With over 10 years of experience in Agricultural and Environmental Sciences, I am passionate about understanding how ecosystems function and how they can provide sustainable services to society under climate change and in wider sense on how can we feed the world sustainably and healthy in the coming years?
As an Executive Board Member and the Head of the Strategic Research Division Agroecology and Environment at Agroscope, the Swiss Confederation's center of excellence for agricultural research, I lead a research division with approx. 200 scientists and experts who work on identifying innovative solutions for the challenges facing the agri-food sector and the environment today and in the future.
My core competencies include environmental sciences, biogeochemistry, soil science, ecology, system ecology, education, and mentoring the next generation scientist. I have a Doctor of Sciences degree in Environmental Science/Agricultural Sciences from ETH Zurich, and I have published >130 papers in peer-reviewed journals on topics such as greenhouse gas emissions, carbon and nitrogen cycles, and ecosystem responses to climate change, sustainable agricultural production and its linkages to animal and human health, agroecological assessment as well as modelling future scenarios.
I am motivated to share my knowledge and expertise with the next generation of researchers, as well as to apply my research findings in the real world together with farmers, advisors, funders and decision makers to support sustainable agriculture and a healthy environment.
projects and outputs to be updated as soon as time allows...
Consequences of agricultural intensification in Africa in GHG emissions (2019)
We investigated the potential consequences of agricultural intensification (ie. via improved fertilisation rates) on the environment, namely nitrous oxide emissions. Simultaneously, it remains a challenge to evaluate climate smart agricultural practices holistically, encompassing the three angles mitigation, adaptation and food security. Thus, we carried out two studies: One that models the increase in nitrous oxide emissions if the yield gap in essential staple crops is filled due to enhanced fertilisation and secondly we reviewed the most dominant tools that allow assessing climate smart agricultural practices in order to identify the best available tools.
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GHG emissions from different land use types in East Africa (2018-2021)
During this PhD project we aim at quantifying soil GHG emissions and identifying its drivers from a variety of land use types in Southern Kenya. The systems observed include, natural grassland, scrublands, croplands, mountain forests, sisal plantations and more.
Besides deriving annual soils GHG emission estimates we are interested in the seasonality of these GHG emissions as well as the effects of management (stand age, grazing intensity, crop management etc.) on them. Read our papers here 1: Soil Greenhouse Gas Emissions under Different Land-Use Types in Savanna Ecosystems of Kenya 2: Soil greenhouse gas emissions from a sisal chronosequence in Kenya |
Nitrous oxide emissions from livestock enclosures (2017-2019)
During this project we investigated nitrous oxide (N2O) emissions from livestock enclosures (bomas, corrals, kraals) in East Africa. We specifically quantified the N2O emissions from a chronosequence (1 week to 40 year old) of enclosures. The enclosures are found in arid and semi-arid landscapes in Sub-Saharan Africa (SSA) and are used to protect livestock from predators and thieves during nighttime while the animals grate during the day. As a consequence animal manure accumulated in the enclosures over time and is hardly being used. Thus, we see a translocation of nutrients (nitrogen) from the savanna to these enclosures and an accumulation of nutrients within the enclosures. The enclosures are being used for days/weeks/months before being abandoned or re-used during specific seasons. Our results show substantial N2O losses even 40 years after abandonment of the enclosures. We estimated that approx. a minimum 5% of the continental N2O emissions originate from livestock enclosures. see our open access Nature Communications paper here.
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Carbon dioxide and water flux measurements in rangelands in East Africa (2018-2020)
The goal of this project is to observe and quantify carbon dioxide and water fluxes from a natural rangeland in Central Kenya. Thereby we apply the eddy covariance technique to continuously observe the the ecosystem and identify temporal variations in CO2 and H2O exchange during the course of multiple years. The site chosen, Kapiti Research Station, is one of the last remaining large pieces of land in Central Kenya and used for livestock production, animal disease trials and environmental research. Similarly, the farm is home to a variety of East African wildlife (zebra, wildebeest, giraffe, lions etc.) and connects almost directly to Nairobi Nationalpark. Consequently the area is not only a showcase for successful livestock-wildlife integration but also acts as a benchmark site for sustainable livestock production in the drylands of Central Kenya. Our measurements can then be related to less-well managed rangelands and potential climate change mitigation and adaptation benefits be quantified.
Manuscripts so far: 1: Nitrogen cycling in pastoral livestock systems in Sub-Saharan Africa: knowns and unknowns 2: Opportunities for an African greenhouse has observation system 3: Greenhouse fas gas emissions from cattle enclosures in semi-arid Sub-Saharan Africa: the case of a rangeland in South-Central Kenya 4: Methane emissions from animal agriculture: Micrometeorological solution for challenging measurements situations |
Estimating Tier 2 GHG baseline emissions from ruminants and manure management in Kenya and Tanzania (2016-2019)
The goal of this IFAD funded project "Greening Livestock: Incentive-based Interventions for reducing the climate impact of livestock in East Africa" aims at quantifying GHG emissions from smallholder farming systems in Kenya and Tanzania. Thereby as specific focus is given to the dairy sector, which develops fast and provides income and nutrition to the population. The purpose is the improvement of current estimates of GHG emissions (Tier 1) from livestock systems by generating currently lacking region specific information (Tier 2) is to identify and to reliably quantify mitigation options in the livestock sector in East Africa.
At the moment three manuscripts are in review that present first results from two counties in Western Kenya. Work in another county in Kenya is ongoing and data collection has recently (09/2017) started in two districts in Tanzania and will be expanded in the upcoming months. see our Emission Factor papers here: Emission Factors Western Kenya Emisssion Factors from sub-maintenance fed cattle |
Supporting EU-African Cooperation on Environmental Research Infrastructures (2017-2019)
African societies face growing global change risks, with rapidly changing patterns of human settlements and intensity of use of ecosystem services. At the same time, climate variability and climate change trends are intensifying stress on the ecosystems that ensure environmental security, both locally (e.g. ecosystem services), regionally (e.g. sustainable development options) and internationally (e.g. carbon sequestration).
Policymakers and land-use decision makers are increasingly dependent on knowledge on the state of the environment. Long-term observational systems and research infrastructures have been identified to be indispensable elements of knowledge generation to serve climate change adaptation, food security, and climate change mitigation. This projects supports EU-African cooperation on research infrastructures. Its aims are to increase coherence and interoperability between infrastructures in Europe and Africa, to enhance technical competence, science awareness and lifelong learning in Africa in order to facilitate the use of research results for evidence-based policy making, and to identify knowledge gaps for future research directions. read our paper on the current state of environmental research infrastructure in Africa here (open access) Video documentation on the project: https://player.vimeo.com/video/367956489 https://vimeo.com/apogeeoy/review/432421750/0d1a9c4aaf |
GHG emissions from manure piles (2016 -2018)
Smallholder farmers in Africa commonly store cattle manure for variable amounts of time on their farms before burning the manure or applying it to their fields. So far the contribution of such manure piles to GHG emissions remains unclear. Therefore we chose two approaches to quantify the GHG emissions from such manure piles: (1) manually measuring GHG emissions using static manual chambers on small farms in the field and (2) by measuring GHG emissions from artifically piles manure under controlled conditions in the lab. The latter enables us to control environmental variables such as temperature and moisture while also allowing for larger sampling frequencies.
see our paper on manure heap GHG emissions here |
GHG emission from soil types after manure amendment (2016 - 2017)
While cattle manure is often stored in piles before being either burned or amended to soils it remains unclear how manure amendment to soils affects GHG emissions. Therefore we set up a small experiment which aims at quantifying GHG emissions from soils (various soil types) following manure, urine and bioslurry application.
read our papers on manure GHG emissions here: 1: Interactive effects of dung deposited onto urine patches on greenhouse gas fluxes from tropical pastures in Kenya 2: The effects of climate on manure decomposition for cattle, sheep and goat in Kenyan tropcial pastures 3: Influence of soil properties on N2O and CO2 emissions from excreta deposited on tropical pastures in Kenya |
GHG and nitrogen emission hot spots in rangelands (2016 - 2019)
The project aims at quantifying GHG emissions and nitrogen losses from cattle enclosures in East African rangelands. Within the project we apply conventional and state-of-the-art environmental measurement techniques:
(1) static manual GHG chambers to quantify the emissions of carbon dioxide, methane and nitrous oxide, (2) shuttles with gradient measurement to estimate ammonia losses and (3) the eddy covariance technique to quantify the three major greenhouse gases (GHGs: CO2, CH4 and N2O) as well as ammonia (NH3). see our paper on Nitrogen cycling in pastoral systems in Ecological Applications here |
Farmer training courses in Western Kenya (2016 - 2017)
Within the project we train innovative smallholder farmers in common farm practices to increase productivity (dairy, beef), to improve the quality of their repsective products as well as to become enviromentally sustainable.
Four training courses - one month duration have been taught. During this time up to 150 farmers and technical officers (60% male/40% female farmers) were trained and whom now act as multipliers in their communities and reach approximately 8000-9000 farmers. for more information click here |
In-situ assessment of GHG emissions from livestock systems (2015-2018)
The goal is to quantify GHG emissions and testing of mitigation options fo two livestock systems in Kenya/East Africa: 1) dairy cattle, economically the most important livestock production system in Kenya; 2) beef/draught oxen, especially important in Eastern Kenya and Ethiopia. The purpose is the improvement of current estimates of GHG emissions from livestock systems by generating currently lacking region specific information. The project encompasses a) generation of accurate baseline data for livestock GHG emissions for locally prevalent livestock systems by identifying current feed types and feeding levels and measuring GHG emissions arising from them. b) exploration of two nutritional intervention options – attempting to improve productivity on present feed types by supplementation with macro nutrients to optimise rumen function; or supplying a level of nutrition optimal for the genetic potential of the livestock being assessed c) assessing effects of animal health on ruminant performance and GHG emissions d) improving the RUMINANT model for simulating livestock performance and ruminant GHG emissions. e) up-scaling of GHG emissions to the rest of East Africa.
read the paper quantifying TIER 2 emissions estimates from enteric fermentation in smallholder farms here (open access) |
Greenhouse gas fluxes in grassland in relation to management in Europe (2014-2018)
Within this project we aimed at consolidating available datasets containing GHG flux measurements of the three major GHGs, carbon dioxide, methane and nitrous oxide, in European grasslands. We specifically investigated the effects of management intensity on ecosystem GHG exchange, quantified net gains/losses of Carbon and Nitrogen from these grassland systems and identified common driver variables.
read our Global Change Biology paper here |
Extrapolating greenhouse gas fluxes (particularly N2O) in time and space - Models4Pastures (2013-2017)
Caused by the fact that not everything can be measured everywhere mathematical models are needed to predict future changes in greenhouse gas emissions from agricultural systems. While modeling of CO2 exchange has been shown in the past and the underlying processes are understood nicely, modelling of N2O exchange remains a major challenge.
Within the project the leading modelling communities of biogeochemical-process models have come together to improve currently available models to reliably predict N2O emissions from grassland ecosystems now and in the future as well as to identify the most promising mitigation strategies for future land management. Models included in this project are DNDC and its derivates, DAYSCENT, APSIM, PASIM and SPACSYS. For more information click here. read the Global Change Biology paper on uncertainties in biogeochemical models here |
How well agree eddy covariance and manual static chamber measurements of greenhouse gas fluxes? (2013)
In order to quantify changes in greenhouse gas emissions over time (several years) it is essential to compare different measurement techniques. Particularly since past budget estimates were and still often are based on gas concentration measurements in static manual chambers (Figure to the right) with low temporal resolution (one measurement every week or two). With the development of easy to deploy in the field quantum cascade laser absorption spectrometers continuous measurements of greenhouse gas exchange of N2O and CH4 using micrometeorological techniques such as eddy covariance have become more common.
Therefore we compared both techniques during an intensive field campaign in summer 2013. This project was jointly organised with Dr. Charlotte Decock from the Sustainable Agroecosystem group at ETH Zurich. see our open access paper in Biogeosciences here |
Greenhouse gas mitigation in Swiss grasslands - Models4Pastures (2014-2016)
As part of the Models4Pastures (funded via the SNSF and proposed by FACCE-JPI) project we aim at experimentally determining greenhouse gas mitigation options in Swiss grasslands. Thereby we can integrate an already existing eddy covariance tower in an experimental setup where both, business-as-usual management and one possible mitigation option are tested. In spring 2015 we resowed one of the grassland parcels to increase the legume content to approx. 50% and reduce organic fertiliser inputs. During the upcoming year we will identify the differences in greenhouse gas emissions, the differences in yield and fertilisation as well as the quality of the grown fodder in both treatments.
click here for further reading and for our open access paper |
ICOS-CH - The Swiss contribution to an Integrated Carbon Observation System in Europe (2013 - ongoing)
Since the beginning of 2014, I coordinate the ICOS-CH project. Within this project a consortium of Swiss universities and Research Institutions aims at long-term observations of greenhouse gas concentrations in the atmosphere (e.g. at Jungfraujoch) as well as greenhouse gas fluxes from a sub-alpine spruce forest as found in Davos.
At the Davos-Seehornwald, one of the longest running eddy covariance towers in Europe a whole range of ecosystem parameters are measured continuously to quantify and understand greenhouse gas exchange at the ecosystem scale. Measurements include ecosystem exchange of CO2, H2O, N2O and CH4, soil greenhouse gas fluxes, basic meteorology, dendrometer and sap flow measurements as well as a whole range of soil climatic variables. More information to ICOS can be found here. |
Identifying source processes of nitrous oxide production in temperate grassland (2013)
Online measurements of isotopologues of N2O has so far only been possible in the laboratory. However with the development of easy to deploy in the field quantum cascade laser absorption spectrometers in combination with a custom made pre-concentration unit by empa (Swiss Federal Laboratories for Material Science and Technology) this restriction could be overcome. The system was tested during an intensive field campaign at the SwissFluxnet site Chamau located in Central Switzerland. The measurements of N2O isotopologues were accompanied by eddy covariance measurements of N2O.
click here for further reading (open access paper) |
Large peaks of nitrous oxide fluxes following grassland restoration (2012/2013)
Providing a full greenhouse gas balance (CO2, CH4 and N2O) for intensively managed grasslands based on in-situ data has only rarely been achieved so far. Studies that focused on the restoration of a current land use type (e.g. grassland for fodder production) to the same land use type without conversion to another does not exist to our knowledge. Therefore we established the first full GHG eddy covariance ecosystem monitoring station in Switzerland to study the effects of grassland restoration. Large losses of nitrogen (N) in form of N2O were observed following different management activities including ploughing, mineral fertilizer application and sowing.
click here for further reading (abstract)
click here for further reading (abstract)
Winter greenhouse gas emission from sub-alpine grasslands in Switzerland (2010/2011)
In recent years I focused on the effects of winter greenhouse gas emissions altering annual CO2 budgets of sub-alpine grasslands in Switzerland.
click here for further reading (abstract)
We compared different measurement techniques to quantify greenhouse gas emissions from the snowpack. Approaches included the eddy covariance technique, manual and automatic GHG concentrations as well as radon measurements as an inert tracer to accurately determine the diffusion coefficient of the snowpack. This study was only made possible with the help of a very motivated M.Sc. student (Christine Steinlin).
click here for further reading (open access)
Identification of potential soil processes contributing to the net emissions of nitrous oxide (N2O) was achieved by sampling air during an intensive field campaign in the Dischma valley followed by laboratory analysis using a recently developed quantum cascade laser absorption spectrometer (QCLAS). The instrument has been shown to reliably distinguish isotopomers of N2O. This study was only possible due to a strong collaboration with EMPA (Joachim Mohn).
click here for further reading (abstract)
click here for further reading (abstract)
We compared different measurement techniques to quantify greenhouse gas emissions from the snowpack. Approaches included the eddy covariance technique, manual and automatic GHG concentrations as well as radon measurements as an inert tracer to accurately determine the diffusion coefficient of the snowpack. This study was only made possible with the help of a very motivated M.Sc. student (Christine Steinlin).
click here for further reading (open access)
Identification of potential soil processes contributing to the net emissions of nitrous oxide (N2O) was achieved by sampling air during an intensive field campaign in the Dischma valley followed by laboratory analysis using a recently developed quantum cascade laser absorption spectrometer (QCLAS). The instrument has been shown to reliably distinguish isotopomers of N2O. This study was only possible due to a strong collaboration with EMPA (Joachim Mohn).
click here for further reading (abstract)
The charcoal trap: miombo forests and the energy needs for people (2010)
Within the CarboAfrica project we instrumented an existing scaffold tower with eddy covariance equipment to investigate the differences in net exchange of CO2 and H2O of a protected miombo woodland and a degraded miombo woodland (2007 - 2009). Woodland degradation was caused by tree removal for charcoal production.
The study was strongly supported by the Zambian Meteorology Department (M. Mukelabai and his team).
click here for further reading (open access)
The study was strongly supported by the Zambian Meteorology Department (M. Mukelabai and his team).
click here for further reading (open access)
Carbon (CO2) and water (H2O) fluxes from African ecosystems - a CARBOAFRICA synthesis activity (2007/2008)
We studied ecosystem carbon and water fluxes across a network of eddy covariance towers distributed across the African continent. Ecosystem monitoring sites included were located in Mali, Niger, Sudan, Congo Brazzaville, Zambia, Botswana and South Africa covering typical land use types such as natural savannas, maize and Eucalyptus plantations as well as tropical grasslands and woodlands.
Our research revealed mean annual precipitation as a crucial variable driving photosynthesis across vegetation types. High values of vapour pressure deficit lead to strong decreases in canopy conductance and thereby photosynthesis at the ecosystem scale.
click here for further reading (open access)
Our research revealed mean annual precipitation as a crucial variable driving photosynthesis across vegetation types. High values of vapour pressure deficit lead to strong decreases in canopy conductance and thereby photosynthesis at the ecosystem scale.
click here for further reading (open access)
Soil respiration variability in miombo woodlands (2008/2009)
An additional interest of the research carried out in Western Zambia focused on the temporal and spatial variation of soil respiration. Therefore, we established clustered soil respiration measurements in four 2500 m2 plots located along a moisture gradient. Locations for soil respiration measurements were chosen a priori according to different classifications of ground cover.
click here for further reading (open access)
click here for further reading (open access)
Studying the effects of drainage on ecosystem greenhouse gas fluxes (CO2 & CH4) in Siberia (2004/2005)
Net ecosystem carbon fluxes were observed over a typical tussock tundra ecosystem in Siberia for three consecutive years (2002-2004). In 2004 the site was drained via a drainage channel surrounding the flux monitoring station to simulate one potential outcome of global warming, e.g. drainage of common wetland due to melting of regularly occurring ice wedges. We continued the measurements for an additional year to estimate the net changes in CO2 and CH4 fluxes from the ecosystem.
click here for further reading (abstract)
click here for further reading (abstract)