Initial effects of burn piles on vegetation and soil following conifer removal from a montane meadow Sheena Hillstrom 2007-2008 SEEDS Fellow Washington State University Charles Halpern University of Washington
Background Encroachment of montane meadows by conifers
Restoration challenges Background
Background Slash disposal
1997 Study Site 1959
Study Site
Study Site January 2006
Study Site November 2006
Study Questions • Do vegetation or soil characteristics vary with distance from the center of the burn scars? • Do burning effects extend beyond the burn scars?
Experimental Design Lower intensity burn (charcoal, duff) C Soil cores E U1 20x50 cm Higher intensity U2 quadrat burn (ash) Analysis: One-way ANOVA, post-hoc tests of means
Results Ground-surface conditions B a re g ro u n d a 8 0 p < 0 .0 0 1 Cover (%) 6 0 4 0 2 0 b b b 0 C E U 1 U 2 P o sitio n F in e litte r p < 0 .0 0 1 8 0 b b b Cover (%) 6 0 Central area: white ash 4 0 2 0 Outer ring: blackened duff, charcoal a 0 C E U 1 U 2 P o sitio n
Results Soil physical properties 1.0 Bulk Density 0.8 Bulk Density (g/L) 0.6 0.4 0.2 0.0 C E U2 Position
Results Soil chemical properties 1 4 T o ta l C T o ta l N 0 .8 p = 0 .3 7 p = 0 .9 1 1 2 0 .6 1 0 C (%) N (%) 8 0 .4 6 4 0 .2 2 0 0 .0 2 5 C :N r a tio p = 0 .0 3 2 p H p < 0 .0 0 1 7 .0 a 2 0 b a b a b 6 .5 a b C:N ratio b b 1 5 pH 6 .0 1 0 5 .5 5 0 0 .0 C E U 1 U 2 C E U 1 U 2 P o s itio n P o s itio n
Results Available N 200 200 NH 4 +- N + NO 3 - - N (mg/kg) + - N - - N + - N and NO - - N NH 4 NO NH 4 3 200 3 a p < 0.001 p = 0.002 a NH 4 +- N (mg/kg) NO 3 - - N (mg/kg) 150 150 p < 0.001 150 100 100 100 b b 50 50 c b 50 c b ab a b a 0 0 0 C E U1 U2 C E U1 U2 C E U1 U2 Position Position Position
Results Vegetation responses 14 Species richness Total plant cover No. species / quadrat Total plant cover (%) 75 p < 0.001 p < 0.001 12 b b 10 c 50 8 c 6 25 4 b a 2 a a 0 0 C E U1 U2 C E U1 U2 Position Position
Results Meadow and forest species No. meadow species / quadrat No. Forest species / quadrat 5 6 Meadow species richness Forest species richness 5 4 p < 0.001 p < 0.001 b b c c 4 3 3 2 b 2 a 1 1 a a 0 0 Meadow species cover (%) Forest species cover (%) Meadow species cover Forest species cover 50 30 b b p < 0.001 p < 0.001 b b 40 20 30 20 10 a 10 a a a 0 0 C E U1 U2 C E U1 U2 Position Position
Conclusions Pile burning has sever but local effects on soil and vegetation. Effects on soil N are likely to be short lived.
Conclusions No direct effects on adjacent unburned soils or vegetation. Some survival or rapid colonization of burn edges by meadow species.
Conclusions Little evidence of ruderal species. Minimal establishment of conifer seedlings.
Acknowledgements Melon Foundation SEEDS Joint Fire Science Program
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