Funding for this research was provided by:
Bundesministerium für Ernährung und Landwirtschaft
Text and Data Mining valid from 2018-05-14
Received: 11 October 2017
Accepted: 4 April 2018
First Online: 14 May 2018
: The authors declare that they have no competing interests.
: Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.