Banca de DEFESA: ANTONIO CARLOS SILVEIRO DA SILVA

Uma banca de DEFESA de DOUTORADO foi cadastrada pelo programa.
DISCENTE : ANTONIO CARLOS SILVEIRO DA SILVA
DATA : 23/11/2020
HORA: 15:00
LOCAL: Nova Xavantina
TÍTULO:

THE ROLE OF FIRE AND DROUGHT EVENTS ON THE SOIL MOISTURE DYNAMICS IN THE TRANSITIONAL FOREST BETWEEN AMAZONIA AND CERRADO

PALAVRAS-CHAVES:

FOREST, FIRE, SOIL MOISTURE

PÁGINAS: 83
GRANDE ÁREA: Ciências Biológicas
ÁREA: Ecologia
SUBÁREA: Ecologia Aplicada
RESUMO:

Soil moisture can both affect and be affected by possible trajectories of forests impacted by disturbances. In the Amazon – Cerrado transition forests, forest fires and extreme drought events have occurred with greater intensity and frequency. With that, we evaluated the post-fire impact on the water content in the soil (Volumetric Water Content - VWC) in a portion burned every three years (2004 to 2010) and another portion burned annually (2004 to 2010), in addition to the control plot. Our data collection covered the period from 2010 to 2018, which made it possible to assess the impacts of extreme drought from 2015-2016 on the water content in the soil in the three plots. To estimate the water content in the soil, we used and evaluated the quality of two methods: time domain reflectometer (TDR) and resistivity, both methods being calibrated using the gravimetric moisture content quantification technique (Gravimetric Water Content - GWC). We tested the hypotheses that (H1) the burnt plots present higher soil moisture in the first post-fire years (between 2011 and 2012) and a reduction in the following years, and (H2) the extreme drought event (between 2015 and 2016) caused a greater water deficit in the soil of the burnt plots. Our results showed that both methods used estimated soil moisture consistently. On the interannual scale, the post-fire soil moisture did not differ much from that recorded in the intact plot (H1). On the other hand, the reduction caused by drought in soil moisture was more intense in the burnt plots (H2), requiring more time to recharge the volume of water from the soil. In addition, forests, both burned and intact, increased water use in the dry season, suggesting that the stressful conditions of seasonal drought are imposing on woody trees a greater demand for soil water, which is accessed mainly from deep soil ( up to 8m). In this sense, the increase in forest fragmentation, widespread fires and extreme drought events may cause greater variability, and even abrupt reductions in soil moisture under transition forests in a short period of time, further increasing the uncertainties for the recovery of these degraded forests.

MEMBROS DA BANCA:
Presidente - 220.974.038-08 - PAULO MONTEIRO BRANDO - NENHUMA
Interno - 996.005.011-49 - DIVINO VICENTE SILVÉRIO - UnB
Externo à Instituição - PAULO TARSO SANCHES OLIVEIRA - UFMS
Externo à Instituição - SONAIRA SOUZA - UFAC
Externo à Instituição - SIMONE MATIAS DE ALMEIDA REIS - Oxford