Amandine Germon

• PhD
• Researcher at French Agricultural Research Centre for International Development

While the number of studies dealing with fine root dynamics in deep soils layers (depth > 1 m) has increased sharply recently, the phenology, the morphology, the anatomy and the role of deep fine roots are still poorly known in forest ecosystems. This review summarizes the current knowledge on fine root production, mortality and longevity in deep s...

Background and Aims Fine roots play a major role in the global carbon cycle through respiration, exudation and decomposition processes, but their dynamics are poorly understood. Current estimates of root dynamics have principally been observed in shallow soil horizons (<1 m), and mainly in forest systems. We studied walnut (Juglans regia × nigra L....

Background and aimsFine-root functioning is a major driver of plant growth and strongly influences the global carbon cycle. While fine-root over-yielding has been shown in the upper soil layers of mixed-species forests relative to monospecific stands, the consequences of tree diversity on fine-root growth in very deep soil layers is still unknown....

Despite the strong ecological importance of ectomycorrhizal (ECM) fungi, their vertical distribution remains poorly understood. To our knowledge, ECM structures associated with trees have never been reported in depths below 2 meters. In this study, fine roots and ECM root tips were sampled down to 4-m depth during the digging of two independent pit...

Stomata regulate CO2 and water vapor exchange between leaves and the atmosphere. Stomata are a target for engineering to improve crop intrinsic water use efficiency (iWUE). One example is by expressing genes that lower stomatal density (SD) and reduce stomatal conductance (gsw). However, the quantitative relationship between reduced SD, gsw, and th...

This study examines the impact of integrated farming systems—specifically crop-livestock and crop-livestock-forestry—on the dynamics of fine roots in crops and pastures. Using various setups, including different tree inter-row distances in integrated systems where corn is rotated with palisade grass, the research explores how these systems affect r...

Integrated crop-livestock-forestry (ICLF) systems explore synergistic interactions between soil, plant, and animals, maximizing land-use efficiency and sustainability. However, belowground dynamics under ICLF have not been investigated deeply, particularly the role of incorporating dead root material, a forefront strategy for releasing nutrients an...

Bioenergy production often focuses on the aboveground feedstock production for conversion to fuel and other materials. However, the belowground component is crucial for soil carbon sequestration, greenhouse gas fluxes, and ecosystem function. Roots maximize feedstock production on marginal lands by acquiring soil resources and mediating soil ecosys...

Fertilization is commonly used to increase growth in forest plantations, but it may also affect tree water relations and responses to drought. Here, we measured changes in biomass, transpiration, sapwood-to-leaf area ratio (As:Al) and sap flow driving force (ΔΨ) during the 6-year rotation of tropical plantations of Eucalyptus grandis under controll...

Aims Belowground interactions are still poorly understood in mixed-species forests. We investigated the effects of soil fertility on belowground processes in mixed planted forests. Methods The dynamics and traits of Eucalyptus and Acacia mangium fine roots (diameter < 2 mm) in plantations with 50% of each species were studied in a randomized bloc...

Une meilleure connaissance de la dynamique spatio-temporelle des racines fines et des gaz à effet de serre dans les couches profondes du sol est indispensable pour identifier des pratiques sylvicoles plus durables pour les forêts plantées dans un contexte de changement climatique. Notre étude visait à évaluer les effets des coupes claires et de la...

Extreme climatic events and depletion of phosphorus and potassium reserves threaten the productivity and survival of crops and planted forests. Deep root exploration is crucial for adaptation, as studies in Brazil show Eucalyptus roots reaching up to 17 m. Various methods, including isotopic tracers and modeling, revealed that low-density deep fine...

The major factors driving greenhouse gas exchanges in forest soils (substrate supply, temperature, water content) vary with soil depth. Our study aimed to assess the effects of clear-cutting and drought on the temporal variability of CO2, CH4 and N2O fluxes throughout very deep soil profiles in Brazilian eucalypt plantations conducted in coppice. S...

Background and aims While the role of deep roots in major ecosystem services has been shown for tropical forests, there have been few direct measurements of fine root dynamics at depths of more than 2 m. The factors influencing root phenology remain poorly understood, creating a gap in the knowledge required for predicting the effects of climate ch...

Moniliophthora Pod Rot (MPR) caused by the fungus Moniliophthora roreri (Cif.) Evans et al., is one of the main limiting factors of cocoa production in Latin America. Currently insufficient information on the biology and epidemiology of the pathogen limits the development of efficient management options to control MPR. This research aims to elucida...

Daily rainfall distribution throughout the experimental period. (TIF)

Absolute values of Pearson’s correlation coefficients (r) within selected microclimatic variables for the status change healthy to diseased without sporulation. The larger the font size, the higher the correlation coefficient. (TIF)

Absolute values of Pearson’s correlation coefficients (r) within selected microclimatic variables for the status change diseased without sporulation to sporulation. The larger the font size, the higher the correlation coefficient. (TIF)

Microclimate records dataset. (XLSX)

Pod observations dataset. (XLS)

Meteorological mean values throughout the day (means of 462 days from 8 May, 2012 to 13 August, 2013). (TIF)

Tropical forests strongly influence the concentrations of carbon dioxide (CO2), nitrous oxide (N2O) and methane (CH4) in the atmosphere. Silvicultural practices in planted forests affect the fluxes of greenhouse gases at the soil surface and the major factors driving greenhouse gas production in forest soils (substrate supply, temperature, water co...

Introduction: Much attention has been paid to agroforestry systems these last decades as they combine food production and provide different ecosystem services such as erosion control, biodiversity enhancement, and climate change mitigation. However, the functioning of these systems and the services they provide mainly depends on belowground process...

Introduction Fine root dynamics control plant growth and development and play a major role in the global carbon cycle through the uptake of water and nutrients as well as respiration and decomposition processes. Fine root elongation rates and lifespan are in direct relation with soil water availability and soil temperature likely depending on seaso...

Agroforestry is a land use type where crops and trees are grown together in the same place and at the same time. Agroforestry systems have the advantage of providing multiple products (e.g. wood, fruits) or services (e.g. biodiversity enhancement, erosion control) whilst maintaining agricultural production. If they are known to store carbon into th...

Agroforestry is a land use type where crops and trees are grown together in the same place and at the same time. Agroforestry systems have the advantage of providing multiple products (e.g. wood, fruits) or services (e.g. biodiversity enhancement, erosion control) whilst maintaining agricultural production. If they are known to store carbon into th...