|
Titel |
Cajander larch (Larix cajanderi) biomass distribution, fire regime and post-fire recovery in northeastern Siberia |
VerfasserIn |
L. T. Berner, P. S. A. Beck, M. M. Loranty, H. D. Alexander, M. C. Mack, S. J. Goetz |
Medientyp |
Artikel
|
Sprache |
Englisch
|
ISSN |
1726-4170
|
Digitales Dokument |
URL |
Erschienen |
In: Biogeosciences ; 9, no. 10 ; Nr. 9, no. 10 (2012-10-15), S.3943-3959 |
Datensatznummer |
250007330
|
Publikation (Nr.) |
copernicus.org/bg-9-3943-2012.pdf |
|
|
|
Zusammenfassung |
Climate change and land-use activities are increasing fire activity across
much of the Siberian boreal forest, yet the climate feedbacks from forest
disturbances remain difficult to quantify due to limited information on
forest biomass distribution, disturbance regimes and post-disturbance
ecosystem recovery. Our primary objective here was to analyse post-fire
accumulation of Cajander larch (Larix cajanderi Mayr.) aboveground
biomass for a 100 000 km2 area of open forest in far northeastern
Siberia. In addition to examining effects of fire size and topography on
post-fire larch aboveground biomass, we assessed regional fire rotation and
density, as well as performance of burned area maps generated from MODIS
satellite imagery. Using Landsat imagery, we mapped 116 fire scar perimeters
that dated c. 1966–2007. We then mapped larch aboveground biomass by linking
field biomass measurements to tree shadows mapped synergistically from
WorldView-1 and Landsat 5 satellite imagery. Larch aboveground biomass tended
to be low during early succession (≤ 25 yr, 271 ± 26 g m−2,
n = 66 [mean ± SE]) and decreased with increasing elevation and
northwardly aspect. Larch aboveground biomass tended to be higher during
mid-succession (33–38 yr, 746 ± 100 g m−2, n = 32), though was
highly variable. The high variability was not associated with topography and
potentially reflected differences in post-fire density of tree regrowth.
Neither fire size nor latitude were significant predictors of post-fire larch
aboveground biomass. Fire activity was considerably higher in the Kolyma
Mountains (fire rotation = 110 yr, fire density = 1.0 ±
1.0 fires yr−1 × 104 km−2) than along the forest-tundra
border (fire rotation = 792 yr, fire density = 0.3 ±
0.3 fires yr−1 × 104 km−2). The MODIS burned area maps
underestimated the total area burned in this region from 2000–2007 by
40%. Tree shadows mapped jointly using high and medium resolution
satellite imagery were strongly associated (r2 ≈ 0.9) with field
measurements of forest structure, which permitted spatial extrapolation of
aboveground biomass to a regional extent. Better understanding of forest
biomass distribution, disturbances and post-disturbance recovery is needed
to improve predictions of the net climatic feedbacks associated with
landscape-scale forest disturbances in northern Eurasia. |
|
|
Teil von |
|
|
|
|
|
|