Ecophysiology of Brazil nuts (Bertholletia excelsa Bonpl.) In the face of climate change
Name: LUCIANA DE SOUZA LORENZONI PASCHOA
Publication date: 12/02/2020
Advisor:
Name |
Role |
|---|---|
| GILSON FERNANDES DA SILVA | Co-advisor * |
| JOSÉ EDUARDO MACEDO PEZZOPANE | Advisor * |
Examining board:
| Name |
Role |
|---|---|
| JOÃO VITOR TOLEDO | External Examiner * |
| JOSÉ EDUARDO MACEDO PEZZOPANE | Advisor * |
| KARLA MARIA PEDRA DE ABREU | External Examiner * |
| TALITA MIRANDA TEIXEIRA XAVIER | Co advisor * |
Summary: The Brazil nut tree (Bertholletia excelsa Bonpl.) are important for the Brazilian forest sector because they generate jobs and income through non-timber extraction. The exploitation of Brazil nuts is concentrated in native areas, however there is potential for the establishment of cultivation areas. For this it is important to understand the interaction climate x species in other regions. In addition, climate change has caused a number of concerns as it can harm plant species. B. excelsa requires greater attention as it is already threatened with extinction. This study aimed to evaluate the effect of temperature, atmospheric vapor pressure deficit (DPV) and climate change on different soil water levels on the ecophysiology and dry mass production of Brazil nuts. Two experiments were carried out in acclimatized greenhouse houses to simulate different microclimates. The first aimed to investigate the ecophysiological responses of juvenile plants of B. excelsa, with and without water deficiency, in environments simulating the climate of central Amazonia and in two other contrasting climates, one with higher DPV and one with lower air temperature. Brazil nut plants have been found to tolerate an average DPV increase of up to 0.9 kPa, but not a reduction in average temperature to 20.9 ° C. The second experiment aimed to verify the influence of climate change scenarios on the ecophysiology and dry mass production of young B. excelsa plants. To this end, the plants were distributed in three scenarios: the current central Amazon and the other two climate change scenarios estimated by the IPCC (2013) for 2100: RCP4.5 and RCP8.5. In each scenario the plants were maintained with two levels of substrate water: 90% and 40% of field capacity. In the present study, climate change had a positive impact on young B. excelsa plants. The variations in climatic conditions described in scenarios RCP4.5 and RCP8.5 were beneficial for ecophysiology, because due to the increase of atmospheric [CO2], there was an increase in net photosynthesis and, consequently, in the dry mass production of irrigated plants. by B. excelsa. These variations in climatic conditions did not intensify the damage caused by water deficiency in plants with water deficiency. Temperature is the factor that most limits photosynthesis and dry matter production of B. excelsa. Young plants of the studied species support the increase in DPV and have managed to acclimate to reverse the damage caused by it. As reduced climate change for 2100 beneficiaries of ecophysiology and dry matter production of B. excelsa. Water deficiency was the treatment that most harmed the species, and was not intensified by the climatic environments tested.
Keywords: Amazon, vapor pressure deficit, photosynthesis, dry mass, climate change, air temperature.
