山地土壤微生物地理分布格局及其驱动机制

土壤微生物不仅是陆地生态系统的重要组成部分,也是地上、地下过程与功能有机结合的重要纽带。分子生物技术的发展以及土壤微生物分离和鉴定准确性的提高,推动了土壤微生物生物地理学的不断发展,但宏观尺度上的格局特征与区域规律尚未揭示。本文集成分析了全球不同气候带、不同植被类型的土壤微生物群落组成（生物多样性）沿海拔梯度的地理分布格局,发现在全球尺度上并无一致规律,线性（递增或递减）、非线性（单峰或双峰）、无固定趋势3种地理格局并存。植被类型、植物多样性、土壤pH及其它物理化学性质、气候等各种因素,都有可能决定某一地区的土壤微生物多样性的海拔梯度分布格局。全球尺度上的现有数据分析发现,海拔跨度和气候的影响较为明显,二者实际上综合反映了大尺度上气候决定着山地土壤微生物的地理分布格局,这与传统的生物地理学观点是一致的,其它生态环境因子如地理坐标、植被类型、土壤微生物类型、土壤pH等的影响处于从属地位。然而,当前山地土壤微生物生物地理学的研究仍有较多局限性,全球更多山地、更大海拔跨度的土壤微生物研究、更精确的微生物分离鉴定技术、更多样的环境与生物驱动因素分析,以及更多现代生物地理学研究方法的使用,将有助于土壤微生物地理分布格局的深入研究,及其与气候、土壤和生态系统关系的深入挖掘,这对深刻认识土壤微生物的空间分布规律,从而更好地开发和利用土壤微生物资源,具有重要的理论与实践意义。     

CO2 adsorption using TiO2 composite polymeric membranes: A kinetic study

CO₂ is the main greenhouse gas which causes global climatic changes on larger scale. Many techniques have been utilised to capture CO₂. Membrane gas separation is a fast growing CO₂ capture technique, particularly gas separation by composite membranes. The separation of CO₂ by a membrane is not just a process to physically sieve out of CO₂ through the controlled membrane pore size. It mainly depends upon diffusion and solubility of gases, particularly for composite dense membranes. The blended components in composite membranes have a high capability to adsorb CO₂. The adsorption kinetics of the gases may directly affect diffusion and solubility. In this study, we have investigated the adsorption behaviour of CO₂ in pure and composite membranes to explore the complete understanding of diffusion and solubility of CO₂ through membranes. Pure cellulose acetate (CA) and cellulose acetate-titania nanoparticle (CA-TiO₂) composite membranes were fabricated and characterised using SEM and FTIR analysis. The results indicated that the blended CA-TiO₂ membrane adsorbed more quantity of CO₂ gas as compared to pure CA membrane. The high CO₂ adsorption capacity may enhance the diffusion and solubility of CO₂ in the CA-TiO₂ composite membrane, which results in a better CO₂ separation. The experimental data was modelled by Pseudo first-order, pseudo second order and intra particle diffusion models. According to correlation factor R², the Pseudo second order model was fitted well with experimental data. The intra particle diffusion model revealed that adsorption in dense membranes was not solely consisting of intra particle diffusion.     

韩国济州岛火山及其与中国五大连池、雷琼火山的对比

论述了韩国济州岛各类型火山与熔岩隧道的地质特征,与中国五大连池、雷琼火山进行对比,指出其各自具有的特色。简述了济州岛世界自然遗产、世界生物圈保护区与世界地质公园概况,并对世界地质公园研究、博物馆建设与室内外石文化解说进行了讨论。     

金丁剖面MIS3阶段黄土地层记录的温湿气候特征初步研究

通过对黄土高原中北部金丁镇马兰黄土中磁化率、Rb/Sr、全铁含量(TFe)与化学蚀变指数(CIA)等气候指标测试分析,并结合光释光年代学数据,着重地探讨了金丁剖面黄土地层记录的MIS3阶段气候变化特征。研究表明,金丁剖面MIS3阶段总体气候特征温湿,冷暖气候频繁波动,可进一步划分为5个阶段:51.6~44.9ka B.P.,弱温湿;42.0~39.9ka B.P.,中等温湿;37.4~27.8ka B.P.,相对强温湿;以及44.9~42.0ka B.P.和39.9~37.4ka B.P.两个冷干期。金丁剖面MIS3温湿气候成因机制的初步探讨认为北半球太阳辐射量增加导致的增温作用更直接,而高纬驱动与低纬过程耦合作用机制尚待开展进一步研究工作。     

长江三角洲2018年土壤NO排放特征

土壤是大气一氧化氮（NO）重要的来源之一,在大气化学中起着重要的作用.基于最新的BDSNP算法构建长三角地区2018年土壤NO排放清单,并进一步分析其时空特征和不确定性.结果表明,长三角地区2018年土壤NO排放量为213.6 kt,占人为源NO_x排放总量的7.3%,排放高值区主要集中在安徽省北部和江苏省大部分地区.从月变化来看,土壤NO排放在6月达到峰值,占全年排放的19.9%,占6月人为源NO_x排放量的19.7%;从小时变化来看,土壤NO排放在16:00点达到峰值,占全天的5.5%.土壤NO排放包括土壤本底、氮肥施用和氮沉降这3个部分;氮肥施用是土壤NO排放的主要来源,占比高达77.8%.随着机动车和工业等NO_x排放的深入减排,土壤NO排放的重要性将日益凸显.     

Growth of non-English-language literature on biodiversity conservation

English is widely recognized as the language of science, and English-language publications (ELPs) are rapidly increasing. It is often assumed that the number of non-ELPs is decreasing. This assumption contributes to the underuse of non-ELPs in conservation science, practice, and policy, especially at the international level. However, the number of conservation articles published in different languages is poorly documented. Using local and international search systems, we searched for scientific articles on biodiversity conservation published from 1980 to 2018 in English and 15 non-English languages. We compared the growth rate in publications across languages. In 12 of the 15 non-English languages, published conservation articles significantly increased every year over the past 39 years, at a rate similar to English-language articles. The other three languages showed contrasting results, depending on the search system. Since the 1990s, conservation science articles in most languages increased exponentially. The variation in the number of non-English-language articles identified among the search systems differed markedly (e.g., for simplified Chinese, 11,148 articles returned with local search system and 803 with Scopus). Google Scholar and local literature search systems returned the most articles for 11 and 4 non-English languages, respectively. However, the proportion of peer-reviewed conservation articles published in non-English languages was highest in Scopus, followed by Web of Science and local search systems, and lowest in Google Scholar. About 20% of the sampled non-English-language articles provided no title or abstract in English; thus, in theory, they were undiscoverable with English keywords. Possible reasons for this include language barriers and the need to disseminate research in countries where English is not widely spoken. Given the known biases in statistical methods and study characteristics between English- and non-English-language studies, non-English-language articles will continue to play an important role in improving the understanding of biodiversity and its conservation.     

Prioritizing forest management actions to benefit marine habitats in data-poor regions

Land-use change is considered one of the greatest human threats to marine ecosystems globally. Given limited resources for conservation, we adapted and scaled up a spatially explicit, linked land–sea decision support tool using open access global geospatial data sets and software to inform the prioritization of future forest management interventions that can have the greatest benefit on marine conservation in Vanuatu. We leveraged and compared outputs from two global marine habitat maps to prioritize land areas for forest conservation and restoration that can maximize sediment retention, water quality, and healthy coastal/marine ecosystems. By combining the outputs obtained from both marine habitat maps, we incorporated elements unique to each and provided higher confidence in our prioritization results. Regardless of marine habitat data source, prioritized areas were mostly located in watersheds on the windward side of the large high islands, exposed to higher tropical rainfall, upstream from large sections of coral reef and seagrass habitats, and thus vulnerable to human-driven land use change. Forest protection and restoration in these areas will serve to maintain clean water and healthy, productive habitats through sediment retention, supporting the wellbeing of neighboring communities. The nationwide application of this linked land–sea tool can help managers prioritize watershed-based management actions based on quantitative synergies and trade-offs across terrestrial and marine ecosystems in data-poor regions. The framework developed here will guide the implementation of ridge-to-reef management across the Pacific region and beyond.     

冬季绿肥对黄土高原旱作春玉米农田土壤温室气体排放的影响

利用田间试验研究了冬季绿肥对旱作春玉米农田土壤温室气体排放的影响.试验设燕麦、小扁豆、燕麦与小扁豆混播和裸地休闲共4个处理,采用静态箱-气相色谱法对冬闲期和春玉米生长期间土壤温室气体（CO₂、N₂ O和CH₄）排放通量进行观测.结果表明,旱作春玉米-冬季绿肥种植系统土壤是CO₂、N₂ O的排放源和CH₄的吸收汇.与裸地休闲相比,燕麦和小扁豆在冬闲期对土壤CO₂累积排放量没有影响,但在春玉米生长期间导致土壤CO₂累积排放量分别增加了7.77%和25.7%（P<0.05）,混播导致冬闲期和春玉米生长期间土壤CO₂累积排放量分别增加了19.1%和14.5%（P<0.05）.种植燕麦后冬闲期和春玉米生长期间土壤N₂ O累积排放量较裸地休闲分别降低了11.6%和14.7%（P<0.05）,而小扁豆分别增加了31.9%和14.9%（P<0.05）;混播导致冬闲期土壤N₂ O累积排放量降低了19.2%（P<0.05）,但在春玉米生长期间差异不显著.与裸地休闲相比,燕麦、小扁豆和混播冬闲期土壤CH₄累积吸收量分别降低了37.9%、23.6%和29.6%（P<0.05）,春玉米生长期间分别降低了19.4%、33.5%和31.5%（P<0.05）,其中小扁豆和混播在冬闲期和春玉米生长期间差异均不显著.燕麦较裸地休闲在农田综合增温潜势（GWP）、春玉米产量和温室气体排放强度（GHGI）差异均不显著.小扁豆和混播显著提高了GWP,其中小扁豆显著高于混播.而与裸地休闲相比,小扁豆和混播分别提高了春玉米产量的20.3%和15.4%（P<0.05）,但对GHGI没有显著影响.综合考虑GWP、春玉米产量和GHGI,本地区冬闲期间将小扁豆和燕麦二者混播能增加春玉米产量的同时有效降低土壤温室气体排放强度.     

珠三角地区人为热排放演变趋势及不确定性分析

人类生产生活中产生的大量废热对城市环境中的温度、城市边界层结构、空气质量及人类健康都有着重要的影响.然而目前人为热排放清单的计算方法存在所需基础资料种类繁多、计算过程复杂,空间分布和排放量有较大偏差等不足.本研究采用统计回归法基于CO和NO_x污染源清单计算了2007—2015年珠江三角洲地区的人为热排放清单,对其排放趋势、热排放来源类型变化以及空间格局的演变进行了梳理.结果表明：2007—2015年珠三角地区年平均人为热均大于9 W·m^-2,人为热排放峰值出现在2010年,趋势为先增加后减少,这与燃料消耗总量的变化趋势基本一致,而工业源和道路移动源是影响人为热排放总量变化的最大因素：2007—2015年珠三角地区大部分区域人为热排放处于0~20 W·m^-2,高值区（>20 W·m^-2）主要分布于珠三角地区中心地带的城市群,高值区缩减的面积和速度在2010—2012年期间达到最大.进一步对2012年人为热清单的不确定性分析表明：总人为热的95%置信区间的不确定性为-16%~49%,其中电厂类别排放估算中的不确定性最小,为-13%~16%,而工业源的不确定性最高,为-46%~73%.     

不同气候带退耕还林对区域气温的影响差异分析

退耕还林改变陆表覆盖状况,导致碳收支和地表能量平衡变化,从而影响区域气温。论文通过定量估算耕地转为林地导致生态系统吸收大气CO₂和地表能量平衡的变化,分析21世纪初10 a中国不同气候区开展退耕还林对区域气候调节的影响差异。结果表明：1）仅考虑碳调节,各气候区退耕还林皆表现为241.6~470.2 Mg CO₂-eq hm^-2的碳蓄积过程,具有2.2~16.5 Mg CO₂-eq hm^-2的碳汇作用即致冷效应,特别是亚热带湿润区。2）仅考虑地表能量平衡,中温带干旱与半干旱区退耕还林引起的净辐射增加程度大于潜热通量的增加程度,因此地表对大气供热表现为增温效应;而亚热带湿润区退耕还林引起净辐射减少及潜热通量增加,青藏高原、中温带湿润区净辐射增加程度小于潜热通量的增加程度,因此地表对大气供热皆表现为致冷效应。3）同时考虑碳调节和地表能量收支,中国亚热带湿润区退耕还林的致冷效应是仅考虑碳调节致冷效应的1.25~1.45倍,而中温带干旱区退耕还林的致冷效应则为仅考虑碳调节效应的近一半。