The drought stress and rehydration influence on chlorophyll fluorescence characteristics of Barbula reflexa (Brid.) Brid. in areas of puding karst rock desertification

摘要

Anshun city is located in the central Guizhou Province, at an average elevation of 1320 m, annual average temperature 15.1oC and annual average rainfall of 1397 mm. The soil in Anshun is predominately calcareous (accounting for 85%). Its forest coverage is 5 - 15%, the vegetation coverage is 10 - 90%, the bare rock is 30 - 90%, the land reclamation is 10 - 70%, and the average rocky desertification is 36.79%. Puding district in Anshun is taken as an example for ecological restoration and treatment research, which provides the basis for scientific selection of drought-resistant plants for cultivation in karst rocky desertification areas. Chlorophyll- fluorescence was measured in moss Erythrodontium julaceum (Schwaegr.) Par. When drought and rehydration affected chlorophyll content and fluorescence under increased drought stress, the total chlorophyll content first dropped and then increased gradually. F 0 and qN of E. julaceum increased while the F m , F v /F m , Yield, ETR and qP decreased with drought stress. Fluorescence parameters after rehydration were restored to normal levels by mild to moderate stress, and severe stress is more difficult to return to the control level.