Treesearch

Capture of spruce beetles, Dendroctonus rufipennis, in multiple-funnel traps baited with frontalin and -pinene was reduced by up to 42% in the presence of synthetic (+)-exo- and (+)-endo-brevicomin, aggregation pheromones of the sympatric species Dryocoetes affaber. (+)-endo-Brevicomin was inhibitory to spruce beetles in two experiments and (+)-exo-brevicomin was inhibitory in one experiment, reducing spruce beetle trap catches by up to 87% and 75%, respectively. Spruce beetle trap catches were also reduced by 85% by (+)- or (+)-ipsdienol, but not by (-)-ipsdienol. Ips tridens, a second...

Estimates of regeneration or growing stock in young oak forests may be too high unless criteria are established that define explicitly acceptable growing stock. In young hardwood stands, crown class can be used to identify acceptable growing stock because it is related to the future growth and survival of reproduction. A method is presented for assigning crown class categories to hardwood stems based on their diameters (dbh). Young upland oak forests originating from clearcuts in the Missouri Ozarks were sampled to determine the relationship between dbh and crown class. Stands were 19 to...

Landscape ecology is based on the premise that there are strong links between ecological pattern and ecological function and process. Ecological systems are spatially heterogeneous, exhibiting consid-erable complexity and variability in time and space. This variability is typically represented by categorical maps or by a collection of samples taken at specific spatial locations (point data). Categorical maps quantize variability by identifying patches that are relatively homogeneous and that exhibit a relatively abrupt transition to adjacent areas. Alternatively, point-data analysis...

Simultaneous and sequential per os inoculations of gypsy moth larvae with the Lymantria dispar nuclear polyhedrosis virus (LdNPV) and a Nosema sp. from Portugal demonstrated that the interaction of two pathogens during coinfection was variable, ranging from synergistic to antagonistic. Susceptibility of gypsy moth larvae to viral infection was unaffected by simultaneous and subsequent microsporidian infection. This resulted from the comparatively slow pathogenesis of the microsporidium when compared to the virus. Viral infectivity, however, increased 10-fold when larvae were preinfected...

This report describes an interrelated set of social science investigations conducted for the ChicagoRivers Demonstration Project. The purpose of these studies was to understand how user and interest groups currently perceive and use the Chicago and Calumet River corridors, and how they would like to see the corridors improved for recreation and related values. An introductory chapter defines overall research objectives and presents a framework for identifying important groups, settings, and issues for study. Four subsequent chapters address these dimensions with respect to a) nearby...

What's been done on Chicago Area Rivers is truly an inspiration. People's ability to improve these rivers shows what can be improved anywhere, even in a highly developed and complex urban setting like Chicago. A veteran staffer with the Friends of the Chicago River recently concluded: "People look at what's being accomplished on the Chicago River and say, `Wow, if you can do that on your trashed river, think what we could do on ours.'" There is no "right way" to do a river project. As you read the project summaries, you will notice that people's needs and desires for an area differ among...

Chicago?s sister rivers, the Chicago and the Calumet, have been joined together to form a single, intertwined network of waterways. Together they affect downstream waters of the Illinois and Mississippi Rivers to the Gulf of Mexico. By calling them Chicago Area Rivers we recognize the vital role they played in the city?s growth while remembering their past as separate waterways.

Seed and litter traps are tools used by foresters and ecologists. We describe two different types of a durable trap constructed from plastic plumbing pipe, which are easily assembled/disassembled for efficient transportation and storage.

Identifies and profiles Michigan's private timberland owners. Estimates the number and distribution of private timberland owners by owner attitudes and objectives concerning forest ownership, management, and use. Provides 45 tables relating to owner and property characteristics for the state and its four survey units.

Lake States pulpwood production decreased 1%--from 9.6 million cords in 1995 to 9.5 million cords in 1996. Central States pulpwood production decreased 26%--from 528 thousand cords in 1995 to 393 thousand cords in 1996. Plains States pulpwood production was 110 thousand cords, a decrease of 4% from 1995. Pulpwood production is shown by county and species group for Michigan, Minnesota, and Wisconsin.