Glomalin-related soil protein responses to elevated CO2 and nitrogen addition in a subtropical forest : Potential consequences for soil carbon accumulation
(2015) In Soil Biology and Biochemistry 83. p.142-149- Abstract
According to the economy theory, plants should preferentially allocate photosynthate to acquire below-ground resources under elevated atmospheric carbon dioxide (eCO2) but decrease below-ground C allocation when nitrogen (N) is sufficient for plant growth. Arbuscular mycorrhizae (AM) represent a critical mechanism of below-ground nutrient acquisition for plants. The dynamics of arbuscular mycorrhizal fungi (AMF) could therefore reflect the response of plant C allocation under eCO2 and N addition. We examined the responses of glomalin-related soil protein (GRSP) to eCO2 (approximately 700μmolmol-1 CO2) and/or N addition (100kgNha-1yr-1 as... (More)
According to the economy theory, plants should preferentially allocate photosynthate to acquire below-ground resources under elevated atmospheric carbon dioxide (eCO2) but decrease below-ground C allocation when nitrogen (N) is sufficient for plant growth. Arbuscular mycorrhizae (AM) represent a critical mechanism of below-ground nutrient acquisition for plants. The dynamics of arbuscular mycorrhizal fungi (AMF) could therefore reflect the response of plant C allocation under eCO2 and N addition. We examined the responses of glomalin-related soil protein (GRSP) to eCO2 (approximately 700μmolmol-1 CO2) and/or N addition (100kgNha-1yr-1 as NH4NO3) in a modeled subtropical forest to better understand its potential influence on soil C storage. We hypothesized that GRSP would increase under eCO2 and decrease under N addition. Furthermore, the positive effects of eCO2 on GRSP would be offset by extra N addition, and GRSP would remain unchanged under combined eCO2 and N addition. Our results showed that the mean concentrations of easily extractable GRSP (EE-GRSP) and total GRSP (T-GRSP) were 0.35±0.05 and 0.72±0.13mgCcm-3, respectively, which accounted for 2.76±0.53% and 5.67±0.92% of soil organic carbon (SOC) in the 0-10cm soil layer. Elevated CO2 significantly increased T-GRSP by 35.02% but decreased EE-GRSP by 5.09% in the top 10cm soil layer. The opposite responses of T-GRSP and EE-GRSP to eCO2 might result from an unchanged photosynthate investment to AMF with possible changes in their decomposition rates. The effect of N on GRSP was contrary to our hypothesis, i.e., there was a 1.72%-48.49% increase in T-GRSP and a slightly increase in EE-GRSP. Both EE-GRSP and T-GRSP concentrations increased under the combination of eCO2 and N addition, which was inconsistent with our hypothesis. The significant increase of EE-GRSP under the combination of eCO2 and N addition was partly caused by more rapid plant growth and reduced microbial diversity, and the marginal increase of T-GRSP indicated that the interaction between eCO2 and N addition offset their independent effects. In addition, the relatively higher accumulation ratios of GRSP (22.6±13.6%) compared with SOC (15.9±9.4%) indicated that more rapid GRSP deposition in the soil might accelerate SOC accumulation under eCO2 and N addition. Our results will improve the understanding of the functioning of GRSP in soil C sequestration under global environmental change scenarios.
(Less)
- author
- Zhang, Jing LU ; Tang, Xuli ; He, Xinhua and Liu, Juxiu
- publishing date
- 2015-04-01
- type
- Contribution to journal
- publication status
- published
- subject
- keywords
- Elevated CO, Glomalin, N deposition, Soil organic carbon, Subtropical forest
- in
- Soil Biology and Biochemistry
- volume
- 83
- pages
- 8 pages
- publisher
- Elsevier
- external identifiers
-
- scopus:84923063159
- ISSN
- 0038-0717
- DOI
- 10.1016/j.soilbio.2015.01.023
- language
- English
- LU publication?
- no
- id
- f2234384-df4b-4a0e-9a82-fbf57fc1d69b
- date added to LUP
- 2016-10-17 15:56:41
- date last changed
- 2022-04-24 18:15:51
@article{f2234384-df4b-4a0e-9a82-fbf57fc1d69b, abstract = {{<p>According to the economy theory, plants should preferentially allocate photosynthate to acquire below-ground resources under elevated atmospheric carbon dioxide (eCO<sub>2</sub>) but decrease below-ground C allocation when nitrogen (N) is sufficient for plant growth. Arbuscular mycorrhizae (AM) represent a critical mechanism of below-ground nutrient acquisition for plants. The dynamics of arbuscular mycorrhizal fungi (AMF) could therefore reflect the response of plant C allocation under eCO<sub>2</sub> and N addition. We examined the responses of glomalin-related soil protein (GRSP) to eCO<sub>2</sub> (approximately 700μmolmol<sup>-1</sup> CO<sub>2</sub>) and/or N addition (100kgNha<sup>-1</sup>yr<sup>-1</sup> as NH<sub>4</sub>NO<sub>3</sub>) in a modeled subtropical forest to better understand its potential influence on soil C storage. We hypothesized that GRSP would increase under eCO<sub>2</sub> and decrease under N addition. Furthermore, the positive effects of eCO<sub>2</sub> on GRSP would be offset by extra N addition, and GRSP would remain unchanged under combined eCO<sub>2</sub> and N addition. Our results showed that the mean concentrations of easily extractable GRSP (EE-GRSP) and total GRSP (T-GRSP) were 0.35±0.05 and 0.72±0.13mgCcm<sup>-3</sup>, respectively, which accounted for 2.76±0.53% and 5.67±0.92% of soil organic carbon (SOC) in the 0-10cm soil layer. Elevated CO<sub>2</sub> significantly increased T-GRSP by 35.02% but decreased EE-GRSP by 5.09% in the top 10cm soil layer. The opposite responses of T-GRSP and EE-GRSP to eCO<sub>2</sub> might result from an unchanged photosynthate investment to AMF with possible changes in their decomposition rates. The effect of N on GRSP was contrary to our hypothesis, i.e., there was a 1.72%-48.49% increase in T-GRSP and a slightly increase in EE-GRSP. Both EE-GRSP and T-GRSP concentrations increased under the combination of eCO<sub>2</sub> and N addition, which was inconsistent with our hypothesis. The significant increase of EE-GRSP under the combination of eCO<sub>2</sub> and N addition was partly caused by more rapid plant growth and reduced microbial diversity, and the marginal increase of T-GRSP indicated that the interaction between eCO<sub>2</sub> and N addition offset their independent effects. In addition, the relatively higher accumulation ratios of GRSP (22.6±13.6%) compared with SOC (15.9±9.4%) indicated that more rapid GRSP deposition in the soil might accelerate SOC accumulation under eCO<sub>2</sub> and N addition. Our results will improve the understanding of the functioning of GRSP in soil C sequestration under global environmental change scenarios.</p>}}, author = {{Zhang, Jing and Tang, Xuli and He, Xinhua and Liu, Juxiu}}, issn = {{0038-0717}}, keywords = {{Elevated CO; Glomalin; N deposition; Soil organic carbon; Subtropical forest}}, language = {{eng}}, month = {{04}}, pages = {{142--149}}, publisher = {{Elsevier}}, series = {{Soil Biology and Biochemistry}}, title = {{Glomalin-related soil protein responses to elevated CO<sub>2</sub> and nitrogen addition in a subtropical forest : Potential consequences for soil carbon accumulation}}, url = {{http://dx.doi.org/10.1016/j.soilbio.2015.01.023}}, doi = {{10.1016/j.soilbio.2015.01.023}}, volume = {{83}}, year = {{2015}}, }