Researchers Found the Stoichiometry Characteristics of Alpine Grassland at North Qinghai-Tibet Plateau

Carbon (C), nitrogen (N) and phosphorus (P) are the most important elements in an ecosystem. The stoichiometry of nutrients reflects their circulation and distribution.

Researchers form the State Key Laboratory of Desert and Oasis Ecology, Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences (CAS), studied the ecological stoichiometry of plants at different elevations in the Altun Mountain Nature Reserve based on the survey of the Altun Mountain area during the Second Tibetan Plateau Scientific Expedition and Research Program.

The results showed that plant C, N, P and soil C, N were linearly correlated with elevation gradient. C: N, C: P of plants and C: P, N: P of soil were linearly correlated with elevation gradient. Plant C and N were mainly affected by soil C and N concentration, but there was no significant correlation between plant P and soil nutrient concentration.

Soil moisture content and soil pH had significant effects on soil nutrients, soil moisture content increased with elevation, and promoting nutrient mineralization and availability to the ecosystem. The increase of soil nutrient availability and soil water content significantly increased species diversity and promoted plant community assembly and succession from alpine desert ecosystem to alpine grassland ecosystem.

The results of stoichiometric analysis of plant and soil with different vegetation types at 3000m to 4000m in the Altun Mountains showed that the nutrient distribution of alpine grassland and alpine desert ecosystems differed greatly at different altitudes. The C concentration of plant community was higher in low altitude alpine desert ecosystem while the N and P concentration of plant community was higher in high altitude alpine grassland ecosystem. The consistency of soil C and N changes and the stability of soil P leaded to the same change of soil C: P and N: P in different soil layers and altitudes. The stoichiometric characteristics of plant communities vary with species composition and ecological strategies.

Ecological stoichiometry reflects the nutrient allocation strategies of different plants in alpine desert ecosystems and alpine grassland ecosystems, which provides a basis for studying the growth and succession of plant communities in extreme environments.

The research results titled "Spatial pattern of C:N:P Stoichiometry characteristics of Alpine Grassland in the Altunshan Nature Reserve at North Qinghai-Tibet Plateau" was published in Catena.

The article links: https://www.sciencedirect.com/science/article/abs/pii/S034181622100549X?via%3Dihub 

Fig. 1 Location of the area and distribution of sample points.

Fig. 2 Structural equation models of altitude on plant and soil nutrient, community indicators, and soil moisture content.