■气候变化引起的降雨变化可能会影响水资源的利用,并影响水分有限的荒漠草原中植物的养分循环。为了了解植物叶片氮磷吸收特性对降水变化的响应,这项研究比较了氮(N)的吸收效率,通过水处理实验对荒漠草原植物磷的吸收效率及其影响因素进行了研究。
■进行了为期4年的田间试验,研究了针茅荒漠草原五种优势植物对模拟降水变化的氮(N)和磷吸收效率的响应及其影响因素。内蒙古,有四个模拟降水梯度,包括减少50%的水,自然降水,增加50%的水,增加100%的水。
■与自然降水相比,增加100%的水分显着增加土壤水分,显着增加了短草的地上生物量,C.Songorica,A.Frigida,降低了短草绿叶中的氮浓度,裂解虫Songorica,冷蒿,KochiaProstrata,降低了C.songorica衰老叶片中的N浓度,降低了K.prostrata和ammanniiConvolvelus的绿叶中的P浓度,降低了短草的NRE。NRE与衰老叶片中N浓度呈显著负相关,PRE与衰老叶片中的P浓度呈极显著负相关。
■增加水分通过降低植物叶片绿叶氮浓度间接降低NRE,减少水分通过减少土壤水分间接减少PRE。
UNASSIGNED: 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.
UNASSIGNED: 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 Stipa breviflora 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%.
UNASSIGNED: Compared with natural precipitation, increasing water by 100% significantly increased soil moisture, and significantly increased the aboveground biomass of S. breviflora, C. songorica, A. frigida, decreased the N concentrations in green leaves of S. breviflora, Cleistogenes songorica, Artemisia frigida, Kochia prostrata, decreased the N concentrations in senesced leaves of C. songorica, decreased the P concentrations in green leaves of K. prostrata and Convolvulus ammannii, decreased the NRE of S. breviflora. NRE was significantly negatively correlated with N concentration in senesced leaves, and PRE was significantly negatively correlated with P concentration in senesced leaves.
UNASSIGNED: Increasing water indirectly reduces NRE by reducing plant leaf green leaves nitrogen concentration, and decreasing water indirectly reduces PRE by reducing soil moisture.