Abstract
The water level fluctuation zone (WLFZ) of the Three Gorges Reservoir (TGR) represents a unique ecotone shaped by reversed hydrological rhythms that significantly influence plant dynamics and soil organic carbon (SOC) processes. However, the contribution of plants to SOC storage after the establishment of stable plant communities remains unclear. A field investigation and soil sampling were conducted in the WLFZ of the TGR in 2023, covering both the main stream and tributary regions in middle- (155-165 m) and high-elevation (165-175 m) zones. The plant composition, diversity, and carbon and nitrogen contents of soil and vegetation and the carbon stable isotope ratio signatures were analyzed. Results showed that plant diversity increased with elevation, while biomass allocation varied significantly between elevation zones. Cynodon dactylon (L.) Pers. had a significantly higher biomass than Xanthium strumarium L., both of which were identified as dominant species in the WLFZ based on their high importance values. The response of SOC storage to elevation differed between regions: in the main stream, SOC storage was 23% higher in the middle-elevation than in the high-elevation zone, while in the tributary, SOC storage in the high-elevation zone exceeding that in the middle-elevation zone by 38%. Soil total nitrogen and the C/N ratio were the primary factors controlling SOC storage, explaining 68.6% of the variance, while plant effects were relatively weak. Isotopic mixing model results indicated that X. strumarium contributed 34.84% to SOC storage at 165-175m, whereas C. dactylon contributed 21.06% at 155-165 m, but this difference occurred within the context of a minor overall plant contribution to SOC. These results highlight that SOC dynamics are primarily controlled by soil factors (soil nitrogen and the C/N ratio), with plants having a secondary effect.
Abstract from the paper’s OpenAlex record; open copy licensed cc-by-nc-nd. Read at the source ↗
The text the model read, with the source record’s inline markup (italics, sub- and superscripts) rendered and its character entities decoded; quote offsets refer to the raw text.
Claims 11
Claim · model-written summary
Plant diversity increased with elevation in the water-level fluctuation zone.
Verbatim
e1“Results showed that plant diversity increased with elevation”
e0“The water level fluctuation zone (WLFZ) of the Three Gorges Reservoir (TGR)”
t0“Dominant plants drive soil organic carbon storage”
Claim · model-written summary
Cynodon dactylon had significantly higher biomass than Xanthium strumarium.
- Taxon
- Cynodon dactylon (L.) Pers.
Cynodon dactylone2 - Outcome
- biomasse2
- Direction
- highere2
- Comparator
- Xanthium strumarium L.e2
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e2“Cynodon dactylon (L.) Pers. had a significantly higher biomass than Xanthium strumarium L., both of which were identified as dominant species in the WLFZ based on their high importance values”
t0“Dominant plants drive soil organic carbon storage”
Claim · model-written summary
Cynodon dactylon was a dominant species in the WLFZ based on high importance values.
- Taxon
- Cynodon dactylon (L.) Pers.Cynodon dactylone2
- Outcome
- dominant speciese2
- Qualifier
- based on their high importance valuese2
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e2“Cynodon dactylon (L.) Pers. had a significantly higher biomass than Xanthium strumarium L., both of which were identified as dominant species in the WLFZ based on their high importance values”
t0“Dominant plants drive soil organic carbon storage”
Claim · model-written summary
Xanthium strumarium was a dominant species in the WLFZ based on high importance values.
- Taxon
- Xanthium strumarium L.
Xanthium strumariume2 - Outcome
- dominant speciese2
- Qualifier
- based on their high importance valuese2
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e2“Cynodon dactylon (L.) Pers. had a significantly higher biomass than Xanthium strumarium L., both of which were identified as dominant species in the WLFZ based on their high importance values”
t0“Dominant plants drive soil organic carbon storage”
Claim · model-written summary
Biomass allocation varied significantly between elevation zones.
Verbatim
e3“biomass allocation varied significantly between elevation zones”
t0“Dominant plants drive soil organic carbon storage”
Claim · model-written summary
In the main stream, SOC storage was 23% higher in the middle-elevation zone than in the high-elevation zone.
Verbatim
e4“in the main stream, SOC storage was 23% higher in the middle-elevation than in the high-elevation zone”
t0“Dominant plants drive soil organic carbon storage”
Claim · model-written summary
In the tributary, SOC storage in the high-elevation zone exceeded that in the middle-elevation zone by 38%.
Verbatim
e5“in the tributary, SOC storage in the high-elevation zone exceeding that in the middle-elevation zone by 38%”
t0“Dominant plants drive soil organic carbon storage”
Claim · model-written summary
Soil total nitrogen and the C/N ratio were the primary factors controlling SOC storage, explaining 68.6% of the variance.
- Taxon
- Dominant plantst0
- Treatment
- Soil total nitrogen and the C/N ratioe6
- Outcome
- SOC storagee6
- Value
- 68.6%e6
- Qualifier
- explaining 68.6% of the variancee6
Not reportedDirection
Verbatim
e6“Soil total nitrogen and the C/N ratio were the primary factors controlling SOC storage, explaining 68.6% of the variance, while plant effects were relatively weak”
t0“Dominant plants drive soil organic carbon storage”
Claim · model-written summary
Plant effects on SOC storage were relatively weak.
Verbatim
e6“Soil total nitrogen and the C/N ratio were the primary factors controlling SOC storage, explaining 68.6% of the variance, while plant effects were relatively weak”
t0“Dominant plants drive soil organic carbon storage”
Claim · model-written summary
X. strumarium contributed 34.84% to SOC storage at 165-175 m.
- Taxon
- X. strumariumXanthium strumariume7
- Outcome
- SOC storagee7
- Value
- 34.84%e7
- Setting
- 165-175me7
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e7“Isotopic mixing model results indicated that X. strumarium contributed 34.84% to SOC storage at 165-175m”
t0“Dominant plants drive soil organic carbon storage”
Claim · model-written summary
C. dactylon contributed 21.06% to SOC storage at 155-165 m.
- Taxon
- C. dactylonCynodon dactylone6
- Outcome
- SOC storagee7
- Value
- 21.06%e6
- Setting
- 155-165 me6
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e7“Isotopic mixing model results indicated that X. strumarium contributed 34.84% to SOC storage at 165-175m”
e6“whereas C. dactylon contributed 21.06% at 155-165 m”
t0“Dominant plants drive soil organic carbon storage”