Mathematical model reveals how extinctions create stable ecosystems
Researchers have developed a formula predicting how many species can coexist when competing for shared resources—and how many will vanish during environmental shocks. The finding could reshape conservation strategies and help businesses anticipate ecological risks in supply chains dependent on biodiversity.
Originaltitel: Biodiversity, extinctions, and evolution of ecosystems with shared resources
<p>We investigate the formation of stable ecological networks where many species share the same resource. We show that such a stable ecosystem naturally occurs as a result of extinctions. We obtain an analytical relation for the number of coexisting species, and we find a relation describing how many species that may become extinct as a result of a sharp environmental change. We introduce a special parameter that is a combination of species traits and resource characteristics used in the model formulation. This parameter describes the pressure on the system to converge, by extinctions. When that stress parameter is large, we obtain that the species traits are concentrated at certain values. This stress parameter is thereby a parameter that determines the level of final biodiversity of the system. Moreover, we show that the dynamics of this limit system can be described by simple differential equations.</p>