Vegetation impacts on ecosystem functioning are mediated by mycorrhizas, plant–fungal associations formed by most plant species. Ecosystems dominated by distinct mycorrhizal types differ strongly in their biogeochemistry. Quantitative analyses of mycorrhizal impacts on ecosystem functioning are hindered by the scarcity of information on mycorrhizal distributions. Here we present global, high-resolution maps of vegetation biomass distribution by dominant mycorrhizal associations. Arbuscular, ectomycorrhizal, and ericoid mycorrhizal vegetation store, respectively, 241 ± 15, 100 ± 17, and 7 ± 1.8 GT carbon in aboveground biomass, whereas non-mycorrhizal vegetation stores 29 ± 5.5 GT carbon. Soil carbon stocks in both topsoil and subsoil are positively related to the community-level biomass fraction of ectomycorrhizal plants, though the strength of this relationship varies across biomes. We show that human-induced transformations of Earth’s ecosystems have reduced ectomycorrhizal vegetation, with potential ramifications to terrestrial carbon stocks. Our work provides a benchmark for spatially explicit and globally quantitative assessments of mycorrhizal impacts on ecosystem functioning and biogeochemical cycling.

* Author to whom correspondence should be addressed Abstract. The influence of the nitro group on the aromatic n-system of pyrene has been studied by comparing the spectroscopic and photochemical properties of the three mononitropyrenes. Whereas the UV and mass spectra of 1-and 4-nitropyrene show an interaction normal for nitro-aromatic compounds, this is not observed for 2-nitropyrene. The lack of interaction is reflected in a UV spectrum very similar to that of pyrene and a mass spectrum with a very low abundance of M-NO. The photochemical behaviour of the three compounds is governed by the degree of interaction. 1 -Nitropyrene shows the nitro-nitrite rearrangement leading to 1-hydroxypyrene (88%) and l-hydroxy--2-nitropyrene (7%). The photoproducts of 4-nitropyrene are pyrene (9%) and unstable products which react with the solvent. 2-Nitropyrene is very stable under photochemical conditions due to lack of interaction. Similarly, the sterically hindered 1-methyl-2-nitropyrene is also very stable towards light. The photochemical nitro-nitrite rearrangement observed for nitro-aromatic compounds was found to be governed by electronic effects.

The global lion (Panthera leo) population decline is partly a result of retaliatory killing in response to livestock depredation. Nairobi National Park (NNP) is a small protected area in Kenya surrounded by a human-dominated landscape. Communities around the park use flashlights to deter lions from their livestock bomas. We investigated the response by lions to the installation of a LED flashlight technique during 2007–2016.We interviewed 80 owners of livestock bomas with flashlights (n = 43) and without (n = 37) flashlights in the surroundings of NNP and verified reported attacks on bomas against predation data over10 years. The frequency of attacks on bomas equipped with flashlights was significantly lower compared to bomas without flashlights. We also found that after flashlight installation at livestock bomas, lion attacks took place further away from the park edge, towards areas where bomas without flashlights were still present. With increased numbers of flashlight installations at bomas in recent years, we further noticed a shift from nocturnal to more diurnal predation incidences. Our study shows that the LED flashlight technique is effective in reducing nocturnal livestock predation at bomas by lions. Long term studies on the effects as well as expansion of this technique into other communities around NNP are recommended.

Dutch water boards have a well-established program for monitoring pesticide contamination of surface waters. These monitoring data have been processed into a graphic format accessible online and designed to provide insight into pesticide presence in Dutch surface waters and trends over time: the Pesticides Atlas (http://www.pesticidesatlas.nl). With this tool one can easily get maps of where a pesticide is being measured and where it might possibly constitute an environmental problem over the years. Presently, results of the periods 1997/1998 until 2005/2006 are available at the level of individual active ingredients. At a national level, the percentage of pesticides concentrations that exceed the maximum tolerable risk has declined 30% to 38% over the years 2003/2004 compared with 1997/1998. This means that surface water quality in the Netherlands has improved with respect to pesticides, however there are still many locations at which the measured concentrations exceed the environmental quality standards. The results on linking land use to pesticides concentrations were shown to assist in optimization of monitoring programs. By developing the present Internet tool, many new opportunities for environmental risk assessment and risk management were identified, e.g. optimization of monitoring strategies and communication to policymakers.

Humans alter the environment at unprecedented rates through habitat destruction, nutrient pollution and the application of agrochemicals. this has recently been proposed to act as a potentially significant driver of pathogen-carrying mosquito species (disease vectors) that pose a health risk to humans and livestock. Here, we use a unique set of locations along a large geographical gradient to show that landscapes disturbed by a variety of anthropogenic stressors are consistently associated with vector-dominated mosquito communities for a wide range of human and livestock infections. this strongly suggests that human alterations to the environment promote the presence and abundance of disease vectors across large spatial extents. As such, it warrants further studies aimed at unravelling mechanisms underlying vector prevalence in mosquito communities, and opens up new opportunities for preventative action and predictive modelling of vector borne disease risks in relation to degradation of natural ecosystems. Habitat destruction, chemical pollution, and climate change are ongoing human disturbances 1 that have resulted in worldwide shifts in insect communities 2. While most insects are declining 2 , many mosquito species are thriving 3,4. Recent laboratory and mesocosm studies provided important clues suggesting that anthropogenic disturbances can promote population growth of several pathogen-transmitting mosquito species, or disease vectors 5-8 , and potentially mediate interactions between mosquito species 9 , their hosts 10 , their pathogens 11,12 , and their predators 13. This hints that, if these patterns hold true for natural systems, the way humans influence their local environment presents a critical driver of disease risk 14. Field data in natural systems has largely focused on the influence of climate-temperature and precipitationin driving the abundance of single species or vector groups 15-19. These studies constitute an important foundation for mechanistic models and risk maps to anticipate disease outbreaks such as malaria, chikungunya and Zika 20,21. Mosquito abundance and composition can also vary across locations and land use types 22-27. However, many comparisons rely on opportunistic sampling across different time periods or targeted sampling at locations to maximize collections 28 , but not always 29,30. Here, we use a paired sampling design to show that human activities beyond climate are strongly associated with high abundances of known vectors across large spatial extents. Kruger National Park (KNP) is the largest natural reserve in South Africa and is fringed with rural and urbanizing areas. The mosaic of waterbodies along its 400 km north-south gradient provides a unique opportunity to assess the effect of human disturbances on mosquito population dynamics and community composition. We simultaneously sampled representative waterbodies within paired sites inside and outside the national park in four regions (Fig. 1); the paired sites have similar geomorphology and climatic conditions (Table S...