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... Show moreIn 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 herbivores. Additionally, I tested the role of PSF in relation to plant population structure and the significance of soil legacy effects in natural conditions. The findings reveal that temporal dynamics in PSF are driven by changes in plant sensitivity and in the soil microbiome. Although bacteria isolated from J. vulgaris roots can negatively affect plant performance, they can also affect aboveground herbivores and other plant species. Consequently, these bacteria may not be suitable for biological control of J. vulgaris. Moreover, I discovered that soil nematodes can mediate plant-plant interactions, but often favoring J. vulgaris. In my field work, I detected soil legacy effects, but seedling recruitment spatial patterns of J. vulgaris were not soil-mediated. The insights gained from studying PSF and above- and belowground interactions have the potential to reshape traditional approaches employed in controlling invasive plants. This thesis emphasizes the importance of transitioning PSF experiments from indoor to outdoor settings considering various influencing factors simultaneously. Show less
In this thesis, the role of plant-mediated soil legacy effects in shaping aboveground plant-insect interactions was investigated. This work shows that soil legacy effects on plant-insect... Show moreIn this thesis, the role of plant-mediated soil legacy effects in shaping aboveground plant-insect interactions was investigated. This work shows that soil legacy effects on plant-insect interactions are a common phenomenon in nature, both in individual responding plant species and their associated herbivores, as well as in responding plant communities and associated herbivores. This thesis elucidates two potential mechanisms how soils can influence aboveground insects. First, soils can alter the way plants defend them selves in terms of secondary chemistry and phytohormonal defenses. Second, soils can also directly impact aboveground insects by changing the insect microbiome. This work shows that a large part of the insect microbiome is taken up directly from the soil microbiome, and leads to exciting new research directions on the longterm and evolutionary implications of soils for aboveground insects. Show less
