Insight into how environmental change determines the production and distribution of cyanobacterial toxins is necessary for risk assessment. Management guidelines currently focus on hepatotoxins (microcystins). Increasing attention is given to other classes, such as neurotoxins (e.g., anatoxin-a) and cytotoxins (e.g., cylindrospermopsin) due to their potency. Most studies examine the relationship between individual toxin variants and environmental factors, such as nutrients, temperature and light. In summer 2015, we collected samples across Europe to investigate the effect of nutrient and temperature gradients on the variability of toxin production at a continental scale. Direct and indirect effects of temperature were the main drivers of the spatial distribution in the toxins produced by the cyanobacterial community, the toxin concentrations and toxin quota. Generalized linear models showed that a Toxin Diversity Index (TDI) increased with latitude, while it decreased with water stability. Increases in TDI were explained through a significant increase in toxin variants such as MC-YR, anatoxin and cylindrospermopsin, accompanied by a decreasing presence of MC-LR. While global warming continues, the direct and indirect effects of increased lake temperatures will drive changes in the distribution of cyanobacterial toxins in Europe, potentially promoting selection of a few highly toxic species or strains.

The Republic of Croatia is spread in geographical and climatic conditions that support a great diversity of habitats and associated plant taxa, many of which can be used for food or medicine. However, urbanization, loss of natural habitats, as well as changes in people’s dependence on the natural resources from the surrounding environment may lead to the loss of valuable knowledge about the use of plants and mushrooms. With the aim of studying and preserving this knowledge in the continental north-western part of Croatia, an ethnobotanical survey was undertaken at the two study areas—Valpovo and Đurđevac, which included a total of 17 settlements. A total of 103 informants, 65% female and 35% male, aged between 22 and 83 years, participated in an interview using pre-planned questionnaires. The informants reported 131 plants belonging to 55 families and 17 mushroom taxa. The largest number of plants belonged to the families of Rosaceae, Lamiaceae, Asteraceae, and Apiaceae. In both areas, the informants cultivate and also gather wild plants, but these practices are better preserved in the area of Đurđevac where 109 taxa from 47 families were recorded. In addition to cultivated and gathered plants, informants from the Valpovo area also reported the use of purchased plants. Plants and mushrooms are mostly used as food (21 plant taxa and 17 mushrooms), but plants also serve as medicine (68 taxa), as both food and medicine (35 taxa), feed for cattle (11 taxa), repellent (four taxa), and/or space freshener (two taxa). The most frequently used wild plants are Chamomilla recutita, Mentha x piperita, and Urtica dioica, while Boletus edulis, Agaricus campestris, and Macrolepiota procera are the most often used mushrooms. The results indicate that the local people in the studied north-western part of Croatia still nurture the practice of cultivating and gathering plants and that herbal remedies are considerably important among the informants. The study should be further extended to broaden and preserve valuable ethnobotanical knowledge and encourage the protection of culturally important plants of the studied area.