Comparison of remote sensing indices for monitoring of desert cienegas     

Natalie R. Wilson  Laura M. Norman  Miguel Villarreal  Leila Gass  Ron Tiller  Andrew Salywon 《Arid Land Research and Management》2016,30(4):460-478

This research considers the applicability of different vegetation indices at 30 m resolution for mapping and monitoring desert wetland (cienega) health and spatial extent through time at Cienega Creek in southeastern Arizona, USA. Multiple stressors including the risk of decadal-scale drought, the effects of current and predicted global warming, and continued anthropogenic pressures threaten aquatic habitats in the southwest and cienegas are recognized as important sites for conservation and restoration efforts. However, cienegas present a challenge to satellite-imagery based analysis due to their small size and mixed surface cover of open water, exposed soils, and vegetation. We created time series of five well-known vegetation indices using annual Landsat Thematic Mapper (TM) images retrieved during the April–June dry season, from 1984 to 2011 to map landscape-level distribution of wetlands and monitor the temporal dynamics of individual sites. Indices included the Normalized Difference Vegetation Index (NDVI), the Soil-Adjusted Vegetation Index (SAVI), the Normalized Difference Water Index (NDWI), and the Normalized Difference Infrared Index (NDII). One topographic index, the Topographic Wetness Index (TWI), was analyzed to examine the utility of topography in mapping distribution of cienegas. Our results indicate that the NDII, calculated using Landsat TM band 5, outperforms the other indices at differentiating cienegas from riparian and upland sites, and was the best means to analyze change. As such, it offers a critical baseline for future studies that seek to extend the analysis of cienegas to other regions and time scales, and has broader applicability to the remote sensing of wetland features in arid landscapes.  相似文献   

Inferring population trends of Araucaria angustifolia (Araucariaceae) using a transition matrix model in an old-growth forest     

Giovani F Paludo  Miguel B Lauterjung  Maurício S dos Reis  Adelar Mantovani 《Southern Forests》2016,78(2):137-143

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Can achene selection in sunflower crop–wild hybrids by pre-dispersal seed predators hasten the return to phenotypically wild sunflowers?     

Alejandro Presotto  Claudio Pandolfo  Mónica Poverene  Miguel Cantamutto 《Euphytica》2016,208(3):453-462

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Influence of Long-Term Storage Operating Conditions on the Reduction of Viable Ascaris Eggs in Sewage Sludge for Agricultural Reuse     

Raquel Pinheiro Pompeo  Cleverson Vitório Andreoli  Edilene Alcântara de Castro  Miguel Mansur Aisse 《Water, air, and soil pollution》2016,227(5):144

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Biosurfactant Synthesized by Azospirillum lipoferum ALM1B2: Characterization and Application for Environmental Protection     

Marcia E. Ojeda-Morales  Marivel Domínguez-Domínguez  Miguel A. Hernández-Rivera  Juan G. Álvarez-Ramírez 《Water, air, and soil pollution》2016,227(6):181

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Aerobic stability of sugar-cane silage inoculated with tropical strains of lactic acid bacteria          下载免费PDF全文

B. F. Carvalho  C. L. S. Ávila  M. G. C. P. Miguel  J. C. Pinto  M. C. Santos  R. F. Schwan 《Grass and Forage Science》2015,70(2):308-323

Aerobic stability is an important feature in the evaluation of silages. The aims were to investigate the chemical and microbiological changes that occur in sugar-cane (Saccharum spp.) silage after aerobic exposure, to identify the major species of yeasts associated with the aerobic deterioration process and to select lactic acid bacteria (LAB) strains that can improve the aerobic stability of this silage. Fourteen wild LAB strains belonging to Lactobacillus plantarum, L. brevis and L. hilgardii were evaluated using experimental silos. Silage samples were collected at 0, 96 and 216 h after aerobic exposure to determinate the DM, WSC, pH, products of fermentation, to evaluate the silage temperatures and to identify yeast species associated with the aerobic deterioration of silage. The strains tested were able to modify the fermentative and chemical parameters and the diversity of yeasts species of silage after aerobic exposure. There was no association between the facultative or obligatory heterofermentative fermentation patterns and the increased aerobic stability of silage. Aerobic stability of sugar-cane silages was associated with high acetic acid and 1,2-propanediol concentrations. L. hilgardii UFLA SIL51 and UFLA SIL52 strains promoted an increase in aerobic stability of silage.  相似文献   

Spat availability of commercial bivalve species recruited on artificial collectors from the northern Gulf of California. Seasonal changes in species composition          下载免费PDF全文

Gaspar Soria  Miguel F Lavín  Richard Cudney‐Bueno 《Aquaculture Research》2015,46(12):2829-2840

This study reports a year‐round recruitment of spat of four commercial bivalve species; Pteria sterna, Euvola vogdesi, Pinctada mazatlanica and Pinna rugosa collected in the region of Puerto Peñasco, north‐eastern coast of the Gulf of California. Bimonthly recruitment of commercial bivalve spat on netlon^® collectors was evaluated for six sites from June 2007 to August 2008. To describe spat recruitment abundances with environmental parameters, sea surface temperature (°C) and surface chlorophyll a concentration (mg m^?3) were characterized by means of monthly Aqua/MODIS satellite data. For each species a repeated measures anova was used to evaluate differences in the number of spat between months, sites and depths. Maximum sea surface temperature was recorded in August–September (~31.5°C) and the minimum in January–February (~15°C), while the minimum surface chlorophyll a was observed in June–September (mean range = 1.5–2 mg m^?3) and the maximum in January–March (mean range = 2–5 mg m^?3). Spat recruitment showed distinct patterns; P. sterna can be characterized as having a Winter–Spring pattern, E. vogdesi a winter pattern, while P. mazatlanica and P. rugosa a summer spat recruitment pattern. This information constitutes part of the fundamental data needed for the development of aquaculture and conservation initiatives in the region based on wild spat supply.  相似文献   

The north‐west of the Iberian Peninsula is crucial for conservation of Margaritifera margaritifera (L.) in Europe          下载免费PDF全文

S. Lois  P. Ondina  A. Outeiro  R. Amaro  E. San Miguel 《水产资源保护:海洋与淡水生态系统》2014,24(1):35-47

Inclusion of fish and krill meal in extruded diets for Octopus vulgaris (Cuvier, 1797): assessment of acceptance     

Pablo Querol  Piedad S Morillo‐Velarde  Jesus Cerezo Valverde  Martinez Llorens Silvia  Andres Vicente Moñino  Miguel Jover Cerdá  Ana Tomás Vidal 《Aquaculture Research》2014,45(8):1421-1424

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Thermal time requirements of root-knot nematodes on zucchini-squash and population dynamics with associated yield losses on spring and autumn cropping cycles     

María Dolores Vela  Ariadna Giné  Manuel López-Gómez  Francisco Javier Sorribas  Cesar Ornat  Soledad Verdejo-Lucas  Miguel Talavera 《European journal of plant pathology / European Foundation for Plant Pathology》2014,140(3):481-490

The present research was undertaken to evaluate the effects of soil temperature on the life cycle of root-knot nematodes (RKN) on zucchini-squash in growth chambers and to assess the relationship between Meloidogyne incognita soil population densities at planting (Pi), its multiplication rate, and crop losses of zucchini in field conditions. Thermal requirements for M. incognita and M. javanica were determined by cultivating zucchini plants in pots inoculated with 200 second stage juveniles (J2) of each Meloidogyne species at constant temperatures of 17, 21, 25, and 28 °C. Number of days from nematode inoculation until appearance of egg laying females and until egg hatching were separately recorded. For life cycle completion, base temperatures (Tb) of 12?ºC and 10.8?ºC and accumulated degree-days above Tb (S) of 456 and 526, were estimated for M. incognita and M. javanica, respectively. The relationship between fruit weight and M. incognita Pi fits the Seinhorst damage function, but differed accordingly to the cropping season, spring or autumn. Tolerance limits for M. incognita on zucchini were 8.1 J2 per 250 cm³ of soil in spring and 1.5 in autumn cropping cycles, and the minimum relative yields were 0.61 in spring and 0.69 in autumn. Zucchini-squash was a poorer host for M. incognita in spring than in autumn, since maximum multiplication rates (a) and equilibrium densities (E) were lower in spring (a?=?16–96; E?=?274–484) than in autumn (a?=?270–2307; E?=?787–1227).  相似文献