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141.
Javier Rey Lourdes Fernández-PeraltaAlba Esteban Ramón García-CancelaFrancisca Salmerón Miguel Ángel PuertoCarmen Piñeiro 《Fisheries Research》2012,113(1):159-172
Fish age determination using otoliths requires a prior understanding of growth mark deposition patterns (translucent rings, TR) as well as their connection with internal or external events experienced by the fish. This study analysed the macrostructural seasonal ring deposition pattern observed in transversal sections of black hake otoliths. A total of 793 black hake otoliths were collected in autumn and spring 2007 from research and commercial surveys carried out in continental and shelf waters off Mauritania. Most of the Merluccius polli otoliths presented narrow and wide translucent rings (NTR and WTR, respectively) regardless of fish size, whereas Merluccius senegalensis otoliths only showed NTR. This seemed to be a sign of ontogenetic discrepancy between the two black hake species, whose otoliths confirmed the existence of significant differences in their growth patterns.The frequency distributions of the number of TR counted along the ventral radius (VR) of the otolith from the nucleus (birth date) and from the ventral edge (death date) were analysed to ascertain whether a specific endogenous event (Hypothesis A) or a precise environmental event (Hypothesis B) could restrain growth leading to the formation of TR. The general TR frequency distribution pattern was somewhat similar for both hake species, which showed marked TR at comparable distances. Within each species, TR frequency distributions of their distances from the nucleus along the otolith VR were quite similar between sexes, seasons, and fish sizes. Our results support the idea of a coincident biological event, such as first maturity, slowing down the growth process and thus provoking the formation of TR in otoliths of both species.This study also experience difficulty using the complex and highly variable macrostructural pattern of black hake otoliths to establish age interpretation criteria for these two species. 相似文献
142.
143.
Environmental effects of a marine fish farm of gilthead seabream (Sparus aurata) in the NW Mediterranean Sea on water column and sediment 下载免费PDF全文
Tania Morata Silvia Falco Isabel Gadea Javier Sospedra Miguel Rodilla 《Aquaculture Research》2015,46(1):59-74
This study examined the effects of organic enrichment on water column, sediments and macrofauna caused by a fish farm in the Mediterranean Sea. Samples were collected on four sampling campaigns over a one‐year cycle. Significant differences were found in the water column in dissolved oxygen, dissolved inorganic nitrogen, phosphate and total phosphorus concentrations between the fish farm and the control. The increase in the dissolved inorganic nitrogen and phosphate concentrations at the fish farm modified the stoichiometric ratios between nutrients, with silicate acting as limiting nutrient at the fish farm 11% more than at the control. Nevertheless, chlorophyll a concentration in the water column was higher at the control station, probably due to the fouling of the underwater fish farm structures. Significant differences were found in sediment concentrations of organic matter, total phosphorus and redox potential between the fish farm and the control. The Canonical Correlation Analysis indicated that organic matter, total phosphorus, redox potential and% of gravels accounted for 68.9% of the total variance in the species data. Changes were observed in macrofauna, with a decrease in number of species and up to a nine‐fold increase in abundance with respect to the control. 相似文献
144.
Walter?D.?CarciochiEmail author Nicolás?Wyngaard Guillermo?A.?Divito Miguel?L.?Cabrera Nahuel?I.?Reussi Calvo Hernán?E.?Echeverría 《Biology and Fertility of Soils》2018,54(3):349-362
The development of simple predictors of sulfur (S) mineralization and its correlation with field-derived data may help improving corn S availability diagnosis. The objectives of this study were (1) to compare methods to estimate soil S mineralization, (2) to develop a model to predict soil S mineralization from S mineralization indexes and edaphic variables, and (3) to predict field-grown corn S uptake (Suptake) and apparent S mineralization (Smin-app) from different S mineralization indexes and edaphic-climatic variables. We evaluated 26 experimental sites where we measured edaphic variables as soil organic C (SOC), organic C in the particulate fraction (C-PF), S mineralization potential (Smin-10wk), S mineralized during a short-term (7 days) aerobic incubation + initial inorganic S (Smin-7d?+?Sinorg), and N mineralized during a short-term (7 days) anaerobic incubation (Nan). Additionally, 18 field experiments were carried out to quantify Suptake and Smin-app. The C-PF, Smin-7d?+?Sinorg, Nan, and SOC were variables significantly correlated with Smin-10wk (r?=?0.89, 0.89, 0.88, and 0.85, respectively). We developed a simple model to predict Smin-10wk from selected edaphic variables (Smin-10wk?=?0.038*Nan?+?0.106*SOC?+?0.74; Ra2 =?0.87). The Smin-10wk, C-PF, and Smin-7d?+?Sinorg showed a liner-plateau association with Suptake (R2?=?0.73, 0.53, and 0.48, respectively). We modified the method to estimate Smin-app to account for S losses (Smin-app (modified)) and developed a model to predict Smin-app (modified) from C-PF (Smin-app (modified)?=?4.65*C-PF?+?9.86; R2?=?0.62) or Smin-10wk (Smin-app (modified)?=?3.0*Smin-10wk?+?7.4; R2?=?0.54). Our results demonstrate that S mineralization indexes can be used to predict corn S availability under field conditions. 相似文献
145.
Fernando Silla Álvaro Camisón Andrea Solana Héctor Hernández Guillermo Ríos Miguel Cabrera Dámaris López Albert Morera-Beita 《Annals of Forest Science》2018,75(4):95
Key message
Quercus secondary forests show a gradual transition toward mixed forests, with sweet chestnut ( Castanea sativa ) becoming increasingly abundant in the western Spanish Central System. Additionally, in chestnut-dominated stands, it shows a certain resistance to competitive displacement by Quercus pyrenaica . Our results partially refute the traditional view that C. sativa is unable to recruit in the absence of cultural inputs.Context
Sweet chestnut, Castanea sativa, is a component of European broadleaf forests and is one of the most managed trees. Due to a reduction in cultural inputs, chestnut-dominated stands tend to be invaded by other species, and it is unclear how chestnut is able to persist in natural mixed forests.Aims
Our work aimed to identity the main factors that limit the establishment of C. sativa and to analyze the recruitment and mortality processes of C. sativa trees.Methods
The age, growth ring patterns, regeneration density, and the spatial structure of trees and saplings in 11 plots in the Spanish Central System were analyzed.Results
Chestnut seedling density increased with C. sativa basal area, but transition toward the sapling stage appeared limited owing to light availability. In Quercus pyrenaica secondary forests, sparse canopies did not constrain chestnut regeneration, and in old chestnut stands, C. sativa showed a certain resistance to competitive displacement. By contrast, mixed young coppices showed a high mortality, most likely due to competition with other vigorous resprouters.Conclusion
Quercus secondary forests showed a gradual transition toward mixed forests with sweet chestnut becoming increasingly more abundant. In old stands, C. sativa is likely to persist under a gap-phase mode of regeneration. Our results partially refute the traditional view that C. sativa is unable to recruit in the absence of cultural inputs.146.
Amalia Boix-Ruiz José Ignacio Marín-Guirao Miguel de Cara-García Francisco Camacho-Ferre Julio César Tello-Marquina 《European journal of plant pathology / European Foundation for Plant Pathology》2017,148(3):607-615
Crown and root rot of tomato and sweet pepper can be caused by Phytophthora parasitica. In this work, 23 P. parasitica isolates from diseased pepper or tomato plants as well as 54 isolates from 23 monocrop tomato soils (from Spain and Chile) and one from a pepper soil were studied for their host–pathogen response. Results show significant host specificity for the isolates from tomato plants and tomato soils (63 of 64 isolates were unable to cause disease in pepper). None of the pepper plant/soil isolates showed pathogenicity on tomato, and only four of 14 reproduced their pathogenicity on pepper. Only one tomato isolate was pathogenic to both Solanaceae species. Two different inoculation protocols were evaluated (substrate irrigation and stem cutting). All isolates which expressed pathogenicity when stem inoculated also did it when root inoculated, but not vice-versa. Therefore, the recommended test protocol for tomato and pepper breeding programmes is that based on root inoculation by irrigation. 相似文献
147.
Evaluation of a decision support strategy for the control of powdery mildew,Erysiphe necator (Schw.) Burr., in grapevine in the central region of Chile 下载免费PDF全文
148.
Synthesis,theoretical studies,and effect on the photosynthetic electron transport of trifluoromethyl arylamides 下载免费PDF全文
149.
María Celina Luján-Hidalgo Deisy Ermeth Gómez-Hernández Juan José Villalobos-Maldonado Miguel Abud-Archila Joaquín Adolfo Montes-Molina Samuel Enciso-Saenz 《Compost science & utilization》2017,25(2):95-101
The aim of this investigation was to determine the effect of vermicompost, vermiwash, and phosphate rock on plant, total phenols, flavonoids, and anti-oxidant activity in Piper auritum Kunth leaves. P. auritum plants were obtained from cuttings and were planted according to the Box-Behnken experimental design with three repetitions at the central point. The factors and levels were vermicompost (10, 20, and 30 g plant?1), vermiwash (5, 10, and 15 mL plant?1), and phosphate rock (1, 2, and 3 g plant?1). Plant growth parameters (plant height, stem diameter, leaves number) and chlorophyll content were measured 1 month after treatment applications. Total phenols, total flavonoids, and 1,1-diphenyl-2-picryl-hydrazyl radical scavenging activity was measured after 4 months. Vermicompost, vermiwash, and phosphate rock had no statistically significant effect on plant growth. Plant height, stem diameter, leaves number, chlorophyll, innermost number, fresh weight stem, fresh weight leaves, fresh weight root, dry weight stem, dry weight leaves, and dry weight root were not different among treatments. Total phenolic compounds were statistically affected for both vermiwash and phosphoric rock (p < 0.05) and the anti-oxidant activity decreased by vermicompost addition. The application of 15 mL plant?1 vermiwash, 1 g phosphate rock, and 20 g vermicompost plant?1 increased the total phenol content. 相似文献
150.
Winfried Schröder Stefan Nickel Simon Schönrock Roman Schmalfuß Werner Wosniok Michaela Meyer Harry Harmens Marina V. Frontasyeva Renate Alber Julia Aleksiayenak Lambe Barandovski Oleg Blum Alejo Carballeira Maria Dam Helena Danielsson Ludwig De Temmermann Anatoly M. Dunaev Barbara Godzik Katrin Hoydal Zvonka Jeran Gunilla Pihl Karlsson Pranvera Lazo Sebastien Leblond Jussi Lindroos Siiri Liiv Sigurður H. Magnússon Blanka Mankovska Encarnación Núñez-Olivera Juha Piispanen Jarmo Poikolainen Ion V. Popescu Flora Qarri Jesus Miguel Santamaria Mitja Skudnik Zdravko Špirić Trajce Stafilov Eiliv Steinnes Claudia Stihi Ivan Suchara Lotti Thöni Hilde Thelle Uggerud Harald G. Zechmeister 《Annals of Forest Science》2017,74(2):31