Tridimensional green biomass measures of Shenyang urban forests

In order to study the measurement method of urban forest tridimensional green biomass(TGB) and its ratio of precision with true color aerial photo and ARC/GIS,using a method of "estimating tridimensional volume by tridemensional volume",the TGB of urban forests of Shenyang in August 2001 was measured.TGB per unit area of recreation forests was 5.35 m³/m²,which was the highest of urban forest types.The TGB of subordinated forests,road forests,ecological and public welfare forests,and production and management forests were 4.93,3.65,3.62 and 2.35 m³/m².TGB per unit area in urban forest distribution area was 4.25 m³/m² and that in Shenyang urban area was 0.35 m³/m².Total TGB of Shenyang urban forests was 161 296 716.85 m³.Subordinated forests,ecological and public welfare forests,landscape and relaxation forests,road forests,and production and management forests accounted for 37.27%,26.86%,18.90%,14.78% and 2.19% of the total,and their TGB were 60 116 966.36,43 321 771.43,30 482 879.04,23 841 208.75 and 3 533 891.27 m³ respectively.Having checked this method,its ratio of precision was up to 85.50%(α=0.05).