Drought-related changes in N and P cycling may affect plant community composition, structure and production. However, understanding on the ecological stoichiometric characteristics of leaf C, N and P in arid and semi-arid regions in response to environmental changes is still limited.
Based on regional-scale transcontinental survey, a research team led by Prof. ZHAO Xueyong from the Northwest Institute of Eco-Environment and Resources of the Chinese Academy of Sciences took 47 plant communities in Inner Mongolia desert steppe ecotone to reveal how abiotic and biotic factors influence the changes in leaf C, N, and P stoichiometry along a desert-grassland transition zone in northern China.
Related results were published in Science of the Total Environment on May 1.
The researchers measured and analyzed the mechanism of change in ecological stoichiometric characteristics of C, N and P in the leaves of 61 plant species. They found that plant taxonomic groups and life forms determined leaf C, N, and P stoichiometry at the individual level. Changes in leaf N and P contents and C:N, C:P and N:P ratios were mainly driven by intraspecific variability at the community level. Soil water content was a key factor affecting leaf C, N and P stoichiometry at these two scales.
At the community level, the intraspecific trait variation may play a key role in regulating plant community structure and function in order to enhance plant community resilience to climate change in desert-grassland transition zones.
Besides, the researchers found that, compared to mean annual precipitation, water availability, i.e., soil water content, should be included as a key parameter in predicting biogeochemical cycling processes in dryland plant-soil systems.
"This study emphasizes the importance of soil water content as a key parameter for modeling the biogeochemical cycle of the plant-soil system in dryland," said Prof. ZHAO. "It may help us to better understand leaf C, N and P stoichiometry models in arid and semi-arid regions, as well as the adaptation of species to individual and community scale factors."
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