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Overstory and understory treatments were established in natural oak stands and red pine plantations in Michigan in 1991 to test the hypotheses that (1) oak seedling survival and growth would be greater in pine than oak stands and (2) removal of competitors would enhance oak seedling performance. Late spring prescribed fires were implemented in 2002 and 2008 to investigate their effectiveness in controlling understory red maple. Performance of planted northern red oaks has been monitored since 1991 and the abundance of naturally regenerating oak and red maple seedlings and sprouts in different size classes has been documented since 2001. A subset of oaks has been protected against deer browsing since planting. Results suggest partial competitor removal enhances oak seedling and sprout performance, whereas complete removal increases mortality from browsing and frost. Increases in red maple abundance and decreases in oak abundance were documented after the prescribed fires in 2015. Greater growth and survival of planted oaks was observed in the pine stands, provided they were protected from browsing. Based on these results, the most viable management scenario for maximizing survival and growth of oak seedlings and sprouts in the study region would include protecting oak seedlings from deer in 25% canopy cover shelterwoods in pine plantations. Opportunities exist for developing systems involving alternating rotations and mixtures of oak and pine.

Establishing herbaceous groundcover is essential for oak woodland and savanna restoration. In the Appalachian region, woody vegetation in the understory can persist through many fires and interfere with achieving this goal. Herbicide applications could reduce such vegetation and interact with canopy-disturbance and fire to accelerate restoration. In stands thinned to woodland (16 m2 ha−1, 75% canopy closure) or savanna (5 m2 ha−1, 24% canopy closure) conditions and burned biennially in the fall (October) or spring (March), we economically applied triclopyr (Garlon® 3A) to understory woody plants using foliar and cut-surface techniques in the fall between fires. From 2011 to 2013, only minor differences in vegetation were observed between areas managed with canopy-disturbance and fire (CF) and areas where herbicides were also used (CFH). Small-sapling (≥1.4 m tall

The removal of fire’s influence on plant community succession has resulted in the near disappearance of oak (Quercus spp.) woodlands and savannas from the Appalachian region. Negative trends in associated plant and wildlife species could be reversed if these communities are restored, but management has been limited by inadequate canopy disturbance, resprouting of woody plants, and a lack of empirical research. To address these issues, we evaluated herbaceous and woody vegetation response (2008–2012) on the Cumberland Plateau in Tennessee to 5 replicated treatments involving canopy reduction (14 m2 ha−1 [woodland] or 7 m2 ha−1 [savanna] residual basal area) and fire-season (mid-March [spring] or early October [fall]) combinations and unmanaged controls. All categories of woody vegetation except large-saplings (⩾1.4 m tall and ⩾7.6 but

Incidentally introduced in 2002, the expansion of emerald ash borer (EAB) led to widespread ash mortality throughout the eastern United States. A great deal of effort has been invested in containing and controlling this forest invasive species, whereas the ability to regenerate ash from extant seedling and sapling populations following the initial EAB invasion has received less attention. Using recent data available from the U.S. Department of Agriculture, Forest Service, Forest Inventory and Analysis program (FIA), we quantified ash seedling and sapling regeneration counts across FIA forest type groups containing white, green, black, blue, pumpkin, and Carolina ash. In addition, all other seedling and sapling species in these stands were quantified to determine overall species composition of the regeneration and the potential for inter-specific competition. Ash seedlings and saplings represented the greatest proportion of regeneration across most forest type groups containing mature ash. Top competitors of ash tended to be far less economically and ecologically valuable. If retaining ash in current stands remains a management goal, and provided that an effective biological control for EAB is identified and established across infested areas, the success of extant ash seedlings and saplings into larger size classes will depend on silvicultural treatments designed for controlling inter-specific competition across stand cohorts.

Loblolly pine (Pinus taeda L.), shortleaf pine (Pinus echinata Mill.), and eastern white pine (Pinus strobus L.) seedlings were multi-cropped with standard and large-diameter white oak (Quercus alba L.) seedlings to test for neutral or positive effects of multi-cropping. The study was established in 2014 in three complete blocks within recent clearcuts in eastern Tennessee, USA. Each block consisted of six multi-cropped treatments and four monocultures randomly assigned to ten 14.63 × 21.95 m plots. Within each block, monocultures of white oak and each pine species were planted in four control plots. Multi-cropped treatments included loblolly pine planted with white oak at a 0.31 m spacing, loblolly pine planted with white oak in alternating rows at a 1.74 m spacing, shortleaf pine planted with white oak at a 0.31 m spacing, shortleaf pine planted with white oak at a 1.74 m spacing, eastern white pine planted with white oak at a 0.31 m spacing, and eastern white pine planted with white oak at a 1.74 m spacing. Each plot with white oak received 20 standard (~0.127 cm in basal diameter) and 20 large-diameter (~0.632 cm in basal diameter) white oak seedlings that were randomly assigned to planting locations. Initial height, basal diameter, and early survival were recorded for each seedling just after planting. Height growth, basal diameter growth, survival, herbivory, and insect damage were recorded in early December 2014, 2015, 2016, 2017, 2018, and 2019. In 2019, percent survival among treatments did not differ significantly for white oak (p = 0.152), loblolly pine (p = 0.396), shortleaf pine (p = 0.246), or eastern white pine (p = 0.065). In addition, mean height growth and mean basal diameter growth did not differ significantly among treatments for white oak (p = 0.698 and 0.437, respectively), loblolly pine (p = 0.630 and 0.762, respectively), shortleaf pine (p = 0.324 and 0.251, respectively), or eastern white pine (p = 0.623 and 0.823, respectively). Survival was greater for large-diameter white oak seedlings than standard seedlings (p

Autumn olive (Elaeagnus umbellata) poses significant challenges for forest managers. The ability to predict when and where this species will become a problem would allow managers to more effectively prioritize control efforts and implement the most efficient management practices available. Several studies have sought to determine which key factors lead to greater abundance of exotic, invasive plants on certain sites and their spread at multiple scales. Previous research suggests that disturbances and increased light can be important. The overall goal of this research was to identify factors associated with forest road edges that are most important in facilitating autumn olive. Specific objectives were to: (1) document site factors significantly related to the presence and success of autumn olive, (2) investigate the hypothesis that southern aspects have greater abundance, patch depth and growth of autumn olive than other aspects, (3) examine the hypothesis that there is a negative relationship between the abundance and height of autumn olive and the abundance and height of native species, and (4) determine if the relationship between autumn olive abundance and height and the abundance and height of other invasive species is positive. Densities of autumn olive, native woody species, and other woody exotic, invasive species in different size classes were quantified in plots located along forest-road edges having northern, southern, eastern, and western aspects. Slopes, elevation, road opening width, canopy cover, and basal area were also quantified at each plot location. In addition, presence and absence of autumn olive, slope, elevation, canopy cover, and road canopy closure were quantified at randomly selected points along major and minor gravel roads within the study area. Larger autumn olive were most abundant along edges with southern aspects and patches of autumn olive were deepest on edges with northern and southern aspects. Autumn olive height and abundance were positively related to the height and abundance of both native and exotic, invasive woody plants. Slope, elevation, road canopy cover, road opening width, and road type were found to be important factors influencing autumn olive establishment and success. As a result, these factors may prove useful in the development of habitat suitability models and GIS-based risk maps that managers could use to more effectively address this invasive species.

Manipulation of the light regime is a primary goal of many silvicultural treatments, but the specific light conditions created remain poorly documented for many forest types and geographic locations. To help quantify effects of silvicultural treatments on light conditions, measurements of basal area, canopy cover, and photosynthetically active radiation (PAR), measured both instantaneously and across time, were collected in central hardwood forests in Kentucky, USA following silvicultural treatments. These measurements were used to: (1) Investigate the magnitudes of differences in understory percent ambient PAR following implementation of shelterwood with reserves and thinning treatments; (2) document the spatial and temporal distribution and variability of understory percent ambient PAR in shelterwood with reserves treatments (mean residual basal area = 5.2 m2/ha), thinning treatments (18.5 m2/ha), and untreated controls (27.1 m2/ha); and (3) examine relationships between: basal area and canopy cover; basal area and measured percent ambient PAR; and canopy cover and measured percent ambient PAR. Mean light levels from instantaneous measurements were 78% of ambient in the shelterwood with reserves, 33% of ambient in the thinning and 9% of ambient in the control. Similarly, only 1.3% of the approximately 140 h of PAR measurements in the controls indicated high light conditions (>60% of ambient), 15.9% in the thinning treatment and 65.4% in the shelterwood with reserves treatment. There were only 32 periods of high light found across all plots in the control, 176 periods of high light in the thinning treatment, and 441 periods of high light in the shelterwood with reserves treatment. Indexes of variability in light across time and among sampling locations within a stand did not differ statistically between the shelterwood with reserves and thinning treatments but both treatments were statistically more spatially and temporally variable than the uncut control. Simple linear regression relationships were observed between stand basal area and mean relative PAR (r2 = 0.8784 for instantaneous measurements, r2 = 0.9697 for continuous measurements), and basal area and canopy cover (r2 = 0.8479). Such relationships provide a means for including light management in forest planning and application of silvicultural treatments. The results for the distribution of light also suggest, however, that treated stands may have similar mean light levels, but differ substantially in the spatial and temporal distribution of light.

Red pine (Pinus resinosa Ait.) was the most abundant species in the overstory on intermediate-quality sites in north central Lower Michigan prior to the lumbering era of the late 1800s. Northern red oak (Quercus rubra L.) stands that replaced portions of the presettlement pinery are maturing. However, these sites are not returning to the former species composition due to greater abundance of red maple (Acer rubrum L.) and white pine (Pinus strobus L.) and a lack of oak and red pine regeneration. Our primary objective was to compare the effects of pine and oak cover types on natural oak and red maple regeneration. We measured oak and red maple regeneration in 2001, 10 years after initial application of canopy cover and understory treatments in natural oak stands and red pine plantations on comparable sites. Oak shelterwoods harvested to 25% canopy cover contained significantly more oak seedlings (∼60 cm height) than all other treatments, a majority of which were located in understory treatment plots, where red maple regeneration was mechanically removed. In agreement with other research in oak-dominated stands, these results suggest that light shelterwoods with understory control may be the most viable means of recruiting oaks. Lack of oak regeneration that was progressing toward the canopy in the oak stands compared to the pine stands suggested that, even with understory control after shelterwood cutting, oak may not compete as well in the understory of oak as in pine stands. In contrast, red maple dominated the understory of oak stands, but exhibited poor development and was significantly less abundant in the pine stands. Oak regeneration was also less dense in the pine stands, but free to grow. Factors in the red pine plantations studied, such as increased litter depth, few seed sources, and decreased availability of soil moisture and nitrogen are likely to have reduced the germination and competitive ability of understory red maple stems, thereby benefiting the growth of oak seedlings having lesser shade tolerance. The differential success of oak and red maple regeneration observed in the red pine stands on intermediate-quality sites has led us to suggest that restoration of beneficial oak and pine interactions and a shift in focus from regenerating oak beneath oak to regenerating oak beneath pine may be warranted.

Both forest harvesting and browsing by white-tailed deer (Odocoileus virginianus Zimmerman) affect the composition and structure of forest vegetation throughout the eastern deciduous forest in the United States. We studied their affect and their interaction by measuring the composition, richness, cover, physical stature, and reproductive potential of vascular plants in the understory of three thinned (uneven-aged, even-aged, managing for old-growth characteristics) and two unthinned (second-growth, old-growth) forests dominated by sugar maple (Acer saccharum Marsh.) in western Upper Michigan. Based on measurements taken five years after deer exclosures were established, we found consistent and strong statistical differences in species richness and percent cover related to forest harvest but not to deer browse. Percent cover of the understory vegetation showed weakly significant interactions between deer browse and forest harvest. Thinned forests had a greater average richness and cover of graminoid species, average cover of wild red raspberry (Rubus strigosus L.) and sugar maple compared to unthinned forests. Measurements of plant morphology and the frequency of flowering and fruiting were more sensitive indicators of deer browse than community measurements such as richness and cover. Based on measures of physical stature and reproductive potential, sugar maple, red-berried elder (Sambucus racemosa L.), bluebead-lily (Clintonia borealis (Aiton) Raf.), small Solomon-seal (Polygonatum pubescens (Willd.) Pursh.), false Solomon-seal (Smilacina racemosa (L.) Desf.), rosy twisted stalk (Streptopus roseus Michaux), and trillium species (Trillium grandiflorum (Michaux) Salisb. and T. cernuum L.) all experienced significant browse damage. A better understanding of the interaction between forest harvest and deer browse and their effect on community composition and structure is critical to maintaining and enhancing biodiversity in managed northern hardwood forests.

We evaluated impacts of disturbance in interior haul roads and skid trails on understory vegetation by documenting the areal extent of these features and plant composition along 10 m ×100 m belt transects. Ten belt transects were sampled in each of three comparable northern hardwood forests under even-aged management. These forests were approximately 80 years old and were last entered for thinning 4–6 years prior to sampling. Soil compaction, canopy cover, and the richness and composition of trees, shrubs, and herbs were quantified within each feature (i.e. haul roads, skid trails, and forest without soil disturbance) encountered along transects. These variables were also quantified in unmanaged northern hardwood stands of comparable age. Differences in photosynthetically active radiation (PAR) and soil moisture between haul roads and adjacent patches of forest were measured along line transects placed across haul roads, perpendicular to their main axis. On average, haul roads and skid trails comprised 1 and 16% of total managed stand area, respectively. Compaction, PAR, and soil moisture were highest in haul roads. Understory plant richness was significantly greater in haul roads than in skid trails and forest, and resulted from significantly greater percentages of introduced species (13%) and wetland species that were native to the area, but not normally abundant in northern hardwood stands (23%). Skid trails had a greater percentage of wetland species (9%) than in forest, but differences in richness between skid trails and forest were not statistically significant. Up to the present time, the impact of haul roads on understory vegetation has received far less attention than impacts on soil properties and water quality. Although haul roads comprise a relatively small proportion of total stand area, they serve as primary conduits for the dispersal of introduced species into the interior of managed stands and contribute to significant shifts in plant richness and composition at the stand level.