Stoichiometry in aboveground and fine roots of Seriphidium korovinii in desert grassland in response to artificial nitrogen addition

Fine roots are essential for water and nutrient uptake in plants, but little is known about the variation in fine root traits and the underlying mechanisms that drive it. Understanding the responses of fine root function traits to changing environmental conditions and the role of fine root traits as drivers of forest ecosystem processes are critical for informing physiological and ecological theory as well as ecosystem management. We measured morphological and physiological traits of fine roots from six soil layers and three diameter classes in Schrenk’s spruce (Picea shrenkiana) forests of the Tianshan mountains, China. We found significant effects of nitrogen addition on these morphological and physiological traits, which varied by soil layer and root diameter. Specifically, specific root length (SRL) was higher in medium N addition group (N2) than in control group (N0). Specific root area (SRA) was higher in the control group (N0) than fertilized groups (N1, N2 and N3). Root tissue density (RTD) was higher in low N addition group (N1) than in the other group. Root dry matter content had no significant difference among four treatment groups. SRL, SRA, and RTD of fine roots in different diameter classes were all significantly different between high N addition (N3) and the control (N0) groups. The physiological characteristics of fine roots showed that soluble sugar (SS), fine root vitality (FRV), and tissue water content (TWC) in different soil layers were higher in the control group than in the fertilized groups. While soluble protein (SP), malondialdehyde (MDA) and free proline (FP) were lower in the control group (N0) than in the fertilized groups. In addition, SS, FRV, SP, TWC, FP, and MDA in all N addition treatments groups were significantly different from the control group. Fine root morphological traits were closely related to physiological traits, and added nitrogen inputs change these correlations. Our study confirms that nitrogen addition has specific effects on the morphological and physiological traits of fine roots of Schrenk’s spruce, and the effects of N addition vary according to the amount added.

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Changes in the carbon and nutrient status of Cryptomeria japonica needles and fine roots following 7 years of nitrogen addition

Plant Root ◽

10.3117/plantroot.9.95 ◽

2015 ◽

Vol 9 (1) ◽

pp. 95-102 ◽

Cited By ~ 3

Author(s):

Junko Nagakura ◽

Akio Akama ◽

Hidetoshi Shigenaga ◽

Takeo Mizoguchi ◽

Takashi Yamanaka ◽

...

Keyword(s):

Fine Roots ◽

Cryptomeria Japonica ◽

Nutrient Status ◽

Nitrogen Addition

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Response of plant community structure and its stability to water and nitrogen addition in desert grassland

Acta Ecologica Sinica ◽

10.5846/stxb202005251334 ◽

2021 ◽

Vol 41 (6) ◽

Author(s):

杜忠毓，安慧，文志林，王波，张馨文 DU Zhongyu

Keyword(s):

Community Structure ◽

Plant Community ◽

Nitrogen Addition ◽

Plant Community Structure ◽

Desert Grassland

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The morphological and chemical properties of fine roots respond to nitrogen addition in a temperate Schrenk’s spruce (Picea schrenkiana) forest

Scientific Reports ◽

10.1038/s41598-021-83151-x ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Haiqiang Zhu ◽

Jingjing Zhao ◽

Lu Gong

Keyword(s):

Nitrogen Deposition ◽

Root Length ◽

Fine Roots ◽

Fine Root ◽

Specific Root Length ◽

Nitrogen Addition ◽

Nonstructural Carbohydrates ◽

High Nitrogen ◽

Picea Schrenkiana ◽

Nitrogen Treatment

AbstractFine roots (< 2 mm in diameter) play an important role in belowground ecosystem processes, and their physiological ecology is easily altered by nitrogen deposition. To better understand the response of physiological and ecological processes of fine roots to nitrogen deposition, a manipulation experiment was conducted to investigate the effects of exogenous nitrogen addition (control (0 kg ha−1 a−1), low (5 kg ha−1 a−1), moderate (10 kg ha−1 a−1), and high nitrogen (20 kg ha−1 a−1)) on the biomass, morphological characteristics, chemical elements and nonstructural carbohydrates of fine roots in a Picea schrenkiana forest. We found that most fine roots were located in the 0–20 cm of soil layer across all nitrogen treatment groups (42.81–52.09% of the total biomass). Compared with the control, the biomass, specific root length and specific root area of the fine roots increased in the medium nitrogen treatment, whereas the fine roots biomass was lower in the high nitrogen treatment than in the other treatments. In fine roots, nitrogen addition promotes the absorption of nitrogen and phosphorus and their stoichiometric ratio, while reducing the content of nonstructural carbohydrates. The content of nonstructural carbohydrates in the small-diameter roots (< 1 mm in diamter) in each nitrogen treatment group was lower than that in the large-diameter roots. Correlation analysis showed that soil carbon and nitrogen were positively correlated with fine root biomass and specific root length and negatively correlated with the nonstructural carbohydrates. Our findings demonstrate that medium nitrogen addition is conducive to the development of fine root morphology, while excessive nitrogen can suppress the growth of root systems.

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