Treesearch

Nature is more than just a collection of physical and biological resources. Is is also an image in our minds and in our hearts. This image includes all the thoughts, feelings, and values that nature evokes--a place of refuge from the demands of society, of encounter with natural forces, and of personal and spiritual transformation.

Stand management activites influence (1) tree growth and quality; (2) stand structure, stocking and composition; (3) wildlife and aquatic habitat quality; and (4) long-term site productivity. The cumulative impacts of stand-level treatments affect ecosystem structure and function at the landscape level.

Poplar hybrids have high light-saturated photosynthetic rates and potential utility as a renewable biofuel, but they lack tolerance to commercially important herbicides that may be needed for successful plantation management. Tolerance to glyphosate (N-(phosphonomethyl)glycine) has been conferred to many plants by Agrobacterium-mediated transfor-mation with the mutant aroA gene, which encodes glyphosate-tolerant 5-enolpyruvylshildmate-3-phosphate (EPSP) synthase (EC 2.5,1.19) (Comai et al. 1985). While foreign DNA has been inserted into the genome of numerous herbaceous species by Agrabacte...

Brown-headed Cowbirds (Molothrus ater) are an obligate brood parasite and a potential threat to some populations of migratory songbirds. I used radio-telemetry to study temporal patterns in behavior, habitat use, and sociality, as well as spatial patterns and movements among breeding, feeding, and roosting areas. I obtained a mean of 42 locations of 84 radio-tagged female cowbirds on three study sites in Illinois and Missouri. Radio-tagged females usually were located in forest and shrub-sapling habitats with a mean of 1.4 males during the morning breeding period. During midmorning to...

The pine engraver, Ips pini Say, and Pityogenes knechteli Swaine often co-exist in lodgepole pine, Pinus contorta var. latifolia Engelmann. We tested the hypotheses that P. knechteli produces an attractive pheromone and that the attraction of P. knechteli and I pini to conspecifics is inhibited by the presence of the other species. Pityogenes knechteli males and females were attracted to bolts infested with conspecific males and to bolts infested with I. pini males; however, there was no significant cross-attraction of I. pini males or females to bolts infested with P. knechteli males....

The effects of different combinations and concentrations of the growth regulators: 6-benzylaminopurine (BA), 6 furfurylaminopurine (KIN), N6- (2-isopentenyl) adenine (2iP), indole-3-butyric acid (IBA), indole-3-acetic acid (IAA) and a-naphthaleneacetic acid (NAA) on axillary shoot multiplication rates for wild cherry (Prunus aviurn L.) shoot explants were determined. Apical shoot tips and axillary buds from juvenile trees (5-year old) and from root suckers of mature trees (55-year old) were used as initial explants for establishment of multiple shoot cultures. Factorial tests for growth...

Timber harvesting affects both composition and structure of the landscape and has important consequences for organisms using forest habitats. A timber harvest allocation model was constructed that allows the input of specific rules to allocate forest stands for clearcutting to generate landscape patterns reflecting the "look and feel" of managed landscapes. Various harvest strategies were simulated on four 237 km2 study areas in Indiana, USA. For each study area, the model was applied to simulate 80 years of management activity. The resulting landscape spatial patterns were quantified...

Septoria leaf spot and canker are serious diseases of many hybrid poplar clones in plantations established for biomass production. Developing resistant clones through breeding is the best long-term strategy to minimize tree damage caused by this disease. Tissue culture and somaclonal selection techniques may reduce the time needed to develop disease resistance in poplars. We used a single source clone of a hybrid Populus to determine the influences of explant tissue source and regeneration method on the frequency of somatic variation in disease resistance. Plants were regenerated adventitio...

Presents the vegetative characteristics of the five forest types that comprised the study plots established to test the hypothesis that the wet sulfate deposition gradient across the Lake States is reflected in the amount of accumulated sulfur in soil and tree tissue, which in turn is reflected in tree growth.

Presents highlights and statistics on area, volume, growth, removals, and mortality from the 1990 forest inventory of the Chippewa National Forest.