湖北网湖自然保护区生态质量评价

湖北网湖自然保护区属于内陆湿地和水域生态系统类型的自然保护区。根据网湖自然保护区的特征,通过选取自然性、多样性、稀有性、代表性、面积适应性、人类干扰、稳定性7个评价指标,运用指标赋分法和加权平均分法进行生态质量综合评价。结果表明,该保护区生态质量很好,气候适宜,动植物种类丰富,并且由于该区域目前经济处于初步发展中,人为干扰对其影响较小,因此短期内其生态环境质量会相对稳定,具有很高的保护和研究价值。同时针对网湖湿地目前所存在的威胁以及国家在治理和恢复其他湿地保护区的经验,提出了几点关于网湖湿地建设和远景开发规划的建议。     

弥苴河口湿地植物残体与底泥资源化利用研究

应用双室堆沤肥技术,以弥苴河口湿地植物残体、湿地底泥和当地养殖业废物制成双室堆沤肥,按不同配比设计5种施肥处理方案进行还田试验。对比研究施肥前后的蔬菜产量、蔬菜品质、土壤肥力以及土壤根际微生物,发现:方案A[50%～60%植物残体(收割物)+40%～50%养殖业废物+微生物菌剂(3 kg/t),活性液体肥作追肥,农药同习惯施肥]对增加蔬菜产量、提高蔬菜品质、增加土壤肥力和改善土壤微生态环境效果最好。在实际应用中也可适当增加1 0%～20%的湿地底泥,相应减少养殖业废物量。     

Risk Assessment of Carbon Sequestration for Terrestrial Ecosystems in China

Abstract

Climate change will alter the capacity of carbon sequestration, and the risk assessment of carbon sequestration for terrestrial ecosystems will be helpful to the decision-making for climate change countermeasures and international climate negotiations. Based on the net ecosystem productivity of terrestrial ecosystems simulated by Atmosphere Vegetation Integrated Model, each grid of the risk criterion was set by time series trend analysis. Then the risks of carbon sequestration of terrestrial ecosystems were investigated. The results show that, in the IPCCSRES-B2 climate scenario, climate change will bring risks of carbon sequestration, and the high-risk level will dominate terrestrial ecosystems. The risk would expand with the increase of warming degree. By the end of the long-term of this century, about 60% of the whole country will face the risk; Northwest China, mountainous areas in Northeast China, middle and lower reaches plain of Yangtze River areas, Southwest China and Southeast China tend to be extremely vulnerable. Risk levels in most regions are likely to grow with the increase of warming degree, and this increase will mainly occur during the near-term to mid-term. Northwest China will become an area of high risks, and deciduous coniferous forests, temperate mixed forests and desert grassland tend to be extremely vulnerable.     

不同龄级南川木波罗幼苗生物量及分配格局

以不同龄级（1~5年生）南川木波罗幼苗为研究对象,研究其生物量及分配,并利用苗高（H）、基径（D）及HD2估测单株木及其器官生物量的适合模型。结果表明：（1）随着苗龄的增加,单株生物量及各器官生物量随之增加,其中枝生物量增加幅度最大;（2）地上部分各器官生物量分配率表现为：干生物量>叶生物量>枝生物量;（3）地下部分各龄级根系生物量分配以主根和粗根为主,表现为：主根>粗根>细根,地上部分生物量分配率高于地下部分,并最后趋于稳定;（4）以基径(D)作为自变量优于利用株高(H)和HD2建立生物量预测模型,并且多以幂函数为最佳,建立的生物量预测模型中,除细根生物量预测模型较差外,其它预测模型效果都较好,相关系数均达到极显著水平,表明利用本文建立的估测南川木波罗各器官生物量模型是可行的     

Effects of iron oxide nanoparticles on phenotype and metabolite changes in hemp clones (Cannabis sativa L.)

● Fe₃O₄ NPs increased the biomass and chlorophyll content of hemp clones. ● Fe₃O₄ NPs penetrated and were internalized by root cells. ● Fe₃O₄ NPs induced the alteration of metabolite profiles in hemp leaves. ● The psychoactive compound THC in hemp leaves was significantly down-regulated. We investigated the effect of iron oxide nanoparticles (Fe₃O₄ NPs, ~17 nm in size) on the phenotype and metabolite changes in hemp (Cannabis sativa L.), an annual crop distributed worldwide. Hemp clones were grown in hydroponic cultures with Fe₃O₄ NPs (50, 100, 200, or 500 mg/L) for four weeks. TEM and ICP-MS were used to determine Fe₃O₄ NPs uptake and translocation. LC-MS-based metabolomics was employed to explore the deep insight into the effect of Fe₃O₄ NPs on hemp plants. The results revealed that plant growth enhanced gradually with increasing concentrations of given NPs up to 200 mg/L, which improved the fresh weight and dry weight by 36.13% and 74.68%, respectively, compared to the control. Even at a high dose (500 mg/L), Fe₃O₄ NPs promoted plant growth, including increased biomass and tissue length. NPs significantly increased the iron and chlorophyll content in plant tissues Increased catalase activity and reduced hydrogen peroxide content in hemp leaves suggested that the Fe₃O₄ NPs activated the defense system. TEM showed that NPs were abundantly attached to the cell wall and dispersed throughout the root cells. Metabolomics revealed that Fe₃O₄ NPs induced metabolic reprogramming in hemp leaves, including the up-regulation of carbohydrates and organic acids, and down-regulation of antioxidants, especially tetrahydrocannabinol (THC). The significantly up-regulated metabolites, including peonidin and 2-hydroxycinnamic acid, could be involved in photosynthesis in hemp plants. These results demonstrate the potential of Fe₃O₄ NPs for promoting hemp growth and decreasing the THC content at low doses.     

Dynamics of antibiotic resistance genes and microbial community in shortcut nitrification–denitrification process under antibiotic stresses

In this study, the performance of shortcut nitrification–denitrification (SCND) at different TC and SD stress conditions (0 μg/L, 1–97 days; 100 μg/L, 98–138 days; 500 μg/L, 139–175 days) was investigated. Higher level antibiotic stress (500 μg/L) led to the serious deterioration of nitrogen removal, and denitrification was more sensitive to antibiotic stress than nitrification. The dynamics of antibiotic resistance genes (ARGs) and microbial community were revealed by quantitative real-time PCR and 16S rDNA high-throughput sequencing, respectively. Tet-genes (tetA, tetQ, tetW), sul-genes (sulI, sulII), and mobile genetic element (intI1) in activated sludge increased by 1.2?~?2.5 logs with long-term exposure of antibiotic stress, and sulI, tetA, tetQ, and tetW were significantly positively correlated with intI1. Long-term antibiotics stress caused the decrease of most denitrifiers, and five genera were identified as the potential host of ARGs. The key impact factors of SCND drove the dynamics of ARGs and microbial community. Except for sulII gene, DO and FA were significantly positively correlated with ARGs, while FNA, NAR, and NO₂^?-N showed opposite effects to ARGs. Overall, maintaining relative lower DO, higher FNA, NAR, and NO₂^?-N conditions are not only benefit to the stable operation of SCND, but may also conducive to the control of ARG dissemination. This study provides theoretical basis on the control of ARGs in the SCND process.

     

Effects of phosphorus-containing material application on soil cadmium bioavailability: a meta-analysis

Environmental Science and Pollution Research - Diverse phosphorus-containing materials (PCMs) were widely applied in remediation of cadmium-contaminated soils, and their effects on the change of...     

Preparation and related properties of geopolymer solidified uranium tailings bodies with various fibers and fiber content

Environmental Science and Pollution Research - Uranium tailing ponds are a potential major source of radioactive pollution. Solidification treatment can control the diffusion and migration of...     

Degradation of sulfadiazine by UV/Oxone: roles of reactive oxidative species and the formation of disinfection byproducts

Environmental Science and Pollution Research - Sulfadiazine (SDZ) is a typical persistent sulfonamide antibiotic, which has been widely detected in natural drinking water sources. The degradation...     

Construction of double tube granular sludge microbial fuel cell and its characteristics and mechanism of azo dye degradation

Environmental Science and Pollution Research - Microbial fuel cells (MFCs) can obtain electrical energy from extensive organic matter and complete wastewater treatment at the same time. The...