Nitrogen: Too much of a vital resource

Nitrogen (N) is a key nutrient, vital for the survival of humans and all other living organisms. While di-nitrogen gas (N2) is abundant in the atmosphere, most organisms are unable to use this chemically unreactive form. First it must be converted or fixed߿ݠinto a reactive form such as ammonia (NH3) or nitrogen oxide (NOx). These and other forms...

Consequences of human modification of the global nitrogen cycle

The demand for more food is increasing fertilizer and land use, and the demand for more energy is increasing fossil fuel combustion, leading to enhanced losses of reactive nitrogen (Nr) to the environment. Many thresholds for human and ecosystem health have been exceeded owing to Nr pollution, including those for drinking water (nitrates), air...

Changes in species composition of European acid grasslands observed along a gradient of nitrogen deposition

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The impact of nitrogen deposition on acid grasslands in the Atlantic region of Europe

A survey of 153 acid grasslands from the Atlantic biogeographic region of Europe indicates that chronic nitrogen deposition is changing plant species composition and soil and plant-tissue chemistry. Across the deposition gradient (2e44 kg N ha_1 yr_1) grass richness as a proportion of total species richness increased whereas forb richness...

Addressing the Impact of Atmospheric Nitrogen Deposition on Western European Grasslands

There is a growing evidence base demonstrating that atmospheric nitrogen deposition presents a threat to biodiversity and ecosystem function in acid grasslands in Western Europe. Here, we report the findings of a workshop held for European policy makers to assess the perceived importance of reactive nitrogen deposition for grassland conservation...

Nitrogen deposition threatens species richness of grasslands across Europe

Evidence from an international survey in the Atlantic biogeographic region of Europe indicates that chronic nitrogen deposition is reducing plant species richness in acid grasslands. Across the deposition gradient in this region (2e44 kg N ha_1 yr_1) species richness showed a curvilinear response, with greatest reductions in species richness...