Name: MARCOS THIAGO GAUDIO GOMES
Type: PhD thesis
Publication date: 07/08/2017
Advisor:
Name |
Role |
|---|---|
| Fábio Murilo DaMatta | Advisor * |
Examining board:
| Name |
Role |
|---|---|
| Alessandra Delazari-Barroso | External Alternate * |
| Antelmo Ralph Falqueto | Internal Alternate * |
| Diolina Moura Silva | Internal Examiner * |
| Fábio Murilo DaMatta | Advisor * |
| Geraldo Rogério Faustini Cuzzuol | Internal Examiner * |
| Leandro Elias Morais | External Examiner * |
| MARIELA MATTOS DA SILVA | External Examiner * |
Summary: The regulation of the photosynthetic process is modified according to the
available light and has a direct effect on the plant's ability to live in a given
habitat. Three tree species of the Atlantic Forest were evaluated while
submitted to three irradiance intensities in order to investigate the effects of light
radiation on the photosynthetic behavior and on the slenderness index (SI). The
plants were cultivated for seven months at 20; 50 and 100% of the solar
radiation. The species used, Schinus terebinthifolius Raddi. and Joannesia
princeps Vell, classified as pioneers, and Lecythis pisonis Camb, as secondary,
are widely used in environmental recovery programs. It was tested the
hypothesis that the three species would present different ecophysiological
behaviors in relation to the applied treatments. Independent of the light regime,
Schinus terebinthifolius Raddi. presented the highest values of A in both area
unit and mass unit, followed by Joannesia princeps Vell. Lecythis pisonis Camb
presented the lowest values of this parameter. Schinus terebinthifolius Raddi.
also showed higher saturation light point and higher gs in the three imposed
irradiances. Schinus terebinthifolius Raddi. and Joannesia princeps Vell
exhibited increased SI value at reduced light availability. However, this value
was higher for Schinus terebinthifolius Raddi., with values higher than 50% in
plants under full sun compared to those under 20% of light showing a
morphological adjustment to the irradiance difference. Lecythis pisonis Camb
showed no changes in this parameter by light variations. This species
presented more negative values of ѰW throughout the day and between the
light regimes when compared to the other two species, demonstrating a lower
hydraulic conductivity. The results confirmed the hypothesis, insofar it was
observed greater acclimatization capacity of Schinus terebinthifolius Raddi. to
the three light treatments imposed. Joannesia princeps Vell showed an
intermediate behavior among the studied species, presenting average values in
almost all the parameters analyzed during the experiment. In turn, Lecythis
pisonis Camb, presented the lowest photosynthetic performance in the three
light regimes. This species exhibited a low acclimatization capacity at high
irradiance.
Key words: Ecophysiology, Atlantic Forest, irradiance, acclimatization, gas
exchange.
