Larix Laricina - Reaction To Competition

Reaction To Competition

Tamarack is very intolerant of shade. Although it can tolerate some shade during the first several years, it must become dominant to survive. When mixed with other species, it must be in the over story. The tree is a good self-pruner, and boles of 25- to 30-year-old trees may be clear for one-half or two-thirds their length.

Because tamarack is very intolerant, it does not become established in its own shade. Consequently, the more tolerant black spruce eventually succeeds tamarack on poor bog sites, whereas northern white-cedar, balsam fir, and swamp hardwoods succeed tamarack on good swamp sites. Recurring sawfly outbreaks throughout the range of tamarack have probably speeded the usual succession to black spruce or other associates.

Various tests on planting and natural reproduction indicate that competing vegetation hinders tamarack establishment.

The intolerance of tamarack dictates the use of even-aged management. Some adaptation of clear cutting or seed-tree cutting is generally considered the best silvicultural system because tamarack seeds apparently germinate better in the open, and the seedlings require practically full light to survive and grow well. Tamarack is also usually wind firm enough for the seed-tree system to succeed. Satisfactory reestablishment of tamarack, however, often requires some kind of site preparation, such as slash disposal and herbicide spraying.