In planting lodgepole pine in British Columbia three major problems have been encountered. They are:
(1) significant mortality shortly after outplanting;
(2) planting check; and
(3) mechanical instability which, in trees over one metre in height, may lead to toppling and the formation of a basal sweep.
All of these problems are attributable, at least in part, to the failure of affected trees to put out a well distributed system of new roots early on. Such failure can be due to a number of factors of which an unfavourable planting site, improper planting, and the mishandling of stock between the time it leaves the nursery and the time that it is planted are likely to be amongst the most significant. However, the use of stock in which the capacity for root growth is severely limited due to inherent causes can also be a factor of great importance.
Evidence of this was provided by an experiment in, which measurements were made of the amount of new root formed by seedlings from 14 batches of lodgepole pine bare root stock (differing with respect to stock type, seed lot, nursery of origin, lifting date, overwintering conditions and cultural treatments) in the course of a 4 week period during which they were grown in a temperature controlled greenhouse under conditions highly favorable to root growth.
Great variation was observed. Sample mean root growth potentials varied over a more than 3-fold range and variation. within samples was even greater. In every sample there were seedlings with a very high root growth capacity (producing 2 to 20 metres or more of new roots during the assay) and others which made little root growth or none at all.
Thus,merely by virtue of differences between them in root growth potential, one seedling may have an excellent chance of surviving, making good top growth, and achieving a firm anchorage even on a difficult site; while another has little prospect of performing satisfactorily under any circumstances.
This experiment gave no definite indication as to why Some seedlings have such a limited capacity for root growth. However, the results of other experiments strongly suggest that root damage during lifting from densely stocked beds is often responsible.
BC Forest Service - Research Division. 9999. Low root growth capacity in bare root lodgepole pine associated with the absence of fibrous roots. British Columbia Ministry of Forests, Lands, Natural Resource Operations and Rural Development. Research Memo (FLNRORD). RM-B
Topic: FLNRORD Research Program
Keywords: FLNRORD, Research Memo, British Columbia
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