Initial effects of burn piles on vegetation and soil following - PowerPoint PPT Presentation

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