Interdisciplinary research has been identified as a critical means of addressing some of our planet's most urgent environmental problems. Yet relatively little is known about the processes and impacts of interdisciplinary approaches to environmental sciences. This study used citation analysis and ordinary least squares regression to investigate the relationship between an article's citation rate and its degree of interdisciplinarity in one area of environmental science; viz., forestry. Three types of interdisciplinarity were recognized-authorship, subject matter, and cited literature-and each was quantified using Brillouin's diversity index. Data consisted of more than 750 articles published in the journal Forest Science during the 10-year period 1985-1994. The results indicate that borrowing was the most influential method of interdisciplinary information transfer. Articles that drew information from a diverse set of journals were cited with greater frequency than articles having smaller or more narrowly focused bibliographies. This finding provides empirical evidence that interdisciplinary methods have made a measurable and positive impact on the forestry literature.

A trend in forestry is to move away from intensive stand establishment practices in favor of prescriptions that are lighter on the land. This study examined the condition and projected yields of nine different site preparation treatments on two high-elevation sites in central British Columbia. Treatments included the following: raw planting (i.e., no site preparation); scalping; mounding; chemical site preparation; chemical brushing; and combinations of mounding and chemical treatments. All treatments were manually planted with 2+1 bare-root interior spruce (Picea glauca (Moench) Voss × Picea engelmannii Parry ex Engelm.) seedlings. By age 15, trees growing on prepared sites had significantly greater survival, larger stem diameters, and taller tree heights than did trees that were raw planted as seedlings. Moreover, site preparation generally led to earlier and less costly compliance with mandatory reforestation requirements. Growth and yield simulations predicted raw-planted timber volumes that were just 33%–51% of the volumes in the most productive treatments. Financial returns varied as well. Site preparation typically resulted in larger land expectation values than that resulting from raw planting; however, the results were sensitive to rotation length and discount rate. Collectively, these results suggest that moderate investments in site preparation may lead to a more profitable allocation of regeneration resources and a greater future timber supply.

Interdisciplinary research has been identified as a critical means of addressing some of our planet's most urgent environmental problems. Yet relatively little is known about the processes and impacts of interdisciplinary approaches to environmental sciences. This study used citation analysis and ordinary least squares regression to investigate the relationship between an article's citation rate and its degree of interdisciplinarity in one area of environmental science; viz., forestry. Three types of interdisciplinarity were recognized—authorship, subject matter, and cited literature—and each was quantified using Brillouin's diversity index. Data consisted of more than 750 articles published in the journal Forest Science during the 10‐year period 1985–1994. The results indicate that borrowing was the most influential method of interdisciplinary information transfer. Articles that drew information from a diverse set of journals were cited with greater frequency than articles having smaller or more narrowly focused bibliographies. This finding provides empirical evidence that interdisciplinary methods have made a measurable and positive impact on the forestry literature.

Increasing forest parcelization has raised concerns about tract-size economies and sustainable timber supply. We explored this issue by examining the logging sector and forest ownership in northern Wisconsin and Michigan's Upper Peninsula. Using 2004 survey data, we found that 48% of logging firms demonstrated a near exclusive reliance on nonindustrial private forests (NIPFs). NIPF-dependent firms derived 87.5% of their stumpage from this ownership, whereas nondependent firms exhibited a significantly more diversified stumpage supply distributed among public (42.6%), industrial-corporate (33.3%), and NIPF (24.0%) sources. Additionally, NIPF-dependent firms operated on significantly fewer, smaller, and less intensely harvested timber sales, and they were more likely to harvest small tracts profitably. There were no significant differences in the forest products harvested or overall firm profitability. We found statistical evidence that NIPF-dependent and nondependent firms organize themselves differently: NIPF dependency was negatively correlated with total number of employees, timberland area in the firm's wood basket, and firm location and positively correlated with owner age. Results suggest the impacts of parcelization on the logging sector are minimal. NIPF-dependent firms appear to have structured themselves to operate profitably; however, it is unclear how continued parcelization might influence these firms and the sector as a whole.

Snag retention is increasingly being incorporated into forest management guidelines. Questions remain, however, in northern hardwood systems regarding factors affecting retention in activelymanaged stands, the effectiveness of snag creation, and the net effects of snag creation and timber harvesting on snag numbers and sizes. To address some of these questions, we examined the dynamics of natural and created snags within mature, even-aged northern hardwood forests under seven different management scenarios: three Harvest Only treatments, three Harvest Plus (created) Snags treatments, and one untreated Control. We found tree diameter, tree species, and stand treatment status (i.e., managed or Control) to be related to the retention of natural snags, created snags, or both. Snags were less likely to remain standing if they had smaller diameters, were species with relatively rapid decay rates, or were found in stands that had been logged. We found girdling trees to be an effective method of dead wood creation, although trees took longer to die than we expected. At least 84% of girdled trees had died in most stands within 4.5 years of girdling, and 30-77% of girdled trees were still standing 5.5 years after treatment. Comparison of net effects of snag creation and timber harvesting among treatments showed that managed stands, on average, experienced net snag losses compared to untreated Controls. These losses were statistically significant for all snag sizes, but not for large snags alone (i.e., dbh ≥25.4 cm). Active management prescriptions that included snag creation demonstrated the potential to mitigate snag losses, with the extent of mitigation varying with the type of management. Surprisingly, mitigation was primarily driven by significantly greater natural snag recruitment in Plus Snags treatments, potentially due to competition from girdled trees that had not yet died. Our results may help inform the development of snag management guidelines in even-aged, 3 second-growth northern hardwood systems for forest managers who are interested in enhancing the structural complexity of these forests.