Douglas-fir (Pseudotsuga menziesii) has a wide distribution in North America and is one of the
tree species most widely distributed outside its natural range. The species has been introduced to
Europe, New Zealand, South America, and elsewhere around the world. At present, Douglas-fir
is an accepted and integral part of...
Douglas-fir (Pseudotsuga menziesii) has a wide distribution in North America and is one of the
tree species most widely distributed outside its natural range. The species has been introduced to
Europe, New Zealand, South America, and elsewhere around the world. At present, Douglas-fir
is an accepted and integral part of...
Douglas-fir (Pseudotsuga menziesii) has a wide distribution in North America and is one of the tree species most widely distributed outside its natural range. The species has been introduced to Europe, New Zealand, South America, and elsewhere around the world. At present, Douglas-fir is an accepted and integral part of...
Perennial woody plants have a complex annual cycle keyed to the environment. Temperate plants have an annual dormant period commonly broken by exposure to low temperatures, although daily photoperiods of 16 hours or longer may partially substitute for the chilling. Shoot growth in the spring is normally stimulated by rising...
Results reported here are from a large study designed to evaluate the effects of certain nursery procedures on subsequent survival of Douglas-fir seedlings. The effects of storage conditions and lifting dates were reported elsewhere (9). The determination of the optimum size of seedling for planting on different sites has been...
Reforestation sometimes is delayed by planting seedlings that do not have high potential for survival. Several factors influence survival. Unstored Douglas-fir lifted and planted in early fall generally are increasingly harmed by moisture stress the farther south in the Douglas-fir region they are. Such early-lifted seedlings are harmed even more...
Although the Douglas-fir region of the northwestern United States and British Columbia is frequently considered to have a common silviculture, obstacles to successful regeneration of the species range from competing vegetation and mammals on the mesic sites to extreme drought and heat on the xeric southerly exposures in northern California...
The effects of a range of thermoperiods and soil temperatures upon growth of Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) seedlings were studied. The seeds, of varieties glauca and menziesii, came from eight widely separated areas. Plants from both varieties made maximum growth with soil and air temperatures between 18 and 24...
"We describe a test procedure developed during growth room and field trials for which we processed hundreds of test lots of seedlings, mainly Douglas-fir (Pseudotsuga menziesii) and ponderosa pine (Pinus ponderosa), as well as lodgepole pine (Pinus contorta), Jeffrey pine (Pinus jeffreyi), and Sitka spruce (Picea sitchensis), noble fir (Abies...