Well-loved landscapes ranging from upland heaths typical of the North York Moors to sand dunes, as found at the Humber Estuary, are losing their variety of plants in the face of increased atmospheric nitrogen, the researchers claimed.
Scientists at Manchester Metropolitan University, which led the environmental study, examined some 135 sites across the UK and they concluded that nitrogen pollution caused by burning fossil fuels and intensive agriculture is causing a “drift towards monocultures”. Without further controls on nitrogen emissions, just a few plant species such as grasses will dominate once special habitats, they warned.
Dr Christopher Field of Manchester Metropolitan University’s School of Science and the Environment, said: “The more pollution, the fewer species, so the consequences are less biodiversity in the ecosystem and fewer of the plants that we love.
“Atmospheric nitrogen has increased as a by-product of fossil fuel burning and intensifying agriculture in industrialised countries, with further increases predicted in developing nations.”
As part of the study the research team visited various locations in Yorkshire. The types of terrain that came under their scrutiny in the region included acid grasslands, bogs, upland heath and lowland heaths found at Worm Sike Rigg and Bransdale in the North York Moors; Malham Tarn and Pateley Bridge in the Yorkshire Dales; Wadsworth Moor near Hebden Bridge; Skipwith near Selby and another site just outside Goole.
Each site was examined for the variety and extent of mosses, lichens, flowering plants known as forbs, and grasses, with the research team taking note of soil, pollution and climate conditions.
The study, published in the journal Ecosystems, found that as pollution increased, the rich diversity of species declined, with the variety of plants cut by up to 40 per cent and some species such as grasses becoming more dominant.
Nitrogen deposits from the atmosphere were a significant cause of the reduction in the richness of species in the habitats, the scientists concluded.
The pollution from nitrogen is “a widespread and pervasive threat” to habitats, their report warned, saying that while it is a vital nutrient for plants to grow, too much of it can cause some species to thrive at the expense of most others, altering the delicate make-up of a habitat.
Dr Field added: “Ultimately, without further reduction in nitrogen emissions, one species can take over and stop diversity by establishing itself as the dominant species. We are seeing more convergence in our ecosystems and a drift towards monocultures, with increased dominance of fast-growing species such as grasses. Careful management of nitrogen emissions are now required.”
A spokesperson for the Department for the Environment, Food and Rural Affairs said the Government was committed to reducing nitrogen emissions and had made strides to cut them in recent years.
“Clean air is vital not just for people’s health but also for the health of our environment, which is why we have committed £2 billion since 2011 to sustainable transport initiatives and introduced the greenhouse gas action plan to clean-up agriculture. Together with international commitments to reduce emissions from power plants these actions have meant pollutant emissions for the UK have fallen significantly in the last decade.”