Long-range estimation of leaf area index using airborne laser altimetry in Siberian boreal forest [Russian Federation]
2006
Kusakabe, T.(Waseda Univ., Tokyo (Japan)) | Tsuzuki, H. | Sweda, T.
Being the most extensively forested region of the world, the carbon budget of the Siberian boreal forest is one of the important subjects of global concern. This study was conducted to quantify leaf area index (LAD, one of the significant factors controlling terrestrial carbon budget, over an extensive range in Siberia as well as to propose a new method of LAI estimation using airborne laser altimetry. Along a 200-km transect set up along the Bakhta River, a tributary of the Yenisey in central Siberia, airborne laser altimetry was conducted to obtain a vegetation profile, from which the distribution of LAI all along the transect was estimate on the basis of allometric relationship among LAI, standing timber stock and vegetation profile area, using ground-truth measurements of LAI and timber stock at ten sample plots laid out directly beneath the flight track. It turned out that the distribution of LAI is controlled not only by temperature which in turn is dictated by the altitude down from the Central Siberian Plateau to the alluvial fiat of the Yenisey, but also significantly by the thickness of active layer on permafrost, which varies considerably both regionally and locally depending upon the topography. With the capability of measuring vegetation characteristics and topographic features simultaneously, airborne laser profiling should turn out to be a powerful tool for monitoring in an integrated manner the Siberian boreal forest and its environment threatened by the impending global warming.
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