Halophytes Differ in Their Adaptation to Soil Environment in the Yellow River Delta: Effects of Water Source, Soil Depth, and Nutrient Stoichiometry

Abstract

The Yellow River Delta is water, salt, and nutrient limited and hence the growth of plants depend on the surrounding factors. Understanding the water, salt, and stoichiometry of plants and soil systems from the perspective of different halophytes is useful for exploring their survival strategies. Thus, a comprehensive investigation of water, salt, and stoichiometry characteristics in different halophytes and soil systems was carried out in this area. Results showed that the oxygen isotopes (δ18O) of three halophytes were significantly different (P < 0.05). Phragmites communis primarily used rainwater and soil water, while Suaeda salsa and Limonium bicolor mainly used soil water. The contributions of rainwater to three halophytes (P. communis, S. salsa, and L. bicolor) were 50.9, 9.1, and 18.5%, respectively. The carbon isotope (δ13C) analysis showed that P. communis had the highest water use efficiency, followed by S. salsa and L. bicolor. Na+ content in the aboveground and underground parts of different halophytes was all followed an order of S. salsa > L. bicolor > P. communis. C content and N:P in leaves of P. communis and N content of leaves in L. bicolor were significantly positively correlated with Na+. Redundancy analysis (RDA) between plants and each soil layer showed that there were different correlation patterns in the three halophytes. P. communis primarily used rainwater and soil water with low salt content in 60–80 cm, while the significant correlation indexes of C:N:P stoichiometry between plant and soil were mainly in a 20–40 cm soil layer. In S. salsa, the soil layer with the highest contribution of soil water and the closest correlation with the C:N:P stoichiometry of leaves were both in 10–20 cm layers, while L. bicolor were mainly in 40–80 cm soil layers. So, the sources of soil water and nutrient of P. communis were located in different soil layers, while there were spatial consistencies of soils in water and nutrient utilization of S. salsa and L. bicolor. These results are beneficial to a comprehensive understanding of the adaptability of halophytes in the Yellow River Delta.

Seasonal Variation Characteristics of C, N, and P Stoichiometry and Water Use Efficiency of Messerschmidia sibirica and Its Relationship With Soil Nutrients

“…Both C:P and N:P were positively correlated between soil and Robinia pseudoacacia L. in the Loess Plateau (Cao and Chen, 2017). In addition, in the YRD, C:P of Phragmites communis leaf and soil N:P were positively correlated, C:P of Limonium bicolor leaf and both C:P and N:P of soil were positively correlated, and C:P of Suaeda salsa leaf and soil N were positively correlated (Li et al, 2021). In this study, we found that the soil N:P in the chenier of YRD was significantly lower than the soil N:P of forest ecosystems in the country, indicating a soil N deficiency in this region.…”

“…There is a close relationship between water and nutrient use by plants, and plants need to constantly coordinate the balance between nutrient and water use during growth to adapt to environmental influences (Li et al, 2021). In recent years, stable isotope 13 C has been widely used to characterize plant water use efficiency (WUE), which provides important technical support for the study of the plant WUE.…”

Ecological stoichiometry, salt ions and homeostasis characteristics of different types of halophytes and soils

“…The Yellow River Delta Nature Reserve is the youngest and most complete wetland ecosystem in the world (Li et al, 2021). However, due to natural factors and anthropogenic activities in recent years, the water and salt balance of wetland soil in the Yellow River Delta has been destroyed and the degree of soil salinization has increased (Zhao et al, 2022), limiting the growth of many plants in the area, which is a key factor affecting the sustainable development of agriculture.…”

Distinguishing Stoichiometric Homeostasis of Soil Microbial Biomass in Alpine Grassland Ecosystems: Evidence From 5,000 km Belt Transect Across Qinghai–Tibet Plateau

“…This theory can be quantified to research on the relationship between biology and environment, biological interaction, and biogeochemical cycle during the process of energy flow and material cycle ( Crous et al, 2019 ; Wang et al, 2021 ; Zhou et al, 2021 ). The scales ranged from genes to biosphere ( Wang et al, 2015 ; Cherif et al, 2017 ; Tian et al, 2018 ) and can be unified ( Zeng and Chen, 2005 ) to reveal ecological structure, function, process, and stability ( Fang et al, 2019 ; Li et al, 2021 ; Wang et al, 2021 ). Numerous studies have demonstrated the stoichiometric homeostasis among various living organisms ( Elser et al, 2000 ; Sterner and Elser, 2002 ), but with large variations among ecological studies ( McGroddy et al, 2004 ; Elser et al, 2010 ; Giordano, 2013 ).…”

“…Nevertheless, the biological characteristics of stoichiometric homeostasis might change with different ontogenetic stages ( Wang et al, 2021 ), stoichiometric variation of their diet ( Hood and Sterner, 2010 ; Wang et al, 2018 ), and various types of species (e.g., weak homeostasis of phototrophs is opposite to strong homeostasis of heterotrophs) ( Sterner and Elser, 2002 ). Furthermore, stoichiometric homeostasis reflects biological adaptation by biochemical and physiological adjustments of multiple elements that respond to living environment ( Elser et al, 2010 ; Li et al, 2021 ). It can be an indicator of ecosystem dynamics ( Guo et al, 2017 ) and the organism’s ability to maintain consistent or stable state ( Meunier et al, 2014 ) facing environmental fluctuations.…”