Treesearch

Populus 'Tristis' trees grown under short-rotation, intensive culture were sampled and chunked in a prototype experimental wood chunking machine. Data presented describe the character of the trees chunked, the energy and power requirements for chunking, and the chunking rates Specific energy requirements for chunking Populus 'Tristis' are compared with chunking and chipping common Lake States species from natural stands.

Height growth of hybrid Populus

Poplar hybrids, being screened for short-rotation intensive culture, can form ecto-, endo-, or ectendo-mycorrhizae or may be autotrophic. Different sections of the genus Populus tend to be selective in the type of mycorrhizae formed. Knowledge of which types are formed influences the kinds of propagule production, site preparation, and herbicide techniques that should be used in establishing poplar plantations.

Container type, provenance, and spacing affect survival, height and d.b.h, growth, and biomass production of intensively cultured jack pine. The Lower Michigan provenance and Tubepak grown plants performed better than the local (Wisconsin) provenance and plants raised in Jiffy 7 pellets. At age 5, biomass of Tubepak plantings was more than 100% higher than that of Jiffy 7 plantings. Plantings of the Michigan provenance had 73% more biomass than those of the local source. The aboveground dry weight yield of the 1.0 x 0.3 m (3.3 x 1 ft) planting at age 5 (60.8 mt/ha (27 tons/acre)), approache...

Forestry research is a multidisciplinary venture and is typically a long-term effort with relatively low funding. The success of forestry research and tree breeding depends greatly on the coordination among forestry practitioners, research managers, and researchers. To coordinate they must have a common understanding of the research process. Therefore, the common understanding is the conceptual foundation for tree breeding and research_ To develop a common understanding (1) the components of the research system must be differentiated in respect to their functions, and (2) the differentiated...

Irrigating forest plantations cannot be justified economically on yield increases alone under present market conditions. Other factors such as bringing noncommercial land into high production, insuring a constant wood supply, or providing a means to dispose of wastewater can add to the value of increasing yields and may make irrigation feasible in certain situations.

Several potentially damaging diseases of hybrid poplars hue been identified in the north-central United States. Among the most serious are leaf and stem diseases caused by Melampsora, Marssonina, and Septoria. Short-term chemical controls are of limited usefulness. The most practical control strategy appears to be the use of resistant clones obtained through local screening, combined with various cultural measures, and integrated into overall management plans.

In this study we evaluated the effect of stem severing method and stump height on coppice growth in a short-rotation intensively cultured Populus plantation 1, 2, and 3 years after cutting. Initially, stumps 46 cm high had smaller and significantly more sprouts than either 8 or 15 cm high stumps. However, the dominant sprouts were not affected by the stump height. After subsequent growing seasons, the dominant sprouts were the only ones to survive, and no effect of stump height was present. Severing method - shearing or chain sawing - did not affect coppicing as long as the stumps were not...

Intensively cultured plantations of Populus 'Tristis # 1' produce more than 10 mt/ha/year of woody biomass at most spacings as long as they are harvested when mean annual biomass increment (MABI) culminates. In addition, fully stocked plantations produce up to 4.4 mt/ha of leaf litter. Plantations of other poplar clones produce about 30% more woody biomass, but leaf litter production is about the same as in P. 'Tristis # 1'. Because projected biomass productions of P. 'Tristis # 1' were 42 to 182% higher than the actual productions, caution must be exercised when using projected production...

Hybrid Populus clones were examined for impact from and resistance to attack from several insects and diseases. Cottonwood leaf beetle, poplar-and-willow borer, and Septoria canker were most injurious. The spotted poplar aphid and poplar-gall saperda, even when abundant, caused only minor impact. The tarnished plant bug, a newly identified pest of Populus, injured young trees near agricultural areas. Hybrid clones show a wide range of susceptibility to pests and provide exceptional breeding material for pest-resistant trees.