Soil is a home for an unbelievable diversity and abundance of microbial life that is essential for supporting life on our planet.

In this thesis I examine how soil biotic and abiotic characteristics change and interact throughout the course of afforestation and how they subsequently impact tree performance.

In this thesis, the role of plant-mediated soil legacy effects in shaping aboveground plant-insect interactions was investigated.

Soil biodiversity is of great importance for the maintenance of multifunctionality in terrestrial ecosystems.

Organic amendments applied to agricultural fields can partially offset our carbon emissions to the atmosphere and improve the resilience of agriculture to the effects of climate change. Driving these benefits, however, are complex and poorly understood interactions between organic amendment properties,…

Kunst en vrije tijd, Kunst en vrije tijd

The soil ecosystem consists of the largest reservoir of biodiversity on Earth.

The main research question of this thesis was: Can nitrogen cycling on dairy farms on peat soil in the Dutch Green Heart area be improved by adapting management to the nitrogen supply from soil and by using other grassland species and crops without affecting milk production?

Promotor: J.A. van Veen, Co-promotor: E.E. Kuramae

By growing in a soil plants change the biotic and abiotic properties of the soil in which they grow.

Promotores: Prof.dr. H. van Veen & Prof.dr. W. de Boer (Wageningen University)

Plants and soils from natural ecosystems harbor great diversity of soil microorganisms, which could potentially contribute to the sustainability of horticulture. The knowledge about using wild plant species and soil from natural ecosystem to improve the crop health will advance the application of ecological…

Promotores: J.A.van Veen, P.L.G.Klinkhamer. Co-promotor: E.E.Kuramae

In this thesis, I focused on studying the above- and belowground interactions of J. vulgaris from a plant-soil feedback (hereafter, PSF) perspective. I investigated the temporal variation of negative PSF and examined the effects of root-associated bacteria on plant performance and aboveground herbiv…

In this PhD study, I aim to deepen our understanding of the influence of major mycorrhizal types, namely arbuscular mycorrhizae (AM) and ectomycorrhizae (EM), on the global soil carbon cycle and their potential distribution changes under future environmental shifts.

The skin is our natural barrier and lipids are a key part of this barrier. In the outer skin layer, the stratum corneum (SC), lipids form a densely organized structure dependent on the composition of these lipids.

The use of N fertilizers has increased worldwide in the past century. While this increased input of N has increased food productivity, it has also contributed to decreases in biodiversity, soil quality and environmental health, including increases in greenhouse gas emissions.

Promotor: Prof.dr. J.A. Bouwstra, Co-promotor: A. El Ghalbzouri

Vinasse is a major by-product generated by the sugarcane biofuel industry. It is a source of microbes, nutrients and organic matter and often it is recycled as fertilizer.

Promotor: J.A. Bouwstra Co-promotor: A. El Ghalbzouri

The stratum corneum is the outermost skin layer and consists of dead cells embedded in a lipid matrix.

The research described in this thesis shows that hypercholesterolemia, a well-established risk factor for atherosclerosis, can impact skin lipid pool and barrier function already at young age. In the field of atherosclerosis, we showed that the small peptide Lyp-1 can be used as a targeting molecule…

The lipids in the uppermost layer of the skin, the stratum corneum (SC), play an important role in the skin barrier function. The three main SC lipid classes are ceramides (CER), cholesterol and free fatty acids.

Striga hermonthica, commonly known as witchweed, infests major cereal crops in Sub-Saharan Africa causing severe yield losses and threatening the livelihood of millions of resource poor farmers.

Barrier function is the natural role of the skin. The lipid matrix present in the outermost layer of the skin, the stratum corneum is important for this function.

Promotor: J. A. Bouwstra

De

Promotors: Prof.dr. G.R. de Snoo, Prof.dr. G.A. Persoon, Prof.dr.ir. H.H. de Iongh

uman skin equivalents (HSEs) are in vitro 3D-skin models that mimic many aspects of the native human skin (NHS) and can be a valuable tool.

Agglomeraties presteren minder goed dan steden met één bestuur. Dat blijkt uit onderzoek van Ton van Raan, professor kwantitatief wetenschapsonderzoek.

‘Wat ik aantrekkelijk vind aan het bodemleven, is dat het stuurbaar is,’ verklapt onderzoeker Martijn Bezemer van het Instituut Biologie Leiden (IBL). ‘Dat je kan zeggen: wat wil je? En dat ik de bodem dan kan omtoveren tot iets wat jij nodig hebt. Ten minste, dat dachten we.’

Jan Willem Erisman wilde als kind al dingen beter maken. Als hoogleraar Duurzaamheid en Milieu is hij daarom ook buiten de universiteit actief. Hij staat bekend als de stikstofprofessor: in de media, maar ookin de Tweede Kamer legt hij het stikstofprobleem uit. Recent trad hij toe tot de Europese Soil…

In vergelijking met andere landen zijn de barrières in Nederland om tot inzet van kroongetuigen te komen hoog. Dat concluderen Leidse rechtsgeleerden in het vandaag verschenen onderzoeksrapport ‘Collaboration with Justice in the Netherlands, Germany, Italy and Canada’. Het rapport geeft een unieke inkijk…

Het Liliane Fonds en het Afrika-Studiecentrum van de Universiteit Leiden hebben de Impact Challenge Award 2019 gewonnen voor het project 'Breaking down barriers to exclusion. Building capacity for lobby and advocacy for children with disabilities'. De Impact Challenge Award is een nationale onderscheiding…

Promotor: M. Danhof, Co-promotor: E.C.M. de Lange

Hans Ulrich Scherer is hoogleraar reumatologie, in het bijzonder translationele reumatologie. Met zijn leerstoel wil hij bruggen slaan tussen onderzoek en kliniek, maar ook tussen afdelingen en organisaties in binnen- en buitenland. Aanstaande vrijdag spreekt Scherer zijn oratie uit. 'Om vooruitgang…

Promotor: Prof.dr. W.J.G.M. Peijnenburg

The rapidly increasing commercial application of metallic nanoparticles within products will inevitably enhance the amount of NPs being released into soil.

Although plant domestication has significantly altered crop genetics and phenotypes, its effects on the taxonomic and functional diversity of plant-associated microbiomes are not well understood.

Promotor: E.F. Smets, Co-promotor: J. Geml

Microbiome composition of the spermosphere and the rhizosphere of wild and modern bean accessions grown in an agricultural and a native soil from Colombia was characterized by metagenomics and cultivation-dependent approaches.

Promotor: E.F. Smets Co-promotor: J. Geml

Kunst en vrije tijd, Kunst en vrije tijd

Muziek van een composteerbare cello, foto’s en geurtjes van schimmels en een geweven wandkleed. Het zijn een aantal voorbeelden uit Super Organism, het kunstproject van Suzette Bousema waarin je de ondergrondse schimmelwereld met al je zintuigen kunt beleven. Leids milieuwetenschapper Nadia Soudzolovskaia…

Herstel van de natuur op uitgeputte landbouwgrond en in natuurgebieden verloopt moeizaam. ‘Bodemtransplantatie’ kan mogelijk uitkomst bieden. Dat betoogt Martijn Bezemer, hoogleraar Ecologie van Plant-Microbe-Insect interacties. Oratie op 18 december.