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Hao Y, Sun A, Lu C, Su JQ, Chen QL. Protists and fungi: Reinforcing urban soil ecological functions against flash droughts. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 950:175274. [PMID: 39117190 DOI: 10.1016/j.scitotenv.2024.175274] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/23/2024] [Revised: 07/31/2024] [Accepted: 08/02/2024] [Indexed: 08/10/2024]
Abstract
Rising instances of flash droughts are contributing to notable variability in soil moisture across terrestrial ecosystems. These phenomena challenge urban ecosystem services, yet the reaction of soil ecological functions (SEFs) to such events is poorly understood. This study investigates the responses of SEFs (about nutrient metabolism capacity and potential) and the microbiome under two specific scenarios: a flooding-drought sequence and a direct drought condition. Using quantitative microbial element cycling analysis, high-throughput sequencing, and enzyme activity measurements, we found that unlike in forests, the microbial composition in urban soils remained unchanged during flash drought conditions. However, SEFs were affected in both settings. Correlation analysis and Mantel test showed that forest soils exhibited more complex interactions among soil moisture, properties, and microbial communities. Positive linear correlation revealed that bacteria were the sole drivers of SEFs. Interestingly, while multi-threshold results suggested bacterial α diversity impeded the maximization of SEFs in urban soils, fungi and protists had a beneficial impact. Cross-domain network of urban soils had higher number of nodes and edges, but lower average degree and robustness than forest soils. Mantel test revealed that fungi and protist had significant correlations with bacterial composition in forest soils, but not in urban soils. In the urban network, the degree and eigenvector centrality of bacterial, fungal and protistan ASVs were significantly lower compared to those in the forest. These results suggest that the lower robustness of the microbial network in urban soils is attributed to limited interactions among fungi, consumer protists, and bacteria, contributing to the failure of microbial-driven ecological functions. Overall, our findings emphasize the critical role of fungi and protists in shielding urban soils from drought-induced disturbances and in enhancing the resistance of urban ecological functions amidst environmental changes.
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Affiliation(s)
- Yilong Hao
- Key Laboratory of Urban Environment and Health, Ningbo Observation and Research Station, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China; University of Chinese Academy of Sciences, Beijing 100049, China; Zhejiang Key Laboratory of Urban Environmental Processes and Pollution Control, CAS Haixi Industrial Technology Innovation Center in Beilun, Ningbo 315830, China
| | - Anqi Sun
- Key Laboratory of Urban Environment and Health, Ningbo Observation and Research Station, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China; Zhejiang Key Laboratory of Urban Environmental Processes and Pollution Control, CAS Haixi Industrial Technology Innovation Center in Beilun, Ningbo 315830, China
| | - Changyi Lu
- Key Laboratory of Urban Environment and Health, Ningbo Observation and Research Station, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China; Zhejiang Key Laboratory of Urban Environmental Processes and Pollution Control, CAS Haixi Industrial Technology Innovation Center in Beilun, Ningbo 315830, China.
| | - Jian-Qiang Su
- Key Laboratory of Urban Environment and Health, Ningbo Observation and Research Station, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China
| | - Qing-Lin Chen
- Key Laboratory of Urban Environment and Health, Ningbo Observation and Research Station, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China; Zhejiang Key Laboratory of Urban Environmental Processes and Pollution Control, CAS Haixi Industrial Technology Innovation Center in Beilun, Ningbo 315830, China.
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Xia H, Zhang T, Li X, He T, Wang X, Zhang J, Zhang K. Effects of drought and nutrient deficiencies on the allocation of recently fixed carbon in a plant-soil-microbe system. TREE PHYSIOLOGY 2023; 43:1903-1916. [PMID: 37584459 DOI: 10.1093/treephys/tpad098] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/04/2023] [Revised: 07/18/2023] [Accepted: 08/08/2023] [Indexed: 08/17/2023]
Abstract
Carbon (C) allocation plays an important role in plant adaptation to water and nutrient stresses. However, the effects of drought and nutrient deficiencies on the allocation of recently fixed C in the plant-soil-microbe system remain largely unknown. Herein, we studied the response of C allocation of Sophora moorcroftiana (an indigenous pioneer shrub in Tibet) to drought, nitrogen (N) deficiency and phosphorus (P) deficiency using a microcosm experiment. The 13CO2 continuous labeling was used to trace C allocation in the plant-soil-microbe system. We found that drought significantly reduced plant 13C, but it increased 13C accumulation in soil. The decreased plant 13C under drought was attributed to the decrease of 13C in stem and root rather than that in leaf. The excess 13C fraction in the microbial biomass (MB13C) was reduced by N deficiency, but it was not affected by the combination of drought and N deficiency, indicating that drought weakened the effects of N deficiency on MB13C. By contrast, MB13C increased under the combination of drought and P deficiency, suggesting that drought enhanced the effects of P deficiency on MB13C. Drought and nutrient deficiencies regulated the belowground 13C allocation. Specifically, drought and P deficiency increased the allocation of 13C to root and N deficiency regulated the allocation of 13C to microbial biomass C and dissolved organic C in soil. Notably, soil 13C decreased with increasing plant 13C, while MB13C first decreased and then increased with increasing plant 13C. Overall, our study demonstrated that drought and nutrient deficiencies interactively affected C allocation in a plant-soil-microbe system and provided insights into C allocation strategies in response to multiple resource (water and nutrient) stresses under environmental changes.
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Affiliation(s)
- Huijuan Xia
- Key Laboratory of Aquatic Botany and Watershed Ecology, Wuhan Botanical Garden, Chinese Academy of Sciences, No. 201 Jiufeng 1 Road, East Lake High-Tech Development Zone, Wuhan 430074, P.R. China
| | - Tiantian Zhang
- College of Science, Tibet University, No. 10 Zangda East Road, Chengguan District, Lhasa 850000, P.R. China
| | - Xinshuai Li
- Key Laboratory of Aquatic Botany and Watershed Ecology, Wuhan Botanical Garden, Chinese Academy of Sciences, No. 201 Jiufeng 1 Road, East Lake High-Tech Development Zone, Wuhan 430074, P.R. China
| | - Tiehu He
- Key Laboratory of Aquatic Botany and Watershed Ecology, Wuhan Botanical Garden, Chinese Academy of Sciences, No. 201 Jiufeng 1 Road, East Lake High-Tech Development Zone, Wuhan 430074, P.R. China
| | - Xia Wang
- Key Laboratory of Aquatic Botany and Watershed Ecology, Wuhan Botanical Garden, Chinese Academy of Sciences, No. 201 Jiufeng 1 Road, East Lake High-Tech Development Zone, Wuhan 430074, P.R. China
| | - Jiehao Zhang
- Key Laboratory of Aquatic Botany and Watershed Ecology, Wuhan Botanical Garden, Chinese Academy of Sciences, No. 201 Jiufeng 1 Road, East Lake High-Tech Development Zone, Wuhan 430074, P.R. China
| | - Kerong Zhang
- Key Laboratory of Aquatic Botany and Watershed Ecology, Wuhan Botanical Garden, Chinese Academy of Sciences, No. 201 Jiufeng 1 Road, East Lake High-Tech Development Zone, Wuhan 430074, P.R. China
- College of Science, Tibet University, No. 10 Zangda East Road, Chengguan District, Lhasa 850000, P.R. China
- Danjiangkou Wetland Ecosystem Field Scientific Observation and Research Station, The Chinese Academy of Sciences & Hubei Province, No. 201 Jiufeng 1 Road, East Lake High-Tech Development Zone, Wuhan 430074, P.R. China
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Zeng W, Wang Z, Chen X, Yao X, Ma Z, Wang W. Nitrogen deficiency accelerates soil organic carbon decomposition in temperate degraded grasslands. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 881:163424. [PMID: 37054788 DOI: 10.1016/j.scitotenv.2023.163424] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/19/2022] [Revised: 03/24/2023] [Accepted: 04/06/2023] [Indexed: 04/15/2023]
Abstract
The impacts of nitrogen (N) availability on soil organic carbon (SOC) decomposition were often explored based on N enrichment (N+) experiments. However, many natural and anthropogenic processes often reduce soil N availability. There is no direct evidence about how decreased N availability (N-) affects SOC decomposition, and the mechanisms of microbe-driven SOC decomposition in response to N availability remain unclear. Here, we used ion-exchange membranes to simulate N-. Soil samples from four temperate grassland sites, ranging from non-degradation to extreme degradation, were incubated with the N- and N+ treatments. We found that the total cumulative carbon (C) release was promoted by the N- treatment (8.60 to 87.30 mg C/g Cinital) but was inhibited by the N+ treatment (-129.81 to -16.49 mg C/g Cinital), regardless of the degradation status. N- dramatically increased recalcitrant C decomposition by increasing soil pH at all grassland sites; while did not affect or even decreased labile C decomposition by significantly increasing microbial C use efficiency and soil microbial biomass N. Interestingly, the effects of N- and N+ on SOC decomposition was asymmetric; with increased grassland degradation, the SOC decomposition was more sensitive to N- than to N+. Our results provide direct evidence for the different effects and mechanisms of N- on SOC decomposition and should be considered in soil process models to better predict the response of the nutrient cycle to global change.
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Affiliation(s)
- Wenjing Zeng
- Qianyanzhou Ecological Research Station, Key Laboratory of Ecosystem Network Observation and Modeling, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing, China; Department of Ecology, College of Urban and Environmental Sciences, Key Laboratory for Earth Surface Processes of the Ministry of Education, Peking University, Beijing, China
| | - Zhaodi Wang
- Department of Ecology, College of Urban and Environmental Sciences, Key Laboratory for Earth Surface Processes of the Ministry of Education, Peking University, Beijing, China
| | - Xinyue Chen
- Department of Ecology, College of Urban and Environmental Sciences, Key Laboratory for Earth Surface Processes of the Ministry of Education, Peking University, Beijing, China
| | - Xiaodong Yao
- Department of Ecology, College of Urban and Environmental Sciences, Key Laboratory for Earth Surface Processes of the Ministry of Education, Peking University, Beijing, China; State Key Laboratory for Subtropical Mountain Ecology of the Ministry of Science and Technology and Fujian Province, School of Geographical Sciences, Fujian Normal University, Fuzhou, China
| | - Zeqing Ma
- Qianyanzhou Ecological Research Station, Key Laboratory of Ecosystem Network Observation and Modeling, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing, China
| | - Wei Wang
- Department of Ecology, College of Urban and Environmental Sciences, Key Laboratory for Earth Surface Processes of the Ministry of Education, Peking University, Beijing, China.
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Zhang H, Dong L, Yao X, Wang W. Soil fertility shifts the relative importance of saprotrophic and mycorrhizal fungi for maintaining ecosystem stability. GLOBAL CHANGE BIOLOGY 2023; 29:1206-1216. [PMID: 36423217 DOI: 10.1111/gcb.16540] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/17/2022] [Accepted: 11/21/2022] [Indexed: 06/16/2023]
Abstract
Soil microbial communities are essential for regulating the dynamics of plant productivity. However, how soil microbes mediate temporal stability of plant productivity at large scales across various soil fertility conditions remains unclear. Here, we combined a regional survey of 51 sites in the temperate grasslands of northern China with a global grassland survey of 120 sites to assess the potential roles of soil microbial diversity in regulating ecosystem stability. The temporal stability of plant productivity was quantified as the ratio of the mean normalized difference vegetation index to its standard deviation. Soil fungal diversity, but not bacterial diversity, was positively associated with ecosystem stability, and particular fungal functional groups determined ecosystem stability under contrasting conditions of soil fertility. The richness of soil fungal saprobes was positively correlated with ecosystem stability under high-fertility conditions, while a positive relationship was observed with the richness of mycorrhizal fungi under low-fertility conditions. These relationships were maintained after accounting for plant diversity and environmental factors. Our findings highlight the essential role of fungal diversity in maintaining stable grassland productivity, and suggest that future studies incorporating fungal functional groups into biodiversity-stability relationships will advance our understanding of their linkages under different fertility conditions.
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Affiliation(s)
- Hongjin Zhang
- Department of Ecology, College of Urban and Environmental Sciences and Key Laboratory for Earth Surface Processes of the Ministry of Education, Peking University, Beijing, China
| | - Lizheng Dong
- Department of Ecology, College of Urban and Environmental Sciences and Key Laboratory for Earth Surface Processes of the Ministry of Education, Peking University, Beijing, China
| | - Xiaodong Yao
- Department of Ecology, College of Urban and Environmental Sciences and Key Laboratory for Earth Surface Processes of the Ministry of Education, Peking University, Beijing, China
- State Key Laboratory for Subtropical Mountain Ecology of the Ministry of Science and Technology and Fujian Province, School of Geographical Sciences, Fujian Normal University, Fuzhou, China
| | - Wei Wang
- Department of Ecology, College of Urban and Environmental Sciences and Key Laboratory for Earth Surface Processes of the Ministry of Education, Peking University, Beijing, China
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