A pioneer exotic tree search for the douglas fir region

After three-quarters of a century of introduction of 152 conifer and broadleaf species, no promising candidate exotic was found for the Douglas-fir region. Growth curves spanning 50 years or longer are figured for many species. Firs, pines, larches, spruces, hemlocks, and cedars originating in northwestern North America had superior growth rates to those from other forest regions. The probable basis for these differences is discussed. The record highlights a general failure of introduced hardwoods, the slow decline of most introduced conifers, the long time needed to express failures, dramatic effects of climatic extremes or of introduced pests, failure of native species of continental origin at Wind River, striking similarities of growth rates for the species originating in each country, and many important contrasts between results from early reports and long-term conclusions.Keywords: Plant introduction, forest genetics, arboreta, conifers, silviculture, growth curves, exotics, seed movement, introduced pests, climatic extremes

A CLINAL model of tree improvement proposed for Douglas-fir

Keywords: Douglas-fir CLINAL mode

The Wind River Arboretum, 1912-1956 /

no.3

Characteristics of low-speed vehicle run-over events in children: An 11-year review

Objectives The purpose of this study was to investigate the characteristics associated with fatal and non-fatal low-speed vehicle run-over (LSVRO) events in relation to person, incident and injury characteristics, in order to identify appropriate points for intervention and injury prevention