Waterbird abundance, and seasonal and spatial distribution, were studied in two natural water pools at Jalisco, México, from December 1997 through November 1998. Maximum monthly abundance in Agua Dulce lake and El Ermitaño estuary was 86 471 birds (29 686 in Agua Dulce and 56 785 in Ermitaño), with a total cummulative abundance of 179 808 individuals (66 976 in Agua Dulce and 112 832 in Ermitaño). A total of 87 waterbirds species were recorded, 78 in Agua Dulce and 73 in Ermitaño. The higher species richness and abundance was observed during winter, when migratory species arrived. Most species prefered shallow waters, except seabirds which prefered protected areas such as dunes in Agua Dulce. Other groups, like ducks and related species, prefered low salinity areas, for example in the south-east area of Ermitaño. The higher abundance of the shorebirds was found when the water level on the estuary was low. Herons were seen often at areas with high salinity and influenced by tides (e.g. mouth of Ermitaño). | Se analizó la presencia y número de aves acuáticas, así como la distribución estacional y espacial de los diferentes grupos en la laguna de Agua Dulce y el estero El Ermitaño, Jalisco, México, entre diciembre de 1997 a noviembre de 1998. Considerando únicamente el mes de máxima abundancia de cada especie hubo 86 471 aves en ambos humedales (29 686 en Agua Dulce y 56 785 en El ermitaño), y una abundancia acumulada (suma de las abundancias mensuales) de 179 808 aves (66 976 en Agua Dulce y 112 832 en Ermitaño). Se identificaron 87 especies de aves, de las cuales 78 especies estuvieron presentes en Agua Dulce y 73 especies en El Ermitaño. La riqueza y abundancia fueron influenciados por la llegada de aves migratorias por lo que el mayor número de especies e individuos se presentó durante el invierno. En general las aves mostraron preferencia por áreas someras, excepto las marinas que prefirieron áreas arenosas y protegidas por dunas como las que se encuentran en Agua Dulce. Los demás grupos como los patos y afines prefirieron las áreas con salinidades bajas, como las que se encuentran al sureste del estero El Ermitaño. La mayor abundancia de aves playeras fue observada en niveles de agua bajos, y al igual que las garzas se les observó con mayor frecuencia en sitios con salinidades altas e influenciados por las variaciones en las mareas, como los que se encuentran cerca de la boca-barra del Ermitaño.

Aquatic insect fauna remains an important tool for bio indication of environmental disturbance, while maintaining a healthy aquatic system. The purpose of the study was to document and to identify the diversity and distribution patterns of aquatic insect, a highly ignored aspect from the Qatar. Following the standard procedures, the samples were collected from aquatic habitats during the period October 2015 to May 2017 on monthly basis. A total of 11,287 individuals, belonging to 6 orders were captured. Dipterans were the abundant with the percentages of 71.01 (n=8,015), while the lowest percentage was observed for Coleoptera 0.04 (n=05). Twelve insects families were identified, among these five were reported under Diptera, followed by Hemiptera (03), while Coleoptera, Tricoptera, Odonata, and Ephemeroptera were represented by single families. Among the selected localities, Dipterans were collected from 10 stations, followed by Hemiptera (9), Coleoptera (4), Odonota (4), Ephemeroptera (3) and Trichoptera (1) respectively. Among the water bodies samples, streams were the most preferred habitats (n=2,767), while drinking water pools were the least (27). Moreover, the highest Simpson diversity index of 1.48 and lowest of 0.47 was recorded for flooded sewage pool and plastic containers respectively, while the low evenness values were observed for ponds, and less than 1 Margalef's diversity values were seen for all habitats. This study documents the patterns of the diversity and distribution of aquatic insects, and provides a baseline for the future studies from Qatar. 2024, Instituto Internacional de Ecologia. All rights reserved. | Scopus

Nos distritos de irrigação, a tarifa de custo variável tem dependido exclusivamente da quantidade de água consumida e não, da energia e da demanda de potência elétrica para o fornecimento de água na pressão e na vazão recomendadas pelo sistema de irrigação. Essa forma de tarifação da água de irrigação é um contrassenso em que os irrigantes mais eficientes subsidiam os irrigantes menos eficientes. Este trabalho propõe que as tarifas de água considerem não somente a quantidade de água consumida no mês, mas também a pressão, já que a demanda de potência hidráulica é função do produto da vazão pela pressão de serviço. O estudo comparou o custo de água de irrigantes que consomem o mesmo volume mensal para a situação atual e pela metodologia proposta. Verificou-se, também, o efeito de irrigações isoladas ou simultâneas e sua implicação no custo da água. Os resultados mostraram que a implementação de tarifa binômia para a água pode reduzir o custo da água para o irrigante de baixa pressão em até 66%. Já para os irrigantes com alta pressão, poderá ter acréscimo de até 133%. A simultaneidade de uso da água também influencia seu custo devido à variação na demanda de potência de energia elétrica. | In irrigation districts, the variable cost tariff have being depended only on the amount of water consumed, and not in the energy and the demand for electric power to supply the water pressure and flow rate recommended by the irrigation system. This way of charge the irrigation water is nonsense, since the less efficient participants subsidized the more efficient ones. Thus, this work proposes that the water tariffs not only consider the amount of water consumed in the month, but also the pressure, since the hydraulic power demand is a function of the product of flow rate times the pressure. The study compared the water cost for participants that consume the same amount monthly for the present situation and the proposed methodology. It was verified, also, the effect of isolated irrigations or simultaneous ones and their implications on the water costs. The results showed that the implementation water tariff that charges the volume of water may reduce the costs for the participants at low pressures up to 66%. On the other hand, high pressure participants may have their water bill increased up to 133%. The simultaneity on the water use also influences its cost due to electrical power demand variation.

Com os dados de 21 parcelas permanentes de 1.000m² (20 x 50m) alocadas no inventário contínuo de uma faixa de cerrado com 152ha (400 x 3.800m) na Fazenda Água Limpa (FAL)-DF (15º56'14"S e 47º46'08"W), foi realizado o estudo da distribuição diamétrica dos indivíduos com mais de 5cm de diâmetro a 30cm do solo. Foram estudadas também as 17 espécies com maior índice de importância (IVI). Para a população total, 63,85% dos indivíduos concentram-se na primeira classe de diâmetro (5-9cm), fato atribuído ao pequeno porte que geralmente apresentam algumas das espécies do cerrado e/ou à incidência de incêndios em intervalos que, na maioria das vezes, não ultrapassam três anos.<br>This paper studied the stem distribution in 152ha of "cerrado" area in the Água Limpa Farm (15º56'14"S and 47º46'08"W), Brasilia-DF, Brazil. Sampling was done only on individuals with, at least, 5cm of stem diameter, 30cm above ground. It was sampled 21 permanent plots, 1,000m² (20 x 50m) each, randomly allocated. The 17 species with the highest importance value (IVI) was studied too. The Liocourt "q" quocients were calculated to permit distribution evaluation. For each species studied, the present situation was evaluated and hypothesis were made about the problems affecting the population.

Con el fin de determinar bajo condiciones de campo la cantidad de agua lluvia que se mueve verticalmente a varias profundidades en la Altillanura, se seleccionó un suelo Tipyc Haplustox isohipertérmico caolinítico del municipio de Puerto López (Meta), trabajado durante varios años (2,4 y 6 pases de rastra por año para un total acumulado al momento de las pruebas de 8, 16 y 32 pases) y diferentes condiciones de manejo (Sabana nativa; Arroz (con 8 y 16 pases de rastra) y Pasto (B. Dictyoneura con 16 y 32 pases de rastra)). Se evaluó in situ la cantidad de agua lluvia que pasa a través de diferentes profundidades del suelo utilizando microlisímetros de embudo instalados a las siguientes profundidades: 3 cm, 5 cm, 10 cm, 15 cm, 20 cm y 30 cm. A cada profundidad se midió el volumen de agua que pasaba por cada lámina de suelo y se determinaron los componentes solubles (NO3, Ca, K, P), pH y Conductividad eléctrica. Adicionalmente se determinó la cantidad de lluvia semanal caída en el área de trabajo, para establecer la relación existente entre la precipitación y la cantidad de agua que pasaba por cada profundidad.&#xA;Se encontró una alta variabilidad en la forma en&#xA;que el agua se mueve dentro del suelo, en lo cual se&#xA;destaca el flujo preferencial; también, que la cantidad&#xA;de componentes solubles que se mueve de una profun&#xA;didad a otra en función de Ja cantidad de agua que&#xA;pasa. Para los suelos de la Altillanura se encontró que&#xA;los pastos permiten una mejor distribución de agua y&#xA;nutrientes puesto que ellos crean y mantienen macro-&#xA;poros mejorando el estado físico del suelo. = With the purpose of determining under field conditions the quantity of rainfall that moves vertically to several depths in the Altillanura, a soil Tipyc Haplustox isohipertérmico caolinítico of the municipality of Port López (Meta) was selected, worked during several years (2, 4 and 6 trail passes per year for a total accumulated to the moment of the tests of 8, 16 and 32 passes) and different handling conditions (native Savanna; Rice (with 8 and 16 trail passes) and I Pasture (B. Dictyoneura with 16 and 32 trail passes)). It was evaluated in situ the quantity of rain that passes through different depths of the soil using funnel microlisímetros installed to the following depths: 3 cm, 5 cm, 10 cm, 15 cm, 20 cm and 30 cm. To each depth the volume of water was measured that it went by each soil sheet and the soluble components were determined (NO3, Ca, K, P), pH and electric Conductivity. Additionally the quantity of rain weekly fall was determined in the work area, to establish the existent relationship between the precipitation and the quantity of water that it went by each depth.&#xA;There was high variability in the form which water moves inside the soil, in which is affected by the preferential flow. The quantity of soluble components that move from a layer to another being function of the quantity of water that passes. For the soils of the Altillanura it was found that the grasses allow a better distribution of water and nutritious since they create and they maintain macroporos improving the physical state of the soil | IG Valenzuela, G Perea, Edgar Amézquita Collazos, 'Evaluación del agua gravitacional a través del perfil de un suelo de la altillanura', Suelos Ecuatoriales, 2014

Hydrological vulnerability in the Matlalcueye region (Tlaxcala, Mexico) has been little explored, and the differences in access that characterize it are not evident. Therefore, this study shows how this factor is presented in an apparently homogeneous region where access to water by urban and rural communities depends on the geographic location of the localities, population density and the location of supply sources, all of which are independent from the cultural and ethnic characteristics of the populations. | La vulnerabilidad hídrica es un tema poco estudiado en la región del Matlalcueye, Tlaxcala, México. Las diferencias en acceso que la caracterizan no son evidentes, razones que llevaron a la elaboración del presente trabajo, que muestra cómo este factor se presenta en una región aparentemente homogénea, pero donde el acceso al agua entre comunidades urbanas y rurales depende de la ubicación geográfica de las localidades, la densidad poblacional, la localización de fuentes de abastecimiento; todo ello con independencia de las características culturales y étnicas de su población.

Se analizó la presencia y número de aves acuáticas, así como la distribución estacional y espacial de los diferentes grupos en la laguna de Agua Dulce y el estero El Ermitaño, Jalisco, México, entre diciembre de 1997 a noviembre de 1998. Considerando únicamente el mes de máxima abundancia de cada especie hubo 86 471 aves en ambos humedales (29 686 en Agua Dulce y 56 785 en El ermitaño), y una abundancia acumulada (suma de las abundancias mensuales) de 179 808 aves (66 976 en Agua Dulce y 112 832 en Ermitaño). Se identificaron 87 especies de aves, de las cuales 78 especies estuvieron presentes en Agua Dulce y 73 especies en El Ermitaño. La riqueza y abundancia fueron influenciados por la llegada de aves migratorias por lo que el mayor número de especies e individuos se presentó durante el invierno. En general las aves mostraron preferencia por áreas someras, excepto las marinas que prefirieron áreas arenosas y protegidas por dunas como las que se encuentran en Agua Dulce. Los demás grupos como los patos y afines prefirieron las áreas con salinidades bajas, como las que se encuentran al sureste del estero El Ermitaño. La mayor abundancia de aves playeras fue observada en niveles de agua bajos, y al igual que las garzas se les observó con mayor frecuencia en sitios con salinidades altas e influenciados por las variaciones en las mareas, como los que se encuentran cerca de la boca-barra del Ermitaño<br>Water birds from Agua Dulce lake and El Ermitaño estuary, Jalisco, Mexico. Waterbird abundance, and seasonal and spatial distribution, were studied in two natural water pools at Jalisco, México, from December 1997 through November 1998. Maximum monthly abundance in Agua Dulce lake and El Ermitaño estuary was 86 471 birds (29 686 in Agua Dulce and 56 785 in Ermitaño), with a total cummulative abundance of 179 808 individuals (66 976 in Agua Dulce and 112 832 in Ermitaño). A total of 87 waterbirds species were recorded, 78 in Agua Dulce and 73 in Ermitaño.The higher species richness and abundance was observed during winter, when migratory species arrived. Most species prefered shallow waters, except seabirds which prefered protected areas such as dunes in Agua Dulce. Other groups, like ducks and related species, prefered low salinity areas, for example in the south-east area of Ermitaño. The higher abundance of the shorebirds was found when the water level on the estuary was low. Herons were seen often at areas with high salinity and influenced by tides (e.g. mouth of Ermitaño). Rev. Biol. Trop. 53(1-2): 229-238. Epub 2005 Jun 24