Watch recorded past seminars on our YouTube channel:
https://www.youtube.com/channel/UCLMcVHn2ZuvzhLOGqPczFMg

Éva Kisdi (University of Helsinki): The evolution of habitat choice facilitates niche expansion

Abstract: Matching habitat choice and local adaptation are two key factors that control the distribution and diversification of species. We study their joint evolution in a structured metapopulation model with a continuous distribution of habitats. Habitat choice follows from dispersal with non-random immigration, a process always acknowledged yet rarely incorporated into theoretical models. For fixed …

Éva Kisdi (University of Helsinki): The evolution of habitat choice facilitates niche expansion Read More »

Vadim Karatayev (University of Guelph): Species heterogeneity can reduce the potential for alternative stable states in food webs

Abstract. Can alternative stable states arise when food webs dissipate feedbacks across many species in diverse systems like coral reefs? Although consumer loss often characterizes degraded ecological states, food web resilience theory predominantly focuses on specific systems and few-species models. After developing a generalized model of consumer collapse, we show that alternative stable states dominated …

Vadim Karatayev (University of Guelph): Species heterogeneity can reduce the potential for alternative stable states in food webs Read More »

André M. de Roos (University of Amsterdam): Dynamics of within-population structure stabilise complex ecological communities

Warning! During this week the time difference between America and Europe is one hour less, than usual. The seminar will begin at 9 am Pacific, as always, but now it will correspond to 4 pm in London and 5 pm in Paris. Abstract: Dynamic models of ecological communities that neglect within-population structure predict that stability …

André M. de Roos (University of Amsterdam): Dynamics of within-population structure stabilise complex ecological communities Read More »

Sebastian Schreiber (UC Davis): Towards a general theory of coexistence: Lyapunov exponents, auxiliary variables, and Hofbauer’s criterion

Warning: this is a Monday! Abstract: In the 1980s, Josef Hofbauer introduced a criterion for mathematically verifying coexistence using per-capita growth rates of species when rare i.e. Lyapunov exponents. This criterion ensures coexistence is robust to large perturbations of the community state (i.e. permanence) and small structural perturbations of the governing equations (i.e. robust permanence). …

Sebastian Schreiber (UC Davis): Towards a general theory of coexistence: Lyapunov exponents, auxiliary variables, and Hofbauer’s criterion Read More »

Stefano Allesina (University of Chicago): A metapopulation model in which patches have memory

Levins' metapopulation model has been extended in numerous ways. Here we analyze a model in which species have distinct colonization rates that depend on which species previously occupied the patch. We connect this model to the Janzen-Connell hypothesis and show some surprising behavior for a simplified version of the model. Zoom link: https://liu-se.zoom.us/j/63158449287 eventbrite link …

Stefano Allesina (University of Chicago): A metapopulation model in which patches have memory Read More »

Nadav Shnerb (Bar-Ilan University): Quantifying coexistence

Abstract. Modern coexistence theory employs mutual invasibility as a coexistence criterion and mean growth rate when rare as an invasibility criterion. When implemented as quantitative metrics, both criteria have shortcomings: persistence time may decline when the chance of invasion grows, and invasibility may decrease as the mean growth rate increases in magnitude. I will discuss …

Nadav Shnerb (Bar-Ilan University): Quantifying coexistence Read More »

Camille Carpentier (University of Namur): A new link-species relationship connects ecosystem structure and stability

Abstract: How does an ecosystem's structure determine its capacity to cope with species removal and perturbations of species densities? To answer this question, we develop a network-specific approach to the link-species relationship, and demonstrate that it formally predicts a robustness-resilience trade-off, both theoretically and in empirical networks. Zoom link: https://liu-se.zoom.us/j/63158449287 eventbrite link (for reminders): https://www.eventbrite.co.uk/e/theoretical-ecology-seminar-series-tickets-119884512805

Stephen Ellner (Cornell): An invitation to spatial coexistence theory

Stephen Ellner (Cornell), Peter Adler (Utah State), Giles Hooker (Cornell), Robin Snyder (Case Western): An invitation to spatial coexistence theory. Abstract: Previously in this series Sebastian Schreiber reviewed stochastic coexistence theory for infinite population models, based on long-term population growth rates of (infinitesimally) rare invaders. Nadav Shnerb presented progress on the challenges posed by demographic …

Stephen Ellner (Cornell): An invitation to spatial coexistence theory Read More »

Thomas Koffel (Michigan State): A niche theory of positive interactions

Abstract: Niche Theory has traditionally focused on competitive interactions. In this talk, we propose a general framework that expands the theory to positive interactions, such as facilitation and mutualism, using angular metrics of niche difference. We develop novel niche concepts such as the Allee niche and niche expansion, and illustrate them using a diverse set …

Thomas Koffel (Michigan State): A niche theory of positive interactions Read More »

James O’Dwyer (University of Illinois): Cooperation, Resource Exchange, and Stability

Abstract: Models of microbial interactions have been developed in recent years, drawing from taxonomic abundances via amplicon sequencing. Many of these models assume that dynamics through time are primarily driven by pairwise interactions between taxa, but with the drawback that how these interaction strengths may change with environmental context is less than clear. Here we …

James O’Dwyer (University of Illinois): Cooperation, Resource Exchange, and Stability Read More »

Géza Meszéna (Eötvös University): Coexistence, niche, adaptation and all that…

Abstract: Why are there so many animals? According an old idea, it is because there are so many different possibilities for life to adapt to. I’ll argue that it is still true, and truer than the suggested alternatives. The challenge is to establish the precise mathematical treatment at this level of generality without losing the …

Géza Meszéna (Eötvös University): Coexistence, niche, adaptation and all that… Read More »

Theresa Ong (Dartmouth College): Complex hysteretic patterns: hidden loops and ecological traps

NOTE: Because of the asynchronous transition to Summer Time, the usual time of the seminar (9 a.m. Pacific) is one hour earlier in Europe: 4 p.m. London and 5 p.m. Paris. Abstract: Critical transitions whereby small changes in conditions can cause large and irreversible changes in ecosystem states are a cause of increasing concern in …

Theresa Ong (Dartmouth College): Complex hysteretic patterns: hidden loops and ecological traps Read More »

György Barabás (Linköping): Coexistence and parameter sensitivity in stationary aperiodic environments

Abstract: First, I present a method for calculating how average population densities respond to parameter perturbations when the dynamics are periodic, and show that this practical problem holds a strong connection with basic questions of coexistence. I then generalize this result to stationary nonperiodic density fluctuations. I finish by discussing the connection with existing formalisms …

György Barabás (Linköping): Coexistence and parameter sensitivity in stationary aperiodic environments Read More »

Priyanga Amarasekare (UCLA): Predicting the effects of climate warming: from chemistry to evolution

Abstract I want to make the argument that understanding life on earth requires developing theory that integrates across levels of information, from chemistry to evolution. I am going to focus on temperature variation and phenotypic plasticity, not least because temperature is integral to all life processes, and climate warming poses one of the greatest threats …

Priyanga Amarasekare (UCLA): Predicting the effects of climate warming: from chemistry to evolution Read More »

Masato Yamamichi (The University of Queensland): How does rapid evolution promote species coexistence?

Note: The event takes place 3 hours earlier than usual, because of the location of our lecturer. He will speak at midnight, local time, even in this way. Abstract: Previous studies have revealed that microevolution (i.e., temporal changes in allele frequencies) is pervasive in the wild and may be an important factor for understanding various …

Masato Yamamichi (The University of Queensland): How does rapid evolution promote species coexistence? Read More »

Cinzia Soresina (University of Graz): The influence of cross-diffusion in pattern formation: multistability and Hopf bifurcations

Abstract The Shigesada-Kawasaki-Teramoto model (SKT) was proposed to account for stable inhomogeneous steady states exhibiting spatial segregation, which describes a situation of coexistence of two competing species. Even though the reaction part does not present the activator-inhibitor structure, the cross-diffusion terms are the key ingredient for the appearance of spatial patterns. We provide a deeper …

Cinzia Soresina (University of Graz): The influence of cross-diffusion in pattern formation: multistability and Hopf bifurcations Read More »

Chuliang Song (McGill University): An environment-dependent framework to study ecological networks

Abstract: Ecological networks—how species interactions are organized within ecological communities—are highly structured, which has motivated generations of ecologists to elucidate how these structures affect species coexistence. Unfortunately, we still do not have a clear and consistent answer about the link between network structure and species coexistence. A possible explanation is that most of the studies …

Chuliang Song (McGill University): An environment-dependent framework to study ecological networks Read More »

Neo Martinez (Indiana University): Predicting Ecosystem Phenotype from Community Genotype: Can Allometric Trophic Network Theory Help Meet the Challenge?

Abstract: Theoretical ecology has investigated a series of concepts from stability and complexity through biodiversity and ecosystem function to coexistence and tipping points for which empirical data typically plays a less-than-satisfying role. To coax theoretical ecology towards increased empirical relevance and broader scientific synthesis, I propose that environmental biologists focus on predicting key characteristics of …

Neo Martinez (Indiana University): Predicting Ecosystem Phenotype from Community Genotype: Can Allometric Trophic Network Theory Help Meet the Challenge? Read More »

Rafael D’Andrea (Stony Brook University): Counting niches: Can spatial patterns reveal niche partitioning in tropical forests?

Abstract: We investigate the idea that tropical biodiversity is maintained by a combination of niche segregation and niche sharing among species by asking whether tree species in Barro Colorado Island, Panama, fall into groups differing by the local conditions where they typically occur. We first group together species often found near each other, then show …

Rafael D’Andrea (Stony Brook University): Counting niches: Can spatial patterns reveal niche partitioning in tropical forests? Read More »

Jacob D. O’Sullivan (Queen Mary): The emergent macroecology of Lotka-Volterra metacommunities

Abstract: For decades Lotka-Volterra community models have been used to try to understand how ecological interactions may drive community-scale properties such as species richness, network structure, and species abundance distributions; in short the various dimensions of biodiversity. Here I show how extending the basic community models into spatially and environmentally heterogeneous landscapes can help us …

Jacob D. O’Sullivan (Queen Mary): The emergent macroecology of Lotka-Volterra metacommunities Read More »

Watch recorded past seminars on our YouTube channel:
https://www.youtube.com/channel/UCLMcVHn2ZuvzhLOGqPczFMg