CLAND Internship Program

Meet the young scientists who have joined the CLAND interns team!

2019 CLAND Interns

	Mr. Aghiles BEN SIDER Aghiles did an internship at EGCE (Evolution Genomes Comportement Ecologie) and is interested in developing and setting up a network of sensors to collect climate measurements as close as possible to what insects will experience. The first step was to define the variables of interest, and then the different types of sensors available and their characteristics. The temperature, relative humidity, soil humidity and wind speed were taken into account. Then, he compared the different models of sensors available in order to choose the most suitable for the project, that is to say minimize costs, better reliability and accuracy of measurement and use adapted to the external environment for insects. Aghiles is now building three-dimensional printer models to host each sensor and its associated microcontroller. Acquired data will be sent using radio frequency to a gateway sending the data to a server hosting a storage and visualization application. This work is part of a scientific program aimed at better characterizing the dynamics of insect pests and proposing predictive models to reduce crop losses and thus contribute to food security in the context of climate change.
	Mr. Florent LELENDA KEBALO There is an increasing use of digestates as organic fertilisers in agriculture but they are sensitive to ammonia volatilisation. The latter has consequences on the environment, agriculture and human health: its control requires better knowledge regarding the underlying factors as well as their integration into modelling. The ability of the Volt’Air model to predict ammonia volatilisation after field application of digestates was assessed by using experimental data mainly collected in the field but also under controlled conditions, as part of two recent projects, MetaMetha and EVAPRO. Study showed a correlation between ammonia volatilisation rate and digestate characteristics, dry matter content and pH, as well as meteorological variables such as rain, temperature and wind speed over two days. The results revealed that ammonia volatilisation is overestimated by Volt’ Air after digestate spreading in both the field and under controlled conditions. Some explanations are suggested: the datasets do not allow to validate that the infiltration is adequately modeled, so this point requires a more in-depth study; on the other hand, it is clear that the effect on volatilisation decrease due to the presence of plant cover is not taken into account. Furthermore, the results highlighted the propensity of Volt' Air to properly simulate the start of ammonia volatilisation subsequent to liquid digestate application. However the volatilisation extends beyond what is measured. It is likely that different processes consuming ammoniacal nitrogen, such as nitrification, equilibria (that decrease ammonia availability) and adsorption are either not or not well modeled. The good adequacy at the start of the volatilisation period, as well as the Volt’Air model's ability to integrate new effects and / or modules is a promising sign of its potential to make a better prediction after been improved.
	Ms. Ruizhen WANG My internship is focused on the construction of a model of animal production at the regional-landscape scale starting from livestock diet, in terms of quantity and quality. The model will be the embedded in an existing model of nitrogen fluxes and agricultural production (crops and livestock) at the regional scale. At a qualitative level, the internship will be focused also on the bibliographic research of the impacts of diet composition on animal welfare and production quality (according to both consumer preferences and nutritional criteria). Starting from this information some scenarios will be developed for simulating the impact of different diets on a set of indicators at the regional scale, such as animal production, feed-food competition, feed import needs, methane emissions from ruminant enteric fermentation, and (qualitatively) on animal welfare and milk and meat quality.

2018 CLAND Interns

	Ms. Meriam ARFAOUI Meriam's internship took place from March to August 2019 in partnership between the Systematic Ecology & Evolution (ESE) laboratory and the International Center for Research on Environment and Development (CIRED), under the supervision of Améline Vallet and Thierry Brunelle. The main objective of the internship was to analyze the dynamics of land use change in the El Marino watershed between 1976 and 2019 and to determine the drivers of these changes. The first part of the internship consisted of a literature review, in order to identify the potential drivers at work in the area. The most relevant drivers were mapped: slope, altitude, accessibility to the land, accessibility to markets, distance to water resources and soil quality, population density and finally, the proximity and zoning of protected natural areas. Then the association between these different drivers and changes in land use were analyzed using descriptive statistics (Student's test). Agricultural colonization, like urbanization, occurred mainly in accessible, low-lying, low-slope areas. These areas saw their population increase over the period. In contrast, reforestation is mainly observed in inaccessible areas, and where the population has declined. Agricultural colonization and deforestation are less important within the protected natural area.
	Mr. Kofi KONADU-BRITWUM The objective of the internship is to empirically study, via an econometric analysis, the determinants of the payment of international aid for the mitigation of climate change from developed countries to developing countries. The aim is to adopt a bilateral (donor-recipient country) and sectoral approach to aid by differentiating the “land-based” sectors (the agricultural, forestry and fishery sectors) from other sectors. The potential determinants of this aid are the mitigation needs in the different sectors of donor and recipient countries, such as sectoral emission levels, but also strategic factors, such as the commercial interests of donor countries (increasing market shares export or import at lower cost). Empirical results show that bilateral trade plays a major role in the likelihood that a country will receive mitigation aid and also in the amount of aid it receives. The results also show that more aid is allocated to sectors where there is more trade flow. Finally, this econometric analysis highlights the result that donor and recipient emissions play no significant role in determining the sectoral allocation of mitigation aid when bilateral trade is taken into account.
	Mr. Issam-Ali MOINDJIE The objective of my internship was to analyze the interactions between ecosystem services (ES) in France using exploratory spatial data analysis tools. Then using spatial modeling, determine the factors (land use and biophysical variables) responsible for this interdependence. The last part aimed to understand how land uses are influenced by economic (land prices, etc.), demographic (population density) variables. Following my internship, I was able to continue on a 3 months fixed-term contract within the UMR Economie Publique, where I was able to initiate a research paper from my internship report. We have generalized the approach to other ES and we have simulated the impact of land use change scenarios on ES. The preliminary results of this work in progress show that (1) land use and biophysical variables are good predictors of most ES (2) taking spatial autocorrelation into account improves the quality of the predictions of our models (3) the forest is the most favorable land use for the provision of regulatory ES compared to other land uses (agriculture, pasture, urban and others). Finally, we simulate two scenarios of land use change and show how the increase in forest area would favor the provision of multiple regulatory ES.
	Mr. Hunter SMITH Exogenous organic matter (EOM) amendments are used by agricultural producers to improve agronomic yields and to increase the fertility of the soil. Farmers in the Plaine de Versailles et Plateau de Alluets (PVPA) use a variety of organic amendments including: green compost, sewage sludge, cattle slurry, pig slurry, cattle manure, horse manure, anaerobic digestate, and others (Moinard 2018). The addition of these organic fertilizers has environmental implications, such as the increase of carbon storage in agricultural soils, leaching of nitrates, and emission of greenhouse gases. Due to these implications, it is useful to monitor EOM fertilization practices. Remote monitoring of these practices via satellite imagery offers the potential to acquire this data more efficiently. The Sentinel-2 satellite series is the instrument of choice for this study since it is freely available and offers frequent revisit intervals. Using the Sentinel2 series, the spectral changes that occur following EOM fertilization were documented. The most significantly impacted spectral regions were used to construct three Exogenous Organic Matter Indices (EOMI), which were evaluated based on separability. The EOMI exhibiting the most separability was used to create a time series and map of predicted EOM amendments. The overall results show that the created EOMI can be used to distinguish between bare soil and the EOM fertilization events.