Interplay between exogenous and endogenous factors in seasonal vegetation oscillations.

ABSTRACT: A fundamental question in ecology is whether vegetation oscillations are merely a result of periodic environmental variability, or rather driven by endogenous factors. We address this question using a mathematical model of dryland vegetation subjected to annual rainfall periodicity. We show that while spontaneous oscillations do not exist in realistic parameter ranges, resonant response to periodic precipitation is still possible due to the existence of damped oscillatory modes. Using multiple time-scale analysis, in a restricted parameter range, we find that these endogenous modes can be pumped by the exogenous precipitation forcing to form sustained oscillations. The oscillations amplitude shows a resonance peak that depends on model parameters representing species traits and mean annual

SUBMITTER: Tzuk O 

PROVIDER: S-EPMC6344492 | biostudies-literature | 2019 Jan

REPOSITORIES: biostudies-literature