Treesearch

Knowledge of factors affecting song rates is important because biologists use song in estimating or monitoring bird populations. Perhaps for no other species have song censuses played such a major role in population assessment and management as for the Kirtland`s Warbler (Dendroica kirtlandiz). In 1951, this endangered songbird was first censused within the known nesting range, which is restricted exclusively to Michigan (Mayfield 1953). The entire population was censused again in 1961 (Mayfield 1962) and every year after 1970. This information has been used to assess the response of this...

In 1983, the fourth Wisconsin forest inventory found 14.8 million acres of commercial forest land, an increase of nearly 2% since 1968. This bulletin analyzes findings from the inventory and presents detailed tables of forest area.

Presents the results of a mail canvass of nonindustrial private forest landowners in Minnesota to relate owner attitudes and intentions concerning ownership, management, harvest and recreational use of their forest property. Provides 55 tables contrasting owner characteristics, management actions, and attitudes for the state and its four survey units.

Shows 1984 veneer log production and receipts by species in the Lake States (Michigan, Minnesota, and Wisconsin) and in the Central States (Illinois, Indiana, Iowa, and Missouri). Comparisons are made with the 1980 data. Includes tables showing veneer log production and receipts (for selected years) since 1946 in the Lake States and since 1956 in the Central States.

Discusses 1984 production and receipts and recent production for other years in the Lake and Central States. Shows Michigan, Minnesota, and Wisconsin production by species for each county and compares production by Forest Survey Unit with that of previous years. Presents 1984 production and receipt data for Illinois, Indiana, Iowa, and Missouri, and shows four production classes by county.

Describes the taxonomy, distribution biology, and control of the European and North American strains of Scleroderris canker as it applies to North America.

Low intensity, spring prescribed burns have been used since 1964 at the Cedar Creek Natural History Area in Minnesota in an attempt to restore the area to an oak savanna. Burned areas are now more savanna like (having greater grass and forb and lower shrub and lower tree representation) than unburned areas but still have higher overstory densities than apparently existed in presettlement times. No particular burning frequency could be distinguished as best for savanna restoration. Results indicated a possible interaction between fire effects and pretreatment and stand structure and...

An updated version of the Lake States variant of STEMS is evaluated and compared with the previous version. The new version is slightly more accurate and precise. The strengths and weaknesses of this tree growth projection system are also identified.

Aerial radio-tracking and observation showed total number of wolves per year in 2,060-sq. km. Area varied from 35 to 87 in winter and from 30 to 78 in spring and generally declined because of a decreasing deer herd. Since winter 1977-1978, the population has remained relatively stable because an increasing population has switched to preying on moose. The number of wolves preying on deer has continued to decline.

Deer were aerially censused each winter from 1976 through 1985 in a 400 sq. km. area near Isabella, Minnesota, in the central Superior National Forest; a correction factor based on aerial observability of radio-tagged deer in the same region was then applied to the census figures. Deer numbers, which had reached an estimated 3.6/sq. km., declined drastically in the early 1970s, fluctuated between about 0.43 and 0.97/sq. km. from 1976 through 1985, and began increasing in 1985.