A recent study by Chinese scientists showed that continuous nitrogen addition in a long run will inhibit the herb plant community in arid regions.
A three-year study, carried out in the Gurbantunggut desert, a typical temperate desert of central Asia, found that nitrogen addition reduced plant richness. The species richness will cut in half with a chronic high nitrogen application in three generations.
“Evenness and density were relatively insensitive to all but the greatest levels of N addition for two generations, but negative effects emerged in the third generation,” said professor ZHANG Yuanming, who led this research.
ZHANG and his team from the Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences monitored dynamic responses of community structure, richness, evenness, density and biomass of herbaceous plants to experimental nitrogen addition in three seasons in each of three years. A collaborator, Dr. Matthew Bowker, from Northern Arizona University also joined the research.
Their study found that low and intermediate levels of nitrogen deposition increased biomass, but the stimulatory effects disappeared in the third generation. When nitrogen deposition reaches a high level, it will suppress biomass.
“The interrelationships between N deposition and the different plant community attributes change not only seasonally, but also progressively change through time,” said ZHANG.
Their research result was published on Science of The Total Environment entitled “Chronic nitrogen addition induces a cascade of plant community responses with both seasonal and progressive dynamics”.