Emergence of white pine needle damage in the northeastern United States is associated with changes in pathogen pressure in response to climate change

Abstract

The defoliation of the eastern white pine (Pinus strobus) across the northeastern United States is an escalating concern threatening the ecological health of northern forests and economic vitality of the region's lumber industry. First documented in the spring of 2010 affecting 24 328 hectares in the state of Maine, white pine needle damage (WPND) has continued to spread and is now well established in all New England states. While causal agents of WPND are known, current research is lacking in both sampling distribution and the specific environmental factor(s) that affect the development and spread of this disease complex. This study aims to construct a more detailed distribution map of the four primary causal agents within the region, as well as utilize long-term WPND monitoring plots and data collected from land-based weather stations to develop a climatic model to predict the severity of defoliation events in the proceeding year. Sampling results showed a greater distribution of WPND than previously reported. WPND was generally found in forest stands that compromised >50% eastern white pine by basal area. No single species, nor a specific combination of species had a dominating presence in particular states or regions, thus supporting the disease complex theory that WPND is neither caused by an individual species nor by a specific combination of species. In addition, regional weather data confirmed the trend of increasing temperature and precipitation observed in this region with the previous year's May, June, and July rainfall being the best predictor of defoliation events in the following year. Climatic models were developed to aid land managers in predicting disease severity and accordingly adjust their management decisions. Our results clearly demonstrate the role changing climate patterns have on the health of eastern white pine in the northeastern United States.

Lecanosticta acicola: A growing threat to expanding global pine forests and plantations

“…Here it can result in mortality reaching 50% and higher in the southeastern USA (Cordell et al ., ). New reports of L. acicola causing damage on P. strobus have emerged since 2005 in the northeastern USA and Canada and these have been attributed to changes in precipitation and climate in the regions (Broders et al ., ; Wyka et al ., , ). Lecanosticta acicola is also recognized as a component of a complex of pathogens that cause white pine needle damage (WPND) in this region (Broders et al ., ).…”

“…A recent taxonomic reevalu ation of isolates previously identified as L. acicola, applying phy logenetic analyses based on DNA sequences, has led to various isolates being recognized as distinct species (Quaedvlieg et al, 2012;van der Nest et al, 2019). This and a number of recent publications (Adamson et al, 2018;Cleary et al, 2019;Mullett et al, 2018;Ondrušková et al, 2018;Ortíz de Urbina et al, 2017;Sadiković et al, 2019;Schneider et al, 2019;Wyka et al, 2017) justifies the need for a review of current knowledge regarding BSNB and the Lecanosticta species that cause this disease. This is the first review of the topic to be presented in 75 years subse quent to that of Siggers (1944).…”

Dendrochronological Analyses and Whole-Tree Dissections Reveal Caliciopsis Canker (Caliciopsis pinea) Damage Associated with the Declining Growth and Climatic Stressors of Eastern White Pine (Pinus strobus)

“…This suggests that, in addition to site factors, an external force is likely influencing canker incidence and severity. Recent studies on other fungal pathogens have shown a marked increase in infection occurrence associated with changes in climate [64], which could also be driving the increase in Caliciopsis canker damage on white pine. In the present study, the year with the greatest number and width of cankers at each site was associated with a drought period ( Figure 6A, Figure 7A).…”

Silviculture in the United States: An Amazing Period of Change over the Past 30 Years

“…Changes in disturbance regimes, host population structure, and environmental conditions have also led to increasing effects of native plants, insects, and pathogens on forest health in various regions of the United States (Royo and Carson 2006, Weed et al 2013, Wyka et al 2017. As with non-natives, these stressors have created novel conditions over large portions of the landscape that require similar integrated and adaptive approaches to those applied to non-native species.…”