Nitrogen hotspots pose global pollution threat to plants
Posted on 5 April 2006
An international research team led by scientists at the Stockholm Environment Institute (SEI), at the University of York, and the Department of Animal and Plant Sciences at the University of Sheffield, have looked at atmospheric nitrogen inputs to 34 plant biodiversity hotspots identified by Conservation International, to which half of the world's plant species are restricted (they are 'endemic' and occur no where else in the world). They used a combination of emissions predictions and atmospheric chemistry models to estimate current nitrogen deposition and likely changes over the next half-century.Using computer modelling, the researchers discovered that some of the global hotspots already receive potentially damaging amounts of nitrogen deposition. With the anticipated global increase in nitrogen emissions by 2050, all but one of the 34 will see an increase in their deposition, with the average total more than doubling.
Understanding the impacts of nitrogen deposition in hotspots is, therefore, a priority for future research
Dr Kevin Hicks
Half the hotspots will receive more nitrogen deposition than amounts that can typically damage sensitive ecosystems in Europe. The most polluted location - the tropical Western Ghats and Sri Lanka - is predicted to receive an average pollution load that is double the current average for the UK. The Mountains of Southwest China and Indo-Burma are also among the areas predicted to receive significantly elevated levels of nitrogen pollution by 2050, along with three areas of the world with some of the highest numbers of species as endemics, the Tropical Andes, the Atlantic Forest and the Mediterranean Basin.
Dr Gareth Phoenix, of the Department of Animal and Plant Sciences at the University of Sheffield, said: "Until recently, scientists have focused on the threat of atmospheric nitrogen deposition in Europe and North America - partially since these were the first areas of the world to receive high levels of this pollutant. However, our work shows that atmospheric nitrogen deposition is becoming a global threat."
This coincidence of high levels of atmospheric nitrogen deposition with areas of particularly high plant diversity may significantly increase the threat to plant biodiversity over the coming century. Dr Kevin Hicks, at the Stockholm Environment Institute at the University of York, said: "Scientists know very little about the sensitivity of the hotspot ecosystems to nitrogen deposition, so accurate estimates of the amount of likely species loss are not possible. Understanding the impacts of nitrogen deposition in hotspots is, therefore, a priority for future research."
Notes to editors:
- Original paper published in Global Change Biology (2006) 12, 470-476. Atmospheric nitrogen deposition in world biodiversity hotspots: the need for a greater global perspective in assessing N deposition impacts. Copies are available upon request.
- This work evolved out of the Global Nitrogen Enrichment project workshop in 2001, which was funded by the Natural Environment Research Council (NERC).
- NERC delivers independent research, survey, training and knowledge transfer in the environmental sciences. Their work covers the full range of atmospheric, earth, biological, terrestrial and aquatic sciences, from the deep oceans to the upper atmosphere, and from the poles to the equator. Their mission is to gather and apply knowledge, create understanding and predict the behaviour of the natural environment and its resources, and communicate all aspects of their work. www.nerc.ac.uk/
- The GANE thematic programme aims to study the problems arising from nitrogen enrichment of our environment. Further information is available at gane.ceh.ac.uk/
- The Stockholm Environment Institute (SEI) at York is one of the constituent centres of the Stockholm Environment Institute, an independent, international research organisation committed to the implementation of practices supportive of global sustainable development. SEI conducts a comprehensive research, consulting and training programme which focuses on the links between the ecological, social and economic systems at global, regional and national and local levels.
- The University of Sheffield is one of the UK's leading and largest universities, and a member of the Russell Group. It has over 24,000 students from 118 countries. With its reputation for world-class teaching and research excellence across a wide range of disciplines, it has well-established partnerships with a number of universities both in the UK and abroad, as well as with many leading UK and global companies.
- The Natural Environment Research Council (NERC) is one of the UK's eight research councils. It uses a budget of about £350m a year to fund and carry out impartial scientific research in the sciences of the environment. NERC trains the next generation of independent environmental scientists. It is addressing some of the key issues facing mankind such as global warming, renewable energy and sustainable economic development.