“央视火灾”反思什么

2月9日晚，正当全国人民欢度元宵佳节之际，中央电视台新大楼北京配楼却成了一片火海。根据2月10日的通报，“央视大火”已造成7人受伤，1名消防员牺牲。而火灾原因“系业主单位不听治安民警劝阻，执意违法燃放烟花造成的”。     

Effects of four decades of fire manipulation on woody vegetation structure in Savanna

The amount of carbon stored in savannas represents a significant uncertainty in global carbon budgets, primarily because fire causes actual biomass to differ from potential biomass. We analyzed the structural response of woody plants to long-term experimental burning in savannas. The experiment uses a randomized block design to examine fire exclusion and the season and frequency of burn in 192 7-ha experimental plots located in four different savanna ecosystems. Although previous studies would lead us to expect tree density to respond to the fire regime, our results, obtained from four different savanna ecosystems, suggest that the density of woody individuals was unresponsive to fire. The relative dominance of small trees was, however, highly responsive to fire regime. The observed shift in the structure of tree populations has potentially large impacts on the carbon balance. However, the response of tree biomass to fire of the different savannas studied were different, making it difficult to generalize about the extent to which fire can be used to manipulate carbon sequestration in savannas. This study provides evidence that savannas are demographically resilient to fire, but structurally responsive.