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121.
Elorri Arevalo Henrique N. Cabral Bertrand Villeneuve Carl Possémé Mario Lepage 《Fish and Fisheries》2023,24(3):466-487
Early life stages of fish (eggs and larvae) are particularly vulnerable with mortality rates of up to 99% recorded for a large number of species. High mortality rates result from the limited swimming ability of larvae preventing them from escaping sub-optimal environmental conditions, predators or low prey density areas. In this context, estuaries are key nursery areas for larval and juvenile fish. Estuarine habitats offer environmental conditions favourable to the survival and growth of early stages, through abundant good-quality prey and protection from predators. A vast literature on larvae occurring in temperate estuaries exists, but an overall perspective is lacking. The occurrence of fish larvae in temperate estuaries depends on several factors. First, the choice of spawning time and location is primordial, as they have evolved to optimise the entry and the retention of larvae in the estuary as well as the conditions experienced by young stages. Secondly, larval growth and survival depend on key environmental factors (e.g. salinity, water temperature, freshwater inputs, turbidity and dissolved oxygen concentration). Knowledge of the larval dynamics in temperate estuaries is scarce for some topics and biased towards some species or geographical areas. The main goal of the present literature review is to synthesise existing knowledge regarding spawning timing and location and larval ecology for fish species occurring in coasts and estuaries, identifying the main patterns, consensus or conflicting hypotheses and highlighting major gaps. Research needs and future perspectives were outlined. 相似文献
122.
Ranil Waliwitiya Christopher J Kennedy Carl A Lowenberger 《Pest management science》2009,65(3):241-248
BACKGROUND: Aedes aegypti L. is the major vector of dengue fever and dengue hemorrhagic fever. In an effort to find effective tools for control programs to reduce mosquito populations, the authors assessed the acute toxicities of 14 monoterpenoids, trans‐anithole and the essential oil of rosemary against different larval stages of Ae. aegypti. The potential for piperonyl butoxide (PBO) to act as a synergist for these compounds to increase larvicidal activity was also examined, and the oviposition response of gravid Ae. aegypti females to substrates containing these compounds was evaluated in behavioral bioassays. RESULTS: Pulegone, thymol, eugenol, trans‐anithole, rosemary oil and citronellal showed high larvicidal activity against all larval stages of Ae. aegypti (LC50 values 10.3–40.8 mg L?1). The addition of PBO significantly increased the larvicidal activity of all test compounds (3–250‐fold). Eugenol, citronellal, thymol, pulegone, rosemary oil and cymene showed oviposition deterrent and/or repellent activities, while the presence of borneol, camphor and β‐pinene increased the number of eggs laid in test containers. CONCLUSIONS: This study quantified the lethal and sublethal effects of several phytochemical compounds against all larval stages of Aedes aegypti, providing information that ultimately may have potential in mosquito control programs through acute toxicity and/or the ability to alter reproductive behaviors. Copyright © 2008 Society of Chemical Industry 相似文献
123.
Nicolas Tremblay Zhijie Wang Bao-Luo Ma Carl Belec Philippe Vigneault 《Precision Agriculture》2009,10(2):145-161
Nitrogen (N) fertilizer rates applied spatially according to crop requirements can improve the efficiency of N use. The study
compares the performance of two commercial sensors, the Yara N-Sensor/FieldScan (Yara International ASA, Germany) and the
GreenSeeker (NTech Industries Inc., Ukiah, California, USA), for assessing the status of N in spring wheat (Triticum aestivum L.) and corn (Zea mays L.). Four experiments were conducted at different locations in Quebec and Ontario, Canada. The normalized difference vegetation
index (NDVI) was determined with the two sensors at specific growth stages. The NDVI values derived from Yara N-Sensor/FieldScan
correlated with those from GreenSeeker, but only at the early growth stages, where the NDVI values varied from 0.2 to 0.6.
Both sensors were capable of describing the N condition of the crop or variation in the stand, but each sensor had its own
sensitivity characteristics. It follows that the algorithms developed with one sensor for variable-rate N application cannot
be transferred directly to another sensor. The Yara N-Sensor/FieldScan views the crop at an oblique angle over the rows and
detects more biomass per unit of soil surface compared to the GreenSeeker with its nadir (top-down) view of the crop. The
Yara N-Sensor/FieldScan should be used before growth stage V5 for corn during the season if NDVI is used to derive crop N
requirements. GreenSeeker performed well where NDVI values were >0.5. However, unlike GreenSeeker, the Yara N-Sensor/FieldScan
can also record spectral information from wavebands other than red and near infrared, and more vegetation indices can be derived
that might relate better to N status than NDVI. 相似文献
124.
Carl O. Sauer 《Euphytica》1965,14(3):301-306
125.
126.
127.
Carl Börner 《Journal of pest science》1932,8(5):52-54
Ohne Zusammenfassung 相似文献
128.
129.
Carl Heber 《European Journal of Forest Research》1902,24(8):415-421
Ohne Zusammenfassung 相似文献
130.
Carl Eduard Reh 《Forstwissenschaftliches Centralblatt》1903,25(4):177-189
Ohne Zusammenfassung 相似文献