Guo Ning, Jiang Jichun, Wang Guoqiang, et al. Effects of Different Precipitation Gradients on Stoichiometric Characteristics of Grassland Communities in Loess Hilly Region[J]. Bulletin of Soiland Water Conservation, 2020, 40(2): 1-8.
DOI:
Guo Ning, Jiang Jichun, Wang Guoqiang, et al. Effects of Different Precipitation Gradients on Stoichiometric Characteristics of Grassland Communities in Loess Hilly Region[J]. Bulletin of Soiland Water Conservation, 2020, 40(2): 1-8. DOI: 10.13961/j.cnki.stbctb.2020.02.001.
Effects of Different Precipitation Gradients on Stoichiometric Characteristics of Grassland Communities in Loess Hilly Region
nitrogen and phosphorus of each component (plant leaves
roots and soil) of grassland community to precipitation change was studied
in order to reveal the influence of precipitation on the stoichiometric characteristics of grassland ecosystem in loess hilly region.[Methods] The natural restored grassland in loess hilly region was taken as the research object
a field rain control test platform was established at Ansai experimental station during 2017-2018
with 7 treatments including 60% rain reduction
40% rain reduction
20% rain reduction
natural precipitation
20% rain increase
40% rain increase
and 60% rain increase. The canopy method was adopted to study the influence of precipitation change on the leaves
roots and soil ecological stoichiometric characteristics of plants.[Results] ① With the increase of precipitation
the water restriction in plant growth was effectively alleviated
and the effect of water stress gradually slowed down
so that the N and P contents in leaves showed a significant decline (p<0.05). And the C/N and C/P of the leaves also showed a significant downward trend (p<0.05). ② The change of precipitation gradient had a significant effect on the P contents of root system (p<0.05). The change of precipitation gradient had significant influence on root C/P and N/P (p<0.05). ③ Rain control treatment only had significant effect on soil C content (p<0.05)
which may be because extreme precipitation affected the activity of soil microorganisms
resulting in a slow accumulation of soil organic C.[Conclusion] Water is the limiting factor for the absorption and utilization of N and P by grassland plants in loess hilly region. Precipitation can change the nutrient restriction pattern of grassland community. With the increase of precipitation
plant growth is more restricted by P
and plant growth will changed from being restricted by both N and P to being restricted by P.
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