Climate Change Might Enhance Grassland Productivity

Results of a study conducted by researchers at the University of Bayreuth and the Helmholtz Center in Munich revealed that frequent freeze-thaw cycle in winter can increase biomass production. For their experiments, the researchers installed underground heating on their plots. This enables five additional thawing periods to take place in the winter of 2005/2006. They found that manipulated plots produced 10 percent more above-ground biomass than the control plots. Freeze-thaw cycle, however, reduced root length over the whole subsequent growing season. The scientists said that the increase in biomass can be explained by several factors, including increase in nitrogen supply and microbial activity in spring.

Global warming is expected to increase the frequency of soil freeze–thaw cycles in the cool-temperate and high-latitude regions. According to the scientists, changes in productivity resulting in an increased shoot-to-root ratio and shifts in timing are capable of altering ecosystem stability and ecosystem services, such as productivity and nutrient retention.

Subscribers to New Phytologist can download the full article at http://dx.doi.org/10.1111/j.1469-8137.2007.02309.x For more information, read http://www.ufz.de/index.php?en=17550