TY - JOUR
T1 - Disentangling the effects of edaphic and vegetational properties on soil aggregate stability in riparian zones along a gradient of flooding stress
AU - Liu, Yan
N1 - Funding Information:
We would like to thank Technology Innovation and Application Development Project of Chongqing (No. cstc2019jscx-dxwtBX0007), Chongqing Municipal Bureau of Science and Technology (No. cstc2020jcyj-zdxmX0018) and The University of Manchester for financial support. We thank Wenjuan Li andZhimei Liu for their valuable laboratory work. The insightful comments from Irene Cordero Herrera helped us to improve the manuscript. Finally, Yan Liu wants to thank to her partner Canglong Liu for invaluable support and patience over the past years.
Funding Information:
This work was funded by the National Natural Science Foundation of China (41771266, 41401243), Research Fund of State Key Laboratory of Soil and Sustainable Agriculture , Nanjing Institute of Soil Science, Chinese Academy of Science (No. Y812000005), the Youth Innovation Promotion Association of the Chinese Academy of Sciences (No. 2017391), and China Scholarship Council (CSC).
Publisher Copyright:
© 2020 Elsevier B.V.
PY - 2021/3/1
Y1 - 2021/3/1
N2 - Riparian zone is an ecotone between aquatic and terrestrial ecosystems, where soil aggregate stability is fundamental in supporting ecosystem functions and associated services. Yet, little is known about the resilience of riparian soil aggregate stability along a gradient of flooding stress. Here, we studied a riparian ecosystem across hillslopes in an early successional stage (a grass-dominated successional stage) along a gradient of flooding intensity (FI) of a hydrological regime triggered by operation of the Three Gorges Dam (TGD), China, which is one of the biggest dams in the world. Size distribution and stability of soil aggregates were tested by the wet-sieving method. Path analysis and structural equation modelling (SEM) were applied to determine the contributions of abiotic and biotic factors (including environmental variables, soil physicochemical properties, vegetational properties) to soil aggregate stability. Results showed that soil aggregate stability decreased with FI (a ratio of flooded days to whole days) which was a major determinant of soil aggregation. Also, increasing soil water content (SWC) greatly contributed to the decrease of aggregate stability, while contents of soil organic matter and total nitrogen correlated with an increase of aggregate stability. In terms of vegetational properties, aboveground biomass, plant species richness, and plant functional types partially explained soil aggregation. Significantly, distribution of the riparian dominant pioneer species, Cynodon dactylon, was affected by FI and SWC, and a higher density of the species led to a lower amount of small macro-aggregates (0.25–2 mm). Our study reveals that the soil stabilizing process is mainly governed by FI and edaphic factors, although vegetational properties have potentials to influence the soil aggregate stability. Our study highlights the vital processes for ecological restoration of riparian ecosystem in an early successional stage under a drastic change in hydrological regime.
AB - Riparian zone is an ecotone between aquatic and terrestrial ecosystems, where soil aggregate stability is fundamental in supporting ecosystem functions and associated services. Yet, little is known about the resilience of riparian soil aggregate stability along a gradient of flooding stress. Here, we studied a riparian ecosystem across hillslopes in an early successional stage (a grass-dominated successional stage) along a gradient of flooding intensity (FI) of a hydrological regime triggered by operation of the Three Gorges Dam (TGD), China, which is one of the biggest dams in the world. Size distribution and stability of soil aggregates were tested by the wet-sieving method. Path analysis and structural equation modelling (SEM) were applied to determine the contributions of abiotic and biotic factors (including environmental variables, soil physicochemical properties, vegetational properties) to soil aggregate stability. Results showed that soil aggregate stability decreased with FI (a ratio of flooded days to whole days) which was a major determinant of soil aggregation. Also, increasing soil water content (SWC) greatly contributed to the decrease of aggregate stability, while contents of soil organic matter and total nitrogen correlated with an increase of aggregate stability. In terms of vegetational properties, aboveground biomass, plant species richness, and plant functional types partially explained soil aggregation. Significantly, distribution of the riparian dominant pioneer species, Cynodon dactylon, was affected by FI and SWC, and a higher density of the species led to a lower amount of small macro-aggregates (0.25–2 mm). Our study reveals that the soil stabilizing process is mainly governed by FI and edaphic factors, although vegetational properties have potentials to influence the soil aggregate stability. Our study highlights the vital processes for ecological restoration of riparian ecosystem in an early successional stage under a drastic change in hydrological regime.
KW - Environmental stress
KW - Flooding intensity
KW - Plant community
KW - Soil physicochemical property
KW - Structural equation modelling
KW - Three Gorges Dam
UR - http://www.scopus.com/inward/record.url?scp=85098739499&partnerID=8YFLogxK
U2 - 10.1016/j.geoderma.2020.114883
DO - 10.1016/j.geoderma.2020.114883
M3 - Article
SN - 0016-7061
VL - 385
JO - Geoderma
JF - Geoderma
M1 - 114883
ER -