Environmental niche of the smut lizard population on a sandy coastal ecosystem of Southeastern Tenerife (Canary Islands)

Relationships among environmental patterns and population size of the smut lizard Gallotia galloti galloti Oudart, 1839 (Sauria Lacertidae) were examined in the context of longer time-scale variability on a sandy beach and adjacent environments of Southeastern Tenerife. Seasonal and yearly patterns in the population size were likewise analyzed in relation to climatic and anthropic variables. Six sampling plots (coastal, sweet tabaiba, tuff, lava, sandy lava and crater) were selected following a perpendicular transect to the sandy fringe that extends from the beach toward the volcanic interior. Pitfall trapping was conducted from 1984 to 2005, and capture–mark–recapture technique and the Jolly–Seber method were used to estimate population sizes. The highest population size estimates were shown on the sandy lava plot and the neighboring lava plot, reaching values of about 3500 individuals ha⁻¹ during the spring. The population was active almost the whole year, with seasonal patterns of activity from March to October. Seasonal temperature and population size patterns were correlated but the 'calima' episodes produced some disturbance. Gallotia galloti galloti was one of the most abundant lizards of all the species studied and its population size has not remained stable over the study period, probably because of the absence of predation and competition, and because of human interference and environmental instability.     

Granulometric selectivity in Liza ramado and potential contamination resulting from heavy metal load in feeding areas

The stomach contents of thin-lipped grey mullets Liza ramado were analysed in terms of granulometric composition and compared to the sediment of potential feeding areas in the Tagus estuary. Total organic matter (TOM) content and heavy metal content were determined in the surface sediment of three areas and eight trace elements were quantified: Cd, Co, Cr, Cu, Hg, Ni, Pb and Zn. The three sampled areas did not differ in TOM; and the heavy metal content was below Effects Range-Low level for most elements. The mean observed concentrations were present in the following sequence: Zn > Pb > Cr > Cu ≈ Ni > Co > Cd > Hg. Stomach contents granulometric composition provided information about the feeding selectivity of the mullets. Sediment fractions with particle size between 20 and 50 μm are preferred, independently of the fishes' length. Smaller standard length (SL) fishes have a higher positive selection of fine grained sediments than those with a larger SL. Finer fractions usually have higher concentration of heavy metals, which makes younger specimens of the thin-lipped grey mullet potentially more exposed to heavy metal load in the estuary. Metal concentration was not independent from the sampling point, presenting higher values near the margins and the estuary tidal drainage system. This means that during the first period of each tidal cycle, the mullets will feed first on the most contaminated areas, as a consequence of their movement following the rising tide to feed on previously exposed areas.     

用陆地卫星TM6数据演算地表温度的单窗算法

陆地卫星 TM数据 (TM6)热波段表示地表热辐射和地表温度变化。长期以来 ,从 TM6数据中演算地表温度通常是通过所谓大气校正法。这一方法需要估计大气热辐射和大气对地表热辐射传导的影响 ,计算过程很复杂 ,误差也较大 ,在实际中应用不多。根据地表热辐射传导方程 ,推导出一个简单易行并且精度较高的演算方法 ,把大气和地表的影响直接包括在演算公式中。该算法需要用地表辐射率、大气透射率和大气平均温度 3个参数进行地表温度的演算。验证表明 ,该方法的地表温度演算较高。当参数估计没有误差时 ,该方法的地表温度演算精度达到 <0 .4℃ ,在参数估计有适度误差时 ,演算精度仍达 <1 .1℃。因该方法适用于仅有一个热波段的遥感数据 ,故称为单窗算法。     

Loss on ignition: a qualitative or quantitative method for organic matter and carbonate mineral content in sediments?

Since the publication of the paper of , loss on ignition (LOI) has been widely used as a method to estimate the amount of organic matter and carbonate mineral content (and indirectly of organic and inorganic carbon) in sediments. The relationships between LOI at 550 °C (LOI₅₅₀) and organic carbon (OC) content and between LOI at 950 °C (LOI₉₅₀) and inorganic carbon (IC) content are currently accepted as a standard. However, the comparison of 150 analyses of samples of diverse lithologies, collected from a single core, reveals that these relationships are affected by sediment composition (presence of clays, salts, and the variable content of organic carbon). This results in an incremental error on the estimation of carbon content from LOI values that invalidates the use of LOI values as a quantitative method for estimating carbon content. Conversely, the general trends of LOI₅₅₀ and LOI₉₅₀ show a good correlation with carbon content (both organic and inorganic) allowing use of LOI as a qualitative test for carbon content. Similarly, in our case, LOI at 105 °C (LOI₁₀₅) is a good qualitative proxy for the trends in gypsum content.     

Stormwater management network effectiveness and implications for urban watershed function: A critical review

Deleterious effects of urban stormwater are widely recognized. In several countries, regulations have been put into place to improve the conditions of receiving water bodies, but planning and engineering of stormwater control is typically carried out at smaller scales. Quantifying cumulative effectiveness of many stormwater control measures on a watershed scale is critical to understanding how small‐scale practices translate to urban river health. We review 100 empirical and modelling studies of stormwater management effectiveness at the watershed scale in diverse physiographic settings. Effects of networks with stormwater control measures (SCMs) that promote infiltration and harvest have been more intensively studied than have detention‐based SCM networks. Studies of peak flows and flow volumes are common, whereas baseflow, groundwater recharge, and evapotranspiration have received comparatively little attention. Export of nutrients and suspended sediments have been the primary water quality focus in the United States, whereas metals, particularly those associated with sediments, have received greater attention in Europe and Australia. Often, quantifying cumulative effects of stormwater management is complicated by needing to separate its signal from the signal of urbanization itself, innate watershed characteristics that lead to a range of hydrologic and water quality responses, and the varying functions of multiple types of SCMs. Biases in geographic distribution of study areas, and size and impervious surface cover of watersheds studied also limit our understanding of responses. We propose hysteretic trajectories for how watershed function responds to increasing imperviousness and stormwater management. Even where impervious area is treated with SCMs, watershed function may not be restored to its predevelopment condition because of the lack of treatment of all stormwater generated from impervious surfaces; non‐additive effects of individual SCMs; and persistence of urban effects beyond impervious surfaces. In most cases, pollutant load decreases largely result from run‐off reductions rather than lowered solute or particulate concentrations. Understanding interactions between natural and built landscapes, including stormwater management strategies, is critical for successfully managing detrimental impacts of stormwater at the watershed scale.     

Nutrient uptake in a highly turbid estuary (the Humber, United Kingdom) and adjacent coastal waters

Surveys were conducted in April and June 1995 to quantify the uptake of dissolved nutrients in a highly turbid estuary (the Humber, United Kingdom) and to determine the factors controlling nutrient uptake rates. A combination of isotope labelling methods were used in conjunction with on-deck incubation techniques to estimate the uptake of dissolved nutrients (PO₄ ^3?, NH₄ ⁺, NO₃ ^?, and urea) in surface samples collected from coastal waters. Similarly, isotope labelling and laboratory incubgation techniques were employed to estimate dissolved nitrogen uptake (NH₄ ⁺, NO₃ ^?, and urea) in surface samples collected from the estuary mouth. Nutrient uptake rates were at the low end of ranges for coastal and estuarine environments reported in the literature. Concentrations of chlorophyll and the availability of photosynthetically active radiation were identified as potentially important factors controlling the uptake rates of nutrients. Uptake rates of dissolved nitrogen in the Humber mouth appeared to be related to the location of smapling sites. Depletion rates of dissolved nutrients in situ were estimated on the basis of integrated water column nutrient uptake rates and indicated assimilation of up to 16% of nutrients in the entire water column. Estimated depletion rates did not indicate preferential loss of any of the nutrient species investigated.     

On the Non-monotonic Variation of the Entrainment Buoyancy Flux with Wind Shear

Boundary-Layer Meteorology - The magnitude of the entrainment buoyancy flux, and hence the growth rate of the convective boundary layer, does not increase monotonically with wind shear....     

Geochemical evolution of groundwater in the Maneadero coastal aquifer during a dry year in Baja California, Mexico

Water pumped from 25 shallow wells (<31 m) in the Maneadero unconfined coastal aquifer was studied geochemically in order to determine the short-term compositional variability of the aquifer due to seawater intrusion during a drier than normal year (Fall 2001 to Fall 2002). The groundwater was commonly found to be mixed with seawater, with TDS concentrations in November 2002 ranging from 0.99 to 9.46 g l^–1, having an intermediate Na⁺Cl^– to Ca²⁺Cl^– water-type. Rapid recharge events of short duration, after low and short rainfall events during the study period, are suggested from short-term fluctuations in water quality. Seawater intrusion is progressing faster in the central and southern coastal sections of the aquifer and has recently affected the quality of the sites pumping water to the nearby city of Ensenada. Only one of the wells used for the Ensenada water supply had a TDS concentration lower than the 1.0 g l^–1 official limit. Low flow rates and high residence times of water are inferred to be the cause for high alkalinity in the east-central section of the aquifer. High NO₃ in the east-central aquifer indicates that any NO₃ infiltration due to fertilizer use was only slightly dispersed. After a short rainfall season during winter 2001, a significant decrease was seen for the previously most enriched site. However, concentrations above the 10 mg l^–1 official limit persisted in 2002, affecting one well for urban supply (15.9 mg l^–1). The water from this well is nevertheless mixed with better-quality water from other wells before being distributed through the citys piping system.

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Resumen Se estudió la geoquímica de aguas bombeadas por medio de 25 pozos no muy profundos (<31 m) en el acuifero costero no confinado de Maneadero con el objetivo de determinar la variación de la composición en el corto plazo en el acuifero por la intrusión de agua de mar durante un año más seco de lo normal (otoño 2001 a otoño 2002). Se observó que comúnmente las aguas subterráneas estaban mezcladas con agua de mar, con concentraciones de sólidos totales disveltos (STD) de entre 0.99--9.46 g l^–1 y un tipo de agua intermedia Na⁺Cl^– to Ca²⁺Cl^–. A partir de las fluctuaciones en la calidad del agua en el corto plazo se puede inferir que se dan eventos de recarga rápida de poca duración después de eventos de poca lluvia de poca duración y poco volumen durante el periodo de estudio. La intrusión de agua de mar está progresando más rápido en el centro y sur del acuifero costero y ha afectado recientemente la calidad de los sitios de bombeo de agua para la ciudad de Ensenada. Solamente uno de los pozos usados para el abastamiento de Ensenada tiene un STD por debajo del límite oficial de 1.0 g l^–1. Se presume que las razones lentas de flujo y los tiempos de residencia largos del agua son la causa de la alta alcalinidad en el centro-este del acuifero. Una concentración alta de NO₃ en el este-centro del acuifero indica que cualquier infiltración de NO₃ por aplicación de fertilizantes ha sido poco dispersad. Después de poca lluvia en el invierno de 2001, se observó una disminución importante en la zona previamente más enriquecida. Sin embargo, concentraciones sobre el límite oficial de 10 mg l^–1 continuaron en 2002, afectando a un pozo para suministro de agua urbana (15.9 mg l^–1). El agua extraída de este pozo es mezclada con agua de mejor calidad y se distribuye por el sistema urbano de suministro de agua.

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Résumé Leau de pompage de 25 puits peu profonds (<31 m) situés dans laquifère côtier non-confiné de Maneadero a été étudiée dans le but de déterminer la variation géochimique à court terme qui résulte de lintrusion deau de mer lors dune année plus sèche quà lhabitude (automne 2001 à automne 2002). Leau souterraine est souvent retrouvée mélangée avec de leau de mer, avec des concentrations en résidus solides dissous (RSD) qui sétalent entre 0.99 et 9.46 g l^–1 pour novembre 2002, avec un type intermédiaire en Na⁺Cl^– jusquà Ca²⁺Cl^–. Les processus suggérés pour les fluctuations rapides de la qualité de leau sont des événements de recharge de courte duré suite à de faibles et brèves périodes de précipitations. Lintrusion deau de mer progresse plus rapidement dans les parties centrales et sud de laquifère côtier où la qualité de leau pompée vers la ville de Ensenada a récemment été affectée. Un seul des puits utilisés par la ville de Ensenada pour lapprovisionnement en eau potable a une concentration en RSD sous la limite officielle permise de 1.0 g l^–1. Le temps de résidence élevé et le faible taux découlement de leau souterraine sont présumés être la cause de lalcalinité élevée dans la partie centrale-est de laquifère. La concentration élevée en NO₃ dans cette partie de laquifère indique que la totalité de linfiltration de NO₃ dû à lutilisation de fertilisants ne sest que très peu dispersée. Suite à une courte saison des pluies à lhiver 2001, une diminution substantielle a été notée au site qui était le plus enrichi avant la saison des pluies. Malgré tout, des concentrations dépassant la limite officielle permise de 10 mg l^–1 ont persisté, affectant un puits utilisé pour lapprovisionnement urbain (15.9 mg l^–1). Leau provenant de ce puits est toutefois mélangée avec de leau de meilleure qualité provenant dautres puits avant dêtre distribuée par laqueduc municipal.