Estimating net primary productivity of Chinese pine forests based on forest inventory data.

摘要

Forest inventory data (FID) include forest resources information at large spatial scale and long temporal scale. They are important data sources for estimating forest net primary productivity (NPP) and carbon budget at landscape and regional scales. More than 100 datasets of biomass, volume, NPP and stand age for Chinese pine (Pinus tabulaeformis) forests from the literature were synthesized to develop regression equations between biomass and volume, and between NPP and biomass as well as stand age. Using these regression equations and the fourth FID surveyed by the Forestry Ministry China from 1989 to 1993, NPP values of Chinese pine forests were estimated. The mean NPP of Chinese pine forests was 4.35 tonnes ha-1 year-1. NPP varied widely among provinces, ranging from 1.5 (Neimenggu) to 13.73 tonnes ha-1 year-1 (Guizhou). Total NPP of Chinese pine was 10.87 Tg year-1 (1 Tg=1012 g). NPP values of Chinese pine forests were not distributed evenly across different provinces in China. This study may be useful not only for estimating forest carbon of other forest types but also for evaluating terrestrial carbon balance at regional and global levels..