ABOVE-AND BELOW-GROUND BIOMASS RELATIONSHIPS IN CHINA'S GRASSLAND VEGETATION
Large grassland biomass stores in belowground,which plays a significant role in ecosystem carbon store and carbon sequestration.Due to the lack of below-ground biomass data,Root:shoot ratio (R/S) or the relationship between above-ground biomass (AGB) and below-ground biomass (BGB) have been used to estimate belowground biomass.By available published grassland biomass data in 2004～2010,the paper explored the R/S and the relationship between above-and below-ground biomass in six grassland types,such as alpine meadow,alpine steppe,temperate desert steppe,temperate meadow steppe,montane meadow,temperate steppe.The results showed that R/S was significantly different in all grassland types (F =3.542,p＜0.01),and R/S of montane meadow was significantly different from other grassland types (p＜0.01).Temperate meadow steppe and temperate desert steppe had relatively higher R/S,the means of which were 7.0 and 6.8,respectively.There were evidence of positive effects of mean annual precipitation on AGB and BGB,and negative effects on R/S.The effects of mean annual temperature on AGB,BGB and R/S were different with that of mean annual precipitation.Although mean annual temperature had the positive effects on AGB,the effects on BGB and R/S were not significant.In order the better to analyze how to estimate BGB based on AGB,the paper explored the relationship between above-and below-ground biomass.The results showed that BGB was significantly positive correlated with AGB in alpine steppe (R2 =0.67) ＞temperate desert steppe (R2 =0.36) ＞alpine meadow (R2 =0.13).The power function fitted well with the relationship between BGB and AGB for these three types of grassland.The relationship between above-and below-ground biomass was not found in other three types of grassland.It was evident that both R/S and the relationship between AGB and BGB must be considered together when BGB was estimated.
grasslandabove-ground biomassbelow-ground biomassroot∶ shoot ratio
NETL
NSTL
万方数据
维普
