Characteristics and Influencing Factors of Ecological Stoichiometry of Shrub Fine Roots in the Alpine Region of Northwest China.

Understanding the relationships between nutrient content in plant roots and ecological stoichiometry is crucial for elucidating nutrient utilization strategies and material cycling in alpine plant communities. However, data characterizing the stoichiometric characteristics of plant roots in this region remain limited. In this study, we collected fine-root and soil samples from five common alpine shrub species—Salix gilashanica, Potentilla fruticosa, Caragana jubata, Caragana tangutica, and Berberis diaphana—to investigate the carbon (C), nitrogen (N), and phosphorus (P) stoichiometric characteristics of their fine roots and examine the potential nutrient control strategies based on the soil properties. Our analysis revealed that the mean C (541.38 g kg−1) and P (1.10 g kg−1) contents in the shrub fine roots exceeded the average levels of the plant roots in China. However, the mean N content (8.61 g kg−1) was lower than the global average. Notably, the mean C:N ratio (71.3) in these fine roots was significantly higher than the global average, whereas both the mean C:P ratio (527.61) and N:P ratio (8.11) were considerably lower. The N:P ratios in the fine roots of the five shrub species were below 14, indicating nitrogen limitation for growth in the degraded alpine shrub communities. Our findings indicate that soil available phosphorus (33.2%) and pH (20.5%) are the primary factors influencing the eco-stoichiometric characteristics of shrub fine roots in the Qilian Mountains. These findings provide valuable data and theoretical support for a better understanding of the role of shrub roots in nutrient cycling within alpine ecosystems. [ABSTRACT FROM AUTHOR]