Back to Search
Start Over
Steal the light: shade vs fire adapted vegetation in forest-savanna mosaics.
- Source :
-
The New phytologist [New Phytol] 2018 Jun; Vol. 218 (4), pp. 1419-1429. Date of Electronic Publication: 2018 Mar 31. - Publication Year :
- 2018
-
Abstract
- Shade cast by trees, which suppresses grass growth, and fire fuelled by grass biomass, which prevents tree sapling establishment, are mutually exclusive and self-reinforcing drivers of biome distribution in savanna-forest mosaics. We investigated how shade depth, represented by canopy leaf area index (LAI), is generated by adult trees across savanna-forest boundaries and how a shade gradient filters tree functioning, and grass composition and biomass. Forest trees exerted greater shading through increased stem density and greater light interception per unit biomass. A critical transition at LAI c. 1.5 was linked to tree shifts from savanna to forest species, functional shifts from fire-tolerant to light-competitive species, and grass composition shifts from C <subscript>4</subscript> to C <subscript>3</subscript> pathways. A second transition to grass fuel loads too low to support fires, occurred at a lower canopy density (LAI > 0.5), accompanied by shifts in C <subscript>4</subscript> subtype dominance. This pattern suggests that shade suppression of grass biomass is an essential first step for the maintenance of alternative stable states.<br /> (© 2018 The Authors. New Phytologist © 2018 New Phytologist Trust.)
Details
- Language :
- English
- ISSN :
- 1469-8137
- Volume :
- 218
- Issue :
- 4
- Database :
- MEDLINE
- Journal :
- The New phytologist
- Publication Type :
- Academic Journal
- Accession number :
- 29604213
- Full Text :
- https://doi.org/10.1111/nph.15117