Seasonal time-course of the above ground biomass production efficiency in beech trees (Fagus sylvatica L.)     

Laura Heid  Christophe Calvaruso  Anjy Andrianantenaina  André Granier  Sébastien Conil  Cyrille B. K. Rathgeber  Marie-Pierre Turpault  Bernard Longdoz 《Annals of Forest Science》2018,75(1):31

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Differences in transpiration between a forest and an agroforestry tree species in the Sudanian belt   总被引：1，自引：1，他引：0  

Kohomlan G. Beranger Awessou  Christophe Peugeot  Alain Rocheteau  Luc Seguis  Frédéric C. Do  Sylvie Galle  Marie Bellanger  Euloge Agbossou  Josiane Seghieri 《Agroforestry Systems》2017,91(3):403-413

Average population growth in the African Sudanian belt is 3 % per year. This leads to a significant increase in cultivated areas at the expense of fallows and forests. For centuries, rural populations have been practicing agroforestry dominated by Vitellaria paradoxa parklands. We wanted to know whether agroforestry can improve local rainfall recycling as well as forest. We compared transpiration and its seasonal variations between Vitellaria paradoxa, the dominant species in fallows, and Isoberlinia doka, the dominant species in dry forests in the Sudanian belt. The fallow and dry forest we studied are located in northwestern Benin, where average annual rainfall is 1200 mm. Sap flow density (SFD) was measured by transient thermal dissipation, from which tree transpiration was deduced. Transpiration of five trees per species was estimated by taking into account the radial profile of SFD. The effect of the species and of the season on transpiration was tested with a generalized linear mixed model. Over the three-year study period, daily transpiration of the agroforestry trees, V. paradoxa (diameters 8–38 cm) ranged between 4.4 and 26.8 L day^?1 while that of the forest trees, I. doka, (diameters 20–38 cm) ranged from 9.8 to 92.6 L day^?1. Daily transpiration of V. paradoxa was significantly lower (15 %) in the dry season than in the rainy season, whereas daily transpiration by I. doka was significantly higher (13 %) in the dry season than in the rainy season. Our results indicate that the woody cover of agroforestry systems is less efficient in recycling local rainfall than forest cover, not only due to lower tree density but also to species composition.  相似文献   

Roach (<Emphasis Type="Italic">Rutilus rutilus</Emphasis>) reproductive cycle: a study of biochemical and histological parameters in a low contaminated site     

Perrine Geraudie  Marie Gerbron  Elisabeth Hill  Christophe Minier 《Fish physiology and biochemistry》2010,36(3):767-777

Fish reproduction is subjected to worrying trends in many aquatic environments. In this study, we report the absence of histological and biochemical alterations in fish sampled in a low contaminated site (characterised by the absence of detectable oestrogenic activity and mutagenicity in sediment extracts). A total of 474 roach (Rutilus rutilus) were monthly sampled during 18 months, and no intersex fish were recorded after careful histological examination, thus indicating that the incidence of this phenomenon may be very low under natural conditions. Furthermore, mean male plasma vitellogenin concentration was 24 ng ml⁻¹ and was only slightly elevated during the spawning period (up to 120 ng ml⁻¹) indicating that these low values may be characteristic of a low contaminated site. Of the male roach, 45.3% were sampled, a sex-ratio that did not significantly deviated from the expected 1:1 ratio between male and female. Results also showed that natural conditions can greatly affect the reproductive cycle of roach. Gametogenesis showed a biphasic pattern with first gonad maturation between September and December and a final maturation occurring at the end of winter/early spring. Under decreasing temperatures, particularly below 6°C, gametogenesis was stopped or even regressed with secondary oocytes becoming rare under histological observation. Conversely, elevated temperatures during the winter lead to an earlier gonad maturation.  相似文献   

Amino Acid Sequence of Wheat Flour Arabinogalactan‐Peptide,Identical to Part of Grain Softness Protein GSP‐1, Leads to Improved Structural Model     

Katie Van den Bulck  Anne‐Marie A. Loosveld  Christophe M. Courtin  Paul Proost  Jozef Van Damme  Johan Robben  Andrew Mort  Jan A. Delcour 《Cereal Chemistry》2002,79(3):329-331

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