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Title: Influence of dynamic vegetation on carbon-nitrogen cycle feedback in the Community Land Model (CLM4)

Land carbon sensitivity to atmospheric CO 2 concentration (β L) and climate warming (γ L) is a crucial part of carbon-climate feedbacks in the earth system. Using the Community Land Model version 4 with a coupled carbon-nitrogen cycle, we examine whether the inclusion of a dynamic global vegetation model (CNDV) significantly changes the land carbon sensitivity from that obtained with prescribed vegetation cover (CN). For decadal timescale in the late twentieth century, β L is not substantially different between the two models but γ L of CNDV is stronger (more negative) than that of CN. The main reason for the difference in γL is not the concurrent change in vegetation cover driving the carbon dynamics, but rather the smaller nitrogen constraint on plant growth in CNDV compared with CN, which arises from the deviation of CNDV's near-equilibrium vegetation distribution from CN’s prescribed, historical land cover. The smaller nitrogen constraint makes the enhanced nitrogen mineralization with warming less effective in stimulating plant productivity to counter moisture stress in a warmer climate, leading to a more negative γ L. This represents a new indirect pathway that has not been identified for dynamic vegetation in the coupled carbon-nitrogen cycle to affect the terrestrialmore » carbon-climate feedbacks in the earth system.« less
Authors:
 [1] ;  [2] ;  [3] ;  [4]
  1. Univ. of Arizona, Tucson, AZ (United States). Dept. of Hydrology and Atmospheric Sciences; Pacific Northwest National Lab. (PNNL), Richland, WA (United States)
  2. Univ. of Arizona, Tucson, AZ (United States). Dept. of Hydrology and Atmospheric Sciences
  3. Pacific Northwest National Lab. (PNNL), Richland, WA (United States)
  4. Chinese Academy of Sciences (CAS), Beijing (China). Inst. of Atmospheric Physics, International Center for Climate and Environment Sciences
Publication Date:
Report Number(s):
PNNL-SA-115218
Journal ID: ISSN 1748-9326; KP1703010
Grant/Contract Number:
AC05-76RL01830; SC0006693
Type:
Published Article
Journal Name:
Environmental Research Letters
Additional Journal Information:
Journal Volume: 11; Journal Issue: 12; Journal ID: ISSN 1748-9326
Publisher:
IOP Publishing
Research Org:
Pacific Northwest National Lab. (PNNL), Richland, WA (United States)
Sponsoring Org:
USDOE; National Science Foundation (NSF)
Country of Publication:
United States
Language:
English
Subject:
60 APPLIED LIFE SCIENCES; dynamic vegetation; carbon cycle; carbon-nitrogen cycle
OSTI Identifier:
1337200
Alternate Identifier(s):
OSTI ID: 1353351