Li Tian, Sun Jingkuan, Fu Zhanyong
Shandong Key Laboratory of Eco-Environmental Science for Yellow River Delta, Binzhou University, Binzhou, China.
School of Chemical and Environmental Engineering, China University of Mining and Technology, Beijing, China.
Front Plant Sci. 2021 Jun 1;12:675921. doi: 10.3389/fpls.2021.675921. eCollection 2021.
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 (δO) of three halophytes were significantly different ( < 0.05). primarily used rainwater and soil water, while and mainly used soil water. The contributions of rainwater to three halophytes (, , and ) were 50.9, 9.1, and 18.5%, respectively. The carbon isotope (δC) analysis showed that had the highest water use efficiency, followed by and . Na content in the aboveground and underground parts of different halophytes was all followed an order of > > . C content and N:P in leaves of and N content of leaves in 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. 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 , 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 were mainly in 40-80 cm soil layers. So, the sources of soil water and nutrient of were located in different soil layers, while there were spatial consistencies of soils in water and nutrient utilization of and . These results are beneficial to a comprehensive understanding of the adaptability of halophytes in the Yellow River Delta.
黄河三角洲地区存在水分、盐分和养分限制，因此植物的生长依赖于周围环境因素。从不同盐生植物的角度了解植物与土壤系统的水分、盐分及化学计量特征，有助于探究它们的生存策略。因此，该地区对不同盐生植物和土壤系统的水分、盐分及化学计量特征进行了全面调查。结果表明，三种盐生植物的氧同位素（δO）存在显著差异（<0.05）。 主要利用雨水和土壤水，而 和 主要利用土壤水。雨水对三种盐生植物（ 、 和 ）的贡献率分别为50.9%、9.1%和18.5%。碳同位素（δC）分析表明， 的水分利用效率最高，其次是 和 。不同盐生植物地上和地下部分的Na含量均遵循 > > 的顺序。 和 叶片中的C含量、N:P以及 叶片中的N含量与Na显著正相关。植物与各土壤层之间的冗余分析（RDA）表明，三种盐生植物存在不同的相关模式。 主要利用60 - 80厘米深度低盐含量的雨水和土壤水，而植物与土壤之间C:N:P化学计量的显著相关指标主要在20 - 40厘米土层。在 中，土壤水贡献率最高且与叶片C:N:P化学计量相关性最密切的土层均在10 - 20厘米土层，而 主要在40 - 80厘米土层。所以， 的土壤水分和养分来源位于不同土层，而 和 在水分和养分利用方面土壤存在空间一致性。这些结果有助于全面了解黄河三角洲盐生植物的适应性。
