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Spatiotemporal remote sensing of ecosystem change and causation across Alaska.
Pastick, Neal J; Jorgenson, M Torre; Goetz, Scott J; Jones, Benjamin M; Wylie, Bruce K; Minsley, Burke J; Genet, Hélène; Knight, Joseph F; Swanson, David K; Jorgenson, Janet C.
Afiliação
  • Pastick NJ; Stinger Ghaffarian Technologies, Inc. (contractor to the U.S. Geological Survey), Sioux Falls, South Dakota.
  • Jorgenson MT; Department of Forest Resources, University of Minnesota, St. Paul, Minnesota.
  • Goetz SJ; Alaska Ecoscience, Fairbanks, Alaska.
  • Jones BM; School of Informatics, Computing, and Cyber Systems, Northern Arizona University, Flagstaff, Arizona.
  • Wylie BK; Alaska Science Center, U.S. Geological Survey, Anchorage, Alaska.
  • Minsley BJ; Earth Resources Observation and Science Center, U.S. Geological Survey, Sioux Falls, South Dakota.
  • Genet H; Crustal Geophysics and Geochemistry Science Center, U.S. Geological Survey, Denver, Colorado.
  • Knight JF; Institute of Arctic Biology, University of Alaska Fairbanks, Fairbanks, Alaska.
  • Swanson DK; Department of Forest Resources, University of Minnesota, St. Paul, Minnesota.
  • Jorgenson JC; National Park Service, Fairbanks, Alaska.
Glob Chang Biol ; 25(3): 1171-1189, 2019 03.
Article em En | MEDLINE | ID: mdl-29808518
ABSTRACT
Contemporary climate change in Alaska has resulted in amplified rates of press and pulse disturbances that drive ecosystem change with significant consequences for socio-environmental systems. Despite the vulnerability of Arctic and boreal landscapes to change, little has been done to characterize landscape change and associated drivers across northern high-latitude ecosystems. Here we characterize the historical sensitivity of Alaska's ecosystems to environmental change and anthropogenic disturbances using expert knowledge, remote sensing data, and spatiotemporal analyses and modeling. Time-series analysis of moderate-and high-resolution imagery was used to characterize land- and water-surface dynamics across Alaska. Some 430,000 interpretations of ecological and geomorphological change were made using historical air photos and satellite imagery, and corroborate land-surface greening, browning, and wetness/moisture trend parameters derived from peak-growing season Landsat imagery acquired from 1984 to 2015. The time series of change metrics, together with climatic data and maps of landscape characteristics, were incorporated into a modeling framework for mapping and understanding of drivers of change throughout Alaska. According to our analysis, approximately 13% (~174,000 ± 8700 km2 ) of Alaska has experienced directional change in the last 32 years (±95% confidence intervals). At the ecoregions level, substantial increases in remotely sensed vegetation productivity were most pronounced in western and northern foothills of Alaska, which is explained by vegetation growth associated with increasing air temperatures. Significant browning trends were largely the result of recent wildfires in interior Alaska, but browning trends are also driven by increases in evaporative demand and surface-water gains that have predominately occurred over warming permafrost landscapes. Increased rates of photosynthetic activity are associated with stabilization and recovery processes following wildfire, timber harvesting, insect damage, thermokarst, glacial retreat, and lake infilling and drainage events. Our results fill a critical gap in the understanding of historical and potential future trajectories of change in northern high-latitude regions.
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Texto completo: 1 Base de dados: MEDLINE Assunto principal: Mudança Climática / Monitoramento Ambiental / Ecossistema / Tecnologia de Sensoriamento Remoto Tipo de estudo: Prognostic_studies País/Região como assunto: America do norte Idioma: En Revista: Glob Chang Biol Ano de publicação: 2019 Tipo de documento: Article

Texto completo: 1 Base de dados: MEDLINE Assunto principal: Mudança Climática / Monitoramento Ambiental / Ecossistema / Tecnologia de Sensoriamento Remoto Tipo de estudo: Prognostic_studies País/Região como assunto: America do norte Idioma: En Revista: Glob Chang Biol Ano de publicação: 2019 Tipo de documento: Article