摘要
Aims Ubiquitous thermal acclimation of leaf respiration could mitigate the respiration increase.However,whether species of different plant functional groups showing distinct or similar acclimation justifies the simple prediction of respiratory carbon(C)loss to a warming climate.Methods In this study,leaf dark respiration(Rd)of illinois bundleflower(IB,legume),stiff goldenrod(GR,C_(3) forbs),indian grass,little bluestem and king ranch bluestem(IG,LB and KB,C_(4) grass)were measured with detached leaves sampled in a 17-year warming experiment.Important Findings The results showed that Rd at 20℃ and 22℃(R_(20) and R_(22))were significantly lower in the warming treatment for all the five species.Lower R_(22) in warmed than R_(20) in control in GR,KB,LB and IG imply acclimation homeostasis,but not in IB.The significant decline in temperature sensitivity of respiration(Q_(10))of GR resulted in the marginal reduction of Q_(10) across species.No significant changes in Q_(10) of C_(4) grasses suggest different acclimation types for C_(3) forbs and C_(4) grass.The magnitude of acclimation positively correlated with leaf C/N.Our results suggest that non-legume species had a rela-tive high acclimation,although the acclimation type was different between C_(3) forbs and C_(4) grasses,and the legume species displayed no acclimation in Rd.Thus,the plant functional types should be taken into account in the grassland ecosystem C models.
