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

How soil microbial composition impacts structure and composition of the aboveground plant and animal communities?

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

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,…

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

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

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

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

How presence, abundance and enzymatic activities of AM and EM fungi differently affect soil carbon sequestration processes?

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

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…

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…

Kunst en vrije tijd, Kunst en vrije tijd

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 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.

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.

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.

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

De

What are the global relationships between environmental conditions and abundance of distinct types of mycorrhizal fungi in soil and plant roots?

‘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…

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

1. To what extent do metallic NPs added to soil extractions change the activity, abundance, or community composition of microbes? 2. How do the effects of metallic NPs on soil microbes differ from the effects of the ions shedding from corresponding NPs?

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

How the global distribution of vegetation stands dominated by arbuscular and ectomycorrhizal plants relate to principle aspects of belowground carbon accumulation processes?

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

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

Promotie

This thesis aimed to investigate the impact of exposure dynamics, relative contributions of ENPs(particle) and ENPs(ion), and dosing regimens on the toxicity of ENPs varying in different physico-chemical properties, on the composition and functioning of soil microbial communities.

The soil-dwelling, filamentous bacteria of the genus Streptomyces are renowned for their production of useful secondary metabolites including antibiotics. The work described in this thesis provides new insights on the role and regulation of antibiotic production and resistance in these bacteria.

Streptomyces are bacteria abundant in soil that participate in diverse and complex interactions. These bacteria are the main producers of the antibiotics we currently use in the clinic.

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.

The filamentous bacteria Streptomyces are widespread inhabitants of terrestrial soils.

Elk onderdeel van de kringloop op een melkveebedrijf heeft een specifieke bacterie- en schimmelsamenstelling. Dat ontdekten de Leidse postdoc onderzoeker Sofia Gomes en haar begeleiders Nadia Soudzilovskaia en Peter van Bodegom in samenwerking met het Louis Bolk instituut en Naturalis Biodiversity Centre.…

Promotie

Promotie

Promotores: Prof.dr.G.R. de Snoo and Dr. R. Heijungs

Gisteren verscheen er een artikel in Biznews over het watertekort in California. David Zetland, universitair docent aan het Leiden University College The Hague, gaf zijn mening over dit probleem.

Projecten van de afdeling Environmental Biology