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Well-stocked natural tree regeneration is critical to sustainable management of northern hardwood forests (NHF) by selection silviculture, but explicit goals and stocking criteria for sapling recruit size classes are lacking. For stems 0–2 in. (0–5.1 cm), we define 171 and 691 stems ac−1 (422.5 and 1,707.5 ha−1) as lower and upper full stocking thresholds for basic NHF management goals (wood and biomass productivity) and overabundant/pest–pathogen-challenged species. We define component stocking targets as 15% of full stocking targets for six additional wildlife (e.g., nut producers) and resilience (e.g., pest–pathogen) goals and individual species representation. Applying our system to 141 managed stands in Michigan, USA, we found several areas of concern. At low threshold, 33% of stands were understocked for biomass and wood goals, whereas 67% were fully stocked with overabundant/pest–pathogen-challenged species. Among goals, component stocking (low threshold) was as low as 5% (nut producers), with more than half the stands component stocked for ≤ 2 goals and ≤ 2 individual species. Stocking varied geographically and decreased with increasing site quality, overstory basal area, and deer use. Study Implications The stocking goals and density criteria we developed can help managers objectively identify areas where current silvicultural practices are ineffective and need modification. Our system is based on an interactive platform that can be readily modified to accommodate new information and management goals. Several management suggestions emerged from applying our system to selection-managed NHF stands in Michigan. First, highest quality sites have the greatest stocking challenges. Stocking outcomes could likely be improved via more intense overstory harvests and mitigation of deer impacts. Second, most stands meeting stocking goals are vulnerable to future changes in climate and pest–pathogen outbreaks, given stocking is often dominated by a small subset of candidate species. Planting, including the incorporation of assisted migration species candidates could help ameliorate this problem, as species could be evaluated based on their contribution to multiple component stocking goals.

Well-designed, robust partnerships are important for addressing forest resource problems that intersect diverse ownerships, management, and research expertise. Here, we describe a case study of a research–management partnership. First, we describe the rationale and design of a large-scale, long-term experiment focused on increasing the sustainability and resilience of managed northern hardwoods. With the experiment as context, we next discuss details of the partnership contributing to its success, as well as some challenges. The experiment is a Michigan-wide evaluation of silvicultural alternatives to the current paradigm of selection silviculture. Our goal is to identify combinations of silvicultural treatments that increase the diversity and density of sapling recruits over forested landscapes where deer-browsing pressure and other limiting factors are at play. Pretreatment data from our 140-site study bolstered justification for the research, with sapling and pole classes generally lacking adequate stocking and diversity of desirable species over large geographic extents. We anticipate that the wildlife and forestry research–management model used to develop this project will be useful for other rapidly developing challenges that cannot wait decades to be addressed without potentially catastrophic losses to forest function. Key beneficial elements of our partnership include: (1) sensitivity to information needs at all management levels (i.e., policy to practice), (2) capitalizing on differences in strengths and reward systems of managers and scientists, (3) structured, frequent scientist–manager meetings to maintain focus on research and management application outcomes, (4) long-term relations and support that build trust, and (5) explicit wildlife and forestry collaboration on problems requiring joint expertise. Challenges to our partnership generally revolved around communication, workload, and implementation issues, and were partially alleviated by planning.

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