Tandem carrying,a new foraging strategy in ants: description,function, and adaptive significance relative to other described foraging strategies

An important aspect of social insect biology lies in the expression of collective foraging strategies developed to exploit food. In ants, four main types of foraging strategies are typically recognized based on the intensity of recruitment and the importance of chemical communication. Here, we describe a new type of foraging strategy, “tandem carrying”, which is also one of the most simple recruitment strategies, observed in the Ponerinae species Pachycondyla chinensis. Within this strategy, workers are directly carried individually and then released on the food resource by a successful scout. We demonstrate that this recruitment is context dependent and based on the type of food discovered and can be quickly adjusted as food quality changes. We did not detect trail marking by tandem-carrying workers. We conclude by discussing the importance of tandem carrying in an evolutionary context relative to other modes of recruitment in foraging and nest emigration.     

Enzymes Involved in the Aerobic Bacterial Degradation of N-Heteroaromatic Compounds: Molybdenum Hydroxylases and Ring-Opening 2,4-Dioxygenases

N  -heteroaromatic compounds are utilized by micro-organisms as a source of carbon (and nitrogen) and energy. The aerobic bacterial degradation of these growth substrates frequently involves several hydroxylation steps and subsequent dioxygenolytic cleavage of (di)hydroxy-substituted heteroaromatic intermediates to aliphatic metabolites which finally are channeled into central metabolic pathways. As a rule, the initial bacterial hydroxylation of a N-heteroaromatic compound is catalyzed by a molybdenum hydroxylase, which uses a water molecule as source of the incorporated oxygen. The enzyme's redox-active centers – the active site molybdenum ion coordinated to a distinct pyranopterin cofactor, two different [2Fe2S] centers, and in most cases, flavin adenine dinucleotide – transfer electrons from the N-heterocyclic substrate to an electron acceptor, which for many molybdenum hydroxylases is still unknown. Ring-opening 2,4-dioxygenases involved in the bacterial degradation of quinaldine and 1H-4-oxoquinoline catalyze the cleavage of two carbon-carbon bonds with concomitant formation of carbon monoxide. Since they contain neither a metal center nor an organic cofactor, and since they do not show any sequence similarity to known oxygenases, these unique dioxygenases form a separate enzyme family. Quite surprisingly, however, they appear to be structurally and mechanistically related to enzymes of the α/β hydrolase fold superfamily. Microbial enzymes are a great resource for biotechnological applications. Microbial strains or their enzymes may be used for degradative (bioremediation) or synthetic (biotransformation) purposes. Modern bioremediation or biotransformation strategies may even involve microbial catalysts or strains designed by protein engineering or pathway engineering. Prerequisite for developing such modern tools of biotechnology is a comprehensive understanding of microbial metabolic pathways, of the structure and function of enzymes, and of the molecular mechanisms of biocatalysis.     

Tetrasphaera聚磷菌研究进展及其除磷能力辨析

强化生物除磷（EBPR）工艺在污水脱氮除磷中扮演着重要角色，其机理研究与工程应用也较为成熟.长期以来，Accumulibacter菌属（A菌）作为EBPR工艺最主要的聚磷菌（PAOs）已被广泛接受.同时，具有聚磷能力的Tetrasphaera菌属（T菌）亦被发现，且在某些特定环境下其丰度甚至远高于A菌，进而引发业内一定的关注.本文通过对T菌发现、研究过程的梳理，总结了关于T菌丰度、代谢途径及影响其活性的因素等方面的研究成果.与A菌不同，T菌代谢途径具有多样性，可依赖发酵代谢进行细胞维持和增殖，其发酵产物甚至可以供给A菌利用.T菌可利用大分子有机物（如葡萄糖、氨基酸等）和VFAs（亲和性较低）进行厌氧释磷，继而完成好氧、甚至缺氧吸磷过程.T菌主要菌株（T.elongata）因缺少合成PHA相关酶基因而不能以PHA作为内聚产物在厌氧环境下储能；糖原和游离氨基酸被检测到可作为T菌的能源/碳源内聚物，但亦有结果相左的研究.借助于拉曼光谱技术，一些污水处理厂中T菌与A菌被证实对磷去除的贡献大小相当.总之，目前对T菌的研究还十分有限，现有研究仍不足以证明它们在EBPR中可稳定发挥除磷贡献.今后应在T菌不同代谢途径控制因素及所需环境条件方面进行深入研究，以确认T菌可否持续、稳定地实现除磷作用.     

Management strategies to mitigate the impacts of climate change on sea turtle’s terrestrial reproductive phase

Climate change poses a serious threat to sea turtles (Cheloniidae) as their terrestrial reproductive phase is only successful within a limited range of environmental and physical conditions. These conditions are likely to become less optimal as climate change progresses. To date, management and conservation of sea turtles has focused almost entirely on non-climatic stressors, due at least in part to practitioners not knowing what strategies to take and the feasibility and risks of potential strategies. To aid the management of sea turtles in a changing environment, we identified management strategies via a focus workshop and surveys to mitigate the impacts of climate change to the terrestrial reproductive phase of sea turtles. The effectiveness, ecological risks and potential social and logistical constraints associated with implementing each of the identified management strategies is discussed. Twenty management strategies were identified; strategies varied from habitat protection to more active and direct manipulation of nests and the nesting environment. Based on our results, we suggest a three-pronged approach to sea turtle conservation in light of climate change, where managers and researchers should: 1) enhance sea turtle resilience to climate change by mitigating other threats; 2) prioritise implementing the ‘no regret’ and ‘reversible’ management strategies identified here; and 3) fill the knowledge gaps identified to aid the trial and implementation of the potential strategies identified here. By combining these three approaches our collective toolkit of sea turtle management strategies will expand, giving us an array of viable approaches to implement as climate change impacts become more extreme.     

氧化还原电位的研究及应用

氧化还原电位(Eh)是一个描述介质氧化还原性质相对程度的化学参数,根据Eh值可以直观的比较介质氧化还原性的强弱。氧化性强,Eh值较高;还原性强,Eh值较低。氧化还原电位的测定广泛应用于水处理、土壤环境监测、金属腐蚀、湿法冶金和资源勘探等领域。本文综述了氧化还原电位在常温常压环境和高温高压环境中众多领域的应用现状,并展望了高温高压水热环境中氧化还原电位原位监测的研究。     

污水磷回收新产物——蓝铁矿

渐行渐近的磷危机使磷回收从理论已经走向实践.磷回收产物形式很多,但经济、具有高附加值的产物才能驱动企业自愿实施.在污水处理生物污泥中新近发现的蓝铁矿(Vivianite,Fe_3(PO_4)_2·8H_2O)沉淀物因潜在的特殊用途以及经济价值而备受关注.自然界,蓝铁矿广泛存在于地表水体沉积物中,是一种非常稳定(K_(sp)=10~(-36))的磷铁化合物.决定蓝铁矿生成的条件除富铁、富磷之内在因素外,还需要环境中存在合适的还原性条件(ORP-300 mV)以及中性上下的pH条件(6～9).实践中,污水或污水处理过程中有时刚好存在蓝铁矿形成的内、外在条件,荷兰污水处理厂在生物污泥中便检测发现有蓝铁矿物质的存在.为推动蓝铁矿基础及其应用研究,本文综述蓝铁矿化学性质、经济价值及回收潜力;分析pH、ORP、微生物、硫化物等环境影响因素;辨析其在生物污泥中的生成路径;提出从污泥中分离、提纯蓝铁矿的研发思路.     

Climate change impacts on groundwater resources in Mekong Delta under representative concentration pathways (RCPs) scenarios

Groundwater is the essential resource for various uses and have a great economic importance especially in the areas like Mekong Delta, which is the home for some 18 million people and produces a half of Vietnam’s rice and contributes substantial part of the country’s gross domestic product (GDP). Sustainable use of the groundwater resource is threatened by its uncontrolled abstraction and climate change. This study assesses groundwater resources in Mekong Delta aquifer system in the context of climate change. A set of models are used for the purpose. Groundwater recharge and its spatial variation are estimated using WETSPASS model, groundwater level and storage are estimated using MODFLOW and future climatic conditions in the area are developed by downscaling the data of five General Circulation Models (GCMs) retrieved from CMIP5 data portal. Two representative concentration pathways (RCPs) scenarios (RCP4.5 and RCP8.5) are considered for projecting future conditions of groundwater resources. Results reveal that the future average annual temperature is projected to increase by 1.5 °C and 4.9 °C by the end of the 21st century under RCP4.5 and RCP8.5 scenarios, respectively. Future rainfall is projected to increase in wet season and decrease in dry season. Groundwater recharge is projected to decline in short-, medium-, and long-terms. As a result, groundwater levels and storage are also projected to decline in future. These findings may help decision-makers and stakeholders for devising sustainable groundwater management strategies in Mekong Delta.     

基于VIKOR法的潍坊市水资源承载力综合评价

水资源承载力综合评价通常涉及到社会、经济、资源和环境等多种因素的影响.多准则妥协解排序法（VIKOR）可协调处理多种因素间的相互关系,是评价城市水资源承载力的有效手段之一.本文利用VIKOR法对潍坊市水资源承载力进行综合评价,通过构建水资源承载力综合评价指标体系,利用CRITIC法计算权重,标准化数据并进行分析计算和排序,以利益比率Q_i作为综合评价值,Q_i值越小,表明水资源承载力越高.结果发现,在2008-2017年,潍坊市水资源承载力综合评价值呈下降趋势,从2008年的0.7378下降至2017年的0.0000,表明潍坊市水资源承载力稳步提高.通过分析潍坊市水资源承载力各子系统的变化趋势发现,潍坊市水资源承载能力依然有较大的提升空间.通过对2017年潍坊市各市、区、县水资源承载力进行对比可知,诸城市、青州市、安丘市和临朐县综合评价值较低,分别为0、0.1645、0.2267和0.2503,说明水资源承载力较高;潍城区、坊子区、寒亭区和奎文区综合评价值较高,分别为0.3475、0.4739、0.5938和0.9131,说明水资源承载力较低.表明潍坊市部分地区产业结构和布局与水资源条件不相匹配,水资源开发利用水平超出当地水资源承载力.     

有机固废堆肥中产臭及除臭技术的微生物作用机制研究进展

持续推进有机固废资源化安全处置是国家环境管理的重要任务,也是落实"无废城市"发展路线的重要一环.堆肥是通过生物转化实现有机固废资源化利用的重要技术手段.然而,堆肥过程中会产生大量组分复杂的恶臭气体,已成为适应国家发展需求的资源化技术瓶颈.对有机固废堆肥恶臭气体的主要组成、生成转化的途径及核心微生物、生物除臭技术进行综述,结果表明:①堆肥中以NH₃、H₂S等含氮、硫类化合物为主要恶臭物质.②氨化细菌、硝化细菌、反硝化细菌及硫酸盐还原菌在恶臭气体生成转化途径中发挥主导作用,由ureC、amoA、napA、nosZ及dsrA等多个功能基因驱动完成;pH、温度等环境条件会影响微生物的活性,并作用于物质转化过程,最终影响到恶臭气体的产生.③原位添加微生物菌剂和异位生物反应器处理中的微生物将恶臭物质作为营养组分进行吸收降解,是绿色减排的重要技术.      

Climate change and the geography of weed damage: Analysis of U.S. maize systems suggests the potential for significant range transformations

By the end of the century, climate change projections under a “business-as-usual” emissions scenario suggest a globally averaged warming of 2.4–6.4 °C. If these forecasts are realized, cropping systems are likely to experience significant geographic range transformations among damaging endemic weed species and new vulnerabilities to exotic weed invasions. To anticipate these changes and to devise management strategies for proactively addressing them, it is necessary to characterize the environmental conditions that make specific weed species abundant, competitive, and therefore damaging the production of particular crops (i.e. defining the damage niche). In this study, U.S. maize is used as a model system to explore the implications of climate change on the distribution of damaging agricultural weeds. To accomplish this, we couple ensemble climate change projections of annual temperature and precipitation with survey data of troublesome weed species in maize. At the state scale, space-for-time substitution techniques are used to suggest the potential magnitude of change among damaging weed communities. To explore how the geography of damage for specific species may evolve over the next century, bioclimatic range rules were derived for two weed species that are pervasive in the Northern (Abutilon theophrasti Medicus, ABUTH) and Southern (Sorghum halepense (L.) Pers., SORHA) U.S. Results from both analyses suggest that the composition of damaging weed communities may be fundamentally altered by climate change. In some states, potential changes in the coming decades are commensurate to those possible by the end of the century. Regions such as the Northeastern U.S. may prove particularly vulnerable with emerging climate conditions favoring few weed species of present-day significance. In contrast, regions like the mid-South are likely to experience fewer shifts even with a similar magnitude in climate change. By the end of the century in the U.S. Corn Belt, cold-tolerant species like A. theophrasti may be of minor importance whereas S. halepense, a predominantly Southern U.S. weed species at present, may become common and damaging to maize production with its damage niche advancing 200–600 km north of its present-day distribution.     

Lessons learned from applying adaptation pathways in flood risk management and challenges for the further development of this approach

Worldwide, an increase in flood damage is observed. Governments are looking for effective ways to protect lives, buildings, and infrastructure. At the same time, a large investment gap seems to exist—a big difference between what should necessarily be done to curb the increase in damage and what is actually being done. Decision-makers involved in climate adaptation are facing fundamental (so-called deep) uncertainties. In the course of time, the scientific community has developed a wide range of different approaches for dealing with these uncertainties. One of these approaches, adaptation pathways, is gaining traction as a way of framing and informing climate adaptation. But research shows that “very little work has been done to evaluate the current use of adaptation pathways and its utility to practitioners and decision makers” (Lin et al. 2017, p. 387). With this paper, the authors, as action researchers and practitioners involved in two of the world’s largest real-life applications of this approach in flood risk management, aim to contribute to filling in that gap. Analysis of the experience in the United Kingdom and the Netherlands in long-term planning in flood risk management shows that the adaptation pathways approach is effective in keeping decision processes going forward, to the final approval of a long-term plan, and helps increase awareness about uncertainties. It contributes to political support for keeping long-term options open and motivates decision-makers to modify their plans to better accommodate future conditions. When it comes to implementing the plans, there are still some major challenges, yet to be addressed, amongst others: the timely detection of tipping points in situations with large natural variability, the inclusion of measures that prepare for a switch to transformational strategies, and the retention of commitment of regional and local authorities, non government organizations, and the private sector, to climate adaptation as national policies move from blueprint planning to adaptive plans. In delivering this feedback, the authors hope to motivate the scientific community to take on these challenges.     

Positive long-term effect of mulching on species and functional trait diversity in a nutrient-poor mountain meadow in Central Europe

Oligotrophic mountain meadows are threatened biodiversity hotspots throughout Europe. The traditional summer hay-making followed by autumn grazing is no longer economic and question is whether alternative managements can maintain both plant species and functional diversity typical of these habitats. In the Bohemian Forest Mts., we applied three treatments (mowing once a year - i.e., cutting and removing the biomass, mulching once a year - cutting and leaving the crushed biomass to decompose in situ, fallowing - no cutting) in order to assess temporal changes in meadow vegetation, plant trait composition and biomass production in a 13-year experiment. We recorded for each species twenty-five traits as to be most informative of plant strategies related to growth, resource acquisition and carbon-water economy. We compared different components of trait composition (community averages that mostly reflect traits of dominant species vs. the Rao index of functional diversity that reflects trait dissimilarity among species) and their impact on biomass production. We show that mulching promotes species and functional diversity by facilitating heliophilous forbs and legumes with more acquisitive strategies in resource use and release, e.g., higher foliar N and P content. This occurs at the expense of tall grasses (with resource-retentive strategies, e.g., high leaf dry matter content) which dominate the mown and fallow plots. The divergence in most quantitative traits indicates that niche complementarity is the dominant assembly process in mulched plots, which can prevent competitive exclusion and enable species coexistence. The divergent development was detected only after 5-6 years. This slow floristic and functional response is caused by acidity of soil and severe mountain climate that preclude rapid responses of vegetation to land-use changes. We conclude that mulching represents a good compromise maintaining both plant species and functional diversity as well as a relatively high biomass production. Mowing without grazing leads to gradual nutrient loss and thus reduces the productivity and diversity in these oligotrophic ecosystems. Fallowing causes gradual loss in diversity by increased grass competition and litter accumulation.     

Applying ecosystem concepts to the planning of industrial areas: a case study of Singapore’s Jurong Island

The application of ecological concepts to the industrial setting has been touched upon by literature across several disciplines. Two emerging ecological planning approaches, landscape ecology and industrial ecology, are applied here to look at alternative ways of planning industrial parks. As an emerging field, landscape ecology provides different viewpoints from the traditional approach of natural conservation, which mainly focuses on the protection of nature. The approach of landscape ecology regards the environment as a land mosaic, a mixture of natural and urban environment, which concerns a manageable human-scale environment across one or two human generations. Industrial ecology, on the other hand, goes beyond the traditional “end of pipe” idea of pollution control and learns from the ecosystem concept. The current paper is an attempt to reconcile these two fields as an integrated approach to the planning of industrial areas. Using a case study of Singapore’s Jurong Island industrial park, two fundamental issues behind the idea of landscape ecology and industrial ecology are raised. If raw materials, energy and by-products are more easily replaced or reused by technology and management, then research on industrial ecology and related knowledge will be crucial for developing natural resource substitution by innovative technology and new ways of environmental management. Where it is difficult to substitute natural resources, the skills of planning and managing natural resources will take priority over other strategies. In this situation, the knowledge of landscape ecology needs to be applied to the prediction, design and evaluation of ecologically optimum resource uses, patterns and processes in the mixture of natural, urban and industrial environment. A new concept, “nurtured landscape”, is proposed for mediating between the natural ecosystem and the urban/industrial environment. The nurtured landscape provides a basis for the development of new ecological technology using landscape to ameliorate the polluting effects of the urban/industrial neighbourhood. The planning of Singapore’s Jurong Island industrial park provides a test of applying the principles of landscape ecology and industrial ecology to the possible transformation of an industrial area.     

中国的水安全及其对策探讨

在对相关文献资料进行调研的基础上,阐述了我国水资源的现状及其存在的主要水问题,然后从这些水问题出发,就可能引发的人为性水安全问题：健康安全、粮食安全、生态环境安全、经济安全、国家安全等进行了讨论,最后就如何解决我国的水安全问题提出了：遵循水的自然客观规律．以及利用与保护、管理与调控、开源与节流、监控与预警并重的相关建议。     

自然生境中厌氧氨氧化功能微生物生态学研究进展

自然生境中发生的厌氧氨氧化过程是继反硝化和好氧氨氧化后的又一条氮损失途径,对全球生态系统氮循环具有重要意义,但不同自然生态系统中存在不同种类的厌氧氨氧化微生物.通过阐述厌氧氨氧化反应发生的生理机制,并对不同自然环境中发现的厌氧氨氧化功能微生物进行梳理,分析了厌氧氨氧化菌分布的空间异质性成因.结果表明,适量的无机氮可以促进厌氧氨氧化的发生,有机碳含量低和低氧条件更有利于厌氧氨氧化菌的生存且厌氧氨氧化的活性较高,这与厌氧氨氧化菌的化能自养代谢途径有着紧密的联系,低养分条件下反硝化菌的活性受到短暂抑制,促进了厌氧氨氧化的发生.同时,适当的高盐环境会提高厌氧氨氧化活性并促进厌氧氨氧化菌群落结构转变,高盐度环境下Scalindua属占优势,低盐度环境下Brocadia属更占优势.厌氧氨氧化菌对温度变化有很好的适应性,大部分厌氧氨氧化菌（如Scalindua属、Kuenenia属和Brocadia属）对于极端环境均有较强的环境适应性;此外,悬浮颗粒物浓度、含水量等因素也会影响厌氧氨氧化菌的分布及其代谢活性.建议今后从基因组学、蛋白组学和转录组学相结合的角度对自然环境中的厌氧氨氧化菌开展生理生态机理的研究,并探明厌氧条件下Fe3+、Mn4+、SO₄2-等电子受体与厌氧氨氧化过程的生物化学联系,以更好地应用于工程技术研究,并为生态环境修复提供理论依据.      

Anaerobic Degradation of Phenolic Compounds

Mononuclear aromatic compounds are degraded anaerobically through three main pathways, the benzoyl-CoA pathway, the resorcinol pathway, and the phloroglucinol pathway. Various modification reactions channel a broad variety of mononuclear aromatics including aromatic hydrocarbons into either one of these three pathways. Recently, a further pathway was discovered with hydroxyhydroquinone as central intermediate through which especially nitrate-reducing bacteria degrade phenolic compounds and some hydroxylated benzoates. Comparison of the various strategies taken for the degradation of aromatics in the absence of oxygen demonstrates that the biochemistry of breakdown of these compounds is determined largely by the overall reaction energetics and, more precisely, by the redox potentials of the electron acceptor systems used. Nitrate reducers differ in their strategies significantly from those used by sulfate-reducing or fermenting bacteria.     

Factor Biases and Promoting Sustainable Development: Adaptation to Drought in the Senegal River Basin

The ongoing drought in the Sahel region of West Africa highlights the vulnerability of food-producing systems to climate change and variability. Adaptation to climate should therefore increase the sustainability of agriculture under a long-term drought. Progress towards sustainability and adaptation in the the Senegal River Basin is hampered by an existing set of social and ecological relationships that define the control over the means of production and how people interact with their environment. These relationships are sensitive to the technological inputs and the administration of food production, or the factor bias in the different policy alternatives for rural development. One option is based on state-controlled, irrigated plantations to provide rice (Oryza) for the capital, Dakar. This policy emphasizes a top-down management approach, mechanized agriculture and a reliance on external inputs which strengthens the relationships introduced during the colonial period. A time series decomposition of the annual flow in the Senegal River at Bakel in Senegal suggests that water resources availability has been substantially curtailed since 1960, and a review of the water resources budget or availability in the basin suggests that this policy's food production system is not sustainable under the current climate of the basin. Under these conditions, this program is exacerbating existing problems of landscape degradation and desertification, which increases rural poverty. A natural resource management policy offers two adaptation strategies that favour decentralized management and a reduction of external inputs. The first alternative, “Les Perimetres Irrigués”, emphasizes village-scale irrigation, low water consumption cereal crops and traditional socio-political structures. The second alternative emphasizes farm-level irrigation and agro-forestry projects to redress the primary effects of desertification.