Picea sitchensis


Since no systematic study of Sitka spruce second growth has been made, it can only be predicted from knowledge of its habits that while in favorable situation it will yield as heavily as Douglas fir, in other localities its growth in early life is slower and less regular, making it less likely to produce a good crop before the carrying charges become burdensome. If this proves true, taxation rates and land values will be extremely important factors, offset to some degree by a smaller fire hazard and the probability of high stumpage.

Sitka Spruce (Picea sitchensis )

Although found in the moister mountain regions, this exceedingly valuable tree seldom occurs to a commercially important extent except along the coast, where it is common on swales and fertile benches and in river bottoms often forms pure stands of great density. Yields of 100,000 feet an acre are not unusual and the trees are very large. It is also common, although of small size, in swamps.

This spruce reproduces readily in openings, whether made by fire or cutting. Unthrifty specimens may be found under shade, but considerable light is necessary for successful development. Even then, height growth in youth averages slower than that of fir or hemlock. The leader shoot is likely to die, so that hardly more than 25 per cent of the young trees establish a regular form of growth before a height of 20 or 30 feet is reached. After this stage spruce grows uniformly and rapidly, still somewhat slower than fir in height but exceeding it in diameter. The branches are slow to die, however, so that the tree remains bushy for most of its length until it reaches 60 or 80 feet in height, and even afterward a dense stand is required to clear it. In many pure spruce forests the larger trees have been able to withstand the pruning influences and remain limby, while the smaller ones, being pushed in height growth to reach sufficient light for survival, have cleared themselves with remarkable rapidity.

The natural occurrence of Sitka spruce, except in Alaska, is probably limited chiefly to situations where it escapes competition, in youth at least, with the more hardy and rapid-growing species. It has the greatest advantage over these on river bottoms and flats where there is a dense growth of deciduous brush and where the soil is very wet in spring. In considering it as a possible second crop, the same competition must be remembered. Whether seeding is natural or artificial, the extent to which it will hold its own with any considerable quantity of other species is doubtful. If such are present and the situation is adapted to them, any expensive effort to get spruce merely by modifying methods of logging or handling the slash is certainly likely to be disappointing. Under the conditions mentioned as peculiarly favorable for spruce, gradual natural restocking may be expected if some seed supply is preserved, but since the growth is rather slow and a thin stand will remain limby, it may pay to hasten returns by supplementary artificial planting. Some authorities question the financial practicability of this on the ground that since spruce is of slower growth it will pay better to use the ground for fir, but the latter is unlikely to be true of bottom land.

After summing all its advantages, the peculiar merits of spruce for certain purposes should be weighed, for sufficiently higher stumpage value will compensate for delay in harvesting the crop. Moreover, Sitka spruce has not been as thoroughly studied by foresters as the more prominent Western trees, and while the foregoing notes represent general present opinion, further figures on rate of height growth may be more encouraging. There is no doubt that diameter increase is rapid from the start. Most of the disadvantages mentioned also decrease toward the southern limit of the spruce range, the growth on the Oregon Coast being rapid.