Poorter, H. [P:(DE-Juel1)129384] ; Niklas, K.J. [P:(DE-HGF)0] ; Reich, P.B. [P:(DE-HGF)0] ; Oleksyn, J. [P:(DE-HGF)0] ; Poot, P. [P:(DE-HGF)0] ; Mommer, L. [P:(DE-HGF)0]