Preprints
https://doi.org/10.5194/gmd-2021-116
https://doi.org/10.5194/gmd-2021-116

Submitted as: development and technical paper 02 Jun 2021

Submitted as: development and technical paper | 02 Jun 2021

Review status: a revised version of this preprint was accepted for the journal GMD and is expected to appear here in due course.

Modeling the short-term fire effects on vegetation dynamics and surface energy in Southern Africa using the improved SSiB4/TRIFFID-Fire model

Huilin Huang1, Yongkang Xue1,2, Ye Liu1, Fang Li3, and Gregory Okin1 Huilin Huang et al.
  • 1Department of Geography, University of California, Los Angeles, CA 90095, USA
  • 2Department of Atmospheric & Oceanic Sciences, University of California, Los Angeles, CA 90095, USA
  • 3International Center for Climate and Environmental Sciences, Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing, China

Abstract. Fire causes abrupt changes in vegetation properties and modifies flux exchanges between land and atmosphere at subseasonal to seasonal scales. Yet these short-term fire effects on vegetation dynamics and surface energy balance have not been comprehensively investigated in the vegetation model coupled with the fire module. This study applies the SSiB4/TRIFFID-Fire model to study the short-term fire impact in Southern Africa with comprehensive evaluations of simulated fire regimes, vegetation productivity, and surface fluxes. We find an annual average reduction in grass cover by 4–8 % for widespread areas between 5–20° S and a tree cover reduction by 1 % at the southern periphery of tropical rainforests. The fire effects on regional scales accumulate during June–October and peak in November, the beginning of the rainy season. After the fire season ends, the grass cover quickly returns to unburned conditions before the next fire season, while the tree fraction hardly recovers in one rainy season. The vegetation clearance by fire has reduced the leaf area index (LAI) and gross primary productivity (GPP) by 3–5 % and 5–7 % annually, respectively. The exposure of bare soil has enhanced surface albedo and therefore decreased the absorption of shortwave radiation. Annual mean sensible heat has dropped by 1.4 W m−2 while the latent heat reduction is small (0.1 W m−2) due to the compensating effects between canopy transpiration and soil evaporation. A slight warming effect is simulated after fire, which could be enhanced when the surface darkening effect is incorporated.

Huilin Huang et al.

Status: closed

Comment types: AC – author | RC – referee | CC – community | EC – editor | CEC – chief editor | : Report abuse
  • RC1: 'Comment on gmd-2021-116', Anonymous Referee #1, 28 Jul 2021
    • AC1: 'Response to Reviewer #1', Huilin Huang, 07 Nov 2021
  • RC2: 'Comment on gmd-2021-116', Anonymous Referee #2, 12 Oct 2021
    • AC2: 'Response to Reviewer #2', Huilin Huang, 07 Nov 2021

Status: closed

Comment types: AC – author | RC – referee | CC – community | EC – editor | CEC – chief editor | : Report abuse
  • RC1: 'Comment on gmd-2021-116', Anonymous Referee #1, 28 Jul 2021
    • AC1: 'Response to Reviewer #1', Huilin Huang, 07 Nov 2021
  • RC2: 'Comment on gmd-2021-116', Anonymous Referee #2, 12 Oct 2021
    • AC2: 'Response to Reviewer #2', Huilin Huang, 07 Nov 2021

Huilin Huang et al.

Huilin Huang et al.

Viewed

Total article views: 449 (including HTML, PDF, and XML)
HTML PDF XML Total BibTeX EndNote
334 106 9 449 3 4
  • HTML: 334
  • PDF: 106
  • XML: 9
  • Total: 449
  • BibTeX: 3
  • EndNote: 4
Views and downloads (calculated since 02 Jun 2021)
Cumulative views and downloads (calculated since 02 Jun 2021)

Viewed (geographical distribution)

Total article views: 361 (including HTML, PDF, and XML) Thereof 361 with geography defined and 0 with unknown origin.
Country # Views %
  • 1
1
 
 
 
 
Latest update: 27 Nov 2021
Download
Short summary
This study applies a fire-coupled dynamic vegetation model to quantify the fire impact at monthly to annual scales. We find fire reduces grass cover by 4–8 % annually for widespread areas in Southern Africa savanna and reduces tree cover by 1 % at the periphery of tropical Congolese rainforest. The grass cover reduction peaks at the beginning of the rainy season which quickly diminishes before the next fire season. In contrast, the reduction of tree cover is irreversible within one growing season.