Navon, Yael , Sternberg, Marcelo .
Plant litter decomposition under climate change: An experimental approach along an aridity gradient.
DECOMPOSITION of plant tissues in terrestrial ecosystems regulates the transfer of C and nutrient dynamics in the soil. This process is generally controlled by three main factors: climate, litter quality, and decomposing organisms. Changes in climatic conditions may alter decomposition rates with consequent effects on nutrient dynamics and ecosystem functioning. This study explores the relative importance of biotic and abiotic factors in the control of plant litter decomposition subjected to simulated climate change. The environmental North-South gradient in Israel, running from mesic Mediterranean to arid ecosystems, provides a unique natural environment to test predictions regarding the effects of global climate change on plant litter decomposition. Climate change scenarios were tested with manipulations of rainfall amount using rainout shelters and irrigation. A litter bag experiment containing representative local plant litter, as well as standard hay litter, was set up. Mass loss determination during decomposition was made, followed by monitoring changes in chemical content of the litter. It was found that decomposition rates were significantly different between study sites, and increased gradually with increased precipitation amount. Decomposition rates were higher for local litter in comparison with the standard. A reciprocal field plant litter transplantation experiment showed that plant litter of high quality (low C/N ratio) reached up to 70% of mass loss after one year of decomposition under mesic conditions, whereas litter of low quality did not exceed 40%. Based on our results, it appears that plant litter decomposition is influenced by both litter quality and site conditions along the aridity gradient. Climate limits decomposition processes in arid conditions, while litter quality limits it in mesic environments. Our results provide an empirical test of predicted plant litter decomposition changes in Mediterranean to arid ecosystems in Israel.[c.e.:srb]
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1 - Tel Aviv University, Department of Plant Sciences, Ramat Aviv, Tel Aviv, 69978, Israel
Plant litter decomposition
global climate change
Presentation Type: Oral Paper:Papers for Sections
Date: Tuesday, August 1st, 2006
Time: 9:30 AM