Bai Liu, Wang Jing, Wang Zhongwu, Li Zhiguo, Ren Haiyan, Wang Haiming, Zhang Guogang, Han Guodong
Key Laboratory of Grassland Resources of the Ministry of Education, College of Grassland, Resources and Environment, Inner Mongolia Agricultural University, Hohhot, China.
Key Laboratory of Forage Cultivation, Processing and Higher Efficient Utilization of the Ministry of Agriculture and Rural Affairs, College of Grassland, Resources and Environment, Inner Mongolia Agricultural University, Hohhot, China.
Front Plant Sci. 2023 Aug 30;14:1211182. doi: 10.3389/fpls.2023.1211182. eCollection 2023.
Changes in rainfall induced by climate change will likely influence the utilization of water resources and affect the nutrient cycle in plants in the water-limited desert steppe. In order to understand the response of nitrogen and phosphorus resorption characteristics of plant leaves to precipitation changes, this study compared the nitrogen (N) resorption efficiency, phosphorus (P) resorption efficiency and influencing factors of plants in a desert steppe through water treatment experiments.
A 4-year field experiment was performed to examine the response and influencing factors of nitrogen (N) and phosphorus resorption efficiency of five dominant plants in desert steppe to simulated precipitation change in Inner Mongolia, with four simulated precipitation gradients including reducing water by 50%, natural precipitation, increasing water by 50%, increasing water by 100%.
Compared with natural precipitation, increasing water by 100% significantly increased soil moisture, and significantly increased the aboveground biomass of , , , decreased the N concentrations in green leaves of S. breviflora, , , , decreased the N concentrations in senesced leaves of C. songorica, decreased the P concentrations in green leaves of and , decreased the NRE of . NRE was significantly negatively correlated with N concentration in senesced leaves, and PRE was significantly negatively correlated with P concentration in senesced leaves.
Increasing water indirectly reduces NRE by reducing plant leaf green leaves nitrogen concentration, and decreasing water indirectly reduces PRE by reducing soil moisture.
气候变化引起的降雨变化可能会影响水资源的利用，并影响水分受限的荒漠草原中植物的养分循环。为了了解植物叶片氮磷再吸收特征对降水变化的响应，本研究通过水处理实验比较了荒漠草原中植物的氮（N）再吸收效率、磷（P）再吸收效率及其影响因素。
在内蒙古进行了一项为期4年的田间实验，以研究荒漠草原中5种优势植物的氮（N）和磷再吸收效率对模拟降水变化的响应及其影响因素，设置了4个模拟降水梯度，包括降水减少50%、自然降水、降水增加50%、降水增加100%。
与自然降水相比，降水增加100%显著提高了土壤湿度，显著增加了[植物名称1]、[植物名称2]、[植物名称3]、[植物名称4]的地上生物量，降低了短花针茅绿叶中的N浓度，降低了戈壁针茅衰老叶片中的N浓度，降低了[植物名称5]、[植物名称6]绿叶中的P浓度，降低了[植物名称7]的NRE。NRE与衰老叶片中的N浓度显著负相关，PRE与衰老叶片中的P浓度显著负相关。
增加水分通过降低植物叶片绿叶氮浓度间接降低NRE，减少水分通过降低土壤湿度间接降低PRE。
