全球海岸带国家蓝碳资源价值与类型研究

海岸带蓝碳生态系统已成为应对气候变化重要的基于自然的解决方案。本研究梳理了全球海岸带蓝碳生态系统的分布、碳封存量和封存价值,并根据经济、科技、蓝碳封存量三个指标对各海岸带国家和地区进行分类。海岸带蓝碳生态系统分布最广的国家是澳大利亚、印度尼西亚、墨西哥和美国,而印度尼西亚、澳大利亚、马来西亚和巴西碳埋藏量最高。全球每年蓝碳埋藏价值在碳交易和碳税价格下分别为3.47×109美元和2.35×109美元。中国拥有丰富的海岸带蓝碳资源,生态系统面积排名第10,年封存量排名第21;然而蓝碳自然资源的赋存禀赋与现有碳价格体系下的价值匹配性较差,基于碳交易价格的中国海岸带蓝碳埋藏价值全球排名第27,基于碳税价格仅排名第39。碳价格低迷将会导致在国际蓝碳交易中处于劣势,中国后续应不断完善碳排放交易市场。中国具有在蓝碳研究以及修复投入与实践方面的优势,以及贝藻养殖、海洋牧场等特色蓝碳资源,可结合不同类型的蓝碳国家经济科技条件与自然条件制定多元合作策略。     

三沙永乐龙洞洞内侧壁礁体矿物和元素组成及其晚更新世以来的形成演化

三沙永乐龙洞深度在300m左右,是目前全球已知最深的海洋蓝洞,但是对其性质和成因了解极其有限。本研究使用X射线粉晶衍射仪、X射线荧光光谱仪、AMS14C测年等分析测试方法对采自不同深度的洞壁礁体的矿物物相、元素含量和形成年代进行了测定,探讨了洞壁性质和龙洞的演化。研究结果表明:三沙永乐龙洞洞内侧壁矿物均属于碳酸盐矿物,包括文石、高镁方解石和低镁方解石,平均含量分别为49.0%、46.6%、14.3%,它们主要来自钙质生物碎屑;洞内侧壁的主要元素是Ca、Mg、Sr,平均含量分别为36.8%、0.98%、0.48%。三沙永乐龙洞是一个复合体,17m以上岩石年龄晚于7.5cal kaBP,是全新世海平面上升时期形成的现代珊瑚礁体,没有经历过海平面下降引起的成岩作用; 17—35m岩石形成时代早于25cal ka BP,是经历了大气淡水成岩作用的晚更新世喀斯特溶洞,且在高海平面时期于17—23m以浅的空间内广泛发育洞内珊瑚礁。     

海带CRY-DASH基因的克隆与转录表达分析

利用cDNA末端快速克隆(RACE)技术,获得海带(Saccharina japonica) CRY-DASH基因(SjCRYDASH)全长序列,结构分析发现,其ORF区长1779 bp,编码592个氨基酸。进行氨基酸同源序列比对,其与其他藻类和高等植物间存在两个重要辅基MTHF和FAD结合的保守域。通过不同光质照射诱导海带幼孢子体,发现蓝光、白光诱导1h后,均能使SjCRY-DASH转录水平上升,且SjCRY-DASH对蓝光的响应更强烈。本研究结果为研究大型褐藻-海带CRY-DASH受光诱导调控功能打下基础。     

A word about the teacher

This is a memorial report on the biography and scientific heritage of M.A. Svechnikov — an outstanding scientist and teacher, the founder of the Ural school of close binary stars and the author of the classification scheme for eclipsing variable stars.     

Regional and species specific sexual reproductive patterns of three zooxanthellate scleractinian corals across the Eastern Tropical Pacific

Sexual reproduction of zooxanthellate scleractinian corals in the Eastern Tropical Pacific (ETP) is influenced by the interactive effects of regional and local oceanographic conditions, as well as a variety of other environmental factors. Differences in spatial and temporal gamete development and reproductive patterns of three widespread scleractinian corals of this region—Pocillopora damicornis (branching colony morphology, characterized as hermaphrodite broadcaster), Pavona gigantea (massive colonies, characterized as gonochoric broadcaster/sequential co‐sexually hermaphroditic) and Porites panamensis (encrusting colonies, characterized as gonochoric brooder)—were evaluated at local and regional scales across the ETP. This area extended from the Gulf of California (24°N) to the southern coast of Ecuador (–1°S), including offshore islands, using existing data pooled from prior studies. Predictive models were employed based on environmental variables: sea surface temperature, daylight hours, diffuse attenuation co‐efficient at 490 nm and photosynthetically active radiation. Datasets were extracted from satellite images ( https://oceancolor.gsfc.nasa.gov ) and analysed using WAM_STATIST ver. 6.33® software to obtain monthly average data from each site. The spatial (region, sub‐region and site) and seasonal (wet, dry) variation in reproductive activity (% colonies with gametes) differed among the three species; significant interactions were season × sub‐region for P. damicornis, season × site (sub‐region) for P. gigantea, and season × site for P. panamensis, for which sub‐region was not considered as a factor. The predictive models also suggest that gamete production/maturation of P. damicornis and P. gigantea is influenced by local differences in sea surface temperature and daylight hours. Porites panamensis was not correlated with any environmental variable examined. Variations in local and regional reproductive developmental patterns are likely an acclimatization response by each species imposed by the timing and duration of local stressor events. This analysis has provided insights into the diverse local and regional physical drivers that affect species responses and acclimatization in sexual reproduction across the ETP.     

Radial velocities of population II binary stars. I.

Radial velocities for 114 Hipparcos stars, mostly high transverse velocity binaries without previous radial velocity measurements, are published. Measurements are made with the CORAVEL‐type radial velocity spectrometer. The accuracy of measurements is better than 1 km/s. Two stars, BD +30° 2129A and HD 117466AB are found to be radial velocity variables, and three more stars, HD 119515A, HD 131597AB, and HD 153344, are possible radial velocity variables.     

Delineation of precipitation regions using location and atmospheric variables in two Canadian climate regions: the role of attribute selection

The identification of homogeneous precipitation regions is essential in the planning, design and management of water resources systems. Regions are identified using a technique that partitions climate sites into groups based on the similarity of their attributes; the procedure is known as regionalization. In this paper the ability of four attribute sets to form large, coherent precipitation zones is assessed in terms of the regional homogeneity of precipitation statistics and computational efficiency. The outcomes provide guidance for effective attribute selection for future studies in Canada. The attributes under consideration include location parameters (latitude, longitude), distance to major water bodies, site elevation and atmospheric variables modelled at different pressure levels. The analysis is conducted in two diverse climate regions within Canada including the Prairie and the Great Lakes–St Lawrence lowlands regions. The method consists of four main steps: (i) formation of the attribute sets; (ii) determination of the preferred number of regions (selection of the c-value) into which the sites are partitioned; (iii) regionalization of climate sites using the fuzzy c-means clustering algorithm; and (iv) validation of regional homogeneity using L-moment statistics. The results of the attribute formation, c-value selection, regionalization and validation processes are presented and discussed in a comparative analysis. Based on the results it is recommended for both regions to use location parameters including latitude, longitude and distance to water bodies (in the Great Lakes region) to form precipitation regions and to consider atmospheric variables for future (climate change) applications of the regionalization procedure.     

Temporal and spatial changes of blue water and green water in the Taihang Mountain Region,China, in the past 60 years

ABSTRACT

Appropriate allocation of limited freshwater resources to humans and ecosystems is an important issue hampering sustainable development in mountainous regions. The Taihang Mountain Region (TMR), including the Yellow and Hai river basins, is an important water source area for the North China Plain. The distributed hydrological model Water and Energy transfer Processes in Large river basins (WEP-L) was used to simulate the water cycle processes and to summarize the temporal and spatial changes in the blue and green water in the TMR from 1956 to 2015. The results show that in the period 2011–2015 the annual average blue water decreased by 7.31 × 10⁹ m³, while the annual average green water increased by 13.60 × 10⁹ m³ compared to 1956–1960. At the inter-annual time scale, the blue water exhibited a downward trend while the green water exhibited an upward trend. The amount of seasonal blue water in the TMR is ranked in descending order: summer, autumn, spring and winter, while for green water, the rank is summer, spring, autumn and winter. The amounts of blue and green water are higher on the windward than on the leeward slopes. The blue water yield is generally higher in forests and grasslands than in farmland, while the green water exhibits the opposite response. A greater emphasis should be placed on the widening gap between blue water and green water due to climate warming, and on soil and water conservation measures.     

Hydrological modelling of the Vistula and Odra river basins using SWAT

This paper presents a large-scale application of the SWAT model for water balance and natural streamflow simulation in the entire basins of the Vistula and the Odra, covering most of the territory of Poland. A tailored calibration approach was designed to achieve satisfactory goodness-of-fit across a range of catchment sizes. Model calibration and evaluation driven by high-resolution climate data showed overall good behaviour for 80 benchmark catchments divided into eight clusters, and spatial evaluation for 30 gauges showed that the designed regionalization scheme performed well (median KGE of 0.76). Basin-averaged estimates of blue and green water flow and green water storage estimated using the calibrated model were 185, 517 and 206 mm, respectively. This study provides a basis for future work, such as assessing climate change impacts on hydrology, assessing flow alterations, and water quality simulation. The model output is publicly available through an online research data archive (doi:10.4121/uuid:b8ab4f5f-f692-4c93-a910-2947aea28f42).

EDITOR A. Castellarin

ASSOCIATE EDITOR G. Thirel     

Autocorrelation function bias owed to a limited number of de-trended observations. Applications to autoregressive models with noise

Analytical expressions were derived for the expectation of the autocorrelation function (ACF) corresponding to lowfrequency least squares fits and deviations from them in the case of a limited number of observations N. A vector of values of the autocovariation function may be obtained by multiplication of a N . N matrix Z (dependent on concrete basic functions used for trend determination) by a vector of the unbiased ACF. Because much computational time is needed to obtain such a matrix, its components are to be computed once for concrete N and basic functions, and then stored as a file. An algorithm is proposed for determining the contribution of the correlated signal to the ‘signal+noise’. The expressions are written for general form of the ACF, and illustrated by the application to autoregressive models. The statistical properties of the model parameters are studied. The method is applied to cataclysmic binaries AM Her and TT Ari. The precise expressions allow us to obtain reliable results and to avoid misinterpretation being possible when using the approximate methods.