%0 Journal Article %A Zhi-Ying NING %A Yu-Lin LI %A Hong-Ling YANG %A Zi-Qian ZHANG %T Nitrogen and phosphorus stoichiometric homoeostasis in leaves of dominant sand-fixing shrubs in Horqin Sandy Land, China %D 2019 %R 10.17521/cjpe.2018.0100 %J Chinese Journal of Plant Ecology %P 46-54 %V 43 %N 1 %X

Aims Sand-fixing shrubs play an irreplaceable role in ecological restoration and eco-environmental protection in arid and semiarid regions of northern China. Determination of the stoichiometric homoeostasis of dominant sand-fixing shrubs along soil nutrient gradients could provide insights into ecological adaptability and pattern of changes of sand-fixing vegetation in Horqin Sandy Land.
Methods We measured N and P concentrations in leaves of two dominant sand-fixing shrubs Caragana microphylla and Artemisia halodendron, and the total and available N and P concentrations in soils beneath the canopy of each shrub. The differences between the two shrubs in N and P concentrations and N:P of leaves and soils as well as in stoichiometric homoeostasis were examined.
Important findings Caragana microphylla had higher leaf N concentration and lower leaf P concentration, thereby higher leaf N:P, than A. halodendron. Soils beneath the shrub canopies, regardless of the species, had higher total and available N and P concentrations relative to soils outside the canopy cover. Moreover, the total and available N and P concentrations in soils beneath the C. microphylla canopy were higher than that beneath the A. halodendron canopy. The stoichiometric homoeostasis indexes (H) were ranked in the order of HP > HN:P > HN in A. halodendron and HN:P > HN > HP in C. microphylla, respectively, suggesting N limitation in A. halodendron and P limitation in C. microphylla. Therefore, Caragana microphylla could be used as nursing plants in degraded N-limiting soil because of high HN. However, due to excessive uptake of N, Caragana microphylla might suffer from P limitation, and adequate P supply should be considered during the restoration process in sandy land.

%U https://www.plant-ecology.com/EN/10.17521/cjpe.2018.0100