Externally Funded Research Projects

Completed Projects


  • Principal Investigator: 'Soil greenhouse gas fluxes, nutrient leaching losses and nutrient response efficiency in a large-scale oil palm plantation: conventional versus reduced management practices'.
    PhD completed (2023): Dr. Guan-tao Chen
    Funding: Chinese Scholarship Council (2018-2023) and the German Research Foundation (DFG) (2020-2023)

  • Principal Investigator: 'Soil greenhouse gas balance, yield and profit in intensively fertilized vegetable farms on an Andosol soil in Leyte, Philippines'.
    PhD completed (2023): Dr. Cecille Marie O. Quiñones
    Funding: German Academic Exchange Service (DAAD) 20017-2020

  • Principal Investigator: ‘Soil greenhouse gas (N2O, CH4, CO2) fluxes from cropland agroforestry and monoculture systems in Germany’.
    PhD completed (2022): Dr. Guodong Shao
    Funding: Chinese Scholarship Council 2017-2021 and the German Federal Ministry of Education and Research (BMBF) 2018-2021

  • Principal Investigator: 'Gross rates of soil nitrous oxide emission and uptake in cropland agroforestry and monoculture systems in Germany'.
    PhD completed (2022): Dr. Jie Luo
    Funding: Chinese Scholarship Council 2017-2021 and the German Federal Ministry of Education and Research (BMBF) 2018-2021

  • Principal Investigator: 'Nutrient response efficiencies and ecosystem functions in alley-cropping agroforestry versus open cropland and grassland' in SIGNAL - Sustainable intensification of agriculture through agroforestry.
    Postdoc: Dr. Marcus Schmidt
    Funding: German Federal Ministry of Education and Research (BMBF) 2016-2021

  • Principal Investigator: Project A05 of the Collaborative Research Center 990 (Ecological and Socioeconomic Functions of Tropical Lowland Rainforest Transformation Systems) 'Nutrient use and retention efficiency, free-living N2 fixation and soil and tree-stem N2O and CH4 fluxes in rainforest transformation systems' of the Collaborative Research Center 990 (Ecological and Socioeconomic Functions of Tropical Lowland Rainforest Transformation Systems (Sumatra, Indonesia)).
    PhD completed (2020): Dr. Greta Formaglio
    Funding: DFG 2016-2019
    [read more about CRC 990]

  • Principal Investigator: 'Nitrous oxide emissions from soils and tree stems of rainforests and cacao agroforests in the Congo basin, Cameroon'.
    PhD completed (2020): Dr. Najeeb Al-Amin Iddris
    Funding: DFG 2017-2020

  • Co-Investigator: 'Soil nutrient stocks and greenhouse gas fluxes from conventional and reduced impact logging of forests on highly weathered soils in Cameroon'.
    PhD completed (2020): Dr. Rodine Tchiofo
    Funding: German Academic Exchange Service (DAAD) 20016-2020, and the DFG 2017-2020

  • Principal Investigator: Project A05 of the Collaborative Research Center 990 (Ecological and Socioeconomic Functions of Tropical Lowland Rainforest Transformation Systems) 'Conversion of forests to smallholder rubber and oil palm plantations: landscape-scale and inter-annual variations of soil greenhouse gas fluxes (GHG) and the contribution of tree-stem emission to soil GHG budget'.
    PhD completed (2019): Dr. Joost Koks
    Funding: DFG 2016-2019
    [read more about CRC 990]

  • Principal Investigator: 'Gross N2O fluxes across soil-atmosphere interface and stem N2O emissions from temperate forests in Germany'.
    PhD completed (2017): Dr. Yuan Wen
    Funding: China Scholarship Council 2013-2016 and the DFG 2011-2014

  • Co-Investigator: 'Fire impacts on soil nutrients and trace gas fluxes from savanna systems in Burkina Faso'
    Postdoc: Dr. Sabine Doamba
    Funded: Livelihood, Management, Reforms and Processes of Structural Change program of the Volkswagen Foundation 2015-2016

  • Principal Investigator: Project A05 of the Collaborative Research Center 990 (Ecological and Socioeconomic Functions of Tropical Lowland Rainforest Transformation Systems) 'Consequences of rainforest conversion to smallholder rubber and oil palm plantations on soil trace gas fluxes from highly weathered soil in Sumatra, Indonesia’.
    PhD completed (2016): Dr. Evelyn Hassler (graduation in 2016).
    Funding: DFG 2012-2015
    [read more about CRC 990]

  • Principal Investigator: Project A05 of the Collaborative Research Center 990 (Ecological and Socioeconomic Functions of Tropical Lowland Rainforest Transformation Systems) 'Conversion of lowland forests to rubber and oil palm plantations changes nutrient leaching and nutrient retention efficiency in highly weathered soils of Sumatra, Indonesia'.
    PhD completed (2015): Dr. Syahrul Kurniawan
    Funding: DFG 2012-2015 and Indonesian DGHE Post-graduate Scholarship 2012-2015
    [read more about CRC 990]

  • Principal Investigator: Project A05 of the Collaborative Research Center 990 (Ecological and Socioeconomic Functions of Tropical Lowland Rainforest Transformation Systems) 'Impacts of land-use conversion in Sumatra, Indonesia, on soil nitrogen cycling, soil nutrient stocks and ecosystem dynamics'.
    PhD completed (2015): Dr. Kara Allen
    Funding: DFG 2012-2015
    [read more about CRC 990]

  • Co-Investigator: Sub-project B7 of the Research Training Group 1086 (The role of biodiversity for biogeochemical cycles and biotic interactions in temperate deciduous forest) 'Nutrient response efficiency, tree-microbial biomass competition for nutrients and tree neighborhood dynamics in a mixed-species temperate deciduous forest in central Germany'.
    PhD completed (2015): Dr. Marcus Schmidt
    Funding: DFG 2011-2015
    [read more about RTG 1086]

  • Principal Invistigator: 'Soil water controls on nitrogen oxide fluxes and N2O production and consumption along a rainfall gradient of tropical forests, Panama'.
    Funding: DFG 2011-2014.

  • Co-Invistigator: Changes in soil carbon stocks and mechanisms of carbon stabilization in soils with conversion from secondary forests to grasslands in Leyte, Philippines.
    Postdoc: Dr. Ian Navarrete
    Funding: Alexander von Humboldt Foundation 2012-2014

  • Co-Investigator: Anthropogenic impact on chemical weathering and soil formation in young volcanic soils, Ecuador.
    Postdoc: Dr. Armando Molina
    Funding: Alexander von Humboldt Foundation 2011-2014

  • Co-Investigator: Sub-project A7 of the Research Group 816 (Biodiversity and Sustainable Management of a Megadiverse Mountain Ecosystem in South Ecuador) ´Soil greenhouse gas fluxes under elevated nutrient input along an elevation gradient of tropical montane forests in southern Ecuador'.
    PhD completed (2014): Dr. Dr. Anke K. Müller
    Funding: DFG 2010-2013
    [read more about FOR 816]

  • Co-Investigator: Sub-project A7 of the Research Group 816 (Biodiversity and Sustainable Management of a Megadiverse Mountain Ecosystem in South Ecuador) 'Canopy soil nutrient cycling and response to elevated nutrient levels along an elevation gradient of tropical montane forests'.
    PhD completed (2014): Dr. Amanda L. Matson
    Funding: Natural Sciences and Engineering Research Council of Canada and the DFG 2010 - 2013
    [read more about FOR 816]

  • Co-Investigator: Sub-project A7 of the Research Group 816 (Biodiversity and Sustainable Management of a Megadiverse Mountain Ecosystem in South Ecuador) 'Soil nitrogen cycling and fates of nitrogen in montane forests across a 1000-3000-m elevation gradient in the Ecuadorian Andes'.
    PhD completed (2014): Dr. Angelica P. Baldos
    Funding: DFG 2010 - 2013
    [read more about FOR 816]

  • Co-Investigator: Sub-project A2 'Grassland management and diversity: effects on nitrogen response efficiency of plant biomass production and nitrogen retention efficiency of the soil'. Cluster of Excellence (Functional Biodiversity Research). Site: Germany
    PhD completed (2013): Dr. Andreas Keuter
    Funding: State of Lower Saxony 2008 - 2013
    [read more about Cluster of Excellence]

  • Co-Invistigator: Work Package 3 'Quantification of GHG emissions from tropical deforestation' of REDD-ALERT (Reducing Emissions from Deforestation and Degradation through Alternative Landuses in Rainforests of the Tropics). Sites: Cameroon, Indonesia and Peru.
    Postdoc: Dr. Oliver van Straaten
    Funding: European Union 2009-2012
    [read more about REDD-ALERT]

  • Principal Investigator: Sub-study 'Long-term fates of nitrogen in tropical forest soils exposed to chronic nitrogen addition'. Part of my Independent Research Group, NITROF (Impact of elevated NItrogen input on the biogeochemistry and productivity of TROpical Forests). Site: Panama
    Funding: Robert Bosch Foundation 2005-2011

  • Co-Investigator: Sub-project A2 'Grassland management and diversity effects on soil nitrogen dynamics and losses'. Cluster of Excellence (Functional Biodiversity Research). Site: Germany
    PhD completed (2012): Dr. Ina Hoeft
    Funding: State of Lower Saxony 2008 - 2011
    [read more about Cluster of Excellence]

  • Co-Investigator: Sub-project A2.4 'Soil trace gas fluxes from tropical montane forest soils in South Ecuador'. Research Group 816 (Biodiversity and Sustainable Management of a Megadiverse Mountain Ecosystem in South Ecuador).
    PhD completed (2011): Dr. Guntars Martinson
    Funding: DFG 2007 - 2010
    [read more about FOR 816]

  • Co-Investigator: Effectiveness of exclosures on restoration of soil ecological properties in Tigray, Ethiopia.
    PhD completed (2010): Dr. Wolde Mekuria
    Funding: DAAD, British Ecological Society, International Foundation for Science 2007 - 2010

  • Principal Investigator: Sub-study 'Effects of increased nitrogen input on the net primary production of a tropical lower montane rain forest, Panama'. Part of my Independent Research Group, NITROF (Impact of elevated NItrogen input on the biogeochemistry and productivity of TROpical Forests). Site: Panama
    PhD completed (2009): Dr. Markus Adamek
    Funding: Robert Bosch Foundation 2005-2011

  • Principal Investigator: Sub-study 'Soil nitrogen oxide and carbon dioxide emissions from a tropical lowland and montane forests exposed to elevated nitrogen input'. Part of my Independent Research Group, NITROF (Impact of elevated NItrogen input on the biogeochemistry and productivity of TROpical Forests). Site: Panama
    PhD completed (2009): Dr. Birgit Koehler
    Funding: Robert Bosch Foundation 2005-2011

  • Co-investigator: 'Quantifying the internal soil nitrogen cycle to evaluate the nitrogen status of humid tropical forests'. Site: Panama, Ecuador
    PhD completed (2008): Dr. Julia Arnold
    Funding: DFG 2005 - 2007

  • Principal Investigator: 'Quantitative assessment of changes in internal nitrogen cycling in forest soils along nitrogen deposition gradient in Germany'.
    Funding: DFG 2003 - 2005

  • Co-Investigator: 'Influence of changing atmospheric deposition on N status of a spruce forest in Germany'.
    Funding: DFG 2002

  • Principal Investigator: 'Soil nitrogen cycling in acid forest ecosystem under increased atmospheric nitrogen input in Germany'.
    Funding: Alexander von Humboldt Foundation 1999-2001