scholarly journals Photosynthetic responses of four tropical tree species grown under gap and understorey conditions in a semi-deciduous forest

2010 ◽  
Vol 33 (4) ◽  
pp. 529-538 ◽  
Author(s):  
Gustavo M. Souza ◽  
Agnaldo M. Sato ◽  
Rafael V. Ribeiro ◽  
Carlos Henrique B. A. Prado
2004 ◽  
Vol 28 (1) ◽  
pp. 21-27 ◽  
Author(s):  
Rafael Vasconcelos Ribeiro ◽  
Gustavo Maia Souza ◽  
Angelo Gilberto Manzatto ◽  
Eduardo Caruso Machado ◽  
Ricardo Ferraz de Oliveira

The characterization of different ecological groups in a forest formation/succession is unclear. To better define the different successional classes, we have to consider ecophysiological aspects, such as the capacity to use or dissipate the light energy available. The main objective of this work was to assess the chlorophyll fluorescence emission of tropical tree species growing in a gap of a semi-deciduous forest. Three species of different ecological groups were selected: Croton floribundus Spreng. (pioneer, P), Astronium graveolens Jacq. (early secondary, Si), and Esenbeckia febrifuga A. Juss. (late secondary, St). The potential (Fv/Fm) and effective (deltaF/Fm') quantum efficiency of photosystem II, apparent electron transport rate (ETR), non-photochemical (qN) and photochemical (qP) quenching of fluorescence were evaluated, using a modulated fluorometer, between 7:30 and 11:00 h. Values of Fv/Fm remained constant in St, decreasing in P and Si after 9:30 h, indicating the occurrence of photoinhibition. Concerning the measurements taken under light conditions (deltaF/Fm', ETR, qP and qN), P and Si showed better photochemical performance, i.e., values of deltaF/Fm', ETR and qP were higher than St when light intensity was increased. Values of qN indicated that P and Si had an increasing tendency of dissipating the excess of energy absorbed by the leaf, whereas the opposite was found for St. The principal component analysis (PCA), considering all evaluated parameters, showed a clear distinction between St, P and Si, with P and Si being closer. The PCA results suggest that chlorophyll fluorescence may be a potential tool to differentiate tree species from distinct successional groups.


2008 ◽  
Vol 10 (4) ◽  
pp. 1001-1004 ◽  
Author(s):  
Marcela Corbo Guidugli ◽  
Tatiana de Campos ◽  
Adna Cristina Barbosa de Sousa ◽  
Juliana Massimino Feres ◽  
Alexandre Magno Sebbenn ◽  
...  

2021 ◽  
Author(s):  
Martijn Slot ◽  
Tantawat Nardwattanawong ◽  
Georgia G. Hernández ◽  
Amauri Bueno ◽  
Markus Riederer ◽  
...  

2008 ◽  
Vol 68 (4) ◽  
pp. 781-793 ◽  
Author(s):  
GM. Souza ◽  
RV. Ribeiro ◽  
AM. Sato ◽  
MS. Oliveira

This study addressed some questions about how a suitable leaf carbon balance can be attained for different functional groups of tropical tree species under contrasting forest light environments. The study was carried out in a fragment of semi-deciduous seasonal forest in Narandiba county, São Paulo Estate, Brazil. 10-month-old seedlings of four tropical tree species, Bauhinia forficata Link (Caesalpinioideae) and Guazuma ulmifolia Lam. (Sterculiaceae) as light-demanding pioneer species, and Hymenaea courbaril L. (Caesalpinioideae) and Esenbeckia leiocarpa Engl. (Rutaceae) as late successional species, were grown under gap and understorey conditions. Diurnal courses of net photosynthesis (Pn) and transpiration were recorded with an open system portable infrared gas analyzer in two different seasons. Dark respiration and photorespiration were also evaluated in the same leaves used for Pn measurements after dark adaptation. Our results showed that diurnal-integrated dark respiration (Rdi) of late successional species were similar to pioneer species. On the other hand, photorespiration rates were often higher in pioneer than in late successional species in the gap. However, the relative contribution of these parameters to leaf carbon balance was similar in all species in both environmental conditions. Considering diurnal-integrated values, gross photosynthesis (Pgi) was dramatically higher in gap than in understorey, regardless of species. In both evaluated months, there were no differences among species of different functional groups under shade conditions. The same was observed in May (dry season) under gap conditions. In such light environment, pioneers were distinguished from late successional species in November (wet season), showing that ecophysiological performance can have a straightforward relation to seasonality.


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