Subjects: Statistics >> Social Statistics submitted time 2023-12-03 Cooperative journals: 《中国科学院院刊》
Abstract： Between 2000 and 2020, global wildfires contributed to approximately 7.32 billion metric tons of carbon dioxide (CO2) emissions, accounting for about 18.5% of CO2 emissions released from fossil fuels. Forest fires alone contributed to around 20% of these wildfire emissions, approximately 1.5 billion metric tons of CO2. Due to climate change and human activities, carbon emissions from forest fires are on the rise. For example, the 2023 Canadian fires have emitted 1.268 billion metric tons of CO2 up to August 29th. Despite the simultaneous increase in forest area and volume, the frequency and extent of forest fires have significantly decreased in China since 2010, which has made a significant contribution to global carbon emission reduction. Given forest fires have become a significant global carbon emission source, a comprehensive, objective, and fair carbon emission monitoring and accounting system that considers carbon emissions from both human activities and forest fires should be established. At the same time, effective measures should be taken to reduce the occurrence frequency and intensity of wildfires to lower carbon emissions from forest fires. To address the challenges of predicting and preventing extreme forest fire behavior, it is essential to develop a forest fire risk identification, early warning, prediction, and prevention technology system. Additionally, research should be devoted to carbon emissions from wildfires, aiming to establish a more scientific, comprehensive, and domestically controllable carbon accounting system.
Subjects: Environmental Sciences, Resource Sciences >> Basic Disciplines of Environmental Science and Technology submitted time 2018-09-03 Cooperative journals: 《干旱区研究》
Abstract：人类活动是净第一性生产力（NPP）变化的重要影响因子，计算人类活动对NPP的影响可以定量评估其对生态环境的影响，对评价环境治理工程成效也具有重要意义。本文以石羊河流域为研究区，通过变异系数法计算治理前后的NPP人为影响值，比较2个时段NPP人为影响值的空间格局、变化及趋势，并以行政区为单元评价生态环境治理的成效。研究表明：① 人类活动对植被NPP的影响覆盖了大部分区域，2000—2006年人为影响值介于-588.31~653.57 g·m-2·a-1，2007—2010年介于-644.30~673.63 g·m-2·a-1。2个时段人为作用对全流域植被NPP的正负影响均十分剧烈，整体都表现为正影响，净影响值从0.37T g Ca-1减少到0.33T g·a-1。② 治理后流域60.13%的区域NPP人为影响发生改变，主要表现为正向影响减弱（占36.54%）和负向影响减弱（占12.09%），人类活动在直接作用区域有所放缓；但人为影响的方向变化较少，仅占5.60%。这说明虽然治理局部取得了一定成效，但要从根本上治理将是一个长期的过程。③ 各行政区治理成效各异，民勤与凉州区成效最为显著，其他依次为古浪、天祝、永昌、肃南、金川等县市。
Subjects: Biology >> Bioengineering submitted time 2017-07-24 Cooperative journals: 《中国生物工程杂志》
Abstract： Phenol is a typical environmental pollutant. Biodegradation of phenol Phenol is a typical environmental pollutant. Chlorella sp. is potential strain for wastewater treatment because of its fast growth and strong resistance. Chlorella sp. could degrade phenol in industrial wastewater but oxidative stress induced by high concentration of phenol could cause oxidative damage in algal cells. Adaptive evolution was performed to improve the tolerance to phenol of Chlorella sp (L5). in previous study. The response mechanism of Chlorella sp. to oxidative stress induced by high concentration phenol was explored by de novo comparative transcriptomic analysis on genome scale. It was shown that the evolved strain could tolerate and degrade phenol was related to metabolic regulations in multiple pathways. The results of de novo comparative transcriptomic analysis showed that the genes related to signal transduction, ABC transporter and heat shock protein were significantly up-regulated at 500 mg/L phenol concentration compared to those in the original (L3) cells. Those genes in nitrogen metabolism and tricarboxylic acid cycle (TCA) were also upregulated. The evolved strain (L5) could reduce oxidation pressure induced by high concentration of phenol through the metabolic regulations in these metabolic pathways.
Subjects: Other Disciplines >> Synthetic discipline submitted time 2016-11-04 Cooperative journals: 《中国科学院院刊》
Abstract：由于全球气候变化与人类活动影响，我国海岸带湿地已面临着严重的退化风险。文章通过对海岸带湿地退化多重因素，如海岸带围垦、城市化发展、海岸养殖、外来物种入侵、海岸侵蚀、环境污染及海平面上升等进行分析，探讨并提出适应我国海岸带地区发展特征的“与自然共建”湿地修复、湿地生态系统自然资本有效评估及补偿、湿地综合监测等应对策略，为实现我国海岸带地区科学和合理的可持续发展提供决策依据。
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