Abstract: The study with two varieties of non-heading Chinese cabbage shade-tolerant ‘Aiwang’ and shade-sensitive ‘Lüyou’ showed that after shading, the total chlorophyll and chlorophyll b con-tents of ‘Aiwang’ went up greatly, but the net photosynthetic rate (P_n), light compensation point (LCP), light saturation point (LSP), apparent quantum yield (AQY) and carboxylation efficiency (CE) of both ‘Aiwang’ and ‘Lüyou’ all went down, and the decline of all test parameters except LCP was slighter for ‘Aiwang’ than for ‘Lüyou’. Under weak light condition, the PSⅡ of ‘Lüyou’ was injured, and as a result, the F_v/F_m, ETR, Φ_PSⅡ, and q_P of ‘Lüyou’ had a greater decline than those of ‘Aiwang’. In the chloroplast of ‘Lüyou’, cracks and foveolae appeared, most of stroma lamellae fractured, grana lamellae disaggregated, and mitochondria were nearly empty with the decrease of contents. In contrast, the chloroplast structure of ‘Aiwang’ was flawless, and its mitochondria grew well. It was suggested that weak light could damage the photosynthetic organization of plant, but different varieties showed different responses.

Key words: Ecological services, Sand-fixed poplar forest, Wind-declining index, Soil surface wind erosion, Dust retention