Water uptake and use by plants are essentially energy processes that can be largely modified by percentage of soil cover, plant type; foliage area and its distribution; phenological stage and several environmental factors. Coffee trees (Coffea arabica - cv. Obatã IAC 1669-20) in Agrforestry System (AFS) spaced 3.4x0.9m apart, were planted inside and along rows of 12- year-old rubber trees (Hevea spp.) in Piracicaba-SP, Brazil (22 42'30" S, 47 38'00" W - altitude: 546m). Sap flow of one-year-old coffee plants exposed to 35; 45; 80; 95 and 100% of total solar radiation was estimated by the heat balance technique (Dynamax Inc.). Coffee plants under shade showed greater water loss per unit of incident irradiance. On the other hand, plants in monocrop (full sun) had the least water loss per unit of incident irradiance. For the evaluated positions average water use was (gH2O.m-2Leaf area.MJ-1): 64.71; 67.75; 25.89; 33.54; 27.11 in Dec./2002 and 97.14; 72.50; 40.70; 32.78; 26.13 in Feb./2003. This fact may be attributed to the higher stomata sensitivity of the coffee plants under more illuminated conditions, thus plants under full sun presented the highest water use efficiency. Express transpiration by leaf mass can be a means to access plant adaptation to the various environments, which is inaccessible when the approach is made by leaf area.<br>A absorção e uso da água pelas plantas são processos essencialmente energéticos que podem ser grandemente modificados pela porcentagem de cobertura do solo, tipo de plantas, área foliar e sua distribuição, estágio fenológico e diversos fatores ambientais. Cafeeiros (Coffea arabica - cv. Obatã IAC 1669-20) em Sistema Agroflorestal (AFS) espaçados de 3.4 x 0.9 m foram plantados dentro e ao lado de um seringal de 12 anos de idade (Hevea spp.) em Piracicaba, SP, Brasil (22 42'30"S, 47 38'00" W - altitude: 546 m). O fluxo de seiva dos cafeeiros com 1 ano de idade expostos a 35, 45, 80, 95 e 100% da radiação solar foi estimado pela técnica do balanço de calor (Dynamax Inc.). Cafeeiros sombreados sofreram a maior perda de água por unidade de radiação incidente. No entanto, as plantas em monocultivo (pleno sol) apresentaram a menor perda de água por unidade de radiação incidente. Nas distâncias avaliadas, o uso médio de água foi (gH2O.m-2área foliar.MJ-1): 64,71; 67,75; 25,89; 33,54; e 27,11 em dez./2002 e 97,14; 72,50; 40,70; 32,78; e 26,13 em fev./2003. Tal fato pode ser atribuído à maior sensibilidade estomatal dos cafeeiros sob condições de maior iluminação, o que faz que plantas a pleno sol apresentem eficiência de uso da água mais elevada. Expressar a transpiração por massa de folha pode ser um meio de verificar a adaptação das plantas aos diversos ambientes, a qual é inacessível quando realizado por área foliar.

Estudou-se o comportamento da Musca domestica L. em relação ao efeito repelente do saco plástico transparente contendo água, utilizando lâmpadas ultravioleta BL (luz negra) e BLB (luz negra azul) em um testador de luz em sala escura, com moscas domésticas criadas em laboratório. Em outro experimento utilizaram-se sacos plásticos transparentes contendo água colorida com anilina amarela, vermelha e verde, e um tratamento adicional com saco plástico transparente contendo somente ar. No teste realizado com lâmpadas ultravioleta as maiores coletas foram com lâmpadas de luz negra (BL). Em relação aos testes com água colorida, a amarela foi a mais atrativa e a verde a menos atrativa. O saco plástico transparente contendo água mostrou em média eficiência superior a 30% em repelir a mosca doméstica. | The behavior of the house fly, Musca domestica L., was studied in relation to the effect of transparent plastic bags with water, using a black light (BL) and black light blue (BLB) ultraviolet lamps in a light testator in a dark room. The house fly used in the tests were from laboratory colony. In an additional test plastic bags containing water coloured with yellow, red and green aniline, and with air only were compared. The greatest housefly capture occurred with black light lamps (BL). In relation to the tests with coloured water, yellow was the most attractive and green the least attractive color. Transparent plastic bag with water showed repellency to the house fly greater than 30%.

Con el fin de estudiar el efecto de la espesura de la cubierta forestal en la disponibilidad de luz y agua para las plantas y su supervivencia, se plantaron brinzales de dos savias de Quercus petraea (Matt.) Liebl. (roble albar) y Quercus pyrenaica Willd. (melojo) en el interior de un pinar de Pinus sylvestris L. (pino albar) situado en el NE de la provincia de Madrid sometido previamente a tres tratamientos: clara del 33% de la densidad original, clara del 50% y ausencia de clara. Se midió la humedad volumétrica del suelo con un TDR y la disponibilidad de luz en el sotobosque por medio de fotografías hemisféricas. La supervivencia se midió al final del primer año y al comienzo del verano de los dos años siguientes. La reducción de la densidad del dosel incrementó la luz disponible en el sotobosque, la humedad de los primeros 10 cm de suelo y la supervivencia de las plantas de melojo, aunque no se apreció un efecto diferente según la intensidad de la clara aplicada. La mortalidad de las plantas de roble albar fue elevada en todos los tratamientos, y superior a la del melojo. Estos resultados apuntan a la necesidad de reducir la espesura del pinar albar en la zona de estudio antes de llevar a cabo plantaciones con melojo en su interior. | Information of tree-nurse shelterwood effects on survival of underplanted seedlings is particularly scant in Mediterranean forest ecosystems. To study light and water resources availability and survival associated to overstory density, two-year-old seedlings of Quercus petraea (Matt.) Liebl. (sessile oak) and Quercus pyrenaica Willd. (pyrenean oak) were planted in the understory of an even-aged Scots pine (Pinus sylvestris L.) plantation located in central Spain, which had been previously assigned to three density treatments: uncut, 33% thinned and 50% thinned of the original density, each replicated four times. Soil moisture was measured with a TDR during the first growing season after planting. Light conditions were estimated by hemispherical photography. Survival was measured at the end of the first growing season in the field and at the beginning of the next two growing seasons. The reduction in density after thinning had a positive effect on light availability and on near-surface soil moisture. Pyrenean oak had higher survival rates than sessile oak, which showed similarly high mortality rates in all three overstory treatments. Thinning had a positive effect on the survival of pyrenean oak, though irrespective of the intensity. Overall, these results point to the necessity to reduce canopy tree density in Mediterranean mountain pinewoods before carrying out enrichment plantations beneath.