气候变化背景下中国南方地区季节性干旱特征与适应Ⅰ.降水资源演变特征

基于中国南方地区15个省（市、自治区）262个气象台站1959-2008年的降水量资料,分析了季尺度降水量的趋势系数、降水变率、年际及年代际标准化降水距平的变化特征.结果表明：研究期间,中国南方地区降水变化趋势的季节差异较大,大部分地区春季和秋季降水量呈减少趋势,夏季和冬季降水量呈增多趋势,但西南部分地区略有不同;研究区域春旱发生可能性减小,夏旱、秋旱和冬旱发生的可能性增加;春旱更易发生在华南地区和西南地区,夏旱和秋旱发生可能性较高的地区为长江中下游地区和华南地区,冬旱发生可能性较高地区由华南地区扩大为华南和长江中下游地区.中国南方地区春季和秋季降水自20世纪80年代以来明显偏少,夏季和冬季降水在20世纪90年代以前偏少、20世纪90年代偏多、21世纪以来又偏少.中国南方各区域季节尺度降水量标准距平的年代变化基本一致,研究时段内秋季降水量呈减少趋势,夏季和冬季降水量呈增加趋势.     

Seasonal variations in feeding range and flock structure of the Rook Corvus frugilegus in eastern Ireland

The feeding range and flock structure of Rooks showed temporal variations caused mainly by the dispersion of food and reproductive behaviour.
Feeding range was restricted in spring, autumn and early winter when food availability was high and Rooks were reproductively active. A large feeding range occurred in late summer and late winter, when food availability was either generally low or locally distributed and when Rooks were reproductively inactive. The occurrence of flocks common to several rookeries mirrored variations in feeding range; mixed rookery flocks were more common in late summer and late winter. Similarly, the size of the rookery (as measured by the number of nests) was related to feeding range only when Rooks were reproductively inactive and at such times larger rookeries had greater feeding ranges.
Flock structure showed similar seasonal variations; small widely spaced flocks predominated in summer, autumn, early winter and spring, whereas large dense flocks occurred in late winter. Diurnal variations in flock structure occurred within any one season. Both seasonal and diurnal variations in flock structure may be determined by the dispersion of the prey and the feeding strategy used to obtain it, reproductive behaviour and the risk of predation.     

Influence of the seasons on the circadian rhythm of blood glucose and tissue glycogen in male Wistar rats

Adult, ad libitum fed male Wistar rats were adapted for three weeks to standard laboratory conditions and a 12:12 h light:dark regimen (7 a.m. to 7 p.m., 7 p.m. to 7 a.m.). In January, in April, in July and in October they were decapitated at 3-hour intervals and the glucose level was determined in their blood and the glycogen concentration in their liver, skeletal muscle, heart and white and brown adipose tissue. The influence of the seasons on circadian variation of the given parameters was not the same in all the tissues. Circadian variation of the liver and heart glycogen concentration was the least affected. The liver glycogen curves attained the maximum at the beginning of the light part of the day in all the seasons except the autumn; the rhythm was present everywhere. The rhythm was not demonstrated in the heart in the winter only and except for the summer the curves attained the maximum at the end of the dark part of the day. Pronounced seasonal changes were observed in the blood glucose and skeletal muscle glycogen concentration, whose curves reached the maximum in various parts of the day and where the rhythm was absent in the autumn - and in the case of skeletal muscle in the summer as well. The glycogen concentration in the two adipose tissues displayed the greatest seasonal changes. The shape of the circadian oscillation curves and their maxima in the various seasons were very different, with absence of the rhythm in the autumn. Determination of the influence of the photoperiodic reactions and of changes in hormones and the key enzymes regulating the main metabolic routes might help to explain the basis of circaannual variations in the metabolism of the laboratory rat.     

Seasonal population dynamics of Paraquimpevia tenevvima (Linstow) (Nematoda) in the European eel Anguilla anguilla (Linnaeus) in three localities of southwest England

Seasonal population dynamics of Puraquzmperia tenerrima (Linstow) in the European eel Anguillu anguillu (Linnaeus) have been investigated in three localities in Devon, southwest England. The nematode is common and exhibits very similar seasonal patterns in changes of prevalence and abundance in the three localities. The population increases over winter through to late spring or early summer as the recruitment of the new generation occurs throughout this period. Reproduction of the nematode starts in spring. A sharp decrease of prevalence and abundance accompanies or follows reproduction, and infection levels are very low in autumn and early winter. The dispersion pattern of the nematode varies with the infection levels from over-dispersion in spring and early summer to almost random dispersion in autumn and winter. It is suggested that P. tenerrimu is a common specific parasite of eels, especially in small streams or rivers and that insect larvae or species of crustaceans might serve as intermediate hosts for the nematode.     

Seasonal variation in haematological parameters in male and female Tinca tinca

This study was designed to investigate any seasonal (spring, summer, autumn and winter) changes in haematological parameters in the blood of Tinca tinca measuring the number of red blood cells (RBC), haematocrit, white blood cells, and total plasma proteins.The results show significant changes in RBC and haematocrit in males comparing spring and summer with autumn and winter, whereas in females the RBC remained constant for all 4 seasons but the haematocrit decreased in autumn and winter compared to spring and summer. The white blood cells of male and female animals were significantly lower in spring and winter compared to summer and autumn. In male fish total protein contents significantly decreased in autumn and winter compared to spring and summer, whereas in females protein output significantly decreased in winter compared to the other seasons. The results indicate marked seasonal variation in the blood of male and female Tinca tinca. This variation may play a important protective role for the survival of the animals.     

SEASONAL VARIATION IN SUN-SHADE ECOTYPES OF PLECTONEMA NOTATUM (CYANOPHYTA)1

Clonal cultures of the thermophilic alga Plectonema notatum Schmidle were grown from cells collected in winter from the surface and subsurface zones of the cell mat in Jerry Johnson Hot Spring, Idaho. Both surface and subsurface clones exhibited light saturation curves and concentrations of photosynthetic pigments typical of ecotypes highly adapted to shade environments. These winter clones were compared to surface and subsurface clones collected during summer months. This comparison illustrates the seasonal rotation of ecotypes. The shade adapted winter surface and subsurface types dominated the mat during the low light intensity, short photoperiod winter season. With increasing light intensities and photoperiods the winter ecotypes were replaced by the high light intensity adapted summer ecotypes.     

雄性大熊猫褪黑素与睾酮季节性变化

褪黑素通过调控下丘脑-垂体-性腺内分泌轴使季节性繁殖动物在适宜的季节进行繁殖活动.大熊猫(Ailuropoda melanoleuca)在春季集中繁殖.为探究雄性大熊猫褪黑素和睾酮的季节性变化规律,本研究选取成都大熊猫繁育研究基地3只成年雄性大熊猫作为实验对象,在自然光照下对这3只大熊猫进行每周1次为期1年(2018年...     

Trends in annual and seasonal survival of Pink-footed Geese Anser brachyrhynchus

Adult Pink-footed Geese Anser brachyrhynchus from the Svalbard breeding population were neck-banded and resighted in staging and wintering areas outside the breeding season 1990–1999. We estimated annual and seasonal survival using capture–recapture statistical models. Mean annual survival was 0.829, declining over the study period from 0.90 to 0.79. The annual cycle was partitioned into three periods: summer (1 April–30 September), including both spring and autumn migration, autumn (1 October–31 December), including most shooting, and winter (1 January–31 March). The parsimonious model selected to describe seasonal survival included a declining trend in summer survival, constant autumn and winter survival with lower survival in the severe winter of 1996, and an additive effect of sex on summer and winter survival. Monthly survival was highest during winter. Decreasing summer survival was the main contributor to the overall decline in annual survival, and was attributed mainly to increasing natural mortality on the breeding grounds. Mean annual survival based on the seasonal survival probabilities was 0.835 for females and 0.805 for males. The effect of sex was most pronounced during summer and remains to be explained.     

洞庭湖区社鼠消化道长度和质量的季节变化

对洞庭湖区社鼠（Niviventer confucianus）自然种群四季的消化道各器官的长度和质量进行了测定。结果表明。消化道指标季节变化明显。总体消化道含内容鲜质量、净鲜质量与干质量均具有显著的季节变化。以冬、春季较高。夏、秋季较低。消化道各器官的变化与总消化道不尽相同。其中,以胃的变化相对比较稳定。仅长度的变化达显著水平,以冬季最短,夏、秋季较长。这是动物为适应繁殖季节能量需求而增加摄食量的反应,也与夏秋季食物丰富度有关。小肠、盲肠、大肠的长度和质量指标（内容鲜质量、净鲜质量和干质量）以冬、春季较高。夏、秋季较低。这是该鼠对冬、春季低温和食物匮乏的适应性反应。总体来说。洞庭湖区社鼠为适应夏、秋季繁殖盛期能量需求增加的主要对策是增加摄食量;而为适应冬、春季低温环境和食物数量和质量减少的主要对策是增大消化道。提高消化效率。     

The tempo-spatial variations of phytoplankton diversities and their correlation with trophic state levels in a large eutrophic Chinese lake

Lake Chaohu is one of the most eutrophic lakes in China. Research on this lake's seasonal and spatial variations in phytoplankton diversity is needed to understand the distribution of eutrophication, as well as to find appropriate comprehensive biodiversity indices to assess the eutrophication status of the lake. The present study indicated that the Margalef index of all samples was as low as 0.799 ± 0.543 in summer (August 2011) and as high as 1.467 ± 0.653 in winter (February 2012). The Margalef index of the river samples had a high mean value and substantial variation compared with the lake samples. The Peilou index of the lake samples was higher than that of the river samples in summer and autumn (November 2011) but lower than that of the river samples in winter. In spring (May 2012), the Peilou index of the western samples was lower than that of the eastern samples. The spatial distribution of the Shannon–Wiener index was more similar to that of the Peilou index in autumn and winter, while in spring and summer, the spatial distribution was affected by both species richness and evenness. High eutrophication levels occurred in the western lake in spring and summer, whereas high levels occurred in the eastern lake, especially in the middle of the lake, in autumn and winter. The total trophic state index (TSI) in all samples exhibited a significant negative correlation with the Margalef (r = −0.726) and Peilou (r = −0.530) indices but a significant positive correlation with the Shannon–Wiener (r = 0.654) index. The partial correlation analysis results implied that these phytoplankton biodiversity indices could serve as synthetic ecological indicators to assess the eutrophication condition of Lake Chaohu.     

高原鼠兔肠道微生物中丰富及稀有类群的季节性特征

气候及食物是驱动植食性小哺乳动物肠道菌群产生季节性变化的重要因素。然而,此类研究很少涉及肠道丰富及稀有微生物类群。本文以高原鼠兔（Ochotona curzoniae）为对象,通过16S rRNA基因测序和分析,探讨丰富及稀有肠道微生物类群的结构组成、多样性指数及功能在春、夏、秋、冬四季的变化特征。结果显示,丰富类群对菌群主要门和功能的季节性变异贡献大于稀有类群,稀有类群对菌群OTU和alpha多样性的变异贡献大于丰富类群。丰富类群和稀有类群的香农指数均在冬季显著高于其他季节;丰富类群的ACE指数在秋季显著低于其他季节,而稀有类群的ACE指数则在冬季显著高于春季和夏季。丰富类群中拟杆菌门（Bacteroidetes）的相对丰度在冬季和秋季显著高于春季和夏季,但在稀有类群中,夏季和秋季的相对丰度显著高于冬季和春季。丰富类群中氨基酸代谢通路的相对丰度在冬季显著高于春季和夏季,而在稀有类群中,其相对丰度在春季显著高于夏季和秋季。气温、降水量和植被中的营养物质与肠道菌群中丰富类群和稀有类群的变化均显著相关,环境变量对丰富类群和稀有类群变化的总解释率分别为18%（气温：3%;降水：4%;植被营养成分：10%;联合：1%）和9%（气温：1%;降水：2%;植被营养成分：5%;联合：1%）。以上结果表明肠道微生物中的丰富和稀有类群具有不同的分布模式和季节性特征,二者对整体菌群变异的贡献存在差异,环境因素更多地影响丰富类群,反映了肠道微生物不同类群对季节变化响应的非一致性。本研究增进了我们对哺乳动物肠道菌群季节性变化过程及环境适应性的认识。     

Seasonal changes of semen quality and freezability in Franches-Montagnes stallions

The objective of this study was to investigate seasonal changes of semen quality parameters in Franches-Montagnes stallions and to compare the freezability of ejaculates collected in autumn and winter. Experiments were performed using 15 stallions from the National Stud Farm in Avenches (Switzerland). Ejaculates were collected and evaluated every month during 1 year as well as cryopreserved in autumn and winter (September to February). In fresh semen the gel-free volume, concentration, motility and morphology (normal sperm, major defects, vacuoles and acrosome defects) were evaluated and in frozen-thawed semen the motility as well as the viability (SYBR-14/PI) were performed. To analyse seasonal differences four periods of 3 months each were defined as autumn (September, October, November), winter (December, January, February), spring (March, April, May) and summer (June, July, August). During the 1-year experiment all fresh semen quality parameters demonstrated a clear seasonal and individual pattern. The gel-free volume was significantly (P<0.05) higher in spring and summer compared to autumn and winter while sperm concentration was significantly (P<0.05) lower in spring than at any other time of the year. Total sperm number was significantly (P<0.05) higher and sperm motility significantly (P<0.05) lower in summer than in other seasons. Regarding sperm morphology, normal sperm was significantly (P<0.05) higher in autumn than in winter and summer and major defects were lowest (P<0.05) in autumn. In frozen-thawed semen motility was significantly (P<0.05) improved in the ejaculates collected in autumn compared to winter, while viability showed no obvious differences. Our results clearly demonstrate that individual and seasonal differences occurred in semen quality of Franches-Montagnes stallions. Ejaculates collected in autumn (September, October, November) demonstrated good quality, especially regarding sperm morphology, and were more suitable for cryopreservation because of better motility in frozen-thawed semen collected during autumn than in winter.     

Characterization of commercial yeast strains by flow microcalorimetry

A flow microcalorimetric procedure has been developed for the characterization of representative strains of Saccharomyces cerevisiae and Sacch. uvarum (carlsbergensis) used in the food industry. Growth in a chemically defined medium containing single and mixed sugars gave reproducible and characteristic power-time curves. The technique is proposed as a rapid alternative method for the characterization of yeast strains selected for commercial use.     

Discriminant analysis of microcalorimetric data of bacterial growth

In this work a bacterial classification method based on the discriminant analysis of the microcalorimetric data provided by the growth power-time (p-t) curves is developed. This method is applied to classify several species of Enterobacteria of different origins, and the results are compared with those obtained by conventional techniques. The proposed analysis allows us to classify bacteria into species and discriminate among strains of the same species. The classification is carried out using one run of each isolate after standardization of inocula and growth conditions. The discrimination power of available microcalorimetric data is also discussed, and the most discriminant set of data is proposed as the input variables of the analysis. Finally, the advantages of microcalorimetry as a taxonomical technique are discussed.     

Seasonal patterns in feeding ecology of three small fishes in the Biandantang Lake, China

Feeding ecology of three small fish species, Hypseleotris swinhonis, Ctenogobius giurinus and Pseudorasbora parva was studied seasonally in the Biandantang Lake, a small, shallow lake in central China. Gut length, adjusted for total body length, was significantly higher in spring than in other seasons for all the three species. Seasonal changes in gut length were not associated with changes in food quality. Weight of fore-gut contents, adjusted for body weight, was significantly higher in winter and spring than in summer and autumn in H. swinhonis and C. giurinus , and significantly higher in autumn than in spring and summer for P. parva. Percentage of empty fore-guts was highest in summer and lowest in spring for H. swinhonis and C. giurinus , and highest in winter and lowest in autumn for P. parva. Diet of the three small fishes showed apparent seasonal changes, and these changes reflected partly the seasonal fluctuations of food resources in environment. Diet breadth was high in winter and low in autumn for H. swinhonis , high in winter and low in spring and summer for C. giurinus , and high in autumn and low in spring for P. parva. Diet overlaps between pairs of species were biologically significant in most cases, except between H. swinhonis and P. parva in summer and autumn and between C. giurinus and P. parva in autumn.     

Microcalorimetry is a sensitive method for studying the effect of nucleotide mutation on promoter activity

Microcalorimetric method was successfully used to study the effect of nucleotide mutations on promoter activity and identify the important nucleotide necessary for the promoter function in Escherichia coli. The thermokinetic parameters, such as k, I and IC(50), were calculated from the metabolic power-time curves obtained by microcalorimetric measurement using the TAM air Isothermal Microcalorimeter (manufactured by Thermometric AB company of Sweden). Analysis of these data revealed that different nucleotide mutations in -10 box sequence of RM07 fragment had different effect on the promoter activity. Our research also suggest that the microcalorimetric method is a very sensitive and easily performed method for investigation of promoter mutation.     

长江口海域浮游糠虾类生态特征

利用2002—2003年长江口近海（122°00′—123°30′ E,29°00′—32°00′ N）四季调查资料,研究了长江口近海浮游糠虾类多样性、数量波动过程及其与渔场的关系.结果表明：长江口近海共有浮游糠虾14种,秋季10种,春、秋季8种,冬季2种.种类组成季节更替明显,其中从秋季到冬季更替率最高（90.9%）,春、夏和秋季多样性指数（H′）值均大于2,冬季为1- 夏季丰度均值最高［234.70 ind·(100 m³)^-1］,秋季为103.34 ind·(100 m³)^-1,春季80.36 ind·(100 m³)^-1,冬季最低12.40 ind·(100 m^3)-1,丰度变化与温度一致.因温、盐适应范围最广,漂浮囊糠虾是春、秋、冬3季的优势种;短额刺糠虾是夏、秋两季的优势种;长额刺糠虾是冬季的优势种各季节优势种对总丰度贡献均较大.夏季短额刺糠虾的聚集强度最高.长江口近海浮游糠虾类对长江口渔场及舟山渔场的形成具有重要意义.     

Inhibition patterns and seasonal availability of nematodes for beef cattle grazing on argentina''s western pampas

The seasonal population trends of cattle nematodes in tracer calves are described from 1981 to 1987. Successive worm-free calves were grazed with growing beef cattle for 20–30 days at 6 week intervals and then slaughtered for nematode counts 2 weeks after their removal from pasture. Ostertagia, Cooperia, Trichostrongylus and Haemonchus were the main genera recovered. O.ostertagi was the most often found and acquisition of inhibition-prone larvae began in late winter and reached a peak in spring, while maximum larval availability was in autumn. The seasonal inhibition and larval availability pattern for T. axei was similar to that of Ostertagia. Cooperia showed greatest inhibition during winter with maximum larval availability in autumn and spring. Haemonchus was more prevalent during summer to early autumn and no inhibition was observed. It was concluded that infective larval availability for tracer calves was highest during autumn, and most reduced in summer. All predominant species were able to survive over summer on pasture,     

Fire season and intensity affect shrub recruitment in temperate sclerophyllous woodlands

The season in which a fire occurs may regulate plant seedling recruitment because of: (1) the interaction of season and intensity of fire and the temperature requirements for seed release, germination and growth; (2) post-fire rainfall and temperature patterns affecting germination; (3) the interaction of post-fire germination conditions and competition from surrounding vegetation; and (4) the interaction of post-fire germination conditions and seed predators and/or seedling herbivores. This study examined the effects of different fire intensities and fire seasons on the emergence and survival of shrubs representing a range of fire response syndromes from a summer rainfall cool climate region. Replicated experimental burns were conducted in two seasons (spring and autumn) in 2 consecutive years and fuel loads were increased to examine the effects of fire intensity (low intensity and moderate intensity). Post-fire watering treatments partitioned the effects of seasonal temperature from soil moisture. Higher intensity fires resulted in enhanced seedling emergence for hard-seeded species but rarely influenced survival. Spring fires enhanced seedling emergence across all functional groups. Reduced autumn recruitment was related to seasonal temperature inhibiting germination rather than a lack of soil moisture or competition. In Mediterranean-type climate regions, seedling emergence has been related to post-fire rainfall and exposure of seeds to seed predators. We think a similar model may operate in temperate summer rainfall regions where cold-induced dormancy over winter exposes seeds to predators for a longer time and subsequently results in recruitment failure. Our results support the theory that the effect of fire season is more predictable where there are strong seasonal patterns in climate. In this study seasonal temperature rather than rainfall appears to be more influential.