Application of Dry-Weight-Rank Method in estimating biomass of natural grassland

Dry-Weight-Rank Method (DWR) is a method of estimating the substance and biomass of grassland through the corrected quadrat and establishing the calculation models. The method was originally widely used in pasture, rarely for grassland. However, in recent years, it had been gradually extending to grassland in Australia and Europe. To prove that if this method could apply to the investigation of grassland, we chose the alpine meadows of Luqu in the south of Gansu Province and the typical steppe of Siziwangqi in Inner Mongolia as the study area, which used to compare the dominant species and aboveground biomass using DWR and conventional method (CM). The results showed that the dominant species are Kobresia pygmaea, Carex atrofusca, Potentilla anserine by CM and Kobresia pygmaea, Poa pratensis, Potentilla anserine by DWR in alpine meadow, and Stipa krylovii. Agropyron cristatum, Cleistogenes squarrosa by CM and DWR in typical steppe. There were no significant difference in the total aboveground biomass in alpine meadow (73.18 g·m-2, DWR；82.84 g·m-2，CM) （P>0.05）and the same applies to typical steppe (89.67 g·m-2, DWR；88.10 g·m-2，CM)（P>0.05) between two methods. In a conclusion, DWR is suitable to a certain extent for evaluation of natural grassland in China.