Abstract:

It has been found that leaf anatomical characters would change with environmental factors. The function of leaf was associated with its structure, and its photosynthesis process would cause carbon isotope discrimination, especially. For analyzing the relationship between foliar δ₁₃C values in plants and their leaves anatomical characters, six species samples in karst rocky desertification areas were analyzed. The results showed that the leaves anatomical characters were different among those plant species in karst rocky desertification areas. Generally, the foliar δ₁₃C values increased with the thickness of assimilation tissue, the density of stomata, and the thickness of lower cuticle. Moreover, the correlation analysis indicated that the leading factors of anatomical characters were different. Namely, the leading factor of Broussonetia papyriferawas the thickness of lower cuticle, while that for Pistacia weinmannifoliawas the ratio of palisade to sponge, and the leading factor of Mallotus repandus and Mallotus japonicusvar. floccosuswas the thickness of palisade layer. However, there was no leading factor for some species like Alangium chinense and Alchornea trewioides which would means more comprehensive influences acted on them. In generally, the drought resistance and photosynthesis ration of leaves increased with their structure characters in case of rocky desertification; and leaves δ₁₃C values increased with a stronger desertification degree which indicated the increasing of water use efficiency (WUE) in plants.

Key words: foliar δ₁₃C values, leaf anatomical characters, rocky desertification, karst gorge