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Randé H, Michalet R, Nemer D, Delerue F. Relative contribution of canopy and soil effects between plants with different metal tolerance along a metal pollution gradient. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 904:166905. [PMID: 37699491 DOI: 10.1016/j.scitotenv.2023.166905] [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: 06/21/2023] [Revised: 09/05/2023] [Accepted: 09/05/2023] [Indexed: 09/14/2023]
Abstract
Multiple effects, operating either on the long-term (soil-engineering effects) or on the short-term during plant life (microclimate modification or resources pre-emption), can act simultaneously and determine the outcome of plant-plant interactions. These diverse effects have not been disentangled along a gradient of metal/metalloid pollution, although this is crucial for understanding the dominant species turnover along the gradient, and thus the driving processes of facilitation recurrently found in metalliferous ecosystems, which could help improving ecological restoration of these degraded ecosystems. Here, we experimentally assessed different short-term effects of two dominant forbs of highly polluted habitats (Hutchinsia alpina and Arenaria multicaulis, tolerant to metal stress) and two grasses of less polluted habitats (Agrostis capillaris and Festuca rubra, less tolerant to metal stress) on target plant species (the same as the dominant species mentioned above) transplanted along a large metal pollution gradient. Additionally, in highly polluted environments, we differentiated short- from long-term effects of the two metallicolous forbs, which had different abilities to concentrate metals in their leaves. In line with other studies along metal gradients, variation of short-term interactions appeared to follow the Stress Gradient Hypothesis for plants less adapted to metal pollution (p = 0.030), with positive interactions dominating in most severe areas. Regarding long-term effects, the species with highest leaf metal-accumulation showed no negative effect contrary to the Elemental allelopathy Hypothesis. Long-term effects of the species with lower leaf-metal accumulation could not be determined because of the occurrence of an unexpected difference in micro-habitat conditions (soil depth and humidity) for this species along the metal pollution gradient. Increasing short-term facilitation along metal pollution gradients, which confirmed previous studies, is promising for improving conditions and restoring the most polluted environments. However, long-term results stressed the difficulty to quantify these effects given that these areas are highly fragmented and heterogeneous.
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Affiliation(s)
- Hugo Randé
- Univ. Bordeaux, CNRS, Bordeaux INP, EPOC, UMR 5805, F-33600 Pessac, France
| | - Richard Michalet
- Univ. Bordeaux, CNRS, Bordeaux INP, EPOC, UMR 5805, F-33600 Pessac, France
| | - David Nemer
- Univ. Bordeaux, CNRS, Bordeaux INP, EPOC, UMR 5805, F-33600 Pessac, France
| | - Florian Delerue
- Univ. Bordeaux, CNRS, Bordeaux INP, EPOC, UMR 5805, F-33600 Pessac, France.
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Liu Z, Michalet R, Wang C, Wang Y, Chen J, Cui H, Song H, Wang J, Yang Z, An L, Xiao S, Chen S. Contrasting effects of two phenotypes of an alpine cushion plant on understory species drive community assembly. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 859:160154. [PMID: 36375548 DOI: 10.1016/j.scitotenv.2022.160154] [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: 07/02/2022] [Revised: 10/24/2022] [Accepted: 11/09/2022] [Indexed: 06/16/2023]
Abstract
In alpine systems, cushion plants act as foundation species by ameliorating local environmental conditions. Empirical studies indicate that contrasting phenotypes of alpine cushion species have different effects on understory plant species, either facilitative or competitive. Furthermore, dependent species within each community type might also exhibit different responses to each cushion phenotype, which can be clustered into several "response groups". Additionally, these species-groups specific responses to alpine cushion species phenotypes could alter community assembly. However, very few studies have assessed responses of dependent communities at species-group levels, in particular for both above- and below-ground communities. Here, we selected a loose and a tight phenotype of the alpine cushion species Thylacospermum caespitosum in two sites of northwest China, and use the relative intensity of interactions index to quantify cushion plant effects on subordinate communities of plants and soil fungi and bacteria. We assessed variations in responses of both above- and below-ground organisms to cushion plant effects at species-group level. Species-group level analyses showed that the effects of the phenotype varied among groups of each of the three community types, and different species-groups were composed by unique taxa. Additionally, we found that loose cushions enhanced stochastic processes in community assembly, for plants and soil fungi but not for soil bacteria. These variations of phenotypic effects on different species-group induced contrasting taxonomic composition between groups, and alter community assembly thereby. Our study highlights the occurrence of contrasting effects of two phenotypes of a foundation cushion plant on understory plants, soil fungi and bacteria community composition, but not necessarily on their richness. We also showed that assessing responses of understory species at the species-group level allows a more realistic and mechanistic understanding of biotic interactions both for above- and below-ground communities.
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Affiliation(s)
- Ziyang Liu
- Key Laboratory of Cell Activities and Stress Adaptations Ministry of Education, School of Life Sciences, Lanzhou University, Tianshui Road 222, Lanzhou, Gansu, People's Republic of China
| | - Richard Michalet
- Environnements et Paléoenvironnements Océaniques et Continentaux, University of Bordeaux, Bordeaux, France
| | - Chenyue Wang
- Key Laboratory of Cell Activities and Stress Adaptations Ministry of Education, School of Life Sciences, Lanzhou University, Tianshui Road 222, Lanzhou, Gansu, People's Republic of China
| | - Yajun Wang
- Key Laboratory of Cell Activities and Stress Adaptations Ministry of Education, School of Life Sciences, Lanzhou University, Tianshui Road 222, Lanzhou, Gansu, People's Republic of China
| | - Jingwei Chen
- State Key Laboratory of Herbage Improvement and Grassland Agro-ecosystems, College of Ecology, Lanzhou University, Tianshui Road 222, Lanzhou, Gansu, People's Republic of China
| | - Hanwen Cui
- State Key Laboratory of Herbage Improvement and Grassland Agro-ecosystems, College of Ecology, Lanzhou University, Tianshui Road 222, Lanzhou, Gansu, People's Republic of China
| | - Hongxian Song
- Key Laboratory of Cell Activities and Stress Adaptations Ministry of Education, School of Life Sciences, Lanzhou University, Tianshui Road 222, Lanzhou, Gansu, People's Republic of China
| | - Jiajia Wang
- Key Laboratory of Cell Activities and Stress Adaptations Ministry of Education, School of Life Sciences, Lanzhou University, Tianshui Road 222, Lanzhou, Gansu, People's Republic of China
| | - Zi Yang
- Key Laboratory of Cell Activities and Stress Adaptations Ministry of Education, School of Life Sciences, Lanzhou University, Tianshui Road 222, Lanzhou, Gansu, People's Republic of China
| | - Lizhe An
- Key Laboratory of Cell Activities and Stress Adaptations Ministry of Education, School of Life Sciences, Lanzhou University, Tianshui Road 222, Lanzhou, Gansu, People's Republic of China
| | - Sa Xiao
- State Key Laboratory of Herbage Improvement and Grassland Agro-ecosystems, College of Ecology, Lanzhou University, Tianshui Road 222, Lanzhou, Gansu, People's Republic of China
| | - Shuyan Chen
- Key Laboratory of Cell Activities and Stress Adaptations Ministry of Education, School of Life Sciences, Lanzhou University, Tianshui Road 222, Lanzhou, Gansu, People's Republic of China.
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Chaieb G, Wang X, Abdelly C, Michalet R. Shift from short‐term competition to facilitation with drought stress is due to a decrease in long‐term facilitation. OIKOS 2020. [DOI: 10.1111/oik.07528] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Affiliation(s)
- Ghassen Chaieb
- Faculty of Sciences of Bizerte, Univ. of Carthage Zarzouna Tunisia
- Univ. of Bordeaux, UMR CNRS 5805 EPOC, Allée Geoffroy Saint‐Hilaire – CS 50023 FR‐33615 Pessac France
| | - Xiangtai Wang
- State Key Laboratory of Grassland and Agro‐ecosystems, School of Life Sciences, Lanzhou Univ., Lanzhou Gansu PR China
| | - Chedly Abdelly
- Laboratory of Extremophiles Plants, Center of Biotechnology of Borj Cedria, 2050 Tunisia
| | - Richard Michalet
- Univ. of Bordeaux, UMR CNRS 5805 EPOC, Allée Geoffroy Saint‐Hilaire – CS 50023 FR‐33615 Pessac France
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Wang C, Michalet R, Liu Z, Jiang X, Wang X, Zhang G, An L, Chen S, Xiao S. Disentangling Large- and Small-Scale Abiotic and Biotic Factors Shaping Soil Microbial Communities in an Alpine Cushion Plant System. Front Microbiol 2020; 11:925. [PMID: 32528430 PMCID: PMC7262953 DOI: 10.3389/fmicb.2020.00925] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2019] [Accepted: 04/20/2020] [Indexed: 12/20/2022] Open
Abstract
Microorganisms play a crucial role in biogeochemical cycles and ecosystem processes, but the key factors driving microbial community structure are poorly understood, particularly in alpine environments. In this study, we aim to disentangle the relative contribution of abiotic and biotic factors shaping bacterial and fungal community structure at large and small spatial and integration scales in an alpine system dominated by a stress-tolerant cushion species Thylacospermum ceaspitosum. These effects were assessed in two mountain ranges of northwest China and for two contrasting phenotypes of the cushion species inhabiting two different microtopographic positions. The large- and small-scale abiotic effects include the site and microhabitat effects, respectively, while the large- and small-scale biotic effects include the effects of cushion presence and cushion phenotype, respectively. Soil microbial communities were characterized by Illumina Miseq sequencing. Uni- and multivariate statistics were used to test the effects of abiotic and biotic factors at both scales. Results indicated that the site effect representing the soil pH and abiotic hydrothermal conditions mainly affected bacterial community structure, whereas fungal community structure was mainly affected by biotic factors with an equal contribution of cushion presence and cushion phenotype effects. Future studies should analyze the direct factors contributing to shaping microbial community structure in particular of the cushion phenotypes.
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Affiliation(s)
- Chenyue Wang
- Ministry of Education Key Laboratory of Cell Activities and Stress Adaptations, Lanzhou University, Lanzhou, China
| | - Richard Michalet
- Environnements et Paléoenvironnements Océaniques et Continentaux, University of Bordeaux, Bordeaux, France
| | - Ziyang Liu
- Ministry of Education Key Laboratory of Cell Activities and Stress Adaptations, Lanzhou University, Lanzhou, China
| | - Xingpei Jiang
- Ministry of Education Key Laboratory of Cell Activities and Stress Adaptations, Lanzhou University, Lanzhou, China
| | - Xiangtai Wang
- Ministry of Education Key Laboratory of Cell Activities and Stress Adaptations, Lanzhou University, Lanzhou, China
| | - Gaosen Zhang
- Key Laboratory of Desert and Desertification, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou, China.,Key Laboratory of Extreme Environmental Microbial Resources and Engineering, Lanzhou, China
| | - Lizhe An
- Ministry of Education Key Laboratory of Cell Activities and Stress Adaptations, Lanzhou University, Lanzhou, China
| | - Shuyan Chen
- Ministry of Education Key Laboratory of Cell Activities and Stress Adaptations, Lanzhou University, Lanzhou, China
| | - Sa Xiao
- Ministry of Education Key Laboratory of Cell Activities and Stress Adaptations, Lanzhou University, Lanzhou, China
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Melfo A, Callaway RM, Llambí LD. Interactions between nurse plants and parasitic beneficiaries: A theoretical approach to indirect facilitation. J Theor Biol 2020; 494:110238. [PMID: 32151620 DOI: 10.1016/j.jtbi.2020.110238] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2019] [Revised: 02/08/2020] [Accepted: 03/04/2020] [Indexed: 11/29/2022]
Abstract
When a nurse species facilitates the density of more than one species, strong indirect interactions can occur between the facilitated, or beneficiary, species, and these could lead to cascading interactive effects on community dynamics. In this context, negative effects of beneficiaries on the growth or reproduction of nurses are much more common than positive effects. This suggests beneficiaries frequently act as parasites of their nurses, and the consequences of this are largely unexplored. Our general aim is to analyze whether competition between parasitic beneficiaries can lead to indirect facilitation to nurse species and how this influences nurse-beneficiary systems. We explored potential outcomes of such reciprocal interactions in the general case of one facilitator and two facultative parasitic beneficiary species with different strategies for competing for space, one having a high carrying capacity but low maximum intrinsic growth rate (K-species), and the other having low carrying capacity but a higher intrinsic growth rate (r-species). These are defined in terms of the logistic equation, and reflect the abundances they can reach when growing alone. By considering a set of ordinary differential equations for the abundances of the nurse and the two parasitic beneficiaries in the mean-field approximation (where spatial correlations do not play a role), we first show analytically that coexistence of the three species is only possible when the r-species beneficiary is, at the same time, more harmful than the K-species and receives more benefit from the nurse. We then show that only the K-species can indirectly facilitate the nurse in such system. These are general, analytic results, independent of particular values of the parameters. We then explore these results using a 2-D lattice model informed by cushion plants in alpine ecosystems, and their interactions with beneficiaries with r and K strategies. Interesting spatial effects emerge in this case, such as a seeding effect: facilitation by the nurse increases beneficiary abundances also outside nurse patches. These in turn generate a negative feedback to the nurse, due to local competition for space near its edge. Spatial distribution effects are also crucial for relaxing the conditions for the survival of the r-species, allowing an r-strategist with weaker parasitic effects to indirectly facilitate the nurse through suppression of a more harmful K-species. Unexpectedly, this also has an indirect positive effect on the K species because of increased abundance of nurses. In the case of the r-species representing a ruderal invader, our lattice results would suggest that invaders have the potential to benefit both nurse and native beneficiary species via indirect facilitation. More generally, our results indicate that facilitation of more than one other species varying in competitive ability and which act as parasites on a nurse, can in turn promote indirect facilitation effects. This form of indirect facilitation has not been explicitly studied before, although it may create substantial conditionality in the outcomes of interactions among multiple species and the dynamics of nurse-beneficiary systems.
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Affiliation(s)
- Alejandra Melfo
- Centro de Física Fundamental, Departamento de Física, Universidad de Los Andes, Mérida 5101, Venezuela.
| | | | - Luis D Llambí
- Instituto de Ciencias Ambientales y Ecológicas, Universidad de Los Andes, Mérida 5101, Venezuela
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Pistón N, Michalet R, Schöb C, Macek P, Armas C, Pugnaire FI. The balance of canopy and soil effects determines intraspecific differences in foundation species’ effects on associated plants. Funct Ecol 2018. [DOI: 10.1111/1365-2435.13139] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Nuria Pistón
- Estación Experimental de Zonas Áridas (EEZA‐CSIC) Almería Spain
- Nuria Pistón, Departamento de EcologíaInstituto de BiologiaUniversidade Federal do Rio de Janeiro (UFRJ) Rio de Janeiro Brazil
| | | | - Christian Schöb
- Estación Experimental de Zonas Áridas (EEZA‐CSIC) Almería Spain
- Christian Schöb, Department of Environmental System ScienceSwiss Federal Institute of TechnologyETH Zurich Tannenstrasse 1 8092 Zürich Switzerland
| | - Petr Macek
- Estación Experimental de Zonas Áridas (EEZA‐CSIC) Almería Spain
- Petr Macek, Faculty of ScienceUniversity of South Bohemia Branišovská 1760 CZ‐370 05 České Budějovice Czech Republic
| | - Cristina Armas
- Estación Experimental de Zonas Áridas (EEZA‐CSIC) Almería Spain
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Jiang X, Michalet R, Chen S, Zhao L, Wang X, Wang C, An L, Xiao S. Phenotypic effects of the nurseThylacospermum caespitosumon dependent plant species along regional climate stress gradients. OIKOS 2017. [DOI: 10.1111/oik.04512] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Xingpei Jiang
- State Key Laboratory of Grassland and Agro-ecosystems, School of Life Sciences, Lanzhou Univ., 222 Tianshuinan Road; CN-730000 Lanzhou PR China
| | - Richard Michalet
- Univ. of Bordeaux, U.M.R. CNRS, Allée Geoffroy Saint-Hilaire; Pessac France
| | - Shuyan Chen
- Ministry of Education Key Laboratory of Three Gorges Reservoir Region's Eco-Environment, Chongqing Univ.; Chongqing PR China
| | - Liang Zhao
- Ministry of Education Key Laboratory of Three Gorges Reservoir Region's Eco-Environment, Chongqing Univ.; Chongqing PR China
| | - Xiangtai Wang
- State Key Laboratory of Grassland and Agro-ecosystems, School of Life Sciences, Lanzhou Univ., 222 Tianshuinan Road; CN-730000 Lanzhou PR China
| | - Chenyue Wang
- State Key Laboratory of Grassland and Agro-ecosystems, School of Life Sciences, Lanzhou Univ., 222 Tianshuinan Road; CN-730000 Lanzhou PR China
| | - Lizhe An
- State Key Laboratory of Grassland and Agro-ecosystems, School of Life Sciences, Lanzhou Univ., 222 Tianshuinan Road; CN-730000 Lanzhou PR China
| | - Sa Xiao
- State Key Laboratory of Grassland and Agro-ecosystems, School of Life Sciences, Lanzhou Univ., 222 Tianshuinan Road; CN-730000 Lanzhou PR China
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