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Kandlikar GS. Quantifying soil microbial effects on plant species coexistence: A conceptual synthesis. AMERICAN JOURNAL OF BOTANY 2024; 111:e16316. [PMID: 38659131 DOI: 10.1002/ajb2.16316] [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: 11/01/2023] [Revised: 03/01/2024] [Accepted: 03/04/2024] [Indexed: 04/26/2024]
Abstract
Soil microorganisms play a critical role in shaping the biodiversity dynamics of plant communities. These microbial effects can arise through direct mediation of plant fitness by pathogens and mutualists, and over the past two decades, numerous studies have shined a spotlight on the role of dynamic feedbacks between plants and soil microorganisms as key determinants of plant species coexistence. Such feedbacks occur when plants modify the composition of the soil community, which in turn affects plant performance. Stimulated by a theoretical model developed in the 1990s, a bulk of the empirical evidence for microbial controls over plant coexistence comes from experiments that quantify plant growth in soil communities that were previously conditioned by conspecific or heterospecific plants. These studies have revealed that soil microbes can generate strong negative to positive frequency-dependent dynamics among plants. Even as soil microbes have become recognized as a key player in determining plant coexistence outcomes, the past few years have seen a renewed interest in expanding the conceptual foundations of this field. New results include re-interpretations of key metrics from classic two-species models, extensions of plant-soil feedback theory to multispecies communities, and frameworks to integrate plant-soil feedbacks with processes like intra- and interspecific competition. Here, I review the implications of theoretical developments for interpreting existing empirical results and highlight proposed analyses and designs for future experiments that can enable a more complete understanding of microbial regulation of plant community dynamics.
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Zhang P, Huang M, Chen C, Hu K, Ke J, Liu M, Xiao Y, Liu X. Contrasting roles of fungal and oomycete pathogens in mediating nitrogen addition and winter grazing effects on biomass. Ecology 2024; 105:e4254. [PMID: 38272568 DOI: 10.1002/ecy.4254] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/23/2023] [Revised: 10/26/2023] [Accepted: 12/21/2023] [Indexed: 01/27/2024]
Abstract
Both bottom-up and top-down processes modulate plant communities. Fungal and oomycete pathogens are most common in global grasslands, and due to differences in their physiology, function, host range, and life cycles, they may differentially affect plants (in both intensity and direction). However, how fungal and oomycete pathogens regulate bottom-up and top-down effects on plant community biomass remains unclear. To this end, we conducted a 3-year field experiment in an alpine meadow incorporating mammalian herbivore exclosure, fungicide/oomyceticide application, and nitrogen addition treatments. We arranged 12 blocks with half randomly assigned to be mammalian herbivore exclosures (fenced to exclude grazing sheep), and the other half were fenced most of the year but not in winter (winter grazing control). Six 2.5 × 2.5 m square plots were established in each block, with each of the six plots assigned as control, nitrogen addition, fungicide application, oomyceticide application, nitrogen addition + fungicide application, and nitrogen addition + oomyceticide application. We found that fungicide application significantly increased plant community biomass (mainly Poaceae species) under nitrogen addition and promoted the bottom-up effect of nitrogen addition on plant community biomass by altering the community-weighted mean of plant height (via species turnover). Meanwhile, oomyceticide application significantly increased plant community biomass (mainly Poaceae species) when mammalian herbivores were excluded and weakened the top-down effect of winter grazing on plant community biomass by driving intraspecific variation in plant height. Our results highlight that fungal and oomycete pathogens play important (but differing) roles in mediating the effects of nutrient availability and higher trophic levels on plant community biomass. Mechanistically, we demonstrated that plant pathogen-related modulation of plant community biomass is achieved by alterations to plant height. Overall, this study combines both community and disease ecology to reveal complex interactions among higher trophic levels and their potential impacts on terrestrial ecosystem functioning under human disturbance.
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Affiliation(s)
- Peng Zhang
- State Key Laboratory of Herbage Improvement and Grassland Agro-Ecosystems, College of Ecology, Lanzhou University, Lanzhou, P. R. China
| | - Mengjiao Huang
- State Key Laboratory of Herbage Improvement and Grassland Agro-Ecosystems, College of Ecology, Lanzhou University, Lanzhou, P. R. China
| | - Chaorui Chen
- State Key Laboratory of Herbage Improvement and Grassland Agro-Ecosystems, College of Ecology, Lanzhou University, Lanzhou, P. R. China
| | - Kui Hu
- State Key Laboratory of Herbage Improvement and Grassland Agro-Ecosystems, College of Ecology, Lanzhou University, Lanzhou, P. R. China
| | - Junsheng Ke
- State Key Laboratory of Herbage Improvement and Grassland Agro-Ecosystems, College of Ecology, Lanzhou University, Lanzhou, P. R. China
| | - Mu Liu
- State Key Laboratory of Herbage Improvement and Grassland Agro-Ecosystems, College of Ecology, Lanzhou University, Lanzhou, P. R. China
| | - Yao Xiao
- State Key Laboratory of Herbage Improvement and Grassland Agro-Ecosystems, College of Ecology, Lanzhou University, Lanzhou, P. R. China
| | - Xiang Liu
- State Key Laboratory of Herbage Improvement and Grassland Agro-Ecosystems, College of Ecology, Lanzhou University, Lanzhou, P. R. China
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Bennion LD, Ward D. Eastern redcedar roots create legacy effects that suppresses growth of prairie species. Ecol Evol 2023; 13:e10775. [PMID: 38089900 PMCID: PMC10711520 DOI: 10.1002/ece3.10775] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2023] [Revised: 10/19/2023] [Accepted: 11/14/2023] [Indexed: 10/16/2024] Open
Abstract
The expansion of woody species from their historical ranges into grasslands is a global problem. Understanding the mechanisms that enable species to successfully establish and then re-encroach following their removal is critical to effectively managing problem species. Legacy effects are a mechanism that could be critical to the reestablishment of woody encroachers following their removal. Legacy effects occur when a species alters the biotic and abiotic environment in a way that affects communities that establish subsequently. In this study, we assess whether the eastern redcedar (Juniperus virginiana), a North American woody encroacher, generates legacy effects that affect communities that establish following removal of this species from an experimental grass community. We conducted a series of experiments to evaluate the effects of J. virginiana, roots on the germination and growth of grasses and to determine if the effects of root-addition treatments were derived from a microbial or allelopathic origin. Aqueous extracts of J. virginiana roots were found to inhibit the germination of grasses. We found escalating suppression of overall community biomass and the biomass of each individual species with increasing root treatments. Finally, we determined the origin of the observed suppressive effect is unlikely to be of microbial origin. Synthesis: Our results suggest that J. virginiana exudes an allelochemical into soils that inhibits the growth of certain grasses and thus has the potential to have legacy effects on future occupants. We suggest that the inhibition of the development of grasses in areas where J. virginiana has been removed is a mechanism that may favor the reestablishment of J. virginiana. Our results indicate the legacy effects of J. virginiana must be considered when conducting removal and restoration of J. virginiana infested lands.
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Affiliation(s)
- Leland D. Bennion
- Department of Biological SciencesBoise State UniversityBoiseIdahoUSA
- Department of Biological SciencesKent State UniversityKentOhioUSA
| | - David Ward
- Department of Biological SciencesKent State UniversityKentOhioUSA
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Zhao Y, Liu X, Wang J, Nie Y, Huang M, Zhang L, Xiao Y, Zhang Z, Zhou S. Fungal pathogens increase community temporal stability through species asynchrony regardless of nutrient fertilization. Ecology 2023; 104:e4166. [PMID: 37671835 DOI: 10.1002/ecy.4166] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/01/2023] [Revised: 06/13/2023] [Accepted: 07/28/2023] [Indexed: 09/07/2023]
Abstract
Natural enemies and their interaction with host nutrient availability influence plant population dynamics, community structure, and ecosystem functions. However, the way in which these factors influence patterns of community stability, as well as the direct and indirect processes underlying that stability, remains unclear. Here, we investigated the separate and interactive roles of fungal/oomycete pathogens and nutrient fertilization on the temporal stability of community biomass and the potential mechanisms using a factorial experiment in an alpine meadow. We found that fungal pathogen exclusion reduced community temporal stability mainly through decreasing species asynchrony, while fertilization tended to reduce community temporal stability by decreasing species stability. However, there was no interaction between pathogen exclusion and nutrient fertilization. These effects were largely due to the direct effects of the treatments on plant biomass and not due to indirect effects mediated through plant diversity. Our findings highlight the need for a multitrophic perspective in field studies examining ecosystem stability.
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Affiliation(s)
- Yimin Zhao
- Key Laboratory of Agro-Forestry Environmental Processes and Ecological Regulation of Hainan Province, School of Ecology and Environment, Hainan University, Haikou, China
- Key Laboratory of Genetics and Germplasm Innovation of Tropical Special Forest Trees and Ornamental Plants, Ministry of Education, College of Forestry, Hainan University, Haikou, China
| | - Xiang Liu
- State Key Laboratory of Herbage Improvement and Grassland Agro-ecosystems, College of Ecology, Lanzhou University, Lanzhou, China
| | - Jianbin Wang
- Key Laboratory of Genetics and Germplasm Innovation of Tropical Special Forest Trees and Ornamental Plants, Ministry of Education, College of Forestry, Hainan University, Haikou, China
| | - Yu Nie
- Key Laboratory of Agro-Forestry Environmental Processes and Ecological Regulation of Hainan Province, School of Ecology and Environment, Hainan University, Haikou, China
- Key Laboratory of Genetics and Germplasm Innovation of Tropical Special Forest Trees and Ornamental Plants, Ministry of Education, College of Forestry, Hainan University, Haikou, China
| | - Mengjiao Huang
- Ministry of Education Key Laboratory for Biodiversity Science and Ecological Engineering, Coastal Ecosystems Research Station of the Yangtze River Estuary, Institute of Biodiversity Science, School of Life Sciences, Fudan University, Shanghai, China
| | - Li Zhang
- Co-Innovation Center for Sustainable Forestry in Southern China, Bamboo Research Institute, Nanjing Forestry University, Nanjing, China
| | - Yao Xiao
- State Key Laboratory of Herbage Improvement and Grassland Agro-ecosystems, College of Ecology, Lanzhou University, Lanzhou, China
| | - Zhenhua Zhang
- Qinghai Haibei National Field Research Station of Alpine Grassland Ecosystem, Northwest Institute of Plateau Biology, Chinese Academy of Sciences, Xining, China
| | - Shurong Zhou
- Key Laboratory of Genetics and Germplasm Innovation of Tropical Special Forest Trees and Ornamental Plants, Ministry of Education, College of Forestry, Hainan University, Haikou, China
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Xi N, McCarthy-Neumann S, Feng J, Wu H, Wang W, Semchenko M. Light availability and plant shade tolerance modify plant-microbial interactions and feedbacks in subtropical trees. THE NEW PHYTOLOGIST 2023; 238:393-404. [PMID: 36647239 DOI: 10.1111/nph.18737] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/02/2022] [Accepted: 01/08/2023] [Indexed: 06/17/2023]
Abstract
Plant-soil feedbacks (PSFs) are an important mechanism of species coexistence in forest communities. However, evidence remains limited for how light availability regulates PSFs in species with different shade tolerance via changes in plant-microbial interactions. Here we tested in a glasshouse experiment how PSFs changed as a function of light availability and tree shade tolerance. Soil bacterial and fungal communities were profiled using the 16S rRNA and ITS2 gene sequencing, respectively. Under low light, individual PSFs were positively related to shade tolerance, while the least shade-tolerant species produced the most positive PSFs under high light. Pairwise PSFs between species with contrasting shade tolerance were strongly positive under high light but negative under low light, thereby promoting the dominance of less shade-tolerant species in forest gaps and species coexistence under closed canopy, respectively. Under high light, PSFs were related to soil microbial composition and diversity, with the relative abundance of arbuscular mycorrhizal fungi being the primary driver of PSFs. Under low light, none of soil microbial properties were significantly related to PSFs. These findings indicate PSFs and plant shade tolerance interact to promote species coexistence and improve our understanding of how soil microbes contribute to variation in PSFs.
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Affiliation(s)
- Nianxun Xi
- Key Laboratory of Genetics and Germplasm Innovation of Tropical Special Forest Trees and Ornamental Plants, Ministry of Education, College of Forestry, Hainan University, Haikou, 570228, China
- State Key Laboratory of Biocontrol and School of Life Sciences, Sun Yat-Sen University, Guangzhou, 510275, China
| | - Sarah McCarthy-Neumann
- Department of Forestry, Michigan State University, East Lansing, MI, 48824, USA
- Department of Agricultural and Environmental Sciences, Tennessee State University, Nashville, TN, 37209, USA
| | - Jiayi Feng
- Key Laboratory of Vegetation Restoration and Management of Degraded Ecosystems, Guangdong Provincial Key Laboratory of Applied Botany, South China Botanical Garden, and Center for Plant Ecology, Core Botanical Gardens, Chinese Academy of Sciences, Xingke Road 723, Guangzhou, 510650, China
- Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Haibin Road 1119, Nansha, Guangzhou, 511458, China
| | - Hangyu Wu
- State Key Laboratory of Biocontrol and School of Life Sciences, Sun Yat-Sen University, Guangzhou, 510275, China
| | - Weitao Wang
- State Key Laboratory of Biocontrol and School of Life Sciences, Sun Yat-Sen University, Guangzhou, 510275, China
| | - Marina Semchenko
- Institute of Ecology and Earth Sciences, University of Tartu, Lai 40, 51005, Tartu, Estonia
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Liu X, Parker IM, Gilbert GS, Lu Y, Xiao Y, Zhang L, Huang M, Cheng Y, Zhang Z, Zhou S. Coexistence is stabilized by conspecific negative density dependence via fungal pathogens more than oomycete pathogens. Ecology 2022; 103:e3841. [DOI: 10.1002/ecy.3841] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/31/2021] [Revised: 04/15/2022] [Accepted: 06/16/2022] [Indexed: 11/10/2022]
Affiliation(s)
- Xiang Liu
- Key Laboratory of Genetics and Germplasm Innovation of Tropical Special Forest Trees and Ornamental Plants, Ministry of Education College of Forestry, Hainan University Haikou P. R. China
- State Key Laboratory of Grassland Agro‐Ecosystems College of Ecology, Lanzhou University Lanzhou P. R. China
| | - Ingrid M. Parker
- Department of Ecology and Evolutionary Biology University of California Santa Cruz California U.S.A
| | - Gregory S. Gilbert
- Department of Environmental Studies University of California Santa Cruz California U.S.A
| | - Yawen Lu
- Ministry of Education Key Laboratory for Biodiversity Science and Ecological Engineering Coastal Ecosystems Research Station of the Yangtze River Estuary, Institute of Biodiversity Science, School of Life Sciences, Fudan University Shanghai P. R. China
| | - Yao Xiao
- Ministry of Education Key Laboratory for Biodiversity Science and Ecological Engineering Coastal Ecosystems Research Station of the Yangtze River Estuary, Institute of Biodiversity Science, School of Life Sciences, Fudan University Shanghai P. R. China
| | - Li Zhang
- Ministry of Education Key Laboratory for Biodiversity Science and Ecological Engineering Coastal Ecosystems Research Station of the Yangtze River Estuary, Institute of Biodiversity Science, School of Life Sciences, Fudan University Shanghai P. R. China
| | - Mengjiao Huang
- Ministry of Education Key Laboratory for Biodiversity Science and Ecological Engineering Coastal Ecosystems Research Station of the Yangtze River Estuary, Institute of Biodiversity Science, School of Life Sciences, Fudan University Shanghai P. R. China
| | - Yikang Cheng
- Ministry of Education Key Laboratory for Biodiversity Science and Ecological Engineering Coastal Ecosystems Research Station of the Yangtze River Estuary, Institute of Biodiversity Science, School of Life Sciences, Fudan University Shanghai P. R. China
| | - Zhenhua Zhang
- Key Laboratory of Adaptation and Evolution of Plateau Biota Northwest Institute of Plateau Biology, Chinese Academy of Sciences Xining P. R. China
| | - Shurong Zhou
- Key Laboratory of Genetics and Germplasm Innovation of Tropical Special Forest Trees and Ornamental Plants, Ministry of Education College of Forestry, Hainan University Haikou P. R. China
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