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41.
André?Luiz?Machado?Pessanha Francisco?Gerson?AraújoEmail author Márcia?Cristina?Costa?De?Azevedo Iracema?Dias?Gomes 《Marine Biology》2003,143(6):1047-1055
The effect of diel and seasonal changes in the distribution of fishes on a subtropical sandy beach on the southeastern coast of Brazil were studied. Seine netting was carried out on both seasonal and diel scales between July 1998 and June 1999. A total of 46 fish species was recorded, six being numerically dominant: Anchoa tricolor, Gerres aprion, Harengula clupeola, Atherinella brasiliensis, Mugil liza and Diapterus rhombeus. Seasonal changes in abundance of dominant species were detected. Species dominant in winter were Anchoa tricolor, H. clupeola and Atherinella brasiliensis; in spring, Anchoa tricolor and G. aprion; in summer G. aprion and D. rhombeus; and in autumn M. liza and H. clupeola. Overall, diel patterns did not reveal any significant trends; however, if we consider each season separately, an increase in A. tricolor abundance was recorded during the day in winter/spring, being replaced at night by H. clupeola in winter, and by G. aprion in spring. Increases in number of individuals and biomass at sunset, and decreases during the night were recorded. The winter/spring inshore/offshore movements at diel scale performed by the three most abundant species demonstrate that diel fluctuation acts more at a species-specific level than at a structural one; in summer there was no evidence of diel movements due to a heavy influx of G. aprion and D. rhombeus, which use the area throughout day and night, increasing overall abundance. Seasonal movements seems to be related to ontogenetic change in species, while diel movements in the fish assemblage seem to be more related to physiological requirements, such feeding activity of each particular species, than to physico-chemical conditions.Communicated by O. Kinne, Oldendorf/Luhe 相似文献
42.
Helena Bichão Anna-Karin Borg-Karlson Atle Wibe Jorge Araújo Hanna Mustaparta 《Chemoecology》2005,15(4):211-226
Summary. An important question in insect-plant interactions is which of the numerous plant compounds contribute to the perception of
odour qualities in herbivorous insects and are likely to be used as cues in host-searching behaviour. In order to identify
which plant-produced volatiles the strawberry blossom weevil Anthonomus rubi detects, we have used electrophysiological recordings from single olfactory neurones linked to gas chromatography and mass
spectrometry. We here present 15 receptor neurone types specialised for naturally produced compounds present in the host and
nonhost plants and two types for two aggregation pheromone components. The active compounds were terpenoids, aromatic and
aliphatic esters, alcohols and aldehydes, some of which are induced by feeding activity of the weevils. The neurones were
characterised by a strong response to one or two primary odorants and weaker responses to a few others having similar chemical
structure. With one exception, the molecular receptive range of each neurone type was within one chemical group. Enantiomers
of linalool separated on a chiral column activated two neurone types with different enantioselectivity. Inhibition by linalool
of another neurone type, excited by α-pinene, indicated an additional mechanism for coding the information about this compound.
Altogether, detection of 54 compounds by olfactory receptor neurones is shown, of which 40 have been chemically identified
in this study. Thus A. rubi has the ability to detect a large number of odorants that may be used in host selection behaviour. 相似文献
43.
Foragers of the stingless bees genus Melipona may produce intranidal sounds that are correlated with food location and quality. In this study, we provide the first detailed
analysis of pulsed sounds produced by Melipona panamica foragers while feeding on a carbohydrate food source. We trained foragers to a 2.5-M sucrose feeder under normal, ambient
temperature (23–33°C) and lower temperature (11–25°C) conditions. We recorded forager sounds under both conditions and tested
the effect of temperature of the thorax, feeder plate, and air on sound temporal characteristics. Forager energetic expenditure
and the number of pulses per visit were significantly higher in the cold condition than in the normal condition. Foragers
spent a longer time at the feeder under the cold condition than during the normal condition. Interpulse durations were significantly
shorter in the cold condition than in the normal condition and became progressively and significantly shorter at the end of
each performance. Thus, pulse production increased before departure. Foragers increased their thoracic temperatures above
ambient at all experimental air temperatures. Under chilled conditions, foragers had a significantly greater difference between
thorax temperature and ambient air temperature than under normal conditions. Foragers must achieve a minimum flight muscle
temperature before take-off, and thus forager sounds may be linked to muscle warm-up. 相似文献
44.
Felipe Silva Lilyan Fulginiti Richard Perrin Karina Schoengold 《Journal of the American Water Resources Association》2019,55(5):1085-1101
The High Plains Aquifer (HPA) underlies parts of eight states and 208 counties in the central area of the United States (U.S.). This region produces more than 9% of U.S. crops sales and relies on the aquifer for irrigation. However, these withdrawals have diminished the stock of water in the aquifer. In this paper, we investigate the aggregate county‐level effect on the HPA of groundwater withdrawal for irrigation, of climate variables, and of energy price changes. We merge economic theory and hydrological characteristics to jointly estimate equations describing irrigation behavior and a generalized water balance equation for the HPA. Our simple water balance model predicts, at average values for irrigation and precipitation, an HPA‐wide average decrease in the groundwater table of 0.47 feet per year, compared to 0.48 feet per year observed on average across the HPA during this 1985–2005 period. The observed distribution and predicted change across counties is in the (?3.22, 1.59) and (?2.24, 0.60) feet per year range, respectively. The estimated impact of irrigation is to decrease the water table by an average of 1.24 feet per year, whereas rainfall recharges the level by an average of 0.76 feet per year. Relative to the past several decades, if groundwater use is unconstrained, groundwater depletion would increase 50% in a scenario where precipitation falls by 25% and the number of degree days above 36°C doubles. Editor’s note : This paper is part of the featured series on Optimizing Ogallala Aquifer Water Use to Sustain Food Systems. See the February 2019 issue for the introduction and background to the series. 相似文献
45.
Mapping Outlets of Iowa Flood Center and National Water Center River Networks for Hydrologic Model Comparison
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Felipe Quintero Witold F. Krajewski 《Journal of the American Water Resources Association》2018,54(1):28-39
River networks based on Digital Elevation Model (DEM) data differ depending on the DEM resolution, accuracy, and algorithms used for network extraction. As spatial scale increases, the differences diminish. This study explores methods that identify the scale where networks obtained by different methods agree within some margin of error. The problem is relevant for comparing hydrologic models built around the two networks. An example is the need to compare streamflow prediction from the Hillslope Link Model (HLM) operated by the Iowa Flood Center (IFC) and the National Water Model (NWM) operated by the National Water Center of the National Oceanic and Atmospheric Administration. The HLM uses landscape decomposition into hillslopes and channel links while the NWM uses the NHDPlus dataset as its basic spatial support. While the HLM resolves the scale of the NHDPlus, the outlets of the latter do not necessarily correspond to the nodes of the HLM model. The authors evaluated two methods to map the outlets of NHDPlus to outlets on the IFC network. The methods compare the upstream areas of the channels and their spatial location. Both methods displayed similar performance and identified matches for about 80% of the outlets with a tolerance of 10% in errors in the upstream area. As the aggregation scale increases, the number of matches also increases. At the scale of 100 km2, 90% of the outlets have matches with tolerance of 5%. The authors recommend this scale for comparing the HLM and NWM streamflow predictions. 相似文献
46.
SUMMARY In recent years, indigenous tenure over forest lands has emerged as a means to conserve forests while recognizing indigenous rights. There is concern, however, that indigenous reserves may not be an appropriate policy tool for sustained forest conservation. Our research examined how recognition of indigenous common-property rights has controlled agricultural expansion and conserved forests in Bosawas Biosphere Reserve, Nicaragua. We used satellite imagery with empirical data gathered in the field on land-use institutions, population pressures, and land-use practices to compare whether indigenous communities under territorial management or public management are better able to (1) control the ‘fast threat’ of frontier expansion and (2) address the long-term ecological threats posed by indigenous land-use practices and institutional changes in the region. Our findings are that indigenous residents who share common-property rights over their territories are better able to control agricultural expansion than are indigenous residents living on public lands. With respect to the long-term threats to the region, a series of simulations of possible land-use pressures demonstrate that the enforcement of territorial boundaries and further development of indigenous forest management rules will prove crucial in determining land-use capacity and deforestation over the next 50 years. 相似文献
47.
de F. Araújo Karla C. de P. Barreto Jéssica P. Cardozo Jussara C. dos Santos Elisama Vieira de Araújo Danyelle M. Martínez-Huitle Carlos A. 《Environmental Chemistry Letters》2018,16(2):647-652
Environmental Chemistry Letters - There is increasing concern about contamination by surfactants that are used to extract organic pollutants during remediation of polluted soils and aquifers. For... 相似文献
48.
49.
Baraj B Niencheski F Fillmann G De Martinez Gaspar Martins C 《Environmental monitoring and assessment》2011,179(1-4):155-162
Factorial design plan was experimented in Perna perna in order to find out the contribution of day exposure, Cd and Cu concentrations in water, and their interactions on metallothioneins (MT), Cd, and Cu (the dependent measured variables) in the gills. The picture obtained is more adequate than by studying the factor effect separately. Compared with the control group, the MT concentration after 22?days exposure period in the mixture of 100?μg/mL Cu and Cd is increased almost two times, showing that P. perna might be used as a biomonitor. Cd showed stronger effect than Cu on MT inducing. 相似文献
50.
Jasmin Shah M. Rasul Jan Farhat-un-nisa Shehzad Behisht Ara 《Environmental monitoring and assessment》2011,175(1-4):103-108
A method for the residual pendimethalin in soil and vegetable samples was developed. The method is based on extraction of pendimethalin from samples using microwave-assisted solvent extraction (MASE) with acetone, ethanol, and water as extraction solvent. Extracted pendimethalin samples were analyzed by high-performance liquid chromatography with ultraviolet detector at 240 nm. The MASE parameters, temperature, heating time, and solvent types were optimized with the feasibility of MASE application in the determination of pendimethalin extraction efficiency of pendimethalin from soil and vegetable samples. The maximum temperature that can be used during the heating for MASE is 60°C, where the recovery percentages reached 97%. Linearity for pendimethalin was found in the range of 2?C20 ??g mL???1 with limits of detection and limits of quantification of 0.059 and 0.17 ??g mL???1, respectively. 相似文献