Genomic selection of juvenile height across a single-generational gap in Douglas-fir

Developmental decline in height growth in Douglas-fir.

The characteristic decline in height growth that occurs over a tree's lifespan is often called "age-related decline." But is the reduction in height growth in aging trees a function of age or of size? We grafted shoot tips across different ages and sizes of Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) trees to determine whether the decline in height growth is mediated by tree size or by t...

Douglas-fir beetle

1Principal Entomologist and Project Leader (retired), Forestry Sciences Laboratory, USDA Forest Service, Moscow, ID; 2Forest Entomologist, USDA Forest Service, Forest Health Protection, Northern Region, Coeur d’Alene, ID. Douglas-fir beetle galleries are distinctive, having eggs laid individually in niches alternating on opposite sides of the gallery. The Douglas-fir beetle (Dendroctonus pseudo...

Growth of Young Douglas-Fir Plantations Across a Gradient in Swiss Needle Cast Severity

During the past decade, Swiss needle cast (SNC) damage has intensified in many Douglas-fir plantations in the Coast Range of Oregon, particularly along the immediate north coast. In plantations with severe symptoms, growth losses and reduced tree vigor are evident, but the magnitude of growth losses associated with varying intensities of damage is not known. A growth impact study was conducted ...

Growth of Young Douglas-Fir Plantations Across a Gradient of Swiss Needle Cast Severity

During the past decade, Swiss needle cast (SNC) damage has intensified in many Douglas-fir plantations in the Coast Range of Oregon, particularly along the immediate north coast. In plantations with severe symptoms, growth losses and reduced tree vigor are evident, but the magnitude of growth losses associated with varying intensities of damage is not known. A growth impact study was conducted ...

A flavonone from Douglas-fir heartwood.