- Field observation of water-use strategy in Avicennia marina trees growing on the Red Sea coast in Sudan
（2012/6/22-2012/7/18、Sudan）
Associate professor/first year master's degree student Mie University,
Naoko Matsuo/Tohoru Kasama
Grey mangrove trees (Avicennia marina (Forsk.) Vierh.), which grow in per-arid areas along the Red Sea coast, are characterized by their tree morphology, as branches often extend laterally rather than upward and carry adventitious roots on their main axis. To test the hypothesis that such branch morphology is linked with water-use characteristics in leaves, the relationships between morphological parameters of branch and carbon- and oxygen-isotope ratios of leaf organic matter were examined in A. marina forests in Kulanib and Dungonab, Sudan.
26th June - 6th July, 2012
Leaves and stems were collected from current year shoots at the branch tips in 6 trees in a seaside-, mid- or inland-experimental plot in Kulanib. Their morphological parameters such as vertical height, length between the base and the tip or between the adventitious roots and the tip, and basal diameter were measured. Soil water was also collected for chemical and isotope analysis.
Fig.1 A experimental plot in Kulanib forest
Fig.2 Soil water sampling (Mr. Osama and Mr. Eizaldean [RSU])
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9th - 14th July, 2012
Leaves and stems were collected from current year shoots at the branch tips in tall and dwarf trees in a small experimental plot in Dungonab, and their morphological parameters were measured. Transpiration rate and stomatal conductance were measured to test a model of oxygen isotope enrichment in leaf water during transpiration. Photosynthesis rate (Amax) and stomatal conductance (gsmax) under light saturated conditions were also measured to examine the response of gas exchange to severe environmental conditions in summer.
Fig.3 Measurement of transpiration rate (Mr. Kasama [Mie Univ.], Mr. Osama and Mr. Eizaldean [RSU])
Fig.4 Measurement of photosynthesis rate (Dr. Matsuo [Mie Univ.] and Mr.Wisdin [RSU])
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