Response of C:N:P in the plant-soil system and stoichiometric homeostasis of Nitraria tangutorum leaves in the oasis-desert ecotone, Northwest China

Abstract

Nitraria tangutorum nebkhas are widely distributed in the arid and semi-arid desert areas of China. The formation and development of N. tangutorum nebkhas are the result of the interaction between vegetation and the surrounding environment in the process of community succession. Different successional stages of N. tangutorum nebkhas result in differences in the community structure and composition, thereby strongly affecting the distribution of soil nutrients and ecosystem stability. However, the ecological stoichiometry of N. tangutorum nebkhas in different successional stages remains poorly understood. Understanding the stoichiometric homeostasis of N. tangutorum could provide insights into its adaptability to the arid and semi-arid desert environments. Therefore, we analyzed the stoichiometric characteristics of N. tangutorum in four successional stages, i.e., rudimental, developing, stabilizing, and degrading stages using a homeostasis model in an oasis-desert ecotone of Northwest China. The results showed that soil organic carbon (SOC), total nitrogen (TN), and total phosphorus (TP) contents and their ratios in the 0-100 cm soil depth were significantly lower than the averages at regional and global scales and were weakly influenced by successional stages in the oasis-desert ecotone. TN and TP contents and C:N:P in the soil showed similar trends. Total carbon (TC) and TN contents in leaves were 450.69-481.07 and 19.72-29.35 g/kg, respectively, indicating that leaves of N. tangutorum shrubs had a high storage capacity for C and N. Leaf TC and TN contents and N:P ratio increased from the rudimental stage to the stabilizing stage and then decreased in the degrading stage, while the reverse trend was found for leaf C:N. Leaf TP content decreased from the rudimental stage to the degrading stage and changed significantly in late successional stages. N:P ratio was above the theoretical limit of 14, indicating that the growth of N. tangutorum shrubs was limited by P during successional stages. Leaf N, P, and N:P homeostasis in four successional stages was identified as ''strictly homeostasis''. Redundancy analysis (RDA) revealed that soil acidity (pH) and the maximum water holding capacity were the main factors affecting C:N:P stoichiometric characteristics in N. tangutorum leaves. Our study demonstrated that N. tangutorum with a high degree of stoichiometric homeostasis could better cope with the arid desert environment.

Effect of Plant Growth Regulators on Osmotic Regulatory Substances and Antioxidant Enzyme Activity of Nitraria tangutorum

“…It is a tiny, distinctive, and widespread sand-fixing shrub in Inner Mongolia and China’s arid desert regions [ 35 ]. N. tangutorum is an important component of desert vegetation and is resistant to a variety of stresses, including wind erosion [ 36 ], sand burial [ 37 ], drought [ 38 ], and salt and alkali stress [ 39 , 40 ]. This resistance is related to its well-developed root system, small and fleshy leaves, and quickly grown branches.…”

Transcriptome Profiling and Chlorophyll Metabolic Pathway Analysis Reveal the Response of Nitraria tangutorum to Increased Nitrogen

“…Nitraria tangutorum is the predominant plant class in the Ulan Buh Desert [ 46 , 55 , 56 ], and its leaves had a high storage capacity for C and N [ 51 ]. Previous studies have shown that growth and biomass production of plant was accelerated by N application [ 57 ] but was inhibited when the N supply was excessive [ 24 ].…”

“…tangutorum . For example, abiotic stresses, such as precipitation [ 46 ], drought [ 47 ], soil nutrients [ 51 ], and salt stress [ 52 ], will all affect the growth and development of N. tangutorum . Our previous study also found that the addition of 36 mmol·L −1 N fertilizer could promote the bud and branch formation of of N .…”

Changes in Morphology of <i>Nitraria tangutorum</i> Nebkhas at different Successional Stages in the Oasis-Desert Ecotone, Northwest China

“…We defined four succession stages of nebkhas based on our morphometric measurements, vegetation status and combined with the experience of previous studies [28][29][30]. Successional stages of N. tangutorum nebkhas were classified based mainly on the mortality rate of branches of N. tangutorum, and N. tangutorum nebkhas were divided into rudimental stage (RUD), developing stage (DEV), stabilizing stage (STA), and degrading stage (DEG).…”