Excess atmospheric ammonia (NH3) leads to deleterious effects on biodiversity, ecosystems, air quality and health, and it is therefore essential to monitor its budget and temporal evolution.... Show moreExcess atmospheric ammonia (NH3) leads to deleterious effects on biodiversity, ecosystems, air quality and health, and it is therefore essential to monitor its budget and temporal evolution. Hyperspectral infrared satellite sounders provide daily NH3 observations at global scale for over a decade. Here we use the version 3 of the Infrared Atmospheric Sounding Interferometer (IASI) NH3 dataset to derive global, regional and national trends from 2008 to 2018. We find a worldwide increase of 12.8 ± 1.3 % over this 11-year period, driven by large increases in east Asia (5.80 ± 0.61 % increase per year), western and central Africa (2.58 ± 0.23 %.yr−1), North America (2.40 ± 0.45 %.yr−1) and western and southern Europe (1.90 ± 0.43 %.yr−1). These are also seen in the Indo-Gangetic Plain, while the southwestern part of India exhibits decreasing trends. Reported national trends are analyzed in the light of changing anthropogenic and pyrogenic NH3 emissions, meteorological conditions and the impact of sulfur and nitrogen oxides emissions, which alter the atmospheric lifetime of NH3. We end with a short case study dedicated to the Netherlands and the "Dutch Nitrogen crisis" of 2019. Show less
As a contribution to the changing legislation and evolving societal attitudes concerning environmental issues, this project aims to enhance and manipulate the plants’ own natural defense mechanisms... Show moreAs a contribution to the changing legislation and evolving societal attitudes concerning environmental issues, this project aims to enhance and manipulate the plants’ own natural defense mechanisms against western flower thrips (WFT). Accordingly, an approach based on treatments of seeds (Solanum lycopersicum) and cuttings (Chrysanthemum morifolium) was undertaken to protect plants from their early critical young stage onwards. Known putative defense secondary metabolites were exogenously applied whereas, external application of plant hormones was explored as a means to trigger innate defense responses. Natural Deep Eutectic Solvents (NADES), as environmentally benign solvents, significantly improved the solubilizing properties of poorly-soluble insecticidal metabolites but did not enhance resistance against WFT. On the contrary, seed treatments with the ubiquitous plant hormone jasmonic acid (JA) appeared to induce cultivar dependent defenses as it only reduced silver damage in tomato cultivar Carousel. Sulfuric acid scarification, prior to JA seed incubation, significantly augmented the embryonic receptivity of a non-responsive cultivar thus, highlighting the importance of seed coat permeability. Moreover, we demonstrate that water dipping of indole-3-butyric acid (IBA)-coated chrysanthemum cuttings repeatedly reduced herbivory, both by thrips as well as by leaf miner. Show less
