| Autor: |
Levesque M; Forest Management Group, Department of Environmental Systems Science, Institute of Terrestrial Ecosystems, ETH Zurich, 8092, Zurich, Switzerland. mathieu.levesque@usys.ethz.ch.; Tree-Ring Laboratory, Lamont-Doherty Earth Observatory of Columbia University, Palisades, NY, 10964, USA. mathieu.levesque@usys.ethz.ch., Andreu-Hayles L; Tree-Ring Laboratory, Lamont-Doherty Earth Observatory of Columbia University, Palisades, NY, 10964, USA. lah@ldeo.columbia.edu., Smith WK; School of Natural Resources and the Environment, University of Arizona, Tucson, AZ, 85721, USA., Williams AP; Tree-Ring Laboratory, Lamont-Doherty Earth Observatory of Columbia University, Palisades, NY, 10964, USA., Hobi ML; SILVIS Lab, Department of Forest and Wildlife Ecology, University of Wisconsin-Madison, Madison, WI, 53706, USA.; WSL Swiss Federal Institute for Forest, Snow and Landscape Research, 8903, Birmensdorf, Switzerland., Allred BW; W.A. Franke College of Forestry and Conservation, University of Montana, Missoula, MT, 59812, USA.; Numerical Terradynamic Simulation Group, University of Montana, Missoula, MT, 59812, USA., Pederson N; Harvard Forest, Harvard University, Petersham, MA, 01366, USA. |
| Abstrakt: |
Historical and future trends in net primary productivity (NPP) and its sensitivity to global change are largely unknown because of the lack of long-term, high-resolution data. Here we test whether annually resolved tree-ring stable carbon (δ 13 C) and oxygen (δ 18 O) isotopes can be used as proxies for reconstructing past NPP. Stable isotope chronologies from four sites within three distinct hydroclimatic environments in the eastern United States (US) were compared in time and space against satellite-derived NPP products, including the long-term Global Inventory Modeling and Mapping Studies (GIMMS3g) NPP (1982-2011), the newest high-resolution Landsat NPP (1986-2015), and the Moderate Resolution Imaging Spectroradiometer (MODIS, 2001-2015) NPP. We show that tree-ring isotopes, in particular δ 18 O, correlate strongly with satellite NPP estimates at both local and large geographical scales in the eastern US. These findings represent an important breakthrough for estimating interannual variability and long-term changes in terrestrial productivity at the biome scale. |
