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School of Geography

Bruno Ladvocat Bruno Ladvocat

Contact details


School of Geography
University of Leeds
University Road
Leeds LS2 9JT   UK

Email:
gybblc

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Project title:

Spatial-temporal reconstruction of Amazon flood pulse and dry season length over the past century using tree rings and isotopes of floodplain tree species Macrolobium acaciifolium

Project overview

Over the last decade the Amazon basin has experienced repeated extreme flooding (2009, 2012-2014) and droughts (2005, 2010), corroborating model predictions of increasing frequency of climate extremes (Hartmann et al., 2013; Kitoh et al., 2013). These extreme events may at least partially be due to an intensification of the hydrological cycle over the last decades, possibly caused by a multi-decadal warming trend of the tropical North Atlantic ocean (Gloor et al., 2013). Warm tropical North Altantic ocean temperature is known to have expressive effects on dry season hydrology of the Amazon Basin (Yoon and Zeng, 2010). As dry season hydrology is one of the key controls of forest vegetation (Mahli et al., 2008), and thus affects the functioning of tropical rainforest, it is important to understand the drivers behind recent droughts, and put them into a long-term perspective.

This research aims to evaluate the long-term variations of the dry season length and intensity. This will be done by analyzing tree-ring widths and isotopes signals from the floodplain tree species, Macrolobium accifolium. As floodplain trees grow during the low phase of the rivers, which coincides with the dry season across most of the Amazon, their rings should carry mostly dry season hydrology information.

Aims/objectives

In this project I will use tree ring analysis and isotopes to reconstruct dry season hydrology for the past few centuries, and specifically test whether:

  1. there have been consistent changes in the dry season length (Marengo et al., 2011) for different sub basins of the Amazon;
  2. there are changes in the oxygen isotope signal which are consistent with changes in the severity of the dry season or changes in water recycling across the basin;
  3. the recent climate/river hydrological extremes fall outside the natural variability for the past couple of centuries (and are thus likely due to anthropogenic global change) or are part of a fluctuation of a long-term climate cycle.

Supervisor(s)

Research Affiliations

  • Ecology and Global Change

Funding

Science Without Borders / Brazil

Conferences/training courses attended

  • Cintra, BBL; Schietti, J; Emillio, T; Martins, D; Moulatlet, G; Souza, P; Levis, C; Quesada, CA; Schöngart, J. Soil physical restrictions and hydrology regulate stand age and wood biomass turnover rates of Purus-Madeira interfluvial wetlands in Amazonia. Biogeosciences, v. 10, p. 7759-7774, 2013.

Short Curriculum Vitae

2013-2014: Research affiliate of the Wetlands Monitoring Research Group at the Insituto Nacional de Pesquisas da Amazônia, Manaus/Brazil

2010-2012: Msc. in Biology (Ecology) at the Instituto Nacional de Pesquisas da Amazônia, Manaus/Brazil

2005-2009: Graduation in Biological Sciences at the Universidade Federal Rural do Rio de Janeiro/Brazil.