Cornell University

Regents Professor Emeritus, University of Arizona

Department of Geography, University of Mainz

Director and Professor; Laboratory of Tree-Ring Research, Univ. Arizona

University of Geneva

Regents' Professor of Dendrochronology, University of Arizona

Professor of Plant Ecology and Dedrochronology

Institute of Plant and Animal Ecology, Ural Branch of the Russian Academy of Sciences

Pennsylvania State University

Gondwana Tree Ring Lab