He graduated from the University of Tartu in 1975. His earlier work dealt with ethology and field ecology. He has studied the mechanisms of species coexistence in species-rich communities and developed mathematical modelling in ecophysiology.
He graduated from the University of Tartu in 1975. His earlier research focused on animal behavior (ethology) and field studies (field ecology). He has investigated the mechanisms underlying species coexistence in diverse communities and developed mathematical models to analyze physiological processes (ecophysiology).