植物生态学报 ›› 2021, Vol. 45 ›› Issue (11): 1231-1240.DOI: 10.17521/cjpe.2021.0135

• 研究论文 • 上一篇    下一篇

杉木幼苗生物量分配格局对氮添加的响应

王娇1,3, 关欣1,2, 张伟东1,2, 黄苛1,2, 朱睦楠1,2, 杨庆朋1,2,*()   

  1. 1中国科学院会同森林生态实验站, 中国科学院森林生态与管理重点实验室, 中国科学院沈阳应用生态研究所, 沈阳 110016
    2亚热带森林生态系统结构与服务功能湖南省重点实验室, 湖南会同 418307
    3中国科学院大学资源与环境学院, 北京 101408
  • 收稿日期:2021-04-09 接受日期:2021-07-08 出版日期:2021-11-20 发布日期:2021-09-18
  • 通讯作者: 杨庆朋
  • 作者简介:* (yqp226@iae.ac.cn)
  • 基金资助:
    国家自然科学基金(41630755);国家自然科学基金(41977092);国家自然科学基金(41877092)

Responses of biomass allocation patterns to nitrogen addition of Cunninghamia lanceolata seedlings

WANG Jiao1,3, GUAN Xin1,2, ZHANG Wei-Dong1,2, HUANG Ke1,2, ZHU Mu-Nan1,2, YANG Qing-Peng1,2,*()   

  1. 1Huitong Experimental Station of Forest Ecology, Key Laboratory of Forest Ecology and Management, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang 110016, China
    2Hunan Key Laboratory for Structure and Ecosystem Service of Subtropical Forest, Huitong, Hunan 418307, China
    3College of Resources and Environment, University of Chinese Academy of Sciences, Beijing 101408, China
  • Received:2021-04-09 Accepted:2021-07-08 Online:2021-11-20 Published:2021-09-18
  • Contact: YANG Qing-Peng
  • Supported by:
    National Natural Science Foundation of China(41630755);National Natural Science Foundation of China(41977092);National Natural Science Foundation of China(41877092)

摘要:

大气氮(N)沉降的急剧增加可能会对植物碳(C)固定和分配产生深远影响。然而, N添加如何影响碳水化合物在植物不同器官之间的分配动态并不十分清楚。该研究利用杉木(Cunninghamia lanceolata)幼苗盆栽试验, 设置N添加处理, 测定分析幼苗非结构性碳水化合物(NSC)与结构性碳水化合物(SC)含量和库的变化, 以探讨N添加后杉木幼苗不同器官中NSC与SC的分配模式及调控机制。结果发现: (1) N添加虽然显著增加叶片净光合速率(143.96%), 但却降低了叶片中的NSC含量和库; N添加导致一年生茎的淀粉含量显著下降, 而可溶性糖含量的变化不显著, 当年生茎的NSC组分含量和库没有显著变化; 幼苗根系的NSC及其组分含量和库也有降低的趋势。(2) N添加后地下与地上生物量的比值降低22.09%, 其中SC库比值降低31.07%, 而NSC库比值无显著变化。(3) N添加使地上部分的磷(P)库显著增加, 使地下与地上P库的比值降低了57.02%, 而N库的比值无显著变化。(4) N添加后土壤pH由(4.94 ± 0.09)显著降低到(4.02 ± 0.04), 铵态N和硝态N含量分别增加7.17倍和11.55倍, 土壤有效P含量也增加了42.86%, 而土壤中脲酶(62.75%)和酸性磷酸酶(56.52%)的活性显著降低。研究表明, 低养分条件下杉木幼苗主要通过构建根系结构增加养分吸收, 而非通过向根系分配更多的NSC, 而N添加驱动的养分缓解使更多的碳水化合物分配到地上器官, 导致地上部分SC积累。

关键词: 氮添加, 生物量分配, 碳水化合物, 非结构性碳, 磷, 最优分配理论

Abstract:

Aims Sharply increasing atmospheric nitrogen (N) deposition may have profound effects on carbon (C) fixation and allocation of plants. However, a comprehensive understanding of how nitrogen addition influences allocation dynamics of carbohydrates among different organs in plants is still lacking.
Methods In this study, a pot experiment of seedlings of Cunninghamia lanceolate was established to investigate the allocation pattern and regulation mechanism of non-structural carbohydrates (NSC) and structural carbohydrates (SC) in different organs of C. lanceolate seedlings after N addition. The concentrations and pool sizes of NSC and SC were measured.
Important findings The results showed that: (1) N addition significantly increased the net photosynthetic rate by 143.96%, but decreased the concentration and pool size of NSC in needles. There was no significant change in the components of NSC concentration and pool in current-year stems. Furthermore, N addition resulted in a significant decrease in the starch concentration of one-year-old stems, but a non-significant change in soluble sugar concentration. In addition, the components of NSC concentration and pool in seedlings roots also tended to decrease. (2) After N addition, the ratio of below- to above-ground biomass decreased by 22.09%, and the ratio of below- to above-ground SC pool also decreased by 31.07%, and the ratio of below- to above-ground NSC pool showed no significant difference between control and N addition treatment. (3) N addition significantly increased the phosphorus (P) pool size in the above-ground part and decreased the ratio of below- to above-ground P pool, while the ratio of below- to above-ground N pool showed no obvious difference between control and N addition treatment. (4) Under N addition, soil pH decreased significantly from 4.94 to 4.02, ammonium and nitrate nitrogen concentration increased by 7.17 times and 11.55 times, respectively, and soil available P concentration increased by 42.86%, while the activities of urease (62.75%) and acid phosphatase (56.52%) in the soil decreased significantly compared to control. Our results indicates that C. lanceolate seedlings increased nutrient uptake amount mainly by the construction of root structure, but not by the allocation of more NSC to the root under low nutrient conditions, while nutrient alleviation driven by nitrogen addition resulted in more carbohydrates allocation to above-ground organs, resulting in the accumulation of SC in above-ground parts.

Key words: nitrogen addition, biomass allocation, carbohydrates, non-structural carbohydrates, phosphorus, optimal partitioning theory