Abstract: In this paper, the acute toxicity of glyphosate and acetochlor on Dugesia japonica and the impact of these two chemicals on the ingestion and regeneration of D. japonica were studied. The results showed that the 24 h and 48 h LC₅₀ of glyphosate and acetochlor on D. japonica was 41.78 and 12.22 mg·L^-1, and 35.48 and 8.41 mg·L^-1, respectively. Glyphosate at the concentration of >6.20 mg·L^-1 and acetochlor at the concentration >1.0 mg·L^-1 impact the regeneration of D. japonica（P<0.05）significantly, but the impact decreased gradually with exposure time. If taking 84 hours after operation as a standard, D. japonica could regenerate well in glyphosate and acetochlor solutions at most of test concentrations except at 1.40 mg·L^-1 and 2.00 mg·L^-1 of acetochlor. It was indicated that comparing with glyphosate, acetochlor had stronger acute toxicity and stronger impact on D. japonica and its ingestion and regeneration, and D. japonica could be used as a bio-indicator to monitor glyphosate and acetochlor contamination.

Key words: driving force, Pan-Pearl River basin, land use, Guangdong-Hong Kong-Marco Greater Bay Area, spatiotemporal evolution characteristics