Impacts of Climate and Insect Herbivory on Productivity and Physiology of Trembling Aspen (Populus tremuloides) in Alaskan Boreal Forests

Authors

Melissa A. Boyd, Northern Arizona University
Logan T. Berner, Northern Arizona University
Patricia Doak, University of Alaska Fairbanks
Scott J. Goetz, Northern Arizona University
Brendan M. Rogers, Woods Hole Research Center
Diane Wagner, University of Alaska Fairbanks
Xanthe J. Walker, Northern Arizona University
Michelle C. Mack, Northern Arizona University

Document Type

Article

Author ORCID Identifier

Melissa A. Boyd https://orcid.org/0000-0003-2681-8567

Logan T. Berner https://orcid.org/0000-0001-8947-0479

Scott J. Goetz https://orcid.org/0000-0002-6326-4308

Brendan M. Rogers https://orcid.org/0000-0001-6711-8466

Diane Wagner https://orcid.org/0000-0003-0504-4929

Xanthe J. Walker https://orcid.org/0000-0002-2448-691X

Michelle C. Mack https://orcid.org/0000-0003-1279-4242

Journal/Book Title/Conference

Environmental Research Letters

Volume

14

Publisher

Institute of Physics Publishing Ltd.

First Page

1

Last Page

11

Publication Date

8-2-2019

Creative Commons License

This work is licensed under a Creative Commons Attribution 3.0 License.

Abstract

Climate change is impacting forested ecosystems worldwide, particularly in the Northern Hemisphere where warming has increased at a faster rate than the rest of the globe. As climate warms, trembling aspen (Populus tremuloides) is expected to become more successful in northern boreal forests because of its current presence in drier areas of North America. However, large-scale productivity decline of aspen has recently been documented throughout the United States and Canada as a result of drought and insect outbreaks. We used tree ring measurements (basal area increment (BAI) and stable carbon isotopes (δ 13C)) and remote sensing indices of vegetation productivity (NDVI) to study the impact of climate and damage by the aspen epidermal leaf miner (Phyllocnistis populiella) on aspen productivity and physiology in interior Alaska. We found that productivity decreased with greater leaf mining and was not sensitive to growing season (GS) moisture availability. Although productivity decreased during high leaf mining years, it recovered to pre-outbreak levels during years of low insect damage, suggesting a degree of resilience to P. populiella mining. Climate and leaf mining interacted to influence tree ring δ 13C, with greater leaf mining resulting in decreased δ 13C when GS moisture availability was low. We also found that NDVI was negatively associated with leaf mining, and positively correlated with BAI and the δ 13C decrease corresponding to mining. This suggests that NDVI is capturing not only variations in productivity, but also changes in physiology associated with P. populiella. Overall, these findings indicate that the indirect effects of P. populiella mining have a larger impact on aspen productivity and physiology than climate under current conditions, and is essential to consider when assessing growth, physiology and NDVI trends in interior Alaska.

Recommended Citation

Melissa A Boyd et al 2019 Environ. Res. Lett. 14 085010