5Tuskan G A, Rensema T R. Clonal differences in biomass characteristics, coppice ability, and biomass prediction equations among four Populus clones grown in eastern North Dakota [ J ]. Canadian Journal of Forest Research, 1992,22( 3 ) :348-354.
6Chambers P G S, Borralho N M G. Importance of survival in shortrotation tree breeding programs[ J]. Canadian Journal of Forest Researoh, 1997,27 (6) :911-917.
7Ceulemans R, Deraedt W. Production physiology and growth potential of poplars under short-rotation forestry culture[ J]. Forest Ecology and Management, 1999,121:9-23.