Comparisons of phenology and growth of Michigan and western North American sources of Populus tremuloides

Abstract

Populustremuloides Michaux progeny from 13 local clones and 12 clones from five locations in Alaska, Alberta, and Utah were grown in southeastern Michigan to compare phenology and early growth. The progeny of western clones broke bud as much as 2 weeks before, and stopped growth up to 2 months earlier than local clones. After 2 years the western progeny averaged only 26–38% the height of the Michigan progeny. Survival and growth of ramets from 49 clones collected from British Columbia to Colorado and planted in southeastern Michigan were studied after 7 years. Only 30% of the 116 ramets and 39% of the clones survived. The poor performance of western clones in both experiments is probably due to their adaptation to longer photoperiods and (or) lower growing season minimum temperatures than occur in southeastern Michigan.