Negative spill-over effects of agricultural practices on plant species conservation in nature reserves

Nature reserves are one of the most important instruments for biodiversity protection and to limit regional species extinctions. However, these functions can only be fulfilled if environmental influences from the surroundings, such as agrochemical inputs do not negatively affect the protected habitats.Here, we compare the effectiveness of conservation measures under the influence of yield-optimized cultivation in Germany using vegetation analyses of transects from the edge to the core of protected areas at 21 sites. By analysing nitrogen and phosphate deposition, herbicide number and concentration in soil and vegetation as well as Ellenberg indicator values of plant communities as a function of the distance from the field margin at each site, we aimed at assessing the impact of these stressors in different environmental settings.The results indicate strong chemical edge effects and negative influences for plant communities resulting from increased nutrient input and amounts of herbicide residues closer to the edge of the agricultural fields. Concordantly, the number of endangered plants species decreased with increasing proximity to the field edge. The strong influence of yield-optimized cultivation on the edges of nature reserves which decrease with distance show that nature protection needs effective buffer zones surrounding conservation areas, especially if nature reserves are only small and narrow. To prevent spill-over effects the application of fertilizer and herbicides on croplands adjacent to conservation areas has to be reduced. This could be achieved most effectively through organic farming and targeted agricultural subsidies

Beetles “in red”: are the endangered flat bark beetles Cucujus cinnaberinus

Two native species of the genus Cucujus show a wide geographic distribution in Europe, Cucujus cinnaberinus (Scopoli, 1763) and C. haematodes Erichson, 1845. Although data on the distribution and ecology of these rare and endangered species are increasing, there are few reports on their biology and behaviour, and some aspects of their feeding ecology remain problematic. Our aim was to study, for the first time, the cuticular chemical profiles of these two beetles to (i) investigate the presence of chemicals potentially involved in defence by pathogens and (ii) lay the foundation for understanding the role of their bright red colour. The analysis of the cuticular profile was performed in-vivo by solid phase microextraction coupled with gas chromatography-mass spectrometry. In the cuticular profiles of the two species we identified 24 compounds belonging to different classes of molecules, i.e. hydrocarbons, aldehydes, esters, n-alkyl morpholines, and a high number of organic acids. Qualitative differences in terms of both signal intensity and detected compounds were found between the two species. As reported in other insects, the remarkable array of avoidance substances suggests a strict relationship with the bright red colour of the adults, which probably acts as an aposematic or warning signal. European Cucujus species are probably well protected against enemies because some identified chemicals, particularly fatty acids, are related to an anti-predatory strategy to fight off predators that use their sense of smell to locate their prey. Other substances found on the cuticular layer of these beetles are probably involved in an antimicrobial and antifungal function, as demonstrated in other insects living in habitats that host many pathogens