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161.
Mapping Locust Habitats in the Amudarya River Delta,Uzbekistan with Multi-Temporal MODIS Imagery 总被引:2,自引:0,他引:2
Reed beds of Phragmites australis in the River Amudarya delta near the Aral Sea constitute permanent breeding areas of the Asian Migratory locust, Locusta migratoria migratoria. Every year, thousands of hectares are treated with broad-spectrum insecticides to prevent locust swarms from damaging crops in adjacent areas. To devise efficient locust monitoring and management plans, accurate and updated information about the spatial distribution of reeds is necessary. Given the vast geographic extent of the delta, traditional, ground survey methods are inadequate. Remotely sensed data collected by the MODIS sensor aboard the TERRA satellite provide a useful tool to characterize the spatial distribution of reeds. Multi-temporal MODIS data, collected at different times of the growing season, were used to generate spectral-temporal signatures for reeds and other land cover classes. These spectral-temporal signatures were matched with reed phenology. MODIS information was digitally classified to generate a land cover map with an overall accuracy of 74%. MODIS data captured 87% of the ground-verified reed locations. Estimates derived from MODIS data indicate that 18% of the study area was covered by reeds. However, high commission error resulted from misclassification of reeds mixed with shrubs class and shrubs class as reeds. This could have resulted in overprediction of the area covered by reeds. Additional research is needed to minimize the overlap between reeds and other vegetation classes (shrubs, and reed and shrub mix). Nevertheless, despite its relatively low spatial resolution (250 m), multi-temporal MODIS data were able to adequately capture the distribution of reeds. Instead of blanketing the fragile wetland ecosystem of the Amudarya delta with chemical anti-locust treatments, plant protection specialists can use this information to devise ecologically sound pest management plans aimed at reducing the adverse environmental impact in the zone of the Aral Sea ecological catastrophe. MODIS methodology to identify reed stands can be applicable to the Migratory locust habitats in other geographic areas. 相似文献
162.
Graziela R. Venson Rosemeri C. Marenzi Tito César M. Almeida Alexandre Deschamps-Schmidt Renan C. Testolin Leonardo R. Rörig Claudemir M. Radetski 《Environmental monitoring and assessment》2017,189(3):120
River or alluvial sand mining is causing a variety of environmental problems in the Itajaí-açú river basin in Santa Catarina State (south of Brazil). When this type of commercial activity degrades areas around rivers, environmental restoration programs need to be executed. In this context, the aim of this study was to assess the evolution of a restored riparian forest based on data on the soil microbial activity and plant biomass growth. A reference site and three sites with soil degradation were studied over a 3-year period. Five campaigns were performed to determine the hydrolysis of the soil enzyme fluorescein diacetate (FDA), and the biomass productivity was determined at the end of the studied period. The variation in the enzyme activity for the different campaigns at each site was low, but this parameter did differ significantly according to the site. Well-managed sites showed the highest biomass productivity, and this, in turn, showed a strong positive correlation with soil enzyme activity. In conclusion, soil enzyme activity could form the basis for monitoring and the early prediction of the success of vegetal restoration programs, since responses at the higher level of biological organization take longer, inhibiting the assessment of the project within an acceptable time frame. 相似文献
163.
Elena E. Andreeva Yuriy G. Mikhaylichenko Alexandre N. Vylegjanin 《Journal of Coastal Conservation》2003,9(1):19-24
Coastal area management should be considered as an element of a more general philosophy—that of natural resource management—which
is in the process of replacing the purely ‘protection of the environment’ approach which was dominated most of the 20th century.
Specific legislation on coastal management has been adopted by many countries, and today steps have been taken to acumulate
all experience accumulated and to harmonize legal regulations on the international level. For the Russian Federation, formerly
the Soviet Union, with an enormous sea-shore line to cope with, it is a new experience to develop a concept and a legal regulation
specifically tackling coastal area management. The draft of a legislative act on coastal area management reflects the attempts
to find ways for harmonizing various economic, environmental and social interests in this huge area, encompassing relevant
Russian legislation in force as well as international conventions and treaties, and taking into considerations and treatices,
and taking into consideration foregin expereience in this field. 相似文献
164.
Hassanin A 《Die Naturwissenschaften》2002,89(3):107-110
In 1993, several unusual horn sheaths, collected in the South of Vietnam, were regarded as evidence for a new mammal species, Pseudonovibos spiralis. However, the taxonomic status of P. spiralis remains a highly controversial subject: firstly, it has been related to three different groups of the family Bovidae: Antilopini (gazelles), Bovini (oxen, bisons, and buffaloes), and Caprini sensu lato (goats, sheep and allies). Secondly, certain horns have been shown to be faked. Most recently, it has been suggested, on the basis of 12S rRNA gene sequences, that P. spiralis was a new species of buffalo. I demonstrate here that this conclusion was inaccurate, and base this on the grounds that: (1) the putative sequence of P. spiralis is shown to be a chimera obtained from three different species: Bos taurus, Bubalus bubalis and Saiga tatarica, and (2) several factors indicate that the specimen used was not authentic. This new study confirms earlier suggestions that the horns used to formally describe P. spiralis were bogus and were in fact derived from the horns of domesticated cattle (Bos taurus). The data suggest that P. spiralis never existed. 相似文献
165.
Ricardo M. Trigo Alexandre M. Ramos Paulo J. Nogueira Filipe D. Santos Ricardo Garcia-Herrera Célia Gouveia Fátima E. Santo 《Environmental Science & Policy》2009,12(7):844-854
This paper analyses the impact of the 2003 European heatwave on excessive human mortality in Portugal, a country that presents a relatively high level of exposure to heatwave events. A total of 2399 excessive deaths are estimated in continental Portugal, which implies an increase of 58% over the expected deaths. When these values are split by gender, it is seen that women increase (79%), was considerably higher than that recorded for men (41%). The increment of mortality due to this heatwave was detected for all the 18 districts of the country, but its magnitude was significantly higher in the inner districts close to the Spanish border. When we split by gender all districts reveal significant mortality increments for women, while the impact in men's excess deaths is not significant over 3 districts. Several temperature derived indices were used and evaluated in their capacity to explain, at the regional level, the excessive mortality (ratio between observed and expected deaths) by gender. It is shown that the best relationship is found for the total exceedance of extreme days, an index combining the length of the heatwave and its intensity. Both variables hold a linear relationship with r = 0.79 for women and a poorer adjustment (r = 0.50) for men. Additionally, availability of mortality data split by age also allowed obtaining detailed information on the structure of the population in risk, namely by showing that statistically significant increments are concentrated in the last three age classes (45–64, 65–74 and 75 or more). The use of air conditioning systems in some Portuguese hospitals had a major impact on the decrease (up to 40%) in excessive mortality values. A finer approach is relevant for prevention strategies, since it allows to identify better the target population of any preventive strategy regional and national authorities may be interested to implement. 相似文献
166.
Calcium carbonate transfer was experimentally examined in hydrothermal mussels Bathymodiolus azoricus, which were collected from 850 m depth at Menez Gwen hydrothermal vent site (31°31′W, 37°50′N) on the Mid Atlantic Ridge in
May 2007. In each of four 10-day experiments, groups of mussels were maintained at atmospheric pressure or re-pressurised
to depths relevant to their site of occurrence, i.e. 850 m depth at Menez Gwen, 1,750 m at Lucky Strike (31°31′W, 37°18′N)
and 2,300 m at Rainbow (31°31′W, 36°13′N). The shells of experimental mussels were perforated and mantle tissue was fixed
for light and TEM studies at days 7 and 10 following the injury. Simultaneously, haemocytes from the extrapallial fluid (EPF)
at the site of induction were studied. At day 7 the response was most intense in the middle fold of the mantle margin and
possibly proportional to hydrostatic pressure. At day 10 the epithelial cells on the mantle surface facing the body cavity
produced copious organic secretions that avidly bound calcium. Haemocyte migration was noted within the mantle tissue, and
the haemocytes at the mantle surface facing the shell had a Ca-positive granular content. Large haemocytes were detected in
the EPF at the injury site, and some showed evidence of an immune reaction while others showed Ca-positive granular content.
These results suggest that haemocytes are involved in shell repair in these deep-sea mussels just as in some freshwater and
shallow marine molluscs. 相似文献
167.
168.
Fátima Lima Joana Portugal‐Pereira André F.P. Lucena Pedro Rochedo Jorge Cunha Manuel Lopes Nunes Alexandre Salem Szklo 《Natural resources forum》2015,39(3-4):175-190
This study estimated a series of indicators to assess the energy security of supply and global and local environmental impacts under different mitigation scenarios through 2050 in Brazil, designed with the integrated optimization energy system model MESSAGE‐BRAZIL. The assessment of interactions between environmental impacts and energy security dimensions was complemented through the application of life cycle assessment (LCA) methodology. Overall results imply energy security establishes more synergies than trade‐offs in increasingly stringent mitigation scenarios, especially patent within the sustainability dimension, which increases energy security and provides additional benefits regarding climate change mitigation and air pollution emissions. It is still necessary to extend analysis to other energy sectors in addition to the power supply sector and to promote a better understanding of repercussions of energy scenario expansion in energy security. 相似文献
169.
Mário Cerqueira Daniel Marques Alexandre Caseiro Casimiro Pio 《Atmospheric environment (Oxford, England : 1994)》2010,44(6):867-871
An apartment bedroom located in a residential area of Aveiro (Portugal) was selected with the aim of characterizing the cellulose content of indoor aerosol particles. Two sets of samples were taken: (1) PM10 collected simultaneously in indoor and outdoor air; (2) PM10 and PM2.5 collected simultaneously in indoor air. The aerosol particles were concentrated on quartz fibre filters with low-volume samplers equipped with size selective inlets. The filters were weighed and then extracted for cellulose analysis by an enzymatic method. The average indoor cellulose concentration was 1.01 ± 0.24 μg m?3, whereas the average outdoor cellulose concentration was 0.078 ± 0.047 μg m?3, accounting for 4.0% and 0.4%, respectively, of the PM10 mass. The corresponding average ratio between indoor and outdoor cellulose concentrations was 11.1 ± 4.9, indicating that cellulose particles were generated indoors, most likely due to the handling of cotton-made textiles as a result of routine daily activities in the bedroom. Indoor cellulose concentrations averaged 1.22 ± 0.53 μg m?3 in the aerosol coarse fraction (determined from the difference between PM10 and PM2.5 concentrations) and averaged 0.38 ± 0.13 μg m?3 in the aerosol fine fraction. The average ratio between the coarse and fine fractions of cellulose concentrations in the indoor air was 3.6 ± 2.1. This ratio is in line with the primary origin of this biopolymer. Results from this study provide the first experimental evidence in support of a significant contribution of cellulose to the mass of suspended particles in indoor air. 相似文献
170.
Emmanuel Joyeux Alexandre Carpentier Frédéric Corre Sylvain Haie Julien Pétillon 《Journal of Coastal Conservation》2017,21(3):435-444
The Bay of Aiguillon is a national French Nature Reserve of great importance for birds. Recently, the managers of the Reserve (ONCFS-LPO) paid attention to the influence of saltmarshes management on the nursery function for fish feeding in creeks at high tide. A study carried out from March to July 2012 aimed to evaluate the use of saltmarshes by fish juvenile fraction according to the mowing intensity in salt marshes surrounding creeks: ceased, irregular or annual mowing. This community approach was completed by a focus on the European sea bass Dicentrarchus labrax individual diet, vacuity index and growth, and the biomass of a main potential prey (the amphipod Orchestia gammarella). Whatever the mowing intensity, the juvenile fraction was very high for the main species, which were the grey mullet Liza ramada, the European sea bass, undetermined clupeid and the European flounder Platichthys flesus. Adult and subadult for these species were anecdotic or totally absent. Despite very different biomasses of amphipods between mown and natural sites, vacuity index, prey composition and their relative abundance in the diet of European sea bass juveniles were little different, contrary to their hypothetical growth (i.e. when assuming site fidelity), which appeared higher in non-mown site. The low distance between sampling sites could allow fish exchange over time between optimal and suboptimal creeks to feed on, as a hypothesis to explain such results. Because mowing was subsidized by European Union (EU) to favour open habitats for geese and maintain an economic activity, indirect impacts on nursery for fish called into question the appropriateness of such agro-environmental measure on natural habitats, and related fish nursery function. 相似文献