stabilizing the dynamics of biological populations. However, these methods have typically been evaluated using different population dynamics models and in the context of very different concepts of stability, which makes it difficult to compare their relative efficiencies. Moreover, since the dynamics of populations are dependent on the life-history of the species and its environment, it is conceivable that the stabilizing effects of control methods would also be affected by such factors, a complication that has typically not been investigated. In this study, we compare six different control methods with respect to their efficiency at inducing a common level of enhancement (defined as 50% increase) for two kinds of stability (constancy and persistence) under four different life-history/environment combinations. Since these methods have been analytically studied elsewhere, we concentrate on an intuitive understanding of realistic simulations incorporating noise, extinction probability and lattice effect. We show that for these six methods, even when the magnitude of stabilization attained is the same, other aspects of the dynamics like population size distribution can be very different. Consequently, correlated aspects of stability, like the amount of persistence for a given degree of constancy stability (and vice versa) or the corresponding effective population size (a measure of resistance to genetic drift) vary widely among the methods. Moreover, the number of organisms needed to be added or removed to attain similar levels of stabilization also varies for these methods, a fact that has economic implications. Finally, we compare the relative efficiencies of these methods through a composite index of various stability related measures. Our results suggest that Lower Limiter Control (LLC) seems to be the optimal method under most conditions, with the recently proposed Adaptive Limiter Control (ALC) being a close second.
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Affiliation(s)
- Sudipta Tung
- Population Biology Laboratory, Biology Division, Indian Institute of Science Education and Research-Pune, Dr. Homi Bhabha Road, Pune, Maharashtra 411008, India.
| | - Abhishek Mishra
- Population Biology Laboratory, Biology Division, Indian Institute of Science Education and Research-Pune, Dr. Homi Bhabha Road, Pune, Maharashtra 411008, India.
| | - Sutirth Dey
- Population Biology Laboratory, Biology Division, Indian Institute of Science Education and Research-Pune, Dr. Homi Bhabha Road, Pune, Maharashtra 411008, India.
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Sah P, Dey S. Stabilizing spatially-structured populations through adaptive Limiter Control. PLoS One 2014; 9:e105861. [PMID: 25153073 PMCID: PMC4143321 DOI: 10.1371/journal.pone.0105861] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2013] [Accepted: 07/29/2014] [Indexed: 11/19/2022] Open
Abstract
Stabilizing the dynamics of complex, non-linear systems is a major concern across several scientific disciplines including ecology and conservation biology. Unfortunately, most methods proposed to reduce the fluctuations in chaotic systems are not applicable to real, biological populations. This is because such methods typically require detailed knowledge of system specific parameters and the ability to manipulate them in real time; conditions often not met by most real populations. Moreover, real populations are often noisy and extinction-prone, which can sometimes render such methods ineffective. Here, we investigate a control strategy, which works by perturbing the population size, and is robust to reasonable amounts of noise and extinction probability. This strategy, called the Adaptive Limiter Control (ALC), has been previously shown to increase constancy and persistence of laboratory populations and metapopulations of Drosophila melanogaster. Here, we present a detailed numerical investigation of the effects of ALC on the fluctuations and persistence of metapopulations. We show that at high migration rates, application of ALC does not require a priori information about the population growth rates. We also show that ALC can stabilize metapopulations even when applied to as low as one-tenth of the total number of subpopulations. Moreover, ALC is effective even when the subpopulations have high extinction rates: conditions under which another control algorithm had previously failed to attain stability. Importantly, ALC not only reduces the fluctuation in metapopulation sizes, but also the global extinction probability. Finally, the method is robust to moderate levels of noise in the dynamics and the carrying capacity of the environment. These results, coupled with our earlier empirical findings, establish ALC to be a strong candidate for stabilizing real biological metapopulations.
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Affiliation(s)
- Pratha Sah
- Population Biology Laboratory, Biology Division, Indian Institute of Science Education and Research-Pune, Pashan, Pune, Maharashtra, India
| | - Sutirth Dey
- Population Biology Laboratory, Biology Division, Indian Institute of Science Education and Research-Pune, Pashan, Pune, Maharashtra, India
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Dey S, Goswami B, Joshi A. Effects of symmetric and asymmetric dispersal on the dynamics of heterogeneous metapopulations: Two-patch systems revisited. J Theor Biol 2014; 345:52-60. [DOI: 10.1016/j.jtbi.2013.12.005] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2013] [Revised: 12/02/2013] [Accepted: 12/03/2013] [Indexed: 11/24/2022]
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Adaptive limiter control of unimodal population maps. J Theor Biol 2013; 337:161-73. [PMID: 23988794 DOI: 10.1016/j.jtbi.2013.08.018] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2013] [Revised: 08/14/2013] [Accepted: 08/19/2013] [Indexed: 11/22/2022]
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