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991.
Avifaunal responses to understorey fire disturbance and subsequent changes in habitat structure were examined within 20 burnt and unburnt forest plots of 0.25 ha (10×250 m), 10-15 months after an unprecedented understorey fire swept through the Tapajós-Arapiuns Extractive Reserve of central Brazilian Amazonia following the severe 1997-1998 El-Niño dry season. Although these surface fires in the previously undisturbed primary forest were relatively mild, they resulted in dramatic changes in forest structure consistent with those found elsewhere in Amazonia. Bird species negatively affected by these changes tended to be the least common, the most disturbance-sensitive, and habitat specialists. Considering different guilds, ant followers, dead-leaf gleaners, terrestrial gleaners, and arboreal sallying insectivores were the most negatively affected, whereas nectivores and arboreal granivores became more abundant in the burnt forest. The results highlight the severe consequences of even relatively mild surface fires in neotropical forests, and the importance of controlling haphazard frontier expansion for the conservation of susceptible species that are endemic to fire-prone regions. 相似文献
992.
A heat-induced degradation was carried out over two crude paprika oleoresins diluted with high oleic or high linoleic oil. Occurrence of oxygen was avoided, and changes in individual carotenoids were followed over time. Degradation rate constants were not significantly different, so that carotenoid stability was not linked with unsaturation degree of the oily system. A parallel reaction to degradation, trans to cis carotenoid isomer conversion, was also denoted during the thermal treatment, and it initially showed a higher rate than degradation of cis-isomers. Both processes (isomerization and cis-isomers degradation) were finally compensated, and their development was also unaffected by the nature of the lipid profile. Under the reaction conditions, oleic and linoleic fatty acids showed the same reactivity and induced degradative reactions, equally affecting the carotenoid profile. An enhanced stability of carotenoid content and provitamin A value was not achieved with a decrease in the unsaturation level of the oily system. 相似文献
993.
Marín A Ferreres F Tomás-Barberán FA Gil MI 《Journal of agricultural and food chemistry》2004,52(12):3861-3869
Sweet peppers (Capsicum annuum L.) cv. Vergasa have been studied at four maturity stages (immature green, green, immature red, and red). The individual phenolics (hydroxycinnamic acids and flavonoids), vitamin C (ascorbic acid and dehydroascorbic acid), and individual carotenoids were characterized and quantified. Five hydroxycinnamic derivatives and 23 flavonoids were characterized and quantified from the pericarp of sweet pepper by high-performance liquid chromatography-diode array detection-electrospray ionization-mass spectrometry. Identification was carried out by their UV spectra, chromatographic comparisons with authentic markers, identification of hydrolysis products, and tandem mass spectrometry analysis. Hydroxycinnamic derivatives, O-glycosides of quercetin, luteolin, and chrysoeriol, and a large number of C-glycosyl flavones have been characterized. Some of these compounds were found for the first time in nature. Clear differences in the individual and total phenolic content were detected between the different maturity stages. Immature green pepper had a very high phenolic content while green, immature red, and red ripe peppers showed a 4-5-fold reduction. Ascorbic acid was the main form of vitamin C, and its content increased as the pepper reached maturity. The red ripe stage had a relevant impact on the carotenoids content. Thus, immature green peppers showed the highest content of polyphenols, while red ripe fruits had the highest content of vitamin C and provitamin A. 相似文献
994.
The effect of orientation, location, year, and pruning treatment on mean acorn mass in two open woodland experimental locations (Huelva, South-Western Spain) of Holm Oak (Quercus ilex L. subsp. ballota [Desf.] Samp.) was analyzed during 2001–2006. Data were analyzed by using a mixed linear model, where the covariates were tree size parameters (circumference at 80 cm height, crown size), topographic position (wet index and flow length), intraspecific competition, total acorn crops per tree (weight and number), and climatic parameters. Average estimated acorn mass was 3.17 g acorn?1 in the Calañas location and 4.12 g acorn?1 in the San Bartolomé location, with significant differences between locations, among individual trees and across years. Acorns from the south sides of trees were significantly heavier than those at other positions. The effect of pruning treatment and the interactions location × treatment and treatment × year were not significant. Our study provides no evidence that pruning affects acorn mass. None of the analyzed covariates related to tree size, topographic position and intraspecific competition explained the difference among trees, suggesting that heritable factors play an important role. Specific climatic parameters during September, the most important month for acorn growth, may explain the effects of year and location × year on acorn mass. In addition, there appeared to be a “trade-off” between acorn mass and number of acorns. 相似文献
995.
Silva RD Bueno AL Gallon CW Gomes LF Kaiser S Pavei C Ortega GG Kucharski LC Jahn MP 《Fitoterapia》2011,82(6):818-826
This study analyzed the plasma lipid profile, glucose levels and fat deposits in male rats treated with aqueous extract of gross yerba mate, commercial yerba mate or water. Yerba mate treatment did not change body weight gain and lipid profile. The consumption of gross yerba mate significantly increased blood glucose (6.6 mmol/L) as compared to the water (4.8 mmol/L) and commercial group (5.2 mmol/L) and decreased epididymal and intra-abdominal deposits (10.1 mg/g and 23.7 mg/g of weight) as compared to the water (15.4 mg/g and 36.9 mg/g of weight) and commercial group (12.5 mg/g and 28 mg/g of weight). The results suggest that gross yerba mate reduces fat more efficiently but produces a greater increase in blood glucose when compared to commercial yerba mate and water groups. 相似文献
996.
997.
Anne Ganteaume Mercedes Guijarro Marielle Jappiot Carmen Hernando Corinne Lampin-Maillet Pedro Pérez-Gorostiaga José A. Vega 《Annals of Forest Science》2011,68(3):531-541
• Introduction
Wildfires are considered the most important disturbance in the Mediterranean Basin, and some are propagated over long distances due to lift-off and ignition of firebrands. 相似文献998.
Florence Bobelé Niamké Nadine Amusant Jean-Paul Charpentier Gilles Chaix Yves Baissac Nabila Boutahar Augustin Amissa Adima Séraphin Kati-Coulibaly Christian Jay-Allemand 《Annals of Forest Science》2011,68(1):201-211
• Introduction
Non-structural carbohydrates and phenolic compounds are implicated in the natural durability of wood. In order to find the chemical traits of natural durability in teak wood, the radial distribution of phenolics compounds and non-structural carbohydrates were studied in trees ranked by contrasting natural durability class against Antrodia sp. 相似文献999.
Maria Margarida Ribeiro Leopoldo Sanchez Carla Ribeiro Fátima Cunha José Araújo Nuno M. G. Borralho Cristina Marques 《Annals of Forest Science》2011,68(4):701-714
• Introduction
Tree genetic improvement programs usually lack, in general, pedigree information. Since molecular markers can be used to estimate the level of genetic similarity between individuals, we genotyped a sample of a Portuguese Eucalyptus globulus breeding population—a reference population of 125 individuals—with 16 microsatellites (SSR). 相似文献1000.
Victoria González-Rodríguez Rafael Villar Raquel Casado Elena Suárez-Bonnet José Luis Quero Rafael M. Navarro-Cerrillo 《Annals of Forest Science》2011,68(7):1217-1232