Treesearch

Shows lumber production by species in three Survey Districts of northern Minnesota and by country for softwoods, aspen, and other hardwoods. Compares lumber production in 1960 with 1965

A pilot study in three northern Minnesota spruce-fir stands showed that as cutting intensity increased, defoliation by the spruce budworm decreased. Commercial clear cutting reduced defoliation most.

Culverts too small in diameter or poorly placed were major causes of timber flooding and tree damage. Placement problems were poor culvert slope, poor hydraulic approach, lack of gravel bedding, and too little soil covering the culverts.

In a plantation of four hardwood species on a silt loam soil planted to 1-0 stock, 4 pounds of active atrazine or simazine controlled weeds effectively without injuring the trees. Chemical weed control was better on plowed and disked ground than on unprepared ground. Yellow-poplar and white ash grew faster on prepared ground. Black walnut and red oak did not respond to ground preparation treatments. Guides are presented for proper use of the chemicals in establishing hardwood plantations.

Springflow and ground water levels both rose with winter thaws, even when the ground was frozen. A high soil water content suggests that water moved to the water table through a continuous column of soil water rather than as a wetting front

Gives the average rates of perimeter increase for fires in four broad fuel type groups by four spread index classes.

Presents 1966 forest type areas by counties and shows trends in forest type areas since 1955, by survey units.

Although data on use for 1961 and 1966 are not always comparable, a bare-minimum estimate of the increase in number of visitors between those years in 19 percent. The greatest increase was in number of canoeists and boaters, which rose on the average 9 or 10 percent a year.

Sawtimber and poletimber acreage was half again as large in 1966 as in 1955; seedling and sapling acreage had decreased about one-third; and nonstocked area had dropped from 1.2 million acres to 100,000.

Prescribed burning to prepare a seed-bed, seedling native grasses or fescue on proper sites, and fertilizing are all necessary for successfully establishing good grass production where trees have been killed by aerially applied berbicides.