Effects of warming on the phytoplankton succession and trophic interactions Dissertation in fulfilment of the requirements for the degree “Dr. rer. nat.” of the Faculty of Mathematics and Natural Sciences at Kiel University submitted by Aleksandra Magdalena Lewandowska Kiel, 2011 First referee: Prof. Dr. Ulrich Sommer Second referee: Prof. Dr. Helmut Hillebrand Date of the oral examination: 18.03.2011 Approved for publication: 18.03.2011 Signed: Prof. Dr. Lutz Kipp, Dean Here are things known, and there are things unknown, and in between are the doors Jim Morrison Table of contents CONTENTS SUMMARY .................................................................................................................................... ‐ 3 ‐ ZUSAMMENFASSUNG ................................................................................................................... ‐ 5 ‐ GENERAL INTRODUCTION ............................................................................................................ ‐ 9 ‐ Phytoplankton responses to the recent climate warming ....................................................... ‐ 9 ‐ Trophic reorganisation of the pelagic ecosystem in response to warming ........................... ‐ 11 ‐ Phytoplankton drivers other than temperature increase ...................................................... ‐ 12 ‐ AIM OF THE STUDY .................................