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Where have all the flowers gone? If you seem to be noticing fewer wildflowers decorating the landscape than in years past, do not assume your eyesight is failing – you may be onto something. Though Peter, Paul and Mary blame the young girls for picking them all, Dr. Nancy Dise seems to think otherwise. Her research, conducted with colleagues in the United Kingdom, has identified nitrogen pollution as the most likely culprit behind an alarming disappearance of wildflowers and flowering plants in parts of the United Kingdom. Dise, also a professor at The Open University in the United Kingdom, co-wrote a paper on these research findings that was recently published in Science magazine, an internationally acclaimed magazine issued by the American Association for the Advancement of Science.

The paper explores the negative impact of nitrogen pollution on grassland ecology in the United Kingdom, Europe and possibly North America. They found that as the pollution increased, the species diversity decreased at a drastic rate: the number of species is reduced by about 25 percent in moderately polluted areas and as much as 50 percent in more polluted areas. “That’s a pretty massive reduction of plant diversity,” said Dise, “and these may just be the showy members of a whole, functioning ecosystem that is slowly degraded. It argues strongly for reducing the amount of pollution.”

How has this alarming phenomenon occurred and what are its implications? Nitrogen pollution comes from agricultural emissions, traffic and industry. It is released into the atmosphere, and spread by wind and rain. Just as it does for crops, nitrogen in rainwater acts as a fertilizer: it allows a few species to grow quickly while simultaneously crowding their more delicate, neighboring species. “The winners are a couple of fast-growing grasses, the losers are the wildflowers,” said Dise.

The research was paired in Science magazine with another paper showing a drastic reduction in the number of bird, butterfly and plant species in Great Britain over the past 40 years. Dise and colleagues predict that North America may be similarly affected by the same disappearance in biodiversity, although at a lower level, reflecting less nitrogen pollution here. “We’d predict from our study a reduction of around ten percent in species richness in places like western Pennsylvania and New York or the upper Midwest – but again the wildflowers may be particularly sensitive."