Some Observations on the Irradiance and Carbon Fixation in Grane Langsø

Photosynthetically active radiation (PAR) was registered daily in 0.25 m and 11.25 m in 3 years. Upwards irradiance of green light was 1 % of downward irradiance. Incubator ¹⁴C experiments showed that the phytoplankton enhanced its carbon uptake substantially with increasing concentrations of the carrier CO₂ in the ampoules. Severe carbon limitation of photosynthesis occurred in spring and summer 1961, where the real carbon fixation was only about 34 % of that calculated by the usual procedure. Utilization of light and DIC by the phytoplankton and its compensation depth was determined. Photoinhibition occurred down to 10–11 m, and net primary production was nearly always positive in any depth down to the lake bottom.     

黄腹角雉血液生理生化指标的测定

用常规方法对不同年龄及性别的黄腹角雉血液 2 1项生理生化指标进行了测定 ,结果表明 :黄腹角雉 6～ 2 0月龄组MCH指标显著低于 2年龄以上组 (P <0 0 5 ) ,不同年龄间其它指标及不同性别间所有指标均差异不显著 (P >0 0 5 )。     

Satellite surface reflectance improves habitat distribution mapping: a case study on heath and shrub formations in the Cantabrian Mountains (NW Spain)

Aim We aim to map the distribution of four heath and shrub formations constituting habitats of high conservation priority in Europe, whose occurrence is strongly dependent on human activities. Specifically, we assess whether the use of LANDSAT data in habitat distribution modelling may account for land use management, allowing accurate mapping of real distribution patterns. In particular, we explore whether reflectance values may be a better alternative to other remote sensing data traditionally used in modelling approaches (i.e. spectral vegetation indices and classified land cover maps). Finally, we test whether modelling performance is affected by the ecological traits of the dominant species of the target formations. Location Cantabrian Mountains (NW Spain). Methods We generated maps for the four formations (two specialists vs. two generalists) using MaxEnt. First, we ran the models with environmental predictors only (topography, climate, lithology and human disturbances). Then, we compared the advantages of including, in turn, different data derived from LANDSAT imagery: reflectance values (corresponding to different wavelength channels of the multispectral image), a spectral index and a land cover map. We assessed changes in explanatory power and also in the formation’s predicted distribution patterns. Results Formations dominated by specialist species were accurately mapped on a base of environmental variables only, whereas those dominated by generalists were overpredicted. Average mean temperature, southness and distance to urban areas were the variables contributing most in predictions of environmental models. LANDSAT channels increased the accuracy of all models, but mainly those for formations dominated by generalist species. They showed advantages against other remote sensing data traditionally used in modelling approaches. Main conclusions Habitat distribution models allowed accurate mapping of heath and shrub formations. The use of reflectance values as predictors improved the accuracy of the models, particularly for formations dominated by generalist species, supplying environmental information that was otherwise unavailable.     

Endopolyploidy inHelianthus annuus (Asteraceae), A scanning cytophotometric study

Endopolyploidy has been detected in some varieties ofHelianthus annuus L. (Asteraceae/Compositae) by means of scanning photometry of Feulgen-stained nuclei and analysis of nuclear structure. In the hypocotyl cells of seedlings, ploidy levels reach respectively 8 C and 16 C in different varieties, in the root cells 8 C and 16 C; in the cotyledons of ripening seeds 4 C to 8 C values have been found, while all nuclei of the inflorescence axis of one variety exhibit a DNA content of 4 C.—This is the first report of endopolyploidy in a non-succulentAsteraceae species. The characteristic distribution of the endopolyploidy levels in different varieties suggests a strong genetic and/or hormonal control of the final nuclear DNA content in differentiated cells.     

SPF级封闭群SD大鼠血清生化值及凝血酶原时间值的测定

目的建立SPF级（屏障系统）封闭群SD大鼠血液生化及凝血酶原时间正常参考值,为药物长期毒性试验研究者提供参考。方法采用全自动血液生化分析仪检测19周和31周大鼠血液生化值,采用紫外可见分光光度计检测K＋、Na＋、Cl-值和凝血酶原时间值。结果取得19周和31周龄SD大鼠血清生化值和凝血酶原平均值。CR、TG、TC生化指标受年龄及性别因素影响,CR、TG、TC随年龄增长而逐步升高。TBIL、CR、TG、TC、CK、TP、BUN、ALB、AST、K＋、ALP指标雌雄间差异显著（P＆lt;0.05）。结论在药物长期毒性试验中,同一周龄雌、雄SD大鼠K＋、Cl-、Na＋、凝血酶原时间值可合并统计;雌、雄SD大鼠血液生化指标不宜合并统计。在比对正常参考值时应考虑到性别与年龄的因素。     

Plant communities of the montane mesophilous grasslands (Polygono bistortae–Trisetion flavescentis alliance) in central Europe: Formalized classification and syntaxonomical revision

Abstract

The research conducted here presents a syntaxonomical revision of the montane mesophilous meadows of the Polygono bistortae-Trisetion flavescentis alliance in central Europe – the Slovak part of the western and eastern Carpathians. These typical semi-natural grasslands occur mainly as small islands over the calcareous bedrocks. Associations of this alliance have tight relationships to the Arrhenatherion, Mesobromion and Nardo-Agrostion alliances. Formal definitions based on combination of the species groups were used regarding the diversity and geographical range of the Polygono bistortae-Trisetion flavescentis alliance. Following the formal definitions from the eight associations reported previously for Slovakia, only four of them can be placed within the Polygono bistortae-Trisetion flavescentis: Campanulo glomeratae-Geranietum sylvatici, Geranio sylvatici-Trisetetum, Crepido mollis-Agrostietum capillaries and Geranio-Alchemilletum crinitae. A comparison of traditional and formalized classification, and the advantages/disadvantages of the formalized classification are discussed.     

Measuring natural and sexual selection on breeding values of male display traits in Drosophila serrata

Fundamental to many theories of sexual selection is the expectation that sexual traits, which males use in an attempt to increase mating success, confer costs as well as benefits to individual males. Although evolution of exaggerated male traits is predicted to be halted, by costs applied by natural selection, there is a lack of empirical work devoted to quantitatively establishing whether natural selection opposes sexual selection generated by the preferences of females. In this study, we quantified natural and sexual selection gradients on breeding values for cuticular hydrocarbon (CHC) components of male contact pheromones in Drosophila serrata. As male sexual traits may often be environmentally condition dependent, breeding values were used in the selection analysis to remove the possibility of environmental correlations between the measured trait and fitness biasing estimates of selection. The direction of natural selection was found to oppose sexual selection on a subset of CHCs examined. Opposing natural and sexual selection suggests that further evolution of the male pheromone may in part be limited by costs associated with attractive male CHC blends.     

Ecological indicators of Tuber aestivum habitats in temperate European beech forests

Although Tuber aestivum is widely distributed across Europe, little is known about its biology and ecology. We assess the vegetation composition of wild T. aestivum sites and use this information to characterise suitable habitats in Fagus sylvatica, Carpinus betulus and Ostrya carpinifolia (FCO) forests. Plant species composition at 16 naturally colonised T. aestivum sites in southwestern Germany and Switzerland was compared with that of 232 reference sites in Swiss FCO forest communities. The vegetation composition of truffle sites exhibits a high proportion of herb and shrub species that are indicators of a warm and dry climate, alkaline soil, and open tree canopy and thus typically occur in thermophilous FCO communities on calcareous bedrock. We conclude that T. aestivum is associated with a set of key species in addition to known host species. Based on their floristic composition, we identified FCO forest communities with high and low suitability for T. aestivum.