Treesearch

In response to concerns about yellow birch (Betula alleghaniensis Britton; YB) regeneration in Quebec, new treatments have been tested in the 1990s, including patch cuts and small clearcuts. The objective of this project was to draw an overall portrait, at the scale of the province, on YB regeneration success 10 to 20 years after treatment. We resampled 36 experiments and 466 logging areas. The logging areas sampled were mostly dominated at the sapling stage by sugar maple (Acer saccharum Marsh.; SM) (23 percent) and YB (18 percent). The proportion of sites where YB was the dominant...

Mixed tree-species forest management can increase forest resilience by reducing the impacts of disturbances that disproportionately affect a single tree species or closely related groups of tree species. Beyond disturbance-risk reduction, tree-species diversification may foster functional-diversity effects (e.g., complementarity or facilitation) that alter the performance of a given tree species in mixed versus pure stands, potentially benefitting carbon sequestration and wildlife habitat. Tree species-mixture effects have been explored to only a limited degree in western US forests and,...

During container nursery production of Purshia tridentata (antelope bitterbrush), we found that three fall fertilization applications successfully loaded plants with nitrogen (N) with little effect on plant biomass. Using 15N-labeled fertilizer to track N movements, we observed that N-loaded seedlings attained luxury consumption and ultimately translocated more N toward roots. In trees, such N-loading efforts have been reported to increase seedling survival and growth after outplanting by improving initial root growth. This leads to enhanced access to water and nutrients that increases...

Introduced pests (insects and pathogens) have rapidly increased the numbers of at-risk native forest tree species worldwide. Some keystone species have been functionally extirpated, resulting in severe commercial and ecological losses. When efforts to exclude or mitigate pests have failed, researchers have sometimes applied biotechnology tools to incorporate pest resistance in at-risk species to enable their reintroduction. Often erroneously equated solely with genetic engineering, biotechnology also includes traditional and genome informed breeding - and may provide a holistic approach...

After an unusual, late-fall wildfire in a European beech (Fagus sylvatica L.) forest in the pre-Alps of northern Italy, the finest roots (0-0.3 mm diameter) were generally the most responsive to fire, with the effect more pronounced at the shallowest soil depth. While roots 0.3-1 mm in diameter had their length and biomass at the shallowest soil depth reduced by fire, fire stimulated more length and biomass at the deepest soil depth compared to the control. Fire elevated the total length of dead roots and their biomass immediately and this result persisted through the first spring, after...

We established a field experiment in an even-aged, second-growth northern hardwood forest in north-central Wisconsin, testing the response of tree regeneration to deer exclusion and group-selection harvesting where small (50 m2), medium (200 m2), and large (380 m2) gaps were created. We measured occurrence and height of saplings 9 years post-treatment and modeled incoming solar radiation in gaps to assess light distribution across the gap environments. Densities of tolerant and midtolerant saplings were similar in medium and large gaps but tolerant saplings outnumbered midtolerants...

For over 60 years, northern hardwood stands across the Great Lakes region have primarily been managed using single-tree selection (Tubbs 1977) in which a thinning is applied uniformly across a stand to reach a desired target basal area and diameter distribution. While this form of silviculture can create high quality, shade-tolerant trees, it can also create stands that lack diversity of structure and function (Neuendorff 2007). Increasingly, foresters are looking to manage northern hardwood stands for greater diversity and increased resilience to stressors such as climate or insect...

Forest managers and researchers have proposed group selection as a complementary system to conventional, uneven-aged management in temperate hardwood forests with the goal of counteracting declines in forest diversity (Eyre and Zillgitt 1953, Leak and Sendak 2002, Neuendorff et al. 2007). The intended goals for group openings in this selection system are to establish new age classes and use opening size to influence essential resources and microclimates in openings to complement the desired species composition of regeneration (Coates and Burton 1997, Grubb 1977, Lhotka et al. 2018). Yet...

Accelerating changes due to climate, invasive insects, plants, and diseases; and social values in northern hardwood forests make understanding and predicting impacts of natural and human variables ever more complex. Yet policy-makers are disinvesting in forestry research. We believe that science-management collaboration can help bridge the resulting gap. We give examples of advances in sustainable forestry from such collaboration and identify common elements of successful collaborations. Then we propose a new, three-tiered approach to science-management collaboration to reverse the trend...

Concerning trends in natural tree regeneration emerged over the last few decades following a long history of single-tree selection silviculture in northern hardwood forests. Regeneration in these systems varies geographically and is often inadequate. For example, sapling classes may be understocked, absent, or dominated by a few relatively undesirable species (e.g., American beech [Fagus grandifolia], ironwood [Ostrya virginiana]). Multiple interacting factors may explain these troubling regeneration patterns, including silvicultural practices that provide insufficient light/disturbance,...