Richter A., Nock C. A., Wright S. J. 2011. Long-term change in the nitrogen cycle in tropical forests [...] W., Leis A., Grabner M. and hietz P. 2011. Long-term increases in intrinsic water use efficiency do not [...] 391-399. hietz P., Wanek W., Dünisch O. 2005 Long-term trends in cellulose δ13C and water use efficiency