In Trends in Ecology & Evolution, an international team of scientists, including Leiden biologist Koos Biesmeijer, have listed the consequences of global changes on pollination. Many varieties of plants are pollinated by insects, and if that is not done adequately, we humans will have a problem – because we eat those plants, for one thing.
Biesmeijer and his colleagues studied five major changes: global warming, changing landscapes, agricultural intensification, invasive species and the spread of pathogens. It is difficult enough to assess just one of those changes, but in reality, both plants and insects are exposed to all of them at the same time. Are the effects of those changes reinforcing each other or are they suppressing each other? A cautious conclusion: they are doing both, but mainly reinforcing each other. Furthermore, it is possible that a policy measure which is supposed to combat one of the changes may not be effective if nothing is done about the other changes.