Total aboveground plant biomass is more strongly affected by climate than species diversity on a grassland in Liaoning, China

The objective of this study was to analyze the relationshipsbetween total aboveground plant biomass versus altitude, latitude,longitude, mean annual temperature, mean annual precipitation,and species diversity. Simple linear regression analysis was usedto study these relationships. Results showed that altitude was significantly,positively (R2= 0.038, P<0.01) related with total plant abovegroundbiomass. Meanwhile, when longitude (R2= 0.124, P<0.001)and latitude (R2= 0.221, P<0.001) increased, total aboveground biomassdecreased. The relationship between biomass and mean annualprecipitation was significantly, positively linear (R2= 0.149, P<0.001).Mean annual temperature was significantly, negatively correlatedwith biomass (R2= 0.145, P<0.001). The relationship between speciesdiversity and biomass was significant, but relatively weaker (i.e.,R2<0.063, P<0.05) compared with those for the climatic variables.This is, species diversity explained less than 7% of the total variabilityin total aboveground plant biomass. This result agrees with theidiosyncratic response hypothesis which suggests that ecosystem functionchanges when species diversity changes, but the magnitude anddirection of these changes are unpredictable because the roles of individualplant species are complex and varied.