养分回收加剧了氮沉降背景下盐渍化草地优势植物内在氮磷的失衡
Nutrient resorption exacerbates nitrogen-phosphorus imbalances in plants under increasing nitrogen addition in a saline-alkaline grassland
Yuan Su 1Shuaikai Wu 1Jie Hao 1Huajie Diao 1Kuanhu Dong 1Changhui Wang1
作者信息
- 1. Shanxi Key Laboratory of Grassland Ecological Protection and Native Grass Germplasm Innovation,College of Grassland Science,Shanxi Agricultural University,Taigu 030801,China,2Youyu Loess Plateau Grassland Ecosystem National Research Station,Shanxi Agricultural University,Taigu 030801,China
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摘要
在落叶之前,从衰老组织中重新吸收养分被认为是植物适应养分缺乏的一种策略.然而,养分重吸收如何调节植物体内氮(N)和磷(P)的平衡仍不清楚,特别是在土壤氮有效性增加的情况下.本文研究了不同速率(0、1、2、4、8、16、24 和32 g N m-2 yr-1)氮添加对中国北方盐渍化草地优势植物赖草(Leymus secalinus)叶片和茎秆养分回收的影响,以及养分回收在调控植物内部氮磷平衡的作用.研究结果表明:氮添加6年后,随着施氮量的增加,绿色和衰老组织(叶和茎)的N浓度和氮磷比均呈上升趋势.随着施氮量的增加,绿色组织中P浓度降低,而衰老组织中P浓度无显著变化.N重吸收效率(NRE)、P重吸收效率(PRE)和NRE:PRE比值沿N添加梯度显著降低.此外,我们发现衰老组织(叶和茎)氮磷比比绿色组织(叶和茎)氮磷比对氮素添加的响应更敏感,植物内在氮磷失衡的加剧主要是由于不成比例的减少养分重吸收,尤其是NRE.总的来说,我们的研究表明,NRE和PRE的差异进一步加剧了植物凋落物内部氮磷的失衡.
Abstract
Reabsorbing nutrients from senescent tissues before leaf falling has been recognized as a strategy to adapt to nutrient deficiency.However,how nutrient resorption modulates the nitrogen(N)-phosphorus(P)balance inside plants remains unclear,especially under increased soil N availability.We examined the impacts of N addition at varying rates(0-32 g N m-2 yr-1)on nutrient resorption and the performance of nutrient resorption on controlling the internal N-P balance in the leaf and stem of a dominant grass species,Leymus secalinus,in a saline-alkaline grassland in northern China.After 6 years of N addition,N concentration and N:P ratio in green and senesced tissues(leaf and stem)rose with increasing N addition.The P concentration in green tissues decreased,but did not significantly change in senesced tissues with increasing N addition.The N resorption efficiency(NRE),P resorption efficiency(PRE),and NRE:PRE ratio significantly decreased along the N addition gradient.Moreover,we found more sensitive responses of N:P ratio in senesced tissues than in green tissues;such exacerbation of plant internal N-P imbalances mainly resulted from a disproportionate reduction in nutrient resorption,especially NRE.Overall,our study suggested that differences in NRE and PRE further exacerbated the internal N-P imbalances in plant litters.
关键词
生态化学计量学/氮添加/氮磷失衡/重吸收效率/重吸收能力/重吸收比/盐渍化草地Key words
ecological stoichiometry/nitrogen addition/nitrogen-phosphorus imbalance/resorption efficiency/resorption proficiency/resorption ratio/saline-alkaline grassland引用本文复制引用
基金项目
国家自然科学基金(32371670)
High-Level Talents Project of Shanxi Agricultural University(2021XG008)
Award Fund for Work of Excellent Researchers in Shanxi Province(SXBYKY2022042)
Science and Technology Innovation Foundation of Shanxi Agricultural University(2021BQ64)
出版年
2024
NETL
NSTL
万方数据