101 research outputs found
Variations in water use by a mature mangrove of Avicennia germinans, French Guiana
In the tropical intertidal zones, little is known on water uptake by mangroves. Transpiration rates are generally measured at leaf level, but few studies exist on water use at tree or stand levels. The objective of this study was to measure sap flow in trees of different sizes to appreciate the range of variation in water use that may exist in a site dominated by 80% mature Avicennia germinans. The results showed that from the dry to the wet season the mean water use increased from 3.2 to 5.3 dm3 dâ1 in small trees (DBH ⌠13 cm), from 11.5 to 30.8 dm3 dâ1 in medium trees (âŒ24 cm) and from 40.8 to 64.1 dm3 dâ1 in large ones (âŒ45 cm). Sapwood remained active up to a depth of 8 cm with radial variations within the stem. Weak correlations were obtained with VPD and net radiation. This study confirmed that transpiration was larger under low levels of salinity. Water use at stand level (âŒ1900 living stems haâ1) was estimated to be in the range of 5.8 to 11.8 m3 haâ1 dâ1 according to the season
InfluĂȘncia da compactação do solo em subsuperfĂcie sobre o crescimento aĂ©reo e radicular de plantas de adubação verde de inverno
Uso da radiação solar pelo milho sob diferentes preparos do solo, espaçamento e disponibilidade hĂdrica
Respostas biomĂ©tricas e fisiolĂłgicas ao deficit hĂdrico em cana-de-açĂșcar em diferentes fases fenolĂłgicas
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