Separating Trends in Whitebark Pine Radial Growth Related to Climate and Mountain Pine Beetle Outbreaks in the Northern Rocky Mountains, USA

Abstract

Drought and mountain pine beetle (Dendroctonus ponderosae Hopkins) outbreaks have affected millions of hectares of high-elevation conifer forests in the Northern Rocky Mountains during the past century. Little research has examined the distinction between mountain pine beetle outbreaks and climatic influence on radial growth in endangered whitebark pine (Pinus albicaulis Engelm.) ecosystems. We used a new method to explore divergent periods in whitebark pine radial growth after mountain pine beetle outbreaks across six sites in western Montana. We examined a 100-year history of mountain pine beetle outbreaks and climate relationships in whitebark pine radial growth to distinguish whether monthly climate variables or mountain pine outbreaks were the dominant influence on whitebark pine growth during the 20th century. High mortality of whitebark pines was caused by the overlapping effects of previous and current mountain pine beetle outbreaks and white pine blister rust infection. Wet conditions from precipitation and snowpack melt in the previous summer, current spring, and current summer benefit whitebark pine radial growth during the following growing season. Whitebark pine radial growth and climate relationships were strongest in sites less affected by the mountain pine beetle outbreaks or anthropogenic disturbances. Whitebark pine population resiliency should continue to be monitored as more common periods of drought will make whitebark pines more susceptible to mountain pine beetle attack and to white pine blister rust infection.

Радіальні Прирости Деревостанів Рекреаційно-Оздоровчих Лісів Придністровського Передкарпаття (Івано-Франківська Область)

“…З внутрішніх чинників найбільший вплив мають порода дерева [14,21,26], спадкова індивідуальна мінливість, вік і плодоношення [1,5,11]. Із зовнішніх факторів на величину приросту впливають широтні, поздовжні і висотні градієнти умов місцезростання дерев [3,12,22], температура повітря і опади [4,9,12,21], ґрунтові умови [17], фітоценотичні взаємини [11,19], різного роду катастрофи (пожежі [2], вітровали і буреломи [7], хвороби, напади шкідливих комах [20,27]), господарська діяльність людини [10,15,18] та інші фактори.…”

Radial increment in European spruce (Picea abies) as indicator of sanitary condition of spruce forests in the Ukrainian Carpathians

“…Among the internal factors, the greatest effects are related to the species of the tree (Magnuszewski et al, 2015;Sitková et al, 2018, Burri et al, 2019, inherited individual variability, age and fruiting (Ding et al, 2017;Latreille et al, 2017;Buras et al, 2018). The most influential external factors are latitudinal, longitudinal and height gradients of the conditions of growth locations of the trees (Magnuszewski et al, 2015;Matskovsky, 2016;Chen, 2017;Gao et al, 2018), air temperature and precipitations (Natalini et al, 2015;Rybníček et al, 2016;Rozas & Olano, 2017), wind (Dinulica et al, 2016), mist (Myskow et al, 2019), soil conditions (Mendivelso et al, 2016), phytocenosis relations (Latreille et al, 2017;Moreau et al, 2019), catastrophes of various origin: fires (Gao et al, 2017), windthrows and windsnaps (Holeska et al, 2016), diseases, attacks of harmful insects (Brygadyrenko, 2016;Faly et al, 2017;Van de Gevel et al, 2017;, summer and winter droughts, emissions of CO 2 (Cavlovic et al, 2015;Svobodova et al, 2019), heavy frosts during snowless periods (Su-vanto et al, 2017), and also agricultural activity by humans (Montoro Girona et al, 2016;Tyukavina et al, 2017;Wang et al, 2018). Forest felling, meso-and macro scale effects on the environment lead to negative tendencies of radial increment and deforestation (Rodriguez-Caton, 2015).…”

Is Resistance to Mountain Pine Beetle Associated with Genetic Resistance to White Pine Blister Rust in Limber Pine?

“…Within the MPB distribution in the western United States, the coldest night of the year has warmed approximately 4 • C since 1960 [5,6]. Since air temperatures have been increasingly more favorable for MPB overwinter survival, recent outbreaks are putting high elevation pines such as limber pine and whitebark pine at risk of population decline [7][8][9][10][11][12]. Limber pine is a preferred host of MPB for reproduction, development, and survival [13].…”