Plant nitrogen isotope composition can reflect relative openness of ecosystem nitrogen cycling.Ĭitation: Ma J-Y, Sun W, Liu X-N, Chen F-H (2012) Variation in the Stable Carbon and Nitrogen Isotope Composition of Plants and Soil along a Precipitation Gradient in Northern China. Carbon isotope composition is useful for tracing environmental precipitation changes. We conclude that water availability is the primary environmental factor controlling the variability of plant δ 13C and δ 15N and soil δ 13C in the studied arid and semi-arid regions. SOM became depleted in 13C with increasing MAP, while no significant correlations existed between δ 15N of SOM and MAP.

Species differences in the sensitivity of plant δ 13C and δ 15N to MAP were not observed among three main dominant plants. The sensitivity of δ 13C to MAP in C 3 plants (-0.6☐.07‰/100 mm) was twice as high as that in C 4 plants (−0.3☐.08‰/100 mm). δ 13C and δ 15N for both C 3 and C 4 plants decreased significantly with increasing mean annual precipitation (MAP). We measured δ 13C and δ 15N of plant and soil organic matter (SOM) samples collected from 64 locations across a precipitation gradient with an isotherm in northern China.

However, there are potential differences among locations and/or species in the sensitivity of plant δ 13C and δ 15N to variation in precipitation, which are important for using stable isotope signatures to extract paleo-vegetation and paleo-climate information. Water availability is the most influential factor affecting plant carbon ( δ 13C) and nitrogen ( δ 15N) isotope composition in arid and semi-arid environments.

Isotopic carbon