Combined experimental drought and nitrogen loading: the role of species-dependent leaf level control of carbon and water exchange in a temperate grassland

Nitrogen (N) loading and extreme drought strongly alter biomass production, species composition and carbon and water fluxes of temperate grasslands. Such changes at the community level are often attributed to species- and functional group-specific responses in phenology and/or physiology. In a multifactorial field experiment, we studied the responses of three abundant grassland species (forb Centaurea jacea, grasses Arrhenatherum elatius and Dactylis glomerata) to N loading and extreme drought, focusing on responses of carbon and water relations at the leaf level. We analysed (1) changes in bulk leaf N (uptake efficiency of additional N), (2) adaptation of plant water status (leaf water potential) and (3) impact on leaf carbon and water fluxes. We observed more efficient N utilization in the two grasses compared to C. jacea. Naturally occurring summer drought significantly impacted the plant water status of all species, while extreme drought treatment only further affected water status during and after summer drought. C. jacea was able to maintain much lower leaf water potentials compared to the grasses during drought. Despite these clear species-specific responses to N loading and drought, the species were able to maintain homeostasis of leaf carbon and water fluxes. Thus, strong declines in the (community) carbon sequestration observed at this site during the (natural) summer drought were not related to leaf physiological responses in assimilation, but were driven by phenological adaptions of the species community: the drought-sensitive grasses, even though exhibiting higher N uptake efficiency, responded with a shortened life cycle to severe summer drought.

Perception, Attitudes, and Experiences Regarding Mental Health Problems and Web Based Mental Health Information Amongst Young People with and without Migration Background in Germany. A Qualitative Study

Mental illnesses in adolescence and young adulthood are steadily increasing. Thus, mental disorders represent an individual and societal challenge and an enormous health economic burden, creating an urgent need for research and action. Mental health problems are omnipresent in the life of young people and the internet is the first resource, which helps them to understand their situation. Young people with migration background often have more difficulties accessing health care services. Digital technologies offer an ideal opportunity for a low-threshold platform that addresses the needs of young people. The current project "GeKo:mental" aims to design a multilingual website for Cologne-based adolescents and young adults that will enable them to obtain comprehensive information about mental illness and health, treatment options and first contact points. To design this website, this study aims to find out what kind of health information is needed and how it should best be presented. Nine focus group discussions with adolescents and young adults with and without migration background (N = 68) were conducted; the focus group discussions took place at schools, in an association for social youth work and in an cultural association, which is linked to a mosque in Cologne, Germany. A qualitative content analysis was conducted on the gathered material. The participants reported concrete challenges and needs. The results will form the basis for the development and design of a website.