Caliciopsis canker is an emerging problem in Pinus growing regions of Eastern North America. The fungal disease caused by Caliciopsis pinea is associated with overstocked stands and poor sites, but few quantitative data are available. The objective of this study, therefore, was to assess the extent and severity of Caliciopsis canker and to explore environmental variables associated with disease to identify areas at risk of damage. During 2014, 58 sites across New England with >75% P. strobus basal area in public lands were surveyed. Most sites (72%) had Caliciopsis canker signs or symptoms. Caliciopsis pinea was successfully identified with molecular techniques. In sites with Caliciopsis canker, 36% of the mature pines were symptomatic. Pole sized and suppressed trees were more likely to be damaged than larger trees with dominant crown positions OPEN ACCESSForests 2015, 6 4361 (p < 0.05). Pinus strobus density for sites with Caliciopsis canker was 311 trees/ha (mean P. strobus stand diameter = 40 cm) compared to 220 trees/ha (mean white pine stand diameter = 43 cm) for sites without Caliciopsis canker (p = 0.1). Caliciopsis canker symptoms tended to appear more frequently in stands with excessively drained, coarse textured soils derived from glacial outwash (86%) or stands with poorly drained soils and low fertility (78%) than in stands with well drained, more fertile soils (59%) (p = 0.1). The severity of symptoms varied among soil groups and was greater for excessively drained, nutrient poor soils than for well-drained, more fertile soils (p = 0.027).

Soil and stand density were found to be promising predictive variables associated with damage by the emerging disease of eastern white pine, Caliciopsis canker, in a 2014 survey with randomly selected eastern white pine (Pinus strobus L.) stands. The objective of this study was to further investigate the relationship between soil and stocking in eastern white pine forests of New England by stratifying sampling across soils and measuring stand density more systematically. A total of 62 eastern white pine stands were sampled during 2015-2016. Stands were stratified across soil groups and several prism plots were established at each site to measure stand density and determine stocking. Caliciopsis canker incidence in mature trees was greater in sites with drier or shallow soils compared to sites with loamy soils and in adequately stocked stands compared to understocked stands (p < 0.0001). Caliciopsis canker signs and symptoms were observed in all size classes. Live crown ratio, a measure of forest health, decreased with increasing Caliciopsis canker symptom severity. The fungal pathogen, Caliciopsis pinea Peck, was successfully isolated from cankers on trees growing in each soil group. Forest managers will need to consider damage caused by Caliciopsis canker related to stand factors such as soil and stocking when regenerating white pine stands.

Black ash (Fraxinus nigra), the most highly preferred and vulnerable host of the invasive emerald ash borer (EAB; Agrilus planipennis) in North America, is of cultural and spiritual importance to many Tribal Nations in the US and First Nations in Canada. To date, EAB has invaded nearly 60% of the native range of black ash, with annual spread averaging approximately 50 km per year. On the basis of the predicted expansion of EAB distribution, we estimate that more than 75% of black ash basal area will be lost across 87% of the species’ North American range by 2035. Census data indicate that 98% of Indigenous people currently residing within the geographic range of black ash in the US will be within the area experiencing more than 75% basal area loss by 2035, suggesting broad and multidimensional impacts of EAB invasion for those who value black ash as a cultural keystone species. Collaborative efforts among scientists, resource managers, and Indigenous experts are needed to mitigate EAB impacts and preserve or protect black ash resources, given the species’ vulnerability to EAB and its associated cultural and ecological value.