关键词: 崇义客家梯田系统, 生态服务功能, 生态补偿, 中国重要农业文化遗产, 价值评估

Abstract: A laboratory simulation experiment was conducted to investigate the effects of suspended solid on the survival, growth, and physiology of Mactra veneriformis. The M. veneriformis individuals were exposed to different concentrations of suspended solid (0 mg·L^-1 group A), 100 mg·L^-1 (group B), 1000 mg·L^-1 (group C), and 10000 mg·L^-1 (group D), and the changes of the superoxide dismutase (SOD) and catalase (CAT) activities in the visceral mass and gill filament of M. veneriformis were investigated. Under the stress of suspended solid, M. veneriformis appeared chronic toxic effect, with the survival and growth being inhibited to some extent. The gill SOD activity of the M. veneriformis exposed to 100 and 1000 mg·L^-1 of suspended solid produced an adaptive induced response, but that of the M. veneriformis exposed to 10000 mg·L^-1 of suspended solid was significantly inhibited first and induced then, as compared to the control group. The visceral SOD activity had less change with time and suspended solid concentration (P>0.05). The gill CAT activity of the M. veneriformis exposed to 1000 and 10000 mg·L^-1 of suspended solid was up-regulated first, returned to normal then, and increased again, while that of the M. veneriformis exposed to 100 mg·L^-1 of suspended solid was only upregulated significantly during the later period of the experiment. The visceral CAT activity had less change with time and suspended solid concentration. These findings showed that the visceral mass antioxidant system was not activated under suspended solid stress, but the gill filament antioxidant enzyme activity responded quickly to the stress, suggesting that the gill filament antioxidant system was more sensitive to suspended solid.

Key words: China nationally important agricultural heritage system., Chongyi Hakka Terrace system, economic evaluation, ecosystem services, ecological compensation