Tree-water interactions at varying spatiotemporal scales in a water limited environment

Abstract

This dissertation is approved by: prof. dr. Z. Su (promotor) dr. ir. Maciek W. Lubczynski (co-promotor) I want to extend my gratitude to all the people that directly and/or indirectly supported all the stages of my PhD experience. To my supervisor, Dr. Ir. Maciek Lubczynski, for his patience, involvement, passion, vision and guidance during all these years. To Prof. Bob Su, for his active and timely support in my PhD project. To Dr. J. Martínez Fernández at the Universidad de Salamanca, and all the members of "Grupo de recursos hídricos" (specially Dr. Nilda Sánchez Martín), for hosting me in their lab for three consecutive summers, while providing valuable advice and insights on the Spanish environments. To Lucio and his family for letting me roam free in their land installing weird devices in their trees. To Jean Roy for sharing his knowledge and developments for my project. To Prof. Kathy Steppe and Maurits Vandegehuchte at the University of Gent, for opening the doors of your lab to me, and for engaging on my research ideas. To all my PhD colleages at ITC, especially for those in room 5-116, who became an extension of my family. To Alain Pascal Frances, Enrico Balugani, Guido Baroncini Turrichia, Chandra Prasad Ghimire, Christiaan van der Tol and Tanvir Hassan for all the great memories and experiences shared in our field expeditions and in our scientific discussions. To all the MSc. students that I had the fortune to advise. To all the members of staff at ITC, particularly the Students Affairs staff for their unconditional support. I am especially grateful to my wife Cornelia Reyes and my families, both in Colombia and in Austria, whose support was essential in moments of doubts and confusion. To my brother Oscar and my sister in law Natalia for helping with the design of the cover and for surviving hours of harsh field conditions in the peak of the Spanish summer time. Finally, to my sister Carolina for her cheerful demeanour and positiveness. Without my families this project would not have been successful. To the trees, the water, the land, and the Spanish sky, thanks for being my hosts and companions in those long working days in the forest.

Integration of hydrogeophysics and remote sensing with coupled hydrological models

“…The novelty of that conceptualization involves partitioning and sourcing of subsurface evapotranspiration, in which transpiration, in contrast to evaporation, is water table depth independent and driven mainly by the climatic conditions, while contributions of water sources (saturated or unsaturated zone) are dependent on water potential schematized by set of lumped parameters. The appropriate performance of MARMITES-MODFLOW was confirmed on the La Mata hard rock study case (Chapter 5) and validated against independent studies (van der Tol, 2012;Balugani et al, 2015;Reyes-Acosta, 2015) and states variables measured in the field (soil moisture and hydraulic heads). The capability of MARMITES-MODFLOW in integrating MRS method in the model calibration was also tested in the Carrizal sedimentary rock study case.…”

“…As recent studies focused on the assessment of these components individually (e.g. Shah et al, 2007;Balugani et al, 2014;Reyes-Acosta, 2015), such research created an opportunity to generate tools to integrate these fluxes separately in coupled hydrological models, allowing this way to retrieve a detailed and complete water balance at the catchment scale.…”

Partitioning of subsurface evaporation in water limited invironments

“…To assess the sources of water transpired by trees ( or ), we applied the methodology described by Lubczynski (2009) to experimental data described in Reyes-Acosta et al (2015). Constant doses of deuterated water were injected during 24 h into the groundwater using a network of piezometers drilled around the trees, following Brooks et al (2002).…”

“…This setup maximized the plume shape and the chemical dispersion through the soil. During and after the deuterated water injection, we used sap flow sensors to monitor and collected xylem water, soil water and groundwater samples to assess the sources' contributions to (Reyes-Acosta et al, 2015). To upscale the transpiration estimates for the MF area we: (i) established the upscaling functions for each tree species using the procedure explained in Reyes and Lubczynski (2013) after digital mapping of the trees in the study area using a QuickBird image as reference; (ii) upscaled the 30 min sap flow measurements into whole-tree scale and to the investigated footprint area; (iii) extrapolated the results of the sap flow measurement campaign temporally into the whole dry summer period applying an artificial neural network model (Liu et al, 2009); and (iv) sourced sap flow into and using deuterium tracing experiments (Reyes-Acosta and Reyes-Acosta et al, 2015) for the whole dry summer period (according to the measurements, performed during dry summer campaigns of 2009 and 2010, Reyes-Acosta and Lubczynski, 2011).…”

“…The selected area (Figure 1.3) is located in the northern part of the Sardon Catchment, in the central-western part of the Iberian Peninsula, west of Salamanca, Castilla y León (Spain; latitude: 41.1172; longitude: 6.1471). The area has already been extensively investigated (Lubczynski and Gurwin, 2005;Mahmoudzadeh et al, 2012;Reyes and Lubczynski, 2013;Frances et al, 2014;Hassan et al, 2014;Reyes-Acosta and Lubczynski, 2014;Reyes-Acosta et al, 2015).…”