Genetic variation of the bud and leaf phenology of seventeen poplar clones in a short rotation coppice culture

Abstract: Leaf phenology of 17 poplar ( Populus spp.) clones, encompassing spring phenology, length of growth period and end-of-year phenology, was examined over several years of different rotations. The 17 poplar clones differed in their latitude of origin (45°30'N to 51°N) and were studied on a short rotation experimental field plantation, situated in Boom (province of Antwerpen, Belgium; 51°05'N, 04°22'E). A similar, clear pattern of bud burst was observed during the different years of study for all clones. Clones Columbia River, Fritzi Pauley, Trichobel (Populus trichocarpa) and Balsam Spire (Populus trichocarpa × Populus balsamifera) from 45°30'N to 49°N reached bud burst (expressed as day of the year or degree day sums) almost every year earlier than clones Wolterson (Populus nigra), Gaver, Gibecq and Primo (Populus deltoides × Populus nigra) (50°N to 51°N). This observation could not be generalised to end-of-season phenology, for which a yearly returning pattern for all clones was lacking. Late bud burst and early leaf fall of some clones (Beaupré, Boelare, IBW1, IBW2, IBW3) was brought about by increasing rust incidence during the years of observation. For these clones, the variability in leaf phenology was reflected in high coefficients of variation among years. The patterns of genetic variation in leaf phenology have implications for short rotation intensive culture forestry and management of natural populations. Moreover, the variation in phenology reported here is relevant with regard to the genetic mapping of poplar.     

Taxonomic relationships between Pachycerus and Rhabdorrhynchus (Coleoptera: Curculionidae: Lixinae), with descriptions of two new species of Rhabdorrhynchus from the Arabian Peninsula

Taxonomic relationships between Rhabdorrhynchus and Pachycerus are discussed, and two new species of Rhabdorrhynchus are described: Rhabdorrhynchus sauditus (type locality: Saudi Arabia, As Shāqqah al Yamānīyah, 19°42'N, 40°48'E) and Rhabdorrhynchus emir (type locality: United Arab Emirates, Jebel Ali, 24°59'N, 55°43'E). Some hypotheses on the distribution of the new species in the Arabian Peninsula, based on a biogeographical analysis, are proposed.  © 2008 The Linnean Society of London, Zoological Journal of the Linnean Society , 2008, 152 , 25–37.     

Laboratory studies of egg development and diapause in Isoperla obscura (Plecoptera) from a mountain stream in Norway

SUMMARY 1. A laboratory study of egg development of the stonefly Isoperla obscura (Zetterstedt) collected from the stream Flybekken (southern Norway, 61°25'N, 8°48'E, 1373 m a.s.l.) showed a short diapause followed by a prolonged period of postdiapause quiescence.
2. Diapause occurred over a wide range of temperatures (−20°C to +8°C), but 0–1°C was the most favourable for fast diapause development and successful hatching. Diapause development required temperatures below 12°C, but sub-zero diapause temperatures increased mortality during the postdiapause phase, as well as reducing hatching success.
3. The threshold for initiation of postdiapausal development was about 1–2°C. Development rate increased and variation in development time decreased at higher water temperatures. These may be important characteristics to ensure seasonal and geographical synchrony of development in individual populations. Low postdiapausal temperatures were unfavourable, despite a subsequent increase in water temperature. No response to postdiapausal photoperiod was detected.
4. The results agreed well with conditions noted in the natural environment, and with the abundance of this species at high altitudes and latitudes in Fennoscandia. Nevertheless, Isoperla obscura also occurs in streams in the maritime parts of western Norway. The results of the present study suggest that egg development in these populations will prove to be different.     

Emergence of Baltic salmon, Salmo salar L., in relation to temperature: a laboratory study

Emergence pattern and developmental status at emergence of Baltic salmon fry from the Umeälven hatchery stock (63°50'N, 20°25'E) were studied at 6, 10 and 12°C in the laboratory. The number of days and degree days from hatching to 50% emergence decreased exponentially with increasing temperature. Synchronization of emergence increased with temperature. Optimal temperature for incubation of yolk-sac alevins was 10°C, which resulted in the largest fry at emergence and the lowest death rate. Fry kept at 6°C had the lowest mean weight and at 12°C the highest death rate. The fry emerged at an earlier developmental state with more yolk at 12°C than at 6°C. The Baltic salmon had a faster developmental rate during the gravel-phase, as compared to more southern Atlantic salmon populations.     

Lateral plate morph differentiation of freshwater and marine populations of the three-spined stickleback, Gasterosteus aculeatus, in Poland

The distribution of three main lateral plate morphs of the three–spined stickleback, Gasterosteus aculeatus , in the Polish zone of the Baltic Sea and inland waters is surveyed. Most sites are characterized by predominance of the completely plated morph, although it is only in the Vistula River drainage basin where monomorphic complete populations prevail. Polymorphic populations with a high proportion of the non–complete morphs are found in Puck Bay (the Baltic) and in south–west Poland, Possible causes of this pattern are discussed.     

云南热带和亚热带山地森林鼠形啮齿类的群落结构 Ⅰ、多样性相,对丰盛度,密度和物量

热带山地雨林中捕获鼠形啮齿类6种,社鼠(Rattus niviventer)是优势种,相对丰盛度为81.18%;亚热带中山湿性阔叶林中捕获8种,中华姬鼠(Apodemus draco)为优势种,相对丰盛度为73.63%。两种森林类型鼠形啮齿类种类数目间并无显著差异。 热带山地雨林6种鼠形啮齿类平均密度为13.21只/公顷,平均生物量为711.43克/公顷;亚热带中山阔叶林中5种平均密度为20.25,平均生物量530.19。两种森林中鼠形啮齿类的平均密度差异显著,但生物量平均值却无明显差别。 群落中生物量分布极不均匀,社鼠和中华姬鼠的生物量分别在两种森林中各自占鼠形啮齿类总生物量的77.37%与70.43%。     

天童常绿阔叶树种栲树生殖个体大小及其生殖构件特征

对浙江天童木荷-栲树林内的常绿阔叶树种栲树(Castanopsis fargesii Franch.)的生殖个体大小、生殖构件的分布及其动态变化特征进行了研究。结果表明, 该地区栲树生殖个体的胸径在17~50 cm 间, 平均胸径为31. 2±8.0 cm, 平均年龄约36.3±6.6 年;林缘附近的生殖个体小于木荷-林内。相对稳定的群落和比较丰富的土壤养分条件有利于生殖枝数量和花序数量的增多。栲树生殖个体的数量在两年中变化较大, 部分栲树个体可以在连续年份中生殖。从枝系水平分析:在持续生殖的栲树个体上, 生殖枝数量有明显变化, 并非所有的生殖枝在两年中都可开花或结果, 保持连续生殖的枝系约占48.2%。栲树果序枝数量在连续年份有明显差异(p < 0.01), 而且果序枝上的幼蕾数、果实数量及结实率等都有明显差异(p < 0.05)。     

Presence of Echinorhinus cookei off central Pacific Mexico

On 19 May 1999, the capture of a neonate male of the prickly shark Echinorhinus cookei (377 mm L _T) off Michoacán Coast (18°40'N: 103°47'W) was recorded. The prickly shark was found at a depth of 132 m; it was collected over muddy bottom using a trawl net. In Mexico, representatives of this species are scarce o. the Pacific Coast; this new record extends the known southern range 261 km from 21°01'N to 18°40'N for the continental coast. The organism was deposited in the ichthyological reference collection of the Centro de Investigación en Alimentación y Desarrollo, A.C, Unidad Mazatlán (catalogue number, CIAD 01–03 Mazatlán). Morphometric and meristic characteristics of the specimen are given.     

Alburnoides manyasensis (Actinopterygii,?Cyprinidae), a new species of cyprinid fish from?Manyas?Lake?basin,?Turkey

Alburnoides manyasensis, sp. n., is described from the Koca Stream (Lake Manyas drainage, Marmara Sea basin) in Anatolia. It is distinguished from all species of Alburnoides in Turkey and adjacent regions, Alburnoides tzanevi (Rezovska [Rezve], Istranca and Terkos streams in the western Black Sea drainage), Alburnoides cf. smyrnae (Banaz Stream, a drainage of Büyük Menderes River, Aegean Sea basin), Alburnoides fasciatus (streams and rivers in the eastern Black Sea drainage) and Alburnoides eichwaldii (Kura and Aras rivers [a drainage of Kura River], Caspian Sea basin) by a combination of the following characters (none unique to the species):marked hump at nape, especially in specimens larger than 60 mm SL; partly developed ventral keel between pelvic fin and anal fin, scaleless 1/2 to 2/3 its length; body depth at dorsal-fin origin 29−32% SL; caudal peduncle depth 11−12% SL; 45–52+ 2–3 lateral-line scales; 9–12 scale rows between lateral line and dorsal-fin origin; 4–5 scale rows between lateral line and anal-fin origin, 10½–12½ branched anal-fin rays; 40–42 total vertebrae.     

Geographical variation in egg cold hardiness: a study on the adaptation strategies of the migratory locust Locusta migratoria L.

Abstract. 1. For many species of insect, cold hardiness is an important trait that enables a population to develop in the next season and to extend its range. To elucidate the role of cold hardiness of the migratory locust Locusta migratoria L. in its outbreak and distribution areas, egg cold hardiness was examined in locusts derived from four locations from latitude 18°23'N to latitude 41°10'N in eastern China.
2. The supercooling points of eggs from different geographic populations did not differ significantly for the first development stage, with an average ± SE of −24.5 ± 0.51 °C, or for the second stage, −22.06 ± 0.68 °C, however there was a significant difference for the embryonic development phase among the four geographical populations. The egg supercooling point increased gradually from neonatal egg to old egg; eggs prior to hatching always had a much higher supercooling point.
3. Comparisons of the cold hardiness of four populations were carried out by validating the close correlation between latitude and the effects of cold on hatching, low lethal temperature (Ltemp₅₀), and low lethal time (Ltime₅₀). There were significant differences among the four populations; the northern population was more cold hardy than the southern population, and the two mid-latitude populations were intermediately cold hardy.
4. The cold hardiness of all populations was enhanced to various degrees by short-term cold acclimation at 0 °C and 5 °C. For most populations, a 2-day acclimation period seemed to be optimal.     

Preliminary results of the study of populations of the freshwater pearl mussel from streams of the Lopshenga River basin on Onega Peninsula in Arkhangelsk oblast

Streams of the Lopshenga River basin (Summer Coast of the White Sea) are studied. Sections of the Kamennyi and Zhemchuzhnyi streams with relatively high population densities of the freshwater pearl mussel, the populations of which can be attributed to those that are aging, but with a high abundance, are detected. It is noted that the ratio of morphological forms of the freshwater pearl mussel in the streams of the Lopshenga River basin is characteristic of more southern populations of this species.     

据于矢耳石Sr/Ca值的长江日本鳗鲡迁移格局多样性分析(英文)

长江口是中国日本鳗鳗苗的主要产区和仅存的成鳗渔业水域。日本鳗自长江河口至上游金沙江近3000km干流及许多支流中都有分布,但其迁移行为却不为人了解。该文分析了2008年9～11月采自长江靖江段(31o30′N,120o42′E)的153尾银色鳗样本的生物学特征,测定了其中27尾标本的矢耳石Sr/Ca值。结果显示,153尾样本中有雌性85尾、雄性68尾,雌雄性比1:0.8。雌性由3～7(平均5.52)龄组成,平均体长(669±80)mm,体重(555±229)g,丰满度1.77±0.22,性腺指数(GSI)1.32±0.31。雄性由3～5(平均4.38)龄组成,平均体长(518±51)mm,体重(234±76)g,丰满度1.62±0.18,GSI0.21±0.11。雌性的这些生物学参数均显著大于雄性(P<0.05)。依据矢耳石线鳗标志轮平均Sr/Ca值(7.99±1.05)×10-3进行判断,有17尾(即62.96%个体)为"淡水型",10尾(即37.04%个体)为"河口型"。16尾雌性中有13尾(即81.25%)为"淡水型",3尾为"河口型"。11尾雄性中仅36.36%为"淡水型",63.64%为"河口型"。对每个生长层组的Sr/Ca值分析表明,雌雄间2龄时无显著差异,但3龄、4龄和洄游龄组都有显著或极显著的差异,预示着2龄时两者的栖息水域比较一致,但后来出现了明显栖息地分化。     

Cyclic voles, prey switching in red fox, and roe deer dynamics – a test of the alternative prey hypothesis

Medium-sized predators sometimes switch to alternative prey species as their main prey declines. Our objective of this study was to test the alternative prey hypothesis for a medium sized predator (red fox, Vulpes vulpes ), a small cyclically fluctuating main prey (microtine voles) and larger alternative prey (roe deer fawns, Capreolus capreolus ). We used long-term time series (28 years) on voles, red fox and roe deer from the Grimsö Wildlife Research Area (59°40'N, 15°25'E) in south-central Sweden to investigate interspecific relationships in the annual fluctuations in numbers of the studied species. Annual variation in number of roe deer fawns in autumn was significantly and positively related to vole density and significantly and negatively related to the number of fox litters in the previous year. In years of high vole density, predation on roe deer fawns was small, but in years of low vole density predation was more severe. The time lag between number of fox litters and predation on fawns was due to the time lag in functional response of red fox in relation to voles. This study demonstrates for the first time that the alternative prey hypothesis is applicable to the system red fox, voles and roe deer fawns.     

Genetic divergence among invasive and native populations of Plagioscion squamosissimus (Perciformes, Sciaenidae) in Neotropical regions

The genetic divergence among invasive and native populations of Plagioscion squamosissimus from four Neotropical hydrographic basins was assessed using the hypervariable domain of the mitochondrial DNA (mtDNA) control region. Plagioscion squamosissimus is native to the neighbouring hydrographic basins of the Parnaíba and Amazon Rivers, and the latter includes the Araguaia-Tocantins drainage, but it is invasive in other basins due to introductions. The mtDNA nucleotide polymorphism supported the hypothesis that the Amazon and Parnaíba populations constitute the same species and are separated into two independent evolutionary lineages. Absence of nucleotide polymorphism was observed within and among P. squamosissimus populations invasive to the uppper and middle Paraná River basins. Nucleotide divergence was null or low comparing the Paraná invasive populations with the populations native to the Parnaíba River basin, whereas it was significantly high compared to Tocantins populations. These results ascertain that P. squamosissimus populations invasive to the upper Paraná River basin and to the middle Paraná River basin downstream of the Itaipu dam are derived from the Parnaíba River basin. The genetic data presented are potentially useful to assist further studies on P. squamosissimus taxonomic and geographic distribution, development of ecological guidelines for managing populations invasive to the upper Paraná River basin and for preservation of native fish diversity.     

A new species of Hemibrycon (Characiformes,Characidae, Stevardiinae) from the upper Magdalena River basin in Colombia

Hemibrycon iqueima sp. nov., is described from small streams in the Magdalena drainage at the foothills of the western slope of the Eastern Cordillera of the Colombian Andes, Suarez municipality, Tolima Department, Colombia. The new species is distinguished from its congeners in the Magdalena–Cauca River basin by a combination of characters related to snout–anal‐fin origin length, head length, dorsal–pectoral fin distance, dorsal‐fin–hypural distance, postorbital distance, orbital diameter, snout length, number of total vertebrae, pre‐dorsal scales, scale rows between anal‐fin origin and lateral line, number of branched rays of the anal fin, maxillary teeth number and number and arrangement of hooks on the branched rays of the pectoral and dorsal fins. In addition, the validity of this species is supported by previous molecular analyses that included specimens of the new species that had been erroneously identified. Phylogenetic relationships between the new species and congeners from Pacific coast basins are discussed.     

Genetic differentiation among populations of Caridinazebra (Decapoda: Atyidae) in tropical rainforest streams, northern Australia

1. Caridina zebra is a common atyid shrimp in some tropical rainforest streams in far north Queensland, Australia. Genetic variation at five allozyme loci was used to estimate the level of dispersal among populations of this species, within and between stream systems. Shrimps were sampled from nine streams in the Tully River catchment and two headwater streams in the adjacent Herbert River catchment in an area under consideration for extensive hydroelectric development.
2. High levels of genetic differentiation were recorded among most populations which suggests that, like other fully aquatic species, movement is limited to a very small spatial scale.
3. In the Tully catchment, populations of shrimp from streams with confluences at high altitude showed less genetic differentiation than those from streams which directly entered the lower river. Dispersal between the latter streams is clearly limited by the presence of large waterfalls and cascades.
4. Adjacent stream populations were often highly differentiated, despite their close proximity, suggesting that overland dispersal is unlikely. However, populations of shrimp in the two streams in the Herbert catchment were strikingly similar in genetic structure to those in adjacent headwater streams of the Tully. Such similarity may reflect relatively recent changes in drainage patterns.     

北京地区法医昆虫学研究I 嗜尸性甲虫物种多样性及其地区分异

本项研究系调查北京地区清河、密云、房山三地点与人尸体有关的鞘翅目昆虫,共采集标本878号,经鉴定隶属于13科26属38种,文中列出名录,其中6种为优势种,7种为三个地点都采到标本的普遍分布种。在种类组成上,各地点有明显的地区性差异：仅在清河发现的甲虫有11种(占总种数的40.O%),仅在密云发现的有2种(占15.4%),仅在房山发现的有11种(占52.4%)：房山的物种多样性指数(H’)是2.45,清河是1.72,密云是1.60。所以,房山种类组成比较特殊。根据此结果,特别是地区的差异,为判断异地移尸提供了基本数据。     

小五台山种子植物区系研究

小五台山位于河北省西北部, 共有种子植物97 科, 467 属, 1 148 种。种子植物属的区系成分复杂:温带成分占优势, 温带属280 属, 占总属数的69.31%。通过对小五台山和部分山地植物区系的属相似性比较, 结果显示:小五台山与东灵山、雾灵山十分相似, 与关帝山、太岳山有一定的相似性, 而与长白山、泰山、伏牛山、神农架相似性偏低。     

Chromosomal evidence of downstream dispersal of Astyanax fasciatus (Characiformes, Characidae) associated with river shed interconnection

In the 1960s, as a part of the construction of the Furnas Hydroelectric Power Dam, Minas Gerais, Brazil, the Rio Piumhi was diverted from the Rio Grande drainage to the S?o Francisco River basin, with the resulting introduction of species from one basin to the other. Chromosomal characteristics of various populations of Astyanax fasciatus sensu Eigenmann from the transect region were studied using cytogenetic techniques, with the goal to identify and map the dispersal of invasive species in the Rio S?o Francisco. Populations of the Rio Grande and Rio Piumhi are distinct from those of the S?o Francisco basin based on chromosome markers associated to the heterochromatin, Ag-NORs, 18S rDNA, 5S rDNA, and As-51 satellite DNA sites. Individuals with karyomorph originally present in the Piumhi drainage are now present in the S?o Francisco basin, downstream from the transposition channel. This expansion of the distribution corroborates a hypothesis of progressive substitution of native populations by the invasive Piumhi form.