关键词: 海拔, 酶活性, 有机碳矿化, 代谢熵, 年均温, 微生物熵

Abstract: It is widely accepted that light, one of the critical environmental factors, affects growth and distribution of plants. Leaf traits, which are of crucial importance to capture carbon, are generally consistent across environmental gradients. There are also similar patterns of correlations among different leaf traits, so it is essential to explore how leaf traits respond to and adapt to different light environments for a comprehensive understanding of ecosystem management. Our study aimed to investigate leaf traits and their correlations inside and outside the forests of three typical shrubs (i.e. Salix etosia, Rubus setchuenensis and Hydrangea aspera) in shrubgrassland of southern China. Field sampling survey was carried out to collect leaves under different light environments (inside and outside the forests) in Yunyang County. The results showed that the correlations among leaf traits of three shrubs vary one to another, i.e. speciesspecific. There was no significant difference in leaf traits of S. etosia under different light environments, while significant differences in leaf traits were found for R. setchuenensi and H. aspera. Both SLA and LNC of R. setchuenensi and H. aspera increased inside the forests for adapting to lower illuminance. In addition, LCC of H. aspera increased significantly inside the forests, which indicated a relatively strong carbon fixation capacity. Leaf traits of R. setchuenensis and H. aspera were mainly affected by soil temperature under different light environments. Our study demonstrated that there existed the phenotypic plasticity for plant leaf traits, and different plants had speciesspecific responses as well as strategies to adapt to different environments.

Key words: soil organic carbon mineralization, soil metabolic quotient, microbial quotient, mean annual temperature, elevation, enzymatic activity