西北植物学报 Acta Botanica Boreali-Occidentalia Sinica

增加水分对古尔班通古特沙漠4种短命植物生物量及氮素形态吸收的影响

引用本文：肖钰鑫，王明明，庄伟伟.增加水分对古尔班通古特沙漠4种短命植物生物量及氮素形态吸收的影响[J].西北植物学报,2022,42(8):1373~1383

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作者	单位
肖钰鑫^1,2,3,4，王明明^1,2,3,4，庄伟伟^1,2,3,4*	(1 新疆师范大学生命科学学院，乌鲁木齐 830054；2 干旱区植物逆境生物学实验室，乌鲁木齐 830054；3 新疆特殊环境物种保护与调控生物学实验室，乌鲁木齐 830054；4 中亚区域有害生物联合控制国际研究中心，乌鲁木齐 830054)

基金项目:新疆维吾尔自治区自然科学基金(2021D01A123)

中文摘要:为明确土壤水分含量对荒漠生态系统短命植物生长及氮素吸收偏好性的影响，该研究以古尔班通古特沙漠4种优势短命植物东方旱麦草(Eremopyrum orientale)、尖喙牻牛儿苗(Erodium oxyrhinchum)、琉苞菊(Centaurea pulchella)和卵果鹤虱(Lappula patula)为研究对象，通过盆栽控水实验，设定3个水分梯度分别为：干旱处理(W₁，土壤含水量2％)、正常水分处理(W₂，土壤含水量8％)和湿润处理(W₃，土壤含水量14％)，利用¹⁵N同位素示踪法研究水分对4种植物生物量及不同形态氮素的吸收策略的影响。结果表明：(1)随着土壤含水量的增加，4种短命植物的地上、地下、总生物量呈递增趋势，在正常水分处理时增速最快，且同一生活型不同物种之间的生物量累积速率不同；而4种短命植物的根冠比随土壤水分含量的增加呈显著下降趋势。(2)在不同水分处理下，4种短命植物对不同形态的¹⁵N吸收速率表现为：硝态氮＞铵态氮＞甘氨酸，对3种形态氮素以及总氮的吸收速率均随着水分梯度的增加呈增大趋势。(3)在干旱处理时，硝态氮是4种短命植物最偏好吸收的氮形态，随着土壤含水量的增加东方旱麦草、琉苞菊的氮素形态偏好性不会改变，而在水分持续增大至湿润处理时，铵态氮对尖喙牻牛儿苗和卵果鹤虱的氮素吸收的贡献率超过硝态氮，成为这2种植物最偏好吸收的氮形态。

中文关键词:水分胁迫氮素吸收同位素标记古尔班通古特沙漠

Effects of Increased Water on Biomass and Absorption of Different Nitrogen Forms of Four Ephemeral Plants in Gurbantunggut Desert

Abstract:In order to clarify the effect of soil moisture content on the growth and nitrogen uptake preference of ephemeral plants in desert ecosystems, we selected four dominant ephemeral plants in the Gurbantunggut Desert, Eremopyrum orientale, Erodium oxyrhinchum, Centaurea pulchella, and Lappula patula as the research object. Through the potted water control experiment, setting 3 water gradients: drought treatment (W₁, soil water content 2%)， normal moisture treatment (W₂, soil water content 8%), wet treatment (W₃， soil water content 14%). Using the ¹⁵N isotope tracer method, we studied the effects of water on biomass and nitrogen uptake strategies of four plant species. The results showed: (1) with the increase of the soil moisture content, the aboveground, underground and total biomass of the four ephemeral plants showed an increasing trend, and the growth rate is the highest under normal water treatment, and the biomass accumulation rate was different among different species in the same life form. However, the root shoot ratio of four ephemeral plants decreased significantly with the change of soil moisture content. (2) Under different water treatments, the ¹⁵N uptake rates of the four ephemeral plants for different forms were as follows: nitrate nitrogen > ammonium nitrogen > glycine, and the uptake rates of the three forms of nitrogen and total nitrogen increased with the increase of the water gradient. (3) In drought treatment, nitrate nitrogen was the most preferred nitrogen form to be absorbed by the four ephemeral plants. With the increase of soil moisture content, the nitrogen form preference of Eremopyrum orientale and Centaurea pulchella were not changed. However, when the water continued to increase to wet treatment, the contribution rate of ammonium nitrogen to the nitrogen uptake of Erodium oxyrhinchum and Lappula patula exceeded the nitrate nitrogen, became the most preferred form of nitrogen absorbed by these two plants.

keywords:water stress nitrogen uptake isotope labeling Gurbantunggut Desert

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