Quantitative Life Sciences Guest Seminar - Tue. 2 May at 17:00

[QLS]

*Quantitative Life Sciences Guest Seminar *

Tuesday 2 May at 17:00
ICTP, Central Area, 2nd floor, old SISSA building, Via Beirut

Title: "Higher-order interactions stabilize the dynamics of ecological 
communities"

Speaker: Jacopo Grilli, Department of Ecology and Evolution University 
of Chicago, USA

Abstract:
The difficulty of reconciling the staggering biodiversity found in 
tropical rainforests with classical theories of resource partitioning 
has led ecologists to explore neutral theories of coexistence, in which 
all species are assumed to have the same physiological parameters, and 
variations in species abundance arise from stochastic fluctuations. 
Simple neutral models have led to much progress, for example to the 
investigation of spatial and temporal ecological patterns and to the 
formulation of sampling models that allow contrasting theory and data. 
However, the high sensitivity of neutral models to slight perturbations 
of the parameters and the prediction of a strong correlation between a 
species’ abundance and its age are considered problematic. Here we 
propose a theory of coexistence in which all species have different 
physiological rates, and interact with each other through a network of 
competitive interactions. We show that our models produce robust 
coexistence of many species even when parameters are drawn at random. 
Importantly, the dynamical stability of our models is due to 
higher-order interactions — interactions involving more than two species 
at a time. The existence of higher-order interactions has been debated 
in ecology for decades, but their role in shaping ecological communities 
is still understudied. Our results show that higher-order interactions 
can have dramatic effects on the dynamics of ecological systems. When 
set in a stochastic framework, we recover many results from neutral 
theory but improve on the relationship between age and abundance.

Web page: http://indico.ictp.it/event/8222/


You are all most welcome to attend!

-- 
Erica Sarnataro
Group Secretary
Quantitative Life Sciences
The Abdus Salam International Centre for Theoretical Physics (ICTP)
Trieste,  Italy
Tel. +39-040-2240623
e-mail:qls at ictp.it