TY - JOUR
T1 - Plant functional type aboveground biomass change within Alaska and northwest Canada mapped using a 35-year satellite time series from 1985 to 2020
AU - Orndahl, Kathleen M.
AU - Macander, Matthew J.
AU - Berner, Logan T.
AU - Goetz, Scott J.
N1 - Funding Information:
This research was supported by the National Science Foundation Graduate Research Fellowship under Grant No. 1938054 (to KMO) and NASA ABoVE Grants NNX17AE44G and 80NSSC19M0112 (to SJG). Additional support was provided by NASA New Investigator Program Grant 80NSSC21K1364 (to LTB). The authors extend thanks to all those who assisted in collecting the high-quality field data that made this research possible: Craig Townsend, Joël Potié, Elis Juhlin, Abby Rutrough, Aerin Jacob, Kayla Arey, Laurence Carter, Martin Kienzler, Sonny Parker, Hayleigh Conway and Andrew Davies. Data analysis was facilitated by NAU’s Monsoon computing cluster, funded by Arizona’s Technology and Research Initiative Fund. The authors thank the Monsoon team for technical assistance during data analysis. Analyses were improved by feedback from GEODE lab members at Northern Arizona University (NAU), and the manuscript was much improved by feedback from three anonymous reviewers.
Publisher Copyright:
© 2022 The Author(s). Published by IOP Publishing Ltd.
PY - 2022/11/1
Y1 - 2022/11/1
N2 - Changes in vegetation distribution are underway in Arctic and boreal regions due to climate warming and associated fire disturbance. These changes have wide ranging downstream impacts—affecting wildlife habitat, nutrient cycling, climate feedbacks and fire regimes. It is thus critical to understand where these changes are occurring and what types of vegetation are affected, and to quantify the magnitude of the changes. In this study, we mapped live aboveground biomass for five common plant functional types (PFTs; deciduous shrubs, evergreen shrubs, forbs, graminoids and lichens) within Alaska and northwest Canada, every five years from 1985 to 2020. We employed a multi-scale approach, scaling from field harvest data and unmanned aerial vehicle-based biomass predictions to produce wall-to-wall maps based on climatological, topographic, phenological and Landsat spectral predictors. We found deciduous shrub and graminoid biomass were predicted best among PFTs. Our time-series analyses show increases in deciduous (37%) and evergreen shrub (7%) biomass, and decreases in graminoid (14%) and lichen (13%) biomass over a study area of approximately 500 000 km2. Fire was an important driver of recent changes in the study area, with the largest changes in biomass associated with historic fire perimeters. Decreases in lichen and graminoid biomass often corresponded with increasing shrub biomass. These findings illustrate the driving trends in vegetation change within the Arctic/boreal region. Understanding these changes and the impacts they in turn will have on Arctic and boreal ecosystems will be critical to understanding the trajectory of climate change in the region.
AB - Changes in vegetation distribution are underway in Arctic and boreal regions due to climate warming and associated fire disturbance. These changes have wide ranging downstream impacts—affecting wildlife habitat, nutrient cycling, climate feedbacks and fire regimes. It is thus critical to understand where these changes are occurring and what types of vegetation are affected, and to quantify the magnitude of the changes. In this study, we mapped live aboveground biomass for five common plant functional types (PFTs; deciduous shrubs, evergreen shrubs, forbs, graminoids and lichens) within Alaska and northwest Canada, every five years from 1985 to 2020. We employed a multi-scale approach, scaling from field harvest data and unmanned aerial vehicle-based biomass predictions to produce wall-to-wall maps based on climatological, topographic, phenological and Landsat spectral predictors. We found deciduous shrub and graminoid biomass were predicted best among PFTs. Our time-series analyses show increases in deciduous (37%) and evergreen shrub (7%) biomass, and decreases in graminoid (14%) and lichen (13%) biomass over a study area of approximately 500 000 km2. Fire was an important driver of recent changes in the study area, with the largest changes in biomass associated with historic fire perimeters. Decreases in lichen and graminoid biomass often corresponded with increasing shrub biomass. These findings illustrate the driving trends in vegetation change within the Arctic/boreal region. Understanding these changes and the impacts they in turn will have on Arctic and boreal ecosystems will be critical to understanding the trajectory of climate change in the region.
KW - aboveground biomass
KW - fire
KW - Landsat
KW - plant functional type
KW - remote sensing
KW - tundra
KW - UAV
UR - http://www.scopus.com/inward/record.url?scp=85141928904&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85141928904&partnerID=8YFLogxK
U2 - 10.1088/1748-9326/ac9d50
DO - 10.1088/1748-9326/ac9d50
M3 - Article
AN - SCOPUS:85141928904
SN - 1748-9326
VL - 17
JO - Environmental Research Letters
JF - Environmental Research Letters
IS - 11
M1 - 115010
ER -