The effectiveness of plus-tree selection for yield

Amsterdam

Elsevier

1994

23-34

Sonderdruck

203838

Forest Ecology and Management ; Jrg. 67 (1994) , 23-34

In response to recent suggestions in the literature that plus-tree selction for yield in forest trees might in general be ineffective, the empirical information contained in 24 published reports was examined. It was found that progeny of plus-trees selcted for yield traits tend to be faster frwoing than their controls. It is argued that this observed tendency is likely to be due at least in part to a response to selection. The reported values indicate that genetic gains of up to 15% in height and diameter growth, and up to 35% in volume per unit area, can readily be achieved through plus-tree selction. This is consistent with theoretical expectations. However, it should be emphasised that the amount of gain from any particular plus-tree selction system depends on the values of the parameters that determine the response to selection (selection intensity, genetic variance, heritability). In unfavourable situations, gain could be close to zero.
Keywords: Genetic gain; Competition, Phenotypic selection