Completed Ph.D's (since 1999) Ivan Janssens - Soil CO2 efflux in a mixed forest ecosystem in the Antwerp Campine region. Defended on 30.04.1999. David Salvador-Van Eysenrode - Gaps, diversity, and canopy dynamics in a terra firme rainforest in Amazonian Ecuador. Defended on 02.03.2000. Jan Bogaert - Quantifying habitat fragmentation as a spatial process in a patch-corridor-matrix landscape model. Defended in 2000.  Katrien Bortier - Tree physiological research in view of ozone damage. Defended on 28.06.2000. M. Ewa Jach - Response of young Scots pine trees (Pinus sylvestris L.) to increased carbon dioxide concentration. Defended on 28.06.2000. Liesbeth Van Peer - The effect of species richness on the sensitivity of plant communities to climatic extremes. Defended on 14.03.2003. Birgit Gielen - Effects of elevated atmospheric CO2-concentrations on a fast-growing poplar ecosystem: process and structure. Defended on 09.05.2003. Magdy El-Bana - Environmental and biological effects on vegetation composition and plant diversity of threatened Mediterranean coastal desert of Sinai Peninsula. Defended on 09.07.2003. Ilse Laureysens - Clonal variation in productivity, population dynamics and phytoextraction potential of poplar short rotation coppice culture. Defended on 5.07.2004. Jorge Curiel-Yuste - The importance of soil respiration in the carbon cycle of two contrasting forest types. Defended on 8.07.2004. Ann Milbau - Creation, colonization and invasion of grassland gaps. Defended on 21.09.2005. Fleur Marchand - Climate warming in arctic plant communities: Effects of mean temperature increase and extreme events. Defended on 18.01.2006. Marion Liberloo - Study of the effects of elevated atmospheric CO2- concentrations and nitrogen fertilization on ecosystem processes in a fast growing short rotation coppice of poplars. Defended on 13.12.2006. Hans Verbeeck - The carbon and water balances of two temperate forest ecosystems: a process based modeling approach. Defended on 15.05.2007. Catherine Lemmens - Responses of individual grassland species to climate warming and species richness: ecophysiological processes, development and biomass production. Defended on 29.05.2007. Hans De Boeck - Community-scale effects of climate warming on experimental grasslands of different species richness. Defended on 29.05.2007. Najwa Al Afas - Comparative study of ecophysiological production of different hybrid poplars in a short rotation coppice culture. Defended on 25.06.2007. Evi Rossi - Elucidating invasive success and impact of alien plants by combining plant traits and ecosystem properties. Defended on 24.06.2008.  Sophie Dillen - Genetic variation in growth and its determinants in two poplar families grown at two sites. Defended on 24.04.2009. Johan Neirynck - Exchange of atmospheric nitrogen above a Scots pine forest – implications for nitrogen cycling. Defended on 18.06.2009. Koen Hufkens - Mathematical approaches of landscape ecological studies related to scale dependent spatial patterns. Defended on 11.09.2009. Filip Colson - Quantifying the spatial pattern and ecology of land use in the Amazon Basin. Defended on 15.09.2009. Sara Vicca - Climate change effects on greenhouse gas emissions from wetland soils and on carbon cycling in grasslands ecosystems. Defended on 19.05.2010. Maarten Op De Beeck - Predictive stomatal conductance models: comparison of performance and applications. Defended on 20.05.2010. Raphaël Bequet - Environmental determinants of the temporal and spatial variability of leaf area index in Fagus sylvatica L., Quercus robur L., and Pinus sylvestris L. Defended on 29.04.2011.  Bert Gielen - Analysis of the long-term carbon and water balance of a temperate Scots pine forest. Defended on 10.06.2011. Maya Verlinden - Effects of experimental climate warming on alien vs. native plant species. Defended on 06.07.2011.  Joke Van Den Berge - Changes in the stress sensitivity of plants and ecosystems in a future climate. Defended on 20.10.2011. Kim Naudts - Does the response of grasslands to stress change under climate change conditions? Defended on 28.02.2012.  Wouter Dieleman - Global change effects on soil C and soil C cycling. Defended on 25.05.2012. Yongshuo Fu - Climate warming effects on leaf phenology on decidous trees - a combination of manipulation experiments and model analyses. Defended on 03.07.2012. Marilyn Roland - The role of carbonate geochemistry and non-diffusive gas exchange in the carbon balance of terrestrial ecosystems. Defended on 30.11.2012.  Maarten De Bock -The Impact of tropospheric ozone on Brassica species. Defended on 28 February 2013. Freja Dreesen - Effects of experimentally simulated climate extremes on plant communities. Defended on 18 March 2013.