Michael C. Demchik

Selection of American hazelnut as a potential oilseed crop

Development of perennial oilseed crops for the Lakes States region of the United States would provide another crop opportunity for farmers, while improving ecosystem services from agricultural lands. In order to effectively select hazelnut (Corylus americana Marsh.) genotypes from existing wild populations, we needed to know at least three parameters: (1) measures for indirect assessment of yield, (2) between and within population genetic variability, (3) fatty acid characteristics of the nuts. American hazelnut populations at 21 sites were screened for high-yielding plants. Yield component analysis was used to determine the relationship of specific component of yield (nut clusters/m2, nuts/cluster, mass in-shell/nut, mass of nutmeat/mass in-shell) to yield of nutmeat/m2. Nut clusters/m2 explained the majority of the variation in yield of nutmeat/m2. Ten microsatellite loci were used to determine the within and between population variation. The majority of the variance was between individuals within populations. Fatty acid profiles were determined for a subset of high-producing plants. Hazelnut oil is predominantly oleic acid. The fatty acid profiles do not vary greatly between individual plants, although linoleic acid is the most open to selection.

Should unthinned oak stands of advanced age (≥ 60 yr) be thinned?

ABSTRACT Oaks (Quercus sp.) account for nearly one-third of the sawtimber harvest in Wisconsin. As trees age, their ability to respond to thinning is reduced; therefore, the objective of this study was to determine whether thinning previously unthinned oak stands of advanced age (≥ 60 yr) would achieve biological, financial, and operational objectives. During 2014, we conducted an inventory of 25 oak stands in northern Wisconsin. Fifteen received their first thinning 8–14 yr ago at ages 60–78 yr and 10 had never been thinned. Stand-level volume growth, logging costs, and net present values were estimated for each site. The age and site index of the thinned and unthinned sites were not significantly different (p > .10). Thinned and unthinned sites grew comparable net volumes per ha (5.09 and 5.90 m3, respectively); however, because this growth was concentrated on fewer trees, the trees on the thinned sites responded vigorously to thinning. As age at first thinning increased, growth response was reduced (p = .067); however, thinning still increased the growth of residual trees. Thinned sites had higher net present values compared to unthinned sites (p < .01) and logging costs were 10.6% lower (p = 0.06). Overall, for stands between 60 and 78 years old, thinning was beneficial financially, operationally, and biologically.

Effects of Seasonal Timber Harvesting Restrictions on Procurement Practices

Abstract Wisconsins forest products industry relies on a consistent supply of sustainably produced timber for its mills; however, recent research suggests significant seasonal variation in timber sale availability. We conducted a survey of Wisconsin mills to examine their procurement practices and assess how seasonal timber harvesting restrictions (STHRs) affect the forest products industry. Fifty-seven mills responded to the survey, which represented a 40 percent response rate. Respondents processed approximately 75 percent of the states annual roundwood production. The average procurement radius ranged from 75 miles for small sawmills to over 120 miles for pulp mills. Peak inventory levels exceeded 30 days during each quarter for both pulp mills and sawmills, and peak inventory levels during the first quarter exceeded 60 days. Respondents reported that STHRs were common in the state and mills had adjusted their procurement practices in response. Pulp mills estimated that STHRs cost each firm an averag...