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Liu W, Qiu K, Xie Y, Huang Y, Wang R, Li H, Meng W, He Y, Li Y, Li H, Zhao P, Yang Y. High-Throughput Absolute Quantification Sequencing Reveals that a Combination of Leguminous Shrubs Is Effective in Driving Soil Bacterial Diversity During the Process of Desertification Reversal. Microb Ecol 2022:10.1007/s00248-022-02151-0. [PMID: 36495359 DOI: 10.1007/s00248-022-02151-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/24/2022] [Accepted: 11/03/2022] [Indexed: 06/17/2023]
Abstract
Desertification leads to the extreme fragility of ecosystems and seriously threatens ecosystem functioning in desert areas. The planting of xerophytes, especially leguminous shrubs, is an effective and common means to reverse desertification. Soil microorganisms play a crucial role in nutrient cycling and energy flow in ecosystems. However, the effects of introducing leguminous shrubs on soil microbial diversity and the relevant mechanisms are not clear. Here, we employed the high-throughput absolute quantification 16S rRNA sequencing method to analyze the diversity of soil bacteria in sand-fixing areas of mixed shrublands with three combinations of shrubs, i.e., C. korshinskii × Corethrodendron scoparium (CaKCoS), C. korshinskii × Calligonum mongolicum (CaKCaM), and C. scoparium × C. mongolicum (CoSCaM), in the south of the Mu Us Sandy Land, China. This area suffered from moving dunes 20 years ago, but after introducing these shrubs to fix the dunes, the ecosystem was restored. Additionally, the effects of soil physicochemical properties on soil bacterial composition and diversity were analyzed with redundancy analysis (RDA) and structural equation modeling (SEM). It was found that the Shannon index of soil bacteria in CaKCoS was significantly higher than that in CaKCaM and CoSCaM, and the abundance of the dominant phyla, including Actinobacteria, Proteobacteria, Acidobacteria, Chloroflexi, Planctomycetes, Thaumarchaeota, Armatimonadetes, candidate_division_WPS-1, and Nitrospirae, increased significantly in CaKCoS and CaKCaM compared to that in CoSCaM. RDA showed that the majority of soil properties, such as total nitrogen (TN), available potassium (AK), N:P ratio, soil moisture (SM), and available phosphorus (AP), were important soil environmental factors affecting the abundance of the dominant phyla, and RDA1 and RDA2 accounted for 56.66% and 2.35% of the total variation, respectively. SEM showed that the soil bacterial α-diversity was positively affected by the soil organic carbon (SOC), N:P ratio, and total phosphorus (TP). Moreover, CaKCoS had higher SM, total carbon (TC), total potassium (TK), and AP than CaKCaM and CoSCaM. Collectively, these results highlight a conceptual framework in which the combination of leguminous shrubs can effectively drive soil bacterial diversity by improving soil physicochemical properties and maintaining ecosystem functioning during desertification reversal.
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Affiliation(s)
- Wangsuo Liu
- School of Agriculture, Ningxia University, Yinchuan, 750021, Ningxia, China
- Ningxia Grape Wine and Desertification Prevention Technical College, Yinchuan, 750199, Ningxia, China
| | - Kaiyang Qiu
- School of Agriculture, Ningxia University, Yinchuan, 750021, Ningxia, China.
- Ningxia Grassland and Animal Husbandry Engineering Technology Research Center, Yinchuan, 750021, Ningxia, China.
- Breeding Base for State Key Laboratory of Land Degradation and Ecological Restoration of Northwest China, Yinchuan, 750021, Ningxia, China.
| | - Yingzhong Xie
- School of Agriculture, Ningxia University, Yinchuan, 750021, Ningxia, China
- Ningxia Grassland and Animal Husbandry Engineering Technology Research Center, Yinchuan, 750021, Ningxia, China
- Breeding Base for State Key Laboratory of Land Degradation and Ecological Restoration of Northwest China, Yinchuan, 750021, Ningxia, China
| | - Yeyun Huang
- School of Agriculture, Ningxia University, Yinchuan, 750021, Ningxia, China
| | - Ruixia Wang
- Ningxia Administration of Baijitan National Nature Reserve, Lingwu, 750400, Ningxia, China
| | - Haichao Li
- Ningxia Administration of Baijitan National Nature Reserve, Lingwu, 750400, Ningxia, China
| | - Wenfen Meng
- School of Agriculture, Ningxia University, Yinchuan, 750021, Ningxia, China
| | - Yi He
- School of Agriculture, Ningxia University, Yinchuan, 750021, Ningxia, China
| | - Yayuan Li
- School of Agriculture, Ningxia University, Yinchuan, 750021, Ningxia, China
| | - Haiquan Li
- School of Agriculture, Ningxia University, Yinchuan, 750021, Ningxia, China
| | - Pengbo Zhao
- School of Agriculture, Ningxia University, Yinchuan, 750021, Ningxia, China
| | - Yi Yang
- School of Agriculture, Ningxia University, Yinchuan, 750021, Ningxia, China
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Gomaa NH, Hegazy AK, Latef AAHA. Facilitation Effects of Haloxylon salicornicum Shrubs on Associated Understory Annuals, and a Modified “Stress-Gradient” Hypothesis for Droughty Times. Plants 2020; 9:plants9121726. [PMID: 33297465 PMCID: PMC7762360 DOI: 10.3390/plants9121726] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/10/2020] [Revised: 12/01/2020] [Accepted: 12/04/2020] [Indexed: 11/28/2022]
Abstract
Perennial shrub-annual plant interactions play key roles in desert regions influencing the structure and dynamics of plant communities there. In the present study, carried out in northwestern Saudi Arabia, we examined the effect of Haloxylon salicornicum shrubs on their associated understory annual species across four consecutive growing seasons, along with a record of the seasonal rainfall patterns. We measured density and species richness of all the annual species in permanent quadrats located beneath individual shrubs, as well as in the spaces between shrubs. During wet growing season H. salicornicum shrubs significantly enhanced the density and species richness of sub-canopy species, whereas in the relatively dry seasons they exerted negative effects on the associated species. In all growing seasons, the presence of shrubs was associated with enhanced soil properties, including increased organic carbon content, silt + clay, and levels of nutrients (N, P and K). Shrubs improved soil moisture content beneath their canopies in the wet growing season, while in the dry seasons they had negative effects on water availability. Differences in effects of H. salicornicum on understory plants between growing seasons seem due to the temporal changes in the impact of shrubs on water availability. Our results suggest the facilitative effects of shrubs on sub-canopy annuals in arid ecosystems may switch to negative effects with increasing drought stress. We discuss the study in light of recent refinements of the well-known “stress-gradient hypothesis”.
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Affiliation(s)
- Nasr H. Gomaa
- Department of Botany and Microbiology, Faculty of Science, Beni-Suef University, Beni-Suef 62521, Egypt
- Biology Department, College of Science, Jouf University, P.O. Box 2014, Sakaka 72341, Saudi Arabia
- Correspondence:
| | - Ahmad K. Hegazy
- Department of Botany and Microbiology, Faculty of Science, Cairo University, Giza 12613, Egypt;
| | - Arafat Abdel Hamed Abdel Latef
- Department of Biology, Turabah University College, Turabah Branch, Taif University, P.O. Box 11099, Taif 21944, Saudi Arabia;
- Botany and Microbiology Department, Faculty of Science, South Valley University, Qena 83523, Egypt
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Irvine MA, Jackson EL, Kenyon EJ, Cook KJ, Keeling MJ, Bull JC. Fractal measures of spatial pattern as a heuristic for return rate in vegetative systems. R Soc Open Sci 2016; 3:150519. [PMID: 27069643 PMCID: PMC4821254 DOI: 10.1098/rsos.150519] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/19/2015] [Accepted: 03/02/2016] [Indexed: 06/05/2023]
Abstract
Measurement of population persistence is a long-standing problem in ecology; in particular, whether it is possible to gain insights into persistence without long time-series. Fractal measurements of spatial patterns, such as the Korcak exponent or boundary dimension, have been proposed as indicators of the persistence of underlying dynamics. Here we explore under what conditions a predictive relationship between fractal measures and persistence exists. We combine theoretical arguments with an aerial snapshot and time series from a long-term study of seagrass. For this form of vegetative growth, we find that the expected relationship between the Korcak exponent and persistence is evident at survey sites where the population return rate can be measured. This highlights a limitation of the use of power-law patch-size distributions and other indicators based on spatial snapshots. Moreover, our numeric simulations show that for a single species and a range of environmental conditions that the Korcak-persistence relationship provides a link between temporal dynamics and spatial pattern; however, this relationship is specific to demographic factors, so we cannot use this methodology to compare between species.
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Affiliation(s)
- M. A. Irvine
- Centre for Complexity Science, Zeeman Building, University of Warwick, Coventry CV4 7AL, UK
| | - E. L. Jackson
- School of Medical and Applied Sciences, Central Queensland University, North Rockhampton, Queensland, Australia
| | - E. J. Kenyon
- School of Life Sciences, University of Sussex, Brighton, UK
| | | | - M. J. Keeling
- Mathematics Institute and Department of Biological Sciences, University of Warwick, Gibbet Hill Road, Coventry CV4 7AL, UK
| | - J. C. Bull
- Department of Biosciences, University of Swansea, Swansea, UK
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Tirado R, Bråthen KA, Pugnaire FI. Mutual positive effects between shrubs in an arid ecosystem. Sci Rep 2015; 5:14710. [PMID: 26419958 DOI: 10.1038/srep14710] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2015] [Accepted: 09/07/2015] [Indexed: 11/27/2022] Open
Abstract
One-way facilitation in plants has been found in many harsh environments and their role as structural forces governing species composition in plant communities is now well established. However, reciprocal positive effects benefiting two interacting species have seldom been reported and, in recent reviews, conceptually considered merely as facilitation when in fact there is room for adaptive strategies and evolutionary responses. We tested the existence of such reciprocal positive effects in an arid environment in SE Spain using spatial pattern analysis, a species removal experiment, and a natural experiment. We found that the spatial association between Maytenus senegalensis and Whitania frutescens, two shrub species of roughly similar size intimately interacting in our community, resulted in mutual benefit for both species. Benefits included improved water relations and nutritional status and protection against browsing, and did occur despite simultaneous competition for resources. Our data suggest two-way facilitation or, rather, a facultative mutualism among higher plant species, a process often overlooked which could be a main driver of plant community dynamics allowing for evolutionary processes.
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Zhang J, Zhang Y, Fan D, Qin S, Jia X, Wu B, Chen D, Gao H, Zhu L. Effects of Sand Dune Stabilization on the Spatial Pattern of Artemisia ordosica Population in Mu Us Desert, Northwest China. PLoS One 2015; 10:e0129728. [PMID: 26102584 PMCID: PMC4477905 DOI: 10.1371/journal.pone.0129728] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2014] [Accepted: 05/12/2015] [Indexed: 11/18/2022] Open
Abstract
Vegetation patterns are strongly influenced by sand mobility in desert ecosystems. However, little is known about the spatial patterns of Artemisia ordosica, a dominant shrub in the Mu Us desert of Northwest China, in relation to sand fixation. The aim of this study was to investigate and contrast the effects of sand dune stabilization on the population and spatial distribution of this desert shrub. Spatial autocorrelation, semi-variance analysis, and point-pattern analysis were used jointly in this study to investigate the spatial patterns of A. ordosica populations on dunes in Yanchi County of Ningxia, China. The results showed that the spatial autocorrelation and spatial heterogeneity declined gradually, and the distance between the clustered individuals shortened following sand dune fixation. Seedlings were more aggregated than adults in all stage of dune stabilization, and both were more aggregated on shifting sand dunes separately. Spatial associations of the seedlings with the adults were mostly positive at distances of 0–5 m in shifting sand dunes, and the spatial association changed from positive to neutral in semi-fixed sand dunes. The seedlings were spaced in an almost random pattern around the adults, and their distances from the adults did not seem to affect their locations in semi-fixed sand dunes. Furthermore, spatial associations of the seedlings with the adults were negative in the fixed sand dune. These findings demonstrate that sand stabilization is an important factor affecting the spatial patterns of A. ordosica populations in the Mu Us desert. These findings suggest that, strong association between individuals may be the mechanism to explain the spatial pattern formation at preliminary stage of dune fixation. Sand dune stabilization can change the spatial pattern of shrub population by weakening the spatial association between native shrub individuals, which may affect the development direction of desert shrubs.
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Affiliation(s)
- Jiachen Zhang
- Yanchi Research Station, School of Soil and Water Conservation, Beijing Forestry University, Beijing, China
- Key Laboratory of Soil and Water Conservation and Desertification Combating of the Ministry of Education, Beijing Forestry University, Beijing, China
| | - Yuqing Zhang
- Yanchi Research Station, School of Soil and Water Conservation, Beijing Forestry University, Beijing, China
- Key Laboratory of Soil and Water Conservation and Desertification Combating of the Ministry of Education, Beijing Forestry University, Beijing, China
| | - Dongqing Fan
- Yanchi Research Station, School of Soil and Water Conservation, Beijing Forestry University, Beijing, China
- Key Laboratory of Soil and Water Conservation and Desertification Combating of the Ministry of Education, Beijing Forestry University, Beijing, China
| | - Shugao Qin
- Yanchi Research Station, School of Soil and Water Conservation, Beijing Forestry University, Beijing, China
- Key Laboratory of Soil and Water Conservation and Desertification Combating of the Ministry of Education, Beijing Forestry University, Beijing, China
- * E-mail:
| | - Xin Jia
- Yanchi Research Station, School of Soil and Water Conservation, Beijing Forestry University, Beijing, China
- Key Laboratory of Soil and Water Conservation and Desertification Combating of the Ministry of Education, Beijing Forestry University, Beijing, China
| | - Bin Wu
- Yanchi Research Station, School of Soil and Water Conservation, Beijing Forestry University, Beijing, China
- Key Laboratory of Soil and Water Conservation and Desertification Combating of the Ministry of Education, Beijing Forestry University, Beijing, China
| | - Dong Chen
- Yanchi Research Station, School of Soil and Water Conservation, Beijing Forestry University, Beijing, China
- Key Laboratory of Soil and Water Conservation and Desertification Combating of the Ministry of Education, Beijing Forestry University, Beijing, China
| | - Hao Gao
- Yanchi Research Station, School of Soil and Water Conservation, Beijing Forestry University, Beijing, China
- Key Laboratory of Soil and Water Conservation and Desertification Combating of the Ministry of Education, Beijing Forestry University, Beijing, China
| | - Linfeng Zhu
- Yanchi Research Station, School of Soil and Water Conservation, Beijing Forestry University, Beijing, China
- Key Laboratory of Soil and Water Conservation and Desertification Combating of the Ministry of Education, Beijing Forestry University, Beijing, China
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Takahashi MK, Kubota T, Horner LM, Keller NA, Abrahamson WG. The spatial signature of biotic interactions of a clonal and a non-clonal palmetto in a subtropical plant community. Ecosphere 2012. [DOI: 10.1890/es12-00101.1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
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Abstract
The ecological processes that create spatial patterns have been examined by direct measurement and through measurement of patterns resulting from experimental manipulations. But in many situations, creating experiments and direct measurement of spatial processes can be difficult or impossible. Here, we identify and define a rapidly emerging alternative approach, which we formalize as "space as a surrogate" for unmeasured processes, that is used to maximize inference about ecological processes through the analysis of spatial patterns or spatial residuals alone. This approach requires three elements to be successful: a priori hypotheses, ecological theory and/or knowledge, and precise spatial analysis. We offer new insights into a long-standing debate about process-pattern links in ecology and highlight six recent studies that have successfully examined spatial patterns to understand a diverse array of processes: competition in forest-stand dynamics, dispersal of freshwater fish, movement of American marten, invasion mechanisms of exotic trees, dynamics of natural disturbances, and tropical-plant diversity. Key benefits of using space as a surrogate can be found where experimental manipulation or direct measurements are difficult or expensive to obtain or not possible. We note that, even where experiments can be performed, this procedure may aid in measuring the in situ importance of the processes uncovered through experiments.
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Affiliation(s)
- Eliot J B McIntire
- Département des Sciences du Bois et de la Forêt, Université Laval, Quebec, Quebec G1K 7P4, Canada.
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Wiegand T, Gunatilleke S, Gunatilleke N, Okuda T. Analyzing the spatial structure of a Sri Lankan tree species with multiple scales of clustering. Ecology 2008; 88:3088-102. [PMID: 18229843 DOI: 10.1890/06-1350.1] [Citation(s) in RCA: 151] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Clustering at multiple critical scales may be common for plants since many different factors and processes may cause clustering. This is especially true for tropical rain forests for which theories explaining species coexistence and community structure rest heavily on spatial patterns. We used point pattern analysis to analyze the spatial structure of Shorea congestiflora, a dominant species in a 25-ha forest dynamics plot in a rain forest at Sinharaja World Heritage Site (Sri Lanka), which apparently shows clustering at several scales. We developed cluster processes incorporating two critical scales of clustering for exploring the spatial structure of S. congestiflora and interpret it in relation to factors such as competition, dispersal limitation, recruitment limitation, and Janzen-Connell effects. All size classes showed consistent large-scale clustering with a cluster radius of approximately 25 m. Inside the larger clusters, small-scale clusters with a radius of 8 m were evident for recruits and saplings, weak for intermediates, and disappeared for adults. The pattern of all trees could be divided into two independent patterns: a random pattern (nearest neighbor distance > 8 m) comprising approximately 12% of the trees and a nested double-cluster pattern. This finding suggests two independent recruitment and/or seed dispersal mechanisms. Saplings were several times as abundant as recruits and may accumulate several recruit generations. Recruits were only weakly associated with adults and occupied about half of the large-scale clusters, but saplings almost all. This is consistent with recruitment limitation. For approximately 70% (95%) of all juveniles the nearest adult was less than 26 m away (53 m), suggesting a dispersal limitation that may also be related to the critical large-scale clustering. Our example illustrates the manner in which the use of a specific and complex null hypothesis of spatial structure in point pattern analysis can help us better understand the biology of a species and generate specific hypotheses to be further investigated in the field.
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Affiliation(s)
- Thorsten Wiegand
- UFZ Helmholtz Centre for Environmental Research-Umweltforschungszentrum, Department of Ecological Modeling, PF 500136, D-04301 Leipzig, Germany.
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Warnock AD, Westbrooke ME, Florentine SK, Hurst CP. Does Geijera parviflora Lindl. (Rutaceae) facilitate understorey species in semi-arid Australia? Rangel J 2007. [DOI: 10.1071/rj07032] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Species composition under tree canopies often differs from that of surrounding micro-environments. In arid and semi-arid zones, trees can be beneficial to understorey vegetation. This study examined zones of vegetation composition and soil physiochemical parameters associated with Geijera parviflora Lindl. The importance of shade, rainfall redistribution, seed bank and soil moisture were examined. Species abundance, soil moisture, seed bank composition, rainfall redistribution and soil nutrient concentration were measured under five randomly selected mature G. parviflora trees in south-western New South Wales, Australia. To complement the findings from this study, artificial shade plots were constructed in a canopy-free area and species abundance measured seven months after shade construction. The study demonstrated that G. parviflora was associated with zonation of understorey vegetation. Two zones of understorey vegetation were found in relation to G. parviflora: (i) under the tree canopy with high species diversity, and (ii) beyond the canopy, this community being dominated by Dissocarpus paradoxus throughout the year with Crassula colorata appearing after rainfall. The zone beyond the canopy also had lower soil nutrient concentrations. Soil moisture, nutrient concentration and the seed bank density were significantly higher under the canopy. However, the canopy reduced precipitation reaching the soil surface. The effects of the canopy on understorey species composition and soil moisture were enhanced after winter rainfall. Artificial shade increased species abundance and richness under a 90%-shading treatment. The results indicated that G. parviflora generated spatial heterogeneity over the broader plant community increasing species richness, abundance and diversity under the canopy. This emphasises the importance of arid zone trees in conserving understorey plant diversity. Shading, soil nutrient concentration and increased seed bank density and soil moisture appeared to be key influences on the plant communities under the canopy.
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Rosenblatt DL, Heske EJ, Nelson SL, Barber DM, Miller MA, Macallister B. Forest Fragments in East-central Illinois: Islands or Habitat Patches for Mammals? The American Midland Naturalist 1999; 141:115-23. [DOI: 10.1674/0003-0031(1999)141[0115:ffieci]2.0.co;2] [Citation(s) in RCA: 70] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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