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Vegetation Response to Elevated CO 2 Slows Down the Eastward Movement of the 100th Meridian
Author(s) -
Zhang Cicheng,
Yang Yuting,
Yang Dawen,
Wang Zhengrong,
Wu Xiuchen,
Zhang Shulei,
Zhang Wenjie
Publication year - 2020
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/2020gl089681
Subject(s) - arid , meridian (astronomy) , surface runoff , climatology , environmental science , climate change , vegetation (pathology) , physical geography , geology , geography , oceanography , ecology , physics , astronomy , medicine , paleontology , pathology , biology
The 100th meridian is a conceptual arid‐humid divide that effectively bisects the continent of the United States into the humid east and arid west. Here, we examine the historical and future shifts of the 100th meridian from atmospheric, hydrologic, and agroecological perspectives. We find that the effective arid‐humid divide regarding vegetation greenness and runoff has been moving toward west with a mean shift of 0.73° (1982–2015) and 2.08° (1961–2010), respectively, suggesting decreased agroecological and hydrologic aridity in the region. For future periods, the agroecological divide shows a persistent westward movement, whereas eastward shifts of the 100th meridian are detected from the atmospheric and hydrologic perspectives. Nevertheless, the eastward movements of the atmospheric and hydrologic divide substantially slow down when the vegetation response to elevated atmospheric CO 2 is accounted for. This finding demonstrates that CO 2 fertilization on vegetation could largely alleviate the warming‐induced drying tendency around the 100th meridian region.