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Davinder Pal Singh Jasvirinder Singh Khattar Kanwaldeep Kaur Baljinder Singh Sandhu Yadvinder Singh 《毒物与环境化学》2013,95(7):1304-1318
This study deals with the toxicological impact of the herbicide anilofos on photosynthesis, respiration, nitrogen assimilation, and antioxidant system in a diazotrophic rice field cyanobacterium Anabaena torulosa. Treatment of anilofos (1.25, 2.5, and 5?mg?L?1) affected growth, photosynthetic pigments, photosynthesis, and respiration of the cyanobacterium. Although all the photosynthetic pigments were affected, a maximum effect of the herbicide was observed on phycocyanin (51% reduction) followed by the carotenoids. The effect of the herbicide on photosynthetic pigments resulted in 57% decrease in photosynthetic O2 evolution. Studies on the photochemical activity demonstrated that both photosystems (PS I and PS II) were affected by the herbicide. Decrease in the photosynthesis rate resulted in decreased nitrogen assimilation, as revealed by reduced nitrate (20%) and ammonium (26%) uptake and decreased activities of nitrogenase (63% decrease) and glutamine synthetase (22% decrease). This ultimately resulted in the reduced growth of the organism. Activities of superoxide dismutase, catalase, and peroxidase in the presence of anilofos increased by 1.8–3.5 times over control cultures. Proline content increased by 1.6 times, while the content of ascorbate decreased slightly. These results indicate that the organism was able to tolerate the herbicide stress by activating oxidative stress defense mechanism. 相似文献
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The Effectiveness of Contrasting Protected Areas in Preventing Deforestation in Madre de Dios, Peru 总被引:1,自引:1,他引:0
Accurate monitoring of the effectiveness of protected areas (PAs) in decreasing deforestation is increasingly important given the vital role of forest protection in climate change mitigation. Recent studies on PA effectiveness have used remote-sensing imagery to compare deforestation rates within PAs to surrounding areas. However, remote-sensing data used in isolation provides limited information on the factors contributing to effectiveness. We used landscape-modelling techniques to estimate the effectiveness of ten PAs in Madre de Dios, Peru. Factors influencing PA effectiveness were investigated using in situ key-informant interviews. Although all of the PAs studied had positive effectiveness scores, those with the highest scores were ecotourism and conservation concessions, where monitoring and surveillance activities and good relations with surrounding communities were reported as possible factors in decreasing deforestation rates. Native community areas had the lowest scores, with deforestation mainly driven by internal resource use and population growth. Weak local governance and immigration were identified as underlying factors decreasing the effectiveness of protection, whereas good relations with surrounding communities and monitoring activity increased effectiveness. The results highlight the need to combine remote sensing with in situ information on PA management because identification of drivers and deterrents of deforestation is vital for improving the effectiveness of protection. 相似文献
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