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Green barks of trees from drought deciduous forests ("bosque seco") in northern Peru/southern Ecuador do not perform CAM

  • Trees from drought deciduous forests (“bosque seco”) in northern Peru and southern Ecuador regularly shed their leaves at the onset of seven months-long periods without rain. This way they very effectively reduce the bulk water consumption by leaf transpiration, still loosing small amounts of water through their bark, but at the risk of too little or no carbon gain when leaf-less. Seven species studied here have good developed green cortex tissue on stems and axes, as especially evident for the “bottle tree” Ceiba trischistandra (A. Gray) Bakhuisen (Bombacaceae). In several leaf-less tree species at the end of summer drought, when xylem sap flows are very low, indications of higher xylem flows at night as compared to day-time were found, which led to the question of whether the trees are capable of performing CAM in their axes. However, although quite low in some cases, the pH of the cortex tissues did not fluctuate diurnally. In addition, no night-time carbon uptake could be observed. Although no net carbon gain was measured in C.Trees from drought deciduous forests (“bosque seco”) in northern Peru and southern Ecuador regularly shed their leaves at the onset of seven months-long periods without rain. This way they very effectively reduce the bulk water consumption by leaf transpiration, still loosing small amounts of water through their bark, but at the risk of too little or no carbon gain when leaf-less. Seven species studied here have good developed green cortex tissue on stems and axes, as especially evident for the “bottle tree” Ceiba trischistandra (A. Gray) Bakhuisen (Bombacaceae). In several leaf-less tree species at the end of summer drought, when xylem sap flows are very low, indications of higher xylem flows at night as compared to day-time were found, which led to the question of whether the trees are capable of performing CAM in their axes. However, although quite low in some cases, the pH of the cortex tissues did not fluctuate diurnally. In addition, no night-time carbon uptake could be observed. Although no net carbon gain was measured in C. trischistandra and Erythrina smithiana Krukoff (Fabaceae) photosynthetic activity of the green cortex was sufficient to re-assimilate between 50% to 60% of the carbon released by mitochondrial respiration. In contrast, the obligate CAM plant Cereus diffusus (Britton & Rose) Werdermann (Cactaceae), which was studied as a reference in the same environment, showed both diurnal pH-fluctuations in its green tissue with lowest values before sun rise, and net carbon fixation at night.zeige mehrzeige weniger

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Metadaten
Verfasserangaben: Manfred Küppers, Barbara I. L. Küppers, Viviana Horna, Maik VesteORCiD, Reiner Zimmermann, Marianne Lauerer, Gregor AasGND
URL:https://www.researchgate.net/publication/280945188
DOI:https://doi.org/10.1127/badr/2015/0002
ISSN:1864-3191
Titel der Quelle (Englisch):Basic and Applied Dryland research
Dokumentart:Wissenschaftlicher Zeitschriftenartikel referiert
Sprache:Englisch
Erscheinungsjahr:2015
Seitenzahl:15
Fakultät / Fachgebiet:Fakultät 2 Umwelt und Naturwissenschaften / FG Bodenschutz und Rekultivierung
Name der Einrichtung zum Zeitpunkt der Publikation:Fakultät für Umweltwissenschaften und Verfahrenstechnik (eBTU) / LS Bodenschutz und Rekultivierung
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