Discrepancies in Growth Measurement Methods of Mosses: An Example from Two Keystone Species Grown under Increased CO₂and N Supply in a Restored Peatland

Bryophytes dominate northern peatlands. Obtaining reliable measurements of moss-growth and how it may be affected by global changes are therefore important. Several methods have been used to measure moss-growth but it is unclear how comparable they are in different conditions and this uncertainty undermines comparisons among studies. In a field experiment we measured the growth and production of Sphagnum fallax (Sphagnum) and Polytrichum strictum (Polytrichum) using two handling methods, using cut and uncut plants, and three growth-variables, height-growth, length-growth, and mass-growth. We aimed “benchmarking” a combination of six methodological options against exactly the same set of factorial experiments: atmospheric CO2 enrichment and N addition. The two handling methods produced partly different results: in half of the cases, one method revealed a significant treatment effect but the other one did not: significant negative effects on growth were only observed on uncut plants for elevated CO2 and on cut plants for N addition. Furthermore, the correspondence between measurements made with various growth-variables depended on the species and, to a lesser extent, treatments. Sphagnum and Polytrichum growth was inhibited under elevated CO2, and correlated to higher ammonium values. Sphagnum was however less affected than Polytrichum and the height difference between the two species decreased. N addition reduced the P/N ratio and probably induced P-limiting conditions. Sphagnum growth was more inhibited than Polytrichum and the height difference between the two species increased. Our data show that such a problem indeed exists between the cut and uncut handling methods. Not only do the results differ in absolute terms by as much as 82% but also do their comparisons and interpretations depend on the handling method—and thus the interpretation would be biased—in half of the cases. These results call for caution when comparing factorial studies based on different handling methods.

Sperm collection in Black-legged Kittiwakes and characterization of sperm velocity and morphology

Background:Collecting and studying live sperm is central to many important fields of biology.Yet,a simple method to collect live sperm is lacking in wild seabird species.Here,we describe a non?invasive method to collect viable sperm samples based on a simple massage technique applied to male Black?legged Kittiwakes(Rissa tridactyla).Methods:We studied a colony breeding at Kongsfjorden,Svalbard and successfully obtained sperm samples from 32 males.With a subset of samples(n = 12 males),we compared the suitability of several extenders(0.9% NaCl,PBS,Earle's balance salt solution,Dulbecco's modified Eagle medium) in maintaining sperm alive long enough for analyses.With another 18 ejaculates,we conducted computer assisted sperm analyses using the CASA plugin for ImageJ.We provide details about the settings to be used for such analyses.Lastly,droplets from 20 ejaculates were smeared on glass slides and preserved with formalin to characterize sperm morphology in terms of total sperm length,sperm head length,midpiece length and flagellum length,and percentage of abnormal sperm.Results:With this method and under field conditions,we were able to obtain sufficient amounts of live sperm to assess traits related to sperm quality(e.g.sperm morphology,percentage of motile sperm,sperm velocity).We found that two extenders,Earle's balanced salt solution and Dulbecco modified Eagle's medium,yielded similarly good results.Additionally,we investigated whether specific behaviours were associated with successful sperm collection and whether sperm collection success depended on how long before laying sperm collection was attempted.Finally,we provide mean values for sperm morphology,sperm swimming ability and percentage of motile sperm,which may prove useful for future comparative analyses,and we report high levels of sperm abnormality and within?ejaculate variation in sperm morphology.Conclusions:We discuss the high percentage of abnormal sperm and high within?ejaculate variation in sperm morphology in light of sperm competition theory and conclude that these figures are likely due to relaxed post?cop?ulatory sexual selection,kittiwakes being strictly monogamous.Finally,we suggest that this method could be applied to other seabird species sharing similar ecology.

Vegetation-based bioindication of humus forms in coniferous mountain forests

Humus forms, especially the occurrence and the thickness of the horizon of humified residues （OH）, provide valuable information on site conditions. In mountain forest soils, humus forms show a high spatial variability and data on their spatial patterns is often scarce. Our aim was to test the applicability of various vegetation features as proxy for OH thickness. Subalpine coniferous forests dominated by Picea abies （L.） H. Karst. and Larix decidua Mill. were studied in the Province of Trento, Italian Alps, between ca. 900 and 22o0 m a.s.1. Braun-Blanquet vegetation relevds and OH thickness were recorded at 152 plots. The vegetation parameters, tested for their suitability as indicators of OH thickness, encompassed mean Landolt indicator values of the herb layer （both unweighted and cover-weighted means） as well as parameters of vegetation structure （cover values of plant species groups） calculated from the releves. To our knowledge, the predictive power of Landolt indicator values （LIVs） for humus forms had not been tested before. Correlations between OHthickness and mean LIVs were strongest for the soil reaction value, but indicator values for humus, nutrients, temperature and light were also significantly correlated with OH thickness. Generally, weighting with species cover reduced the indicator quality of mean LIVs for OH thickness. The strongest relationships between OH thickness and vegetation structure existed in the following indicators： the cover of forbs （excluding graminoids and ferns） and the cover of Erieaeeae in the herb layer. Regression models predicting OH thickness based on vegetation structure had almost as much predictive power as models based on LIVs. We conclude that LIVs analysis can produce fairly reliable information regarding the thickness of the OH horizon and, thus, the humus form. If no releve data are readily available, a field estimation of the cover values of certain easily distinguishable herb layer species groups is much faster than a vegetation survey with consecutive indicator value analysis, and might be a feasible way of quickly indicating the humus form.

Modelling of Predictive Hydraulic Impacts of a Potential Radioactive Waste Geological Repository on the Meuse/Haute-Marne Multilayered Aquifer System (France)

The French National Agency for Nuclear Waste Management (Andra) conducted a site investiga- tions program within the project of a deep geological disposal of radioactive waste in the Meuse/ Haute-Marne region. The construction of the tunnel of 5 Km length and the shafts of about 500 m depth to access the repository located in the clay host formation of Callovo-Oxfordian age, will lead to the perturbations of the groundwater flow fields. The prediction of the behaviour of these perturbations is needed to support: 1) the engineering and monitoring operations, and 2) the assessment of the consequences on groundwater resources. A variably-saturated flow model of a local multi-layered aquifer system is developed. It integrates the Oxfordian aquifer (limestone), the Kimmeridgianaquitard (marl) and the Barrois limestone aquifer including the karst conduits network. The variably-saturated flow Richard’s equation is solved with a finite element simulator. Prior to the simulation of the predictive repository impacts, a transient flow model is calibrated with respect to Underground Research Laboratory (URL) construction data. The results are analysed and evaluated by the use of performance measures.

高精度地下水示踪技术及其应用——以毛村地下河流域为例

笔者以桂林毛村岩溶地下河流域的示踪试验为例,探索高精度地下水示踪方法在岩溶水文地质研究中的应用。实践证明,该方法较传统示踪方法具有较大优势。试验中,从地下河主出口回收I号示踪剂为34%,地下水平均流速为35.3m/h,全部回收率约为60%～70%。示踪结果证实毛村地下河流域具有典型河间地块特征,存在多个排泄出口,水文地质边界较复杂;主出口处示踪剂浓度变化呈宽域多峰,说明具有多管道、沿途多个较大溶潭特征;II号示踪剂在所有接收点都没有收到,其原因较为复杂和不确定。枯季部分地下水有沿西南方向断层排泄迹象,雨季是否存在较大径流,还需用示踪试验来证实;流量不均衡,排泄区可能存在潜流。

长白山区典型泥炭藓沼泽的有壳变形虫

选择长白山区哈泥、金川、圆池和赤池4个典型泥炭藓沼泽作为研究地点,在系统采样基础上调查了有壳变形虫的种类组成特征。75个样品共记录到有壳变形虫33种。这些种类均为国外研究中的常见种类,其中优势种类有苔藓鳞盖虫(Assulina muscorum)、表壳圆壳虫(Cyclopyxis arcelloidestype)、蛹壳虫/三足虫(Croythion-Trinematype)、巧茄壳虫(Hyalosphenia eleglans)、结节鳞壳虫(Euglypha tuberculatatype)、网匣壳虫(Centropyxiscassistype)、染色梨壳虫(Nebela tincta)、泥炭藓截口虫(Heleopera sphagni)。特别是凤蝶茄壳虫(H.papilio)为国内新纪录,它是泥炭藓沼泽的典型种类之一。其他研究中常见的Amphitrema flavum在本研究中未发现。

沉积物和悬浮颗粒物在岩溶水系统污染物衰减与运移中的作用(英文)

本文讨论了沉积物和悬浮颗粒物/胶体在岩溶水系统污染物衰减与运移中的作用,介绍了关于瑞士某岩溶水系统内颗粒物与微生物污染间关系的试验结果。该试验场包括一个接纳农田排水的落水洞及与其相连的两个泉,其中一个泉是供水水源地。利用便携式粒子计实时监测泉水中颗粒分布的变化情况,同时对浊度、总有机碳和其它参数进行连续监测;并对水中E型大肠菌群进行了分析。在暴雨过后,观测到了浊度的两种不同表现:在泉排泄量增加时,浊度最初表现为脉状水动力条件下岩溶系统内沉积物的二次运移;几天后观测到的浊度则表明水已从落水洞到了泉口,常常具有高的总有机碳、硝酸盐及E型大肠菌群。颗粒分布分析结果差异更大:早期的浊度是不同粒径颗粒物的混合,而后期的浊度更多的是由较细颗粒构成,因为大颗粒物已沉积在落水洞到泉口之间的岩溶系统内。E型大肠菌群与0.9～1.5μm颗粒物之间具有很好的相关性。因而较细颗粒的相对增加可应用于微生物污染"早期预报系统"。除了水污染,颗粒分布还可以帮助我们研究岩溶环境的其它问题,如土壤侵蚀。

Root symbionts： Powerful drivers of plant above- and belowground indirect defenses

Soil microbial mutualists of plants, including mycorrhizal ftmgi, non- mycorrhizal fungi and plant growth promoting rhizobacteria, have been typically characterized for increasing nutrient acquisition and plant growth. More recently, soil microbes have also been shown to increase direct plant defense against above- and below- ground herbivores. Plants, however, do not only rely on direct defenses when attacked, but they can also recruit pest antagonists such as predators and parasitoids, both above and belowground, mainly via the release of volatile organic compounds （i.e., indirect defenses）. In this review, we illustrate the main features and effects of soil microbial mutualists of plants on plant indirect defenses and discuss possible applications within the framework of sustainable crop protection against root- and shoot-feeding arthropod pests. We indicate the main knowledge gaps and the future challenges to be addressed in the study and application of these rnultifaceted interactions.

Effects of seed type and bruchid genotype on the performance and oviposition behavior of Zabrotes subfasciatus （Coleoptera： Bruchidae）

The effect of different bean varieties on the performance of the bruchid beetle Zabrotes subfasciatus Boheman （Coleoptera： Bruchidae）, was determined by using wild and cultivated seeds of the genus Phaseolus. Results showed that the quality of the host plant affected the performance and the oviposition behavior of female beetles. Overall, bruchid performance was higher on cultivated seeds than on wild seeds. It was also found that the oviposition behavior and the performance of their offspring differed between females that originated from wild versus cultivated seeds. We also demonstrated the importance of a genetic component in bruchid performance： longevity, fecundity, larval development, adult size, and the sex ratio of the progeny varied according to their matemal lineage （‘family＇ ）. For example, on the same host type, some females laid twice as many eggs as females from other‘families＇, and the sex ratio among the offspring correlated with that of their mother. Thus, the performance and behavior of Z. subfasciatus are not only affected by environmental factors such as the quality of the seeds on which they develop, but also have a genetic basis which can counterbalance a less suitable quality of the host plant. For a crop pest such as Z. subfasciatus, its ability to survive and adapt on host plants of differing quality may be an important attribute to consider for pest management.

CHLORAD: Eradicating Translocon Components from the Outer Membrane of the Chloroplast

Around 100 proteins are produced inside the chloroplast but the vast majority must be imported. These proteins are synthesized in the cytosol as preproteins with cleavable targeting sequences. Several plastid types other than chloroplasts exist. During plant development, one plastid type may be converted to another, a process referred to as plastid transition (Jarvis and Lopez-Juez, 2013). During plastid transitions, proteome remodeling occurs, and one set of imported proteins is replaced by another that is functionally adapted (Kleffmann et al., 2007). Moreover, plastid proteomes are known to be regulated in an environmentdependent fashion, and chloroplasts may respond to changing light conditions by regulating the composition and abundance of photosynthetic complexes.

Revisiting the trail pheromone components of the red imported fire ant, Solenopsis invicta Buren

Ants use species-specific trail pheromones to coordinate their sophisticated foraging behavior.During the past decades,many trail pheromone components with various structures have been identified in ants,including the red imported fire ant,Solenopsis invicta,a notorious invasive species worldwide.Four compounds,Z,E-(ZEF)and E,E-α-farnesene(EEF),Z,E-(ZEHF)and E,E-α-homofarnesene(EEHF),have been reported as components of S.invicta trail pheromone.However,another study reported an analog ofα-farnesene,Z,Z,Z-allofarnesene,as a key trail pheromone component.These contrasting results caused some uncertainty about the trail pheromone composition in S.invicta.In this study,we synthesized ZEF and EEF,ZEHF and EEHF,and reanalyzed the chemicals in the Dufour gland extract and in the trail pheromone fraction of S.invicta worker body extract.The reported isomers of farnesene and homofarnesene were detected and showed trail-following activity,with ZEF as the major compound,while no allofarnesene was found,neither in the Dufour gland extract nor in the whole-body extract.Our results confirm ZEF and EEF,ZEHF and EEHF as trail pheromone components of S.invicta.

Experimental manipulation of reproductive tactics in Seba’s short-tailed bats:consequences on sperm quality and oxidative status

To reproduce,males have to fertilize the female’s eggs,sometimes in competition with ejaculates of other males.In species where males display alternative reproductive tactics,whereby territorial males secure mating and non-territorial males have to sneak copulations,the latter might be expected to invest relatively more resources towards sperm quality compared with the territorial males.Sperm cells are especially vulnerable to oxidative stress,which reduces male fertility.Therefore,antioxidant resources are expected to modulate sperm quality,and might be allocated differently between reproductive tactics.To test the link between reproductive tactics,redox profile and sperm quality,we experimentally induced changes in the reproductive tactics of 39 captive males Seba's short-tailed bats Carollia perspicillata.We monitored the blood and ejaculate oxidative balance,and the sperm quality before,7 days and 21 days after the manipulation of reproductive tactic.Although ejaculates'oxidative damage was negatively related to sperm velocity,males exhibited similar blood and ejaculates redox profiles and similar sperm quality,regardless of their reproductive tactic.Possibly,these results arise as a consequence of some constraints having been lifted during the experiment.Our results also suggest that,in Seba's short-tailed bats,the expression of alternative reproductive tactics is not subjected to strong oxidative constraints.Furthermore,our results could reflect an absence of trade-off between pre-and post-copulatory traits in harem males,as they could be selected to invest both in female attraction and sperm quality,as a consequence of their inability to fully monopolize females.

The Rice RMR1 Associates with a Distinct Prevacuolar Compartment for the Protein Storage Vacuole Pathway

Transport of vacuolar proteins from Golgi apparatus or trans-Golgi network （TGN） to vacuoles is a receptor-mediated process via an intermediate membrane-bound prevacuolar compartment （PVC） in plant cells. Both vacuolar sorting receptor （VSR） and receptor homology region-transmembrane domain-RING-H2 （RMR） proteins have been shown to function in transporting storage proteins to protein storage vacuole （PSV）, but little is known about the nature of the PVC for the PSV pathway. Here, we use the rice RMR1 （OsRMR1） as a probe to study the PSV pathway in plants. Immunogold electron microscopy （EM） with specific OsRMR1 antibodies showed that OsRMR1 proteins were found in the Golgi apparatus, TGN, and a distinct organelle with characteristics of PVC in both rice culture cells and developing rice seeds, as well as the protein body type II （PBII） or PSV in developing rice seeds. This organelle, also found in both tobacco BY-2 and Arabidopsis suspension cultured cells, is morphologically distinct from the VSR-positive multivesicular lytic PVC or multivesicular body （MVB） and thus represent a PVC for the PSV pathway that we name storage PVC （sPVC）. Further in vivo and in vitro interaction studies using truncated OsRMR1 proteins secreted into the culture media of transgenic BY-2 suspension cells demonstrated that OsRMR1 functions as a sorting receptor in transporting vicilin-like storage proteins.

Relationships between testate amoeba communities and water quality in Lake Donghu, a large alkaline lake in Wuhan, China

The middle Yangtze Reach is one of the most developed regions of China. As a result, most lakes in this area have suffered from eutrophication and serious environmental pollution during recent decades. The aquatic biodiversity in the lakes of the area is thus currently under significant threat from continuous human activities. Testate amoebae （TA） are benthic （rarely planktonic） microorganisms characterized by an agglutinated or autogenous shell. Owing to their high abundance, preservation potential in lacustrine sediments, and distinct response to environmental stress, they are increasingly used as indicators for monitoring water quality and reconstructing palaeoenvironmental changes. However this approach has not yet been developed in China. This study presents an initial assessment of benthic TA assemblages in eight lakes of Lake Donghu in the region of Wuhan, China. Testate amoeba community structure was most strongly correlated to water pH. In more alkaline conditions, communities were dominated by Centropyxis aculeata, Difflugia oblonga, Pontigulasia compressa, Pon. elisa and Lesquereusia modesta. These results are consistent with previous studies and show that TA could be useful for reconstructing past water pH fluctuations in China. To achieve this, the next step will be to expand the database and build transfer function models.

世界贸易组织法律体系:法律之渊源

Ⅰ引言现在对国际法渊源的探讨通常首先提及《国际法院规约》第38条(1)款,即国际法院对于向其陈诉之各项争端,应依国际法裁判之,

AtSYP51/52 Functions Diverge in the Post-Golgi Traffic and Differently Affect Vacuolar Sorting

Plant sensitive factor attachment protein receptors （SNAREs） encoded by genes of the same sub-family are generally considered as redundant in promoting vesicle-associated membrane fusion events. Nonetheless, the application of innovative experimental approaches highlighted that members of the same gene sub-family often have different functional specificities. In this work, two closely related Qc-SNAREs--the AtSYP51 and the AtSYP52--are compared in their ability to influence different secretory pathways. Their role in the vesicle sorting to the central vacuole has been revised and they were found to have a novel inhibitory function. When transiently overexpressed, the SYP51 and the SYP52 distributed between the TGN and the tonoplast. Our data demonstrate that these SYPs （syntaxin of plants） act as t-SNARE when present on the membrane of TGN/PVC, whereas they behave as inhibitory or interfering SNAREs （i-SNAREs） when they accumulate on the tonoplast. Moreover, the performed functional analysis indicated that the AtSYP51 and the AtSYP52 roles differ in the traffic to the vacuole. The findings are a novel contribution to the functional characterization of plant SNAREs that reveals additional non-fusogenic roles.