69: 41-48
Jesús Manuel Castillo, Alfredo Emilio Rubio-Casal, Enrique Figueroa, Alan Tye
Morphological and physiological responses of Galapagos endemic tree Croton scouleri to site conditions varying through its altitudinal range
Dendrobiology 2013, vol. 69: 41-48
http://dx.doi.org/10.12657/denbio.069.005
Abstract: Galapagos is a natural laboratory offering a great opportunity to study plants functional traits. This study characterises morphological and ecophysiological responses of Croton scouleri, an endemic tree that habits from humid and upper elevations to semiarid lowlands, throughout an altitudinal gradient and in a manipulative experiment. Croton scouleri trees were gradually smaller with less total leaf area due to a gradual reduction in mean leaf size, and they folded their leaves at lower elevations. These results were also recorded after cutting every deep root. Two physiological traits that allowed Croton scouleri to avoid damages to the photosynthetic apparatus were detected between 30 and 150 m a.s.l. Lower variable fluorescence (Fv) and basal fluorescence (F0) keeping constant maximum photochemical efficiency of PSII (Fv/Fm) denoted a drop in chlorophyll concentration. Concomitantly, the recorded increase in the Quantum efficiency of PSII (ΦPSII) with similar Fv/Fm means that Croton scouleri could be using cyclic electron transport as photoprotective mechanism. On the other hand, a deep root system to reach the water table allowed Croton scouleri to behave as a drought-avoider, which was reflected in: (1) unvarying water status Leaf Water Content and Relative Water Content were always higher than 69 and 58%, respectively; (2) stable and low photoinhibition levels; and (3) unvarying leaf area index. However, Croton scouleri was not able to avoid drought at altitudes lower 30 m a.s.l. where similar responses to those recorded after root cutting were recorded.
Additional key words: chlorophyll fluorescence; Croton scouleri; leaf area index; photosynthetic stress; water content.
 |
 |
Zmień kontrast
Dostosuj czcionkę
W ramach dotacji Powiatu Poznańskiego na prace konserwatorskie, restauratorskie lub roboty budowlane przy zabytku, nasze Arboretum otrzymało środki na realizację projektu pt. Wyeksponowanie oryginalnych elementów zabytkowego ogrodu poprzez przebudowę odcinka alejek parkowych w Arboretum w Kórniku.
Przedsięwzięcie pn.: "Doposażenie sal edukacyjnych Instytutu Dendrologii Polskiej Akademii Nauk w Kórniku w sprzęt i pomoce naukowe potrzebne do prowadzenia edukacji przyrodniczej i ekologicznej" dofinansowano ze środków Wojewódzkiego Funduszu Ochrony Środowiska i Gospodarki Wodnej w Poznaniu.
Zakup sprzętu i oprogramowania, materiałów i pomocy dydaktycznych wykorzystywanych w działalności edukacyjnej Instytutu Dendrologii PAN oraz opracowanie i wydruk przewodników przyrodniczych dla dzieci.
