Ecological Factors Affecting White Pine, Red Oak, Bitternut Hickory and Black Walnut Underplanting Success in a Northern Temperate Post-Agricultural Forest

Abstract

This study took place in southern Québec (Canada) where young stands of white ash and grey birch have been underplanted with white pine, red oak, bitternut hickory and black walnut. The establishment success of white pine and red oak was measured with and without tree shelters (to protect from deer). Ecological factors affecting the height growth of the four species were also measured for protected trees. After 6 years, the survival and total height of unprotected oak was 29% and 44.3 cm vs. 80.5% and 138.5 cm for protected oak. White pine was less affected by browsing (survival of 79.5 and 93.5%; height of 138.5 and 217.9 cm for unprotected vs. protected pine). Height of white pine was higher in the grey birch stands, while height of all hardwoods was higher in the white ash stands, which had better soil drainage, higher fertility, and an understory dominated by Rubus species. Total height of all hardwoods was significantly (p < 0.05) correlated with Rubus cover and with soil fertility. Pine and walnut height were strongly correlated (p < 0.001) to shelterwood structure (canopy openness or total basal area). Pine was less sensitive to variations in shelterwood characteristics, while black walnut showed high sensitivity. This study provides evidence that underplanting is suitable for black walnut assisted migration northward and for bitternut hickory restoration, despite soil conditions that were less favorable than in bottomland habitats mainly supporting these species in eastern Canada. Tree shelters offering protection from deer browsing and species-specific site selection are recommended for underplanting in the southern Québec region.

Diversity stabilizes but does not increase sapling survival in a tree diversity experiment

“…Only at the highest level of browse damage (>75% branch tips browsed) was there any indication of decreased survival. Deer browse pressure can be a major driver of tree seedling survival and species composition in temperate forests (Granger et al 2017;Russell et al 2017), especially for preferred browse species (Truax et al 2018;Reed et al 2021), and at densities observed in our experimental area (20 deer/km 2 ; Russell et al 2017). However, many of these studies are from natural forests or naturally regenerating seedlings, while our trees were planted as 1-year-old bareroot seedlings.…”

“…topography, elevation; Yang et al 2013), and disease (Ostry et al 2012). Monocultures may exacerbate the risk of planting failure if the selected species are particularly vulnerable to those mortality risks, or if they are not well suited to site conditions (Truax et al 2018). As multi‐species plantings could mitigate mortality risks by reducing the odds that all species would succumb to the common drivers of seedling mortality, increasing diversity could be an effective strategy to not only increase ecosystem functions but also to reduce the odds of planting failure.…”

A Review of Propagation and Restoration Techniques for American Beech and Their Current and Future Application in Mitigation of Beech Bark Disease

“…grandifolia seedlings would likely be well suited to interplanting because of their tolerance of moderate to high shade in their early regeneration niche [8]. Interplanting, or planting seedlings among existing forest vegetation, has been utilized to enhance regeneration of other challenged species in the Fagaceae family, but careful site preparation is necessary to meet the light demands of these seedlings [73,74]. The same site preparations may not be necessary if natural gaps due to BBD mortality can be utilized as planting sites.…”

Assessing the Efficacy of Seedling Planting as a Forest Restoration Technique in Temperate Hardwood Forests Impacted by Invasive Species

“…In many cases, herbivory pressure is strong enough to warrant the use of tree tubes despite the potential detrimental impacts they may have. Indeed, Q. rubra seedlings planted with tree tubes tend to have faster growth rates and higher survivorship than their unsheltered counterparts [40][41][42] but this is not always the case [43]. Further research is needed to assess the efficacy of the expensive and time-consuming practices of using tree shelters to increase seedling survivorship and performance.…”