51
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Stears AE, Adler PB, Blumenthal DM, Kray JA, Mueller KE, Ocheltree TW, Wilcox KR, Laughlin DC. Water availability dictates how plant traits predict demographic rates. Ecology 2022; 103:e3799. [PMID: 35724968 DOI: 10.1002/ecy.3799] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/16/2021] [Revised: 04/17/2022] [Accepted: 04/21/2022] [Indexed: 11/08/2022]
Abstract
A major goal in ecology is to make generalizable predictions of organism responses to environmental variation based on their traits. However, straightforward relationships between traits and fitness are rare and likely vary with environmental context. Characterizing how traits mediate demographic responses to the environment may enhance predictions of organism responses to global change. We synthesized 15 years of demographic data and species-level traits in a shortgrass steppe to determine whether the effects of leaf and root traits on growth and survival depend on seasonal water availability. We predicted that (1) species with drought-tolerant traits, such as lower leaf turgor loss point (TLP) and higher leaf and root dry matter content (LDMC and RDMC), would be more likely to survive and grow in drier years due to higher wilting resistance, (2) these traits would not predict fitness in wetter years, and (3) traits that more directly measure physiological mechanisms of water use such as TLP would best predict demographic responses. We found that graminoids with more negative TLP and higher LDMC and RDMC had higher survival rates in drier years. Forbs demonstrated similar yet more variable responses. Graminoids grew larger in wetter years, regardless of traits. However, in both wet and dry years, graminoids with more negative TLP and higher LDMC and RDMC grew larger than less negative TLP and low LDMC and RDMC species. Traits significantly mediated the impact of drought on survival, but not growth, suggesting survival could be a stronger driver of species' drought response in this system. TLP predicted survival in drier years, but easier-to-measure LDMC and RDMC were equal or better predictors. These results advance our understanding of the mechanisms by which drought drives population dynamics, and show that abiotic context determines how traits drive fitness.
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Affiliation(s)
- Alice E Stears
- Botany Department and Program in Ecology, University of Wyoming, Laramie, WY
| | - Peter B Adler
- Department of Wildland Resources and the Ecology Center, Utah State University, Logan, UT
| | | | - Julie A Kray
- USDA-ARS Rangeland Resources Research Unit, Fort Collins, CO
| | - Kevin E Mueller
- Department of Biological, Geological and Environmental Sciences, Cleveland State University, Cleveland, OH
| | - Troy W Ocheltree
- Warner College of Natural Resources, Colorado State University, Fort Collins, CO
| | - Kevin R Wilcox
- Department of Ecosystem Science and Management, University of Wyoming, Laramie, WY
| | - Daniel C Laughlin
- Botany Department and Program in Ecology, University of Wyoming, Laramie, WY
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52
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Bowler CH, Weiss-Lehman C, Towers IR, Mayfield MM, Shoemaker LG. Accounting for demographic uncertainty increases predictions for species coexistence: A case study with annual plants. Ecol Lett 2022; 25:1618-1628. [PMID: 35633300 PMCID: PMC9328198 DOI: 10.1111/ele.14011] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2021] [Revised: 03/02/2022] [Accepted: 03/22/2022] [Indexed: 11/29/2022]
Abstract
Natural systems contain more complexity than is accounted for in models of modern coexistence theory. Coexistence modelling often disregards variation arising from stochasticity in biological processes, heterogeneity among individuals and plasticity in trait values. However, these unaccounted‐for sources of uncertainty are likely to be ecologically important and have the potential to impact estimates of coexistence. We applied a Bayesian modelling framework to data from an annual plant community in Western Australia to propagate uncertainty in coexistence outcomes using the invasion criterion and ratio of niche to fitness differences. We found accounting for this uncertainty altered predictions of coexistence versus competitive exclusion for 3 out of 14 species pairs and yielded a probability of priority effects for an additional species pair. The propagation of uncertainty arising from sources of biological complexity improves our ability to predict coexistence more accurately in natural systems.
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Affiliation(s)
- Catherine H Bowler
- School of Biological Sciences, University of Queensland, Brisbane, Queensland, Australia
| | | | - Isaac R Towers
- School of Biological, Earth, and Environmental Sciences, University of New South Wales, Sydney, New South Wales, Australia
| | - Margaret M Mayfield
- School of BioSciences, University of Melbourne, Parkville, Victoria, Australia
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53
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Hawlena H. Coexistence research requires more interdisciplinary communication. Ecol Evol 2022; 12:e8914. [PMID: 35592068 PMCID: PMC9101577 DOI: 10.1002/ece3.8914] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2022] [Revised: 04/06/2022] [Accepted: 04/20/2022] [Indexed: 12/30/2022] Open
Abstract
Coexistence theories develop rapidly at the ecology forefront, outpacing their experimental testing. I discuss the reasons for this gap, call on interdisciplinary researchers to construct a road map for coexistence research, and recommend the actions that should be implemented therein.
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Affiliation(s)
- Hadas Hawlena
- Mitrani Department of Desert Ecology Jacob Blaustein Institutes for Desert Research Ben‐Gurion University of the Negev Midreshet Ben‐Gurion Israel
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54
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Stefan L, Engbersen N, Schöb C. Using spatially-explicit plant competition models to optimise crop productivity in intercropped systems. Basic Appl Ecol 2022. [DOI: 10.1016/j.baae.2022.05.004] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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55
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Chen D, van Kleunen M. Competitive effects of plant invaders on and their responses to native species assemblages change over time. NEOBIOTA 2022. [DOI: 10.3897/neobiota.73.80410] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Alien plant invaders are often considered to be more competitive than natives, and species-rich plant communities are often considered to be more resistant to invaders than species-poor communities. However, the competitive interactions between invaders and assemblages of different species richness are unlikely to be static over time (e.g. during a growth season). To test this, we grew five alien and five native species as invaders in a total of 21 artificial assemblages of one, two or four native competitor species. To test for temporal changes in the reciprocal effects of invaders and the competitor assemblages on each other, and how these depend on the species richness of the assemblages, we harvested plants at three growth stages (weeks 4, 8 and 12). We found that the invaders and competitor assemblages had negative effects on each other. Aboveground biomass of invaders was reduced by the presence of a competitor assemblage, irrespective of its species richness, and this difference gradually increased over time. Alien invaders accumulated more aboveground biomass than the native invaders, but only after 12 weeks of growth. Meanwhile, the invaders also negatively affected the biomass of the competitor assemblages. For multi-species assemblages, the increase in the negative effect of the presence of the invader occurred mainly between weeks 4 and 8, whereas it happened mainly between weeks 8 and 12 for the one-species assemblages. Our results suggest that although alien invaders are more competitive than native invaders, the competitive effects of the invaders on and their responses to native competitor assemblages changed over time, irrespective of the origin of the invaders.
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56
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Yang X, Gómez-Aparicio L, Lortie CJ, Verdú M, Cavieres LA, Huang Z, Gao R, Liu R, Zhao Y, Cornelissen JHC. Net plant interactions are highly variable and weakly dependent on climate at the global scale. Ecol Lett 2022; 25:1580-1593. [PMID: 35460586 DOI: 10.1111/ele.14010] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2022] [Revised: 03/02/2022] [Accepted: 03/28/2022] [Indexed: 11/27/2022]
Abstract
Although plant-plant interactions (i.e. competition and facilitation) have long been recognised as key drivers of plant community composition and dynamics, their global patterns and relationships with climate have remained unclear. Here, we assembled a global database of 10,502 pairs of empirical data from the literature to address the patterns of and climatic effects on the net outcome of plant interactions in natural communities. We found that plant interactions varied among plant performance indicators, interaction types and biomes, yet competition occurred more frequently than facilitation in plant communities worldwide. Unexpectedly, plant interactions showed weak latitudinal pattern and were weakly related to climate. Our study provides a global comprehensive overview of plant interactions, highlighting competition as a fundamental mechanism structuring plant communities worldwide. We suggest that further investigations should focus more on local factors (e.g. microclimate, soil and disturbance) than on macroclimate to identify key environmental determinants of interactions in plant communities.
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Affiliation(s)
- Xuejun Yang
- State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Beijing, China
| | | | | | - Miguel Verdú
- Department of Plant Ecology, Centro de Investigaciones sobre Desertificación, CSIC-UVEG-GV), Valencia, Spain
| | - Lohengrin A Cavieres
- Departamento de Botánica, Facultad de Ciencias Naturales y Oceanográficas, Universidad de Concepción, Concepción, Chile.,Instituto de Ecología y Biodiversidad - IEB, Santiago, Chile
| | - Zhenying Huang
- State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Beijing, China
| | - Ruiru Gao
- The School of Life Sciences, Shanxi Normal University, Shanxi, Linfen, China
| | - Rong Liu
- State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Beijing, China
| | - Yonglan Zhao
- State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Beijing, China
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57
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Sandal L, Grøtan V, Saether BE, Freckleton RP, Noble DG, Ovaskainen O. Effects of density, species interactions, and environmental stochasticity on the dynamics of British bird communities. Ecology 2022; 103:e3731. [PMID: 35416286 PMCID: PMC9539587 DOI: 10.1002/ecy.3731] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/15/2021] [Revised: 12/13/2021] [Accepted: 02/16/2022] [Indexed: 12/03/2022]
Abstract
Our knowledge of the factors affecting species abundances is mainly based on time‐series analyses of a few well‐studied species at single or few localities, but we know little about whether results from such analyses can be extrapolated to the community level. We apply a joint species distribution model to long‐term time‐series data on British bird communities to examine the relative contribution of intra‐ and interspecific density dependence at different spatial scales, as well as the influence of environmental stochasticity, to spatiotemporal interspecific variation in abundance. Intraspecific density dependence has the major structuring effect on these bird communities. In addition, environmental fluctuations affect spatiotemporal differences in abundance. In contrast, species interactions had a minor impact on variation in abundance. Thus, important drivers of single‐species dynamics are also strongly affecting dynamics of communities in time and space.
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Affiliation(s)
- Lisa Sandal
- Centre for Biodiversity Dynamics, Department of Biology, Norwegian University of Science and Technology, Høgskoleringen 5, Trondheim, Norway
| | - Vidar Grøtan
- Centre for Biodiversity Dynamics, Department of Biology, Norwegian University of Science and Technology, Høgskoleringen 5, Trondheim, Norway
| | - Bernt-Erik Saether
- Centre for Biodiversity Dynamics, Department of Biology, Norwegian University of Science and Technology, Høgskoleringen 5, Trondheim, Norway
| | - Robert P Freckleton
- Ecology and Evolutionary Biology, School of Biosciences, University of Sheffield, Sheffield, UK
| | | | - Otso Ovaskainen
- Centre for Biodiversity Dynamics, Department of Biology, Norwegian University of Science and Technology, Høgskoleringen 5, Trondheim, Norway.,Department of Biological and Environmental Science, University of Jyväskylä, P.O. Box 35 (Survontie 9C), Jyväskylä, Finland.,Organismal and Evolutionary Biology Research Program, University of Helsinki, Helsinki, Finland
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58
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Souza ACD, Weber MDM, Prevedello JA. Protection status and density-dependent effects mediate the abundance-suitability relationship of a threatened species. Perspect Ecol Conserv 2022. [DOI: 10.1016/j.pecon.2022.03.002] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022] Open
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59
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Britton TG, Brodribb TJ, Richards SA, Ridley C, Hovenden MJ. Canopy damage during a natural drought depends on species identity, physiology and stand composition. THE NEW PHYTOLOGIST 2022; 233:2058-2070. [PMID: 34850394 DOI: 10.1111/nph.17888] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/28/2021] [Accepted: 11/21/2021] [Indexed: 06/13/2023]
Abstract
Vulnerability to xylem cavitation is a strong predictor of drought-induced damage in forest communities. However, biotic features of the community itself can influence water availability at the individual tree-level, thereby modifying patterns of drought damage. Using an experimental forest in Tasmania, Australia, we determined the vulnerability to cavitation (leaf P50 ) of four tree species and assessed the drought-induced canopy damage of 2944 6-yr-old trees after an extreme natural drought episode. We examined how individual damage was related to their size and the density and species identity of neighbouring trees. The two co-occurring dominant tree species, Eucalyptus delegatensis and Eucalyptus regnans, were the most vulnerable to drought-induced xylem cavitation and both species suffered significantly greater damage than neighbouring, subdominant species Pomaderris apetala and Acacia dealbata. While the two eucalypts had similar leaf P50 values, E. delegatensis suffered significantly greater damage, which was strongly related to the density of neighbouring P. apetala. Damage in E. regnans was less impacted by neighbouring plants and smaller trees of both eucalypts sustained significantly more damage than larger trees. Our findings demonstrate that natural drought damage is influenced by individual plant physiology as well as the composition, physiology and density of the surrounding stand.
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Affiliation(s)
- Travis G Britton
- Biological Sciences, School of Natural Sciences, University of Tasmania, Hobart, Tas., 7001, Australia
- ARC Training Centre for Forest Value, University of Tasmania, Hobart, Tas., 7001, Australia
| | - Timothy J Brodribb
- Biological Sciences, School of Natural Sciences, University of Tasmania, Hobart, Tas., 7001, Australia
| | - Shane A Richards
- School of Natural Sciences, University of Tasmania, Hobart, Tas., 7001, Australia
| | - Chantelle Ridley
- Biological Sciences, School of Natural Sciences, University of Tasmania, Hobart, Tas., 7001, Australia
| | - Mark J Hovenden
- Biological Sciences, School of Natural Sciences, University of Tasmania, Hobart, Tas., 7001, Australia
- ARC Training Centre for Forest Value, University of Tasmania, Hobart, Tas., 7001, Australia
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60
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Mall A, Kasarlawar S, Saini S. Limited Pairwise Synergistic and Antagonistic Interactions Impart Stability to Microbial Communities. Front Ecol Evol 2022. [DOI: 10.3389/fevo.2022.648997] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
One of the central goals of ecology is to explain and predict coexistence of species. In this context, microbial communities provide a model system where community structure can be studied in environmental niches and in laboratory conditions. A community of microbial population is stabilized by interactions between participating species. However, the nature of these stabilizing interactions has remained largely unknown. Theory and experiments have suggested that communities are stabilized by antagonistic interactions between member species, and destabilized by synergistic interactions. However, experiments have also revealed that a large fraction of all the interactions between species in a community are synergistic in nature. To understand the relative significance of the two types of interactions (synergistic vs. antagonistic) between species, we perform simulations of microbial communities with a small number of participating species using two frameworks—a replicator equation and a Lotka-Volterra framework. Our results demonstrate that synergistic interactions between species play a critical role in maintaining diversity in cultures. These interactions are critical for the ability of the communities to survive perturbations and maintain diversity. We follow up the simulations with quantification of the extent to which synergistic and antagonistic interactions are present in a bacterial community present in a soil sample. Overall, our results show that community stability is largely achieved with the help of synergistic interactions between participating species. However, we perform experiments to demonstrate that antagonistic interactions, in specific circumstances, can also contribute toward community stability.
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61
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Toll K, Lowry DB. Frequency-dependent hybridization contributes to habitat segregation in monkeyflowers. Am Nat 2022; 199:743-757. [DOI: 10.1086/719381] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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62
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Weiss-Lehman CP, Werner CM, Bowler CH, Hallett LM, Mayfield MM, Godoy O, Aoyama L, Barabás G, Chu C, Ladouceur E, Larios L, Shoemaker LG. Disentangling key species interactions in diverse and heterogeneous communities: A Bayesian sparse modelling approach. Ecol Lett 2022; 25:1263-1276. [PMID: 35106910 PMCID: PMC9543015 DOI: 10.1111/ele.13977] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2021] [Revised: 12/07/2021] [Accepted: 01/02/2022] [Indexed: 11/30/2022]
Abstract
Modelling species interactions in diverse communities traditionally requires a prohibitively large number of species‐interaction coefficients, especially when considering environmental dependence of parameters. We implemented Bayesian variable selection via sparsity‐inducing priors on non‐linear species abundance models to determine which species interactions should be retained and which can be represented as an average heterospecific interaction term, reducing the number of model parameters. We evaluated model performance using simulated communities, computing out‐of‐sample predictive accuracy and parameter recovery across different input sample sizes. We applied our method to a diverse empirical community, allowing us to disentangle the direct role of environmental gradients on species’ intrinsic growth rates from indirect effects via competitive interactions. We also identified a few neighbouring species from the diverse community that had non‐generic interactions with our focal species. This sparse modelling approach facilitates exploration of species interactions in diverse communities while maintaining a manageable number of parameters.
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Affiliation(s)
| | - Chhaya M Werner
- Botany Department, University of Wyoming, Laramie, Wyoming, USA
| | - Catherine H Bowler
- School of Biological Sciences, University of Queensland, Brisbane, Queensland, Australia
| | - Lauren M Hallett
- Biology Department, University of Oregon, Eugene, Oregon, USA.,Environmental Studies Program, University of Oregon, Eugene, Oregon, USA
| | - Margaret M Mayfield
- School of Biological Sciences, University of Queensland, Brisbane, Queensland, Australia
| | - Oscar Godoy
- Departamento de Biología, Instituto Universitario de Investigación Marina (INMAR), Universidad de Cádiz, Puerto Real, Spain
| | - Lina Aoyama
- Biology Department, University of Oregon, Eugene, Oregon, USA.,Environmental Studies Program, University of Oregon, Eugene, Oregon, USA
| | - György Barabás
- Division of Theoretical Biology, Department of IFM, Linköping University, Linköping, Sweden
| | - Chengjin Chu
- Department of Ecology, State Key Laboratory of Biocontrol and School of Life Sciences, Sun Yat-sen University, Guangzhou, Guangdong, China
| | - Emma Ladouceur
- German Centre for Integrative Biodiversity Research (iDiv) Leipzig-Halle-Jena, Leipzig, Germany.,Department of Physiological Diversity, Helmholtz Centre for Environmental Research -UFZ, Leipzig, Germany
| | - Loralee Larios
- Department of Botany and Plant Sciences, University of California Riverside, Riverside, California, USA
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63
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Resistance of plant communities to invasion by tall fescue: An experimental study combining species diversity, functional traits and nutrient levels. Basic Appl Ecol 2022. [DOI: 10.1016/j.baae.2021.12.002] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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64
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Germain SJ, Lutz JA. Climate warming may weaken stabilizing mechanisms in old forests. ECOL MONOGR 2022. [DOI: 10.1002/ecm.1508] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Sara J. Germain
- Department of Wildland Resources Utah State University Logan Utah USA
| | - James A. Lutz
- Department of Wildland Resources Utah State University Logan Utah USA
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65
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Oduor AMO. Native plant species show evolutionary responses to invasion by Parthenium hysterophorus in an African savanna. THE NEW PHYTOLOGIST 2022; 233:983-994. [PMID: 34170513 DOI: 10.1111/nph.17574] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/20/2021] [Accepted: 06/17/2021] [Indexed: 06/13/2023]
Abstract
Invasive plant species often competitively displace native plant species but some populations of native plant species can evolve adaptation to competition from invasive plants and persist in invaded habitats. However, studies are lacking that examine how variation in abiotic conditions in invaded landscapes may affect fitness of native plants that have adapted to compete with invasive plants. I tested whether invasion by Parthenium hysterophorus in Nairobi National Park - Kenya may have selected for native plant individuals with greater competitive ability than conspecific naïve natives in nutrient-rich and mesic soil conditions. I compared vegetative growth and seed yields of invader-experienced and conspecific naïve individuals of seven native species. Invader-experienced natives grew shorter than naïve natives regardless of growth conditions. Nevertheless, the two groups of native plants also exhibited treatment-specific differences in competitive ability against P. hysterophorus. Invader-experienced natives displayed plasticity in seed yield under drought treatment, while naïve natives did not. Moreover, drought treatment enhanced competitive effects of invader-experienced natives on P. hysterophorus, while nutrient enrichment relaxed competitive effects of invader-experienced natives on the invader. The results suggest that P. hysterophorus may have selected for shorter native plant genotypes that also exhibit plasticity in competitive ability under drought conditions.
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Affiliation(s)
- Ayub M O Oduor
- Department of Applied Biology, Technical University of Kenya, PO Box 52428 - 00200, Nairobi, Kenya
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66
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Ohsaki H, Miyagi A, Kawai‐Yamada M, Yamawo A. Intraspecific interaction of host plants leads to concentrated distribution of a specialist herbivore through metabolic alterations in the leaves. Funct Ecol 2021. [DOI: 10.1111/1365-2435.13988] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Haruna Ohsaki
- Department of Biological Sciences Faculty of Agriculture and Life Science Hirosaki University Hirosaki Aomori Japan
| | - Atsuko Miyagi
- Graduate School of Science and Engineering Saitama University Saitama City Saitama Japan
- Faculty of Agriculture Yamagata University Tsuruoka Yamagata Japan
| | - Maki Kawai‐Yamada
- Graduate School of Science and Engineering Saitama University Saitama City Saitama Japan
| | - Akira Yamawo
- Department of Biological Sciences Faculty of Agriculture and Life Science Hirosaki University Hirosaki Aomori Japan
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67
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Wisnoski NI, Shoemaker LG. Seed banks alter metacommunity diversity: The interactive effects of competition, dispersal and dormancy. Ecol Lett 2021; 25:740-753. [PMID: 34965013 DOI: 10.1111/ele.13944] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2021] [Revised: 11/10/2021] [Accepted: 11/24/2021] [Indexed: 01/12/2023]
Abstract
Dispersal and dormancy are two common strategies allowing for species persistence and the maintenance of biodiversity in variable environments. However, theory and empirical tests of spatial diversity patterns tend to examine either mechanism in isolation. Here, we developed a stochastic, spatially explicit metacommunity model incorporating seed banks with varying germination and survival rates. We found that dormancy and dispersal had interactive, nonlinear effects on the maintenance and distribution of metacommunity diversity. Seed banks promoted local diversity when seed survival was high and maintained regional diversity through interactions with dispersal. The benefits of seed banks for regional diversity were largest when dispersal was high or intermediate, depending on whether local competition was equal or stabilising. Our study shows that classic predictions for how dispersal affects metacommunity diversity can be strongly influenced by dormancy. Together, these results emphasise the need to consider both temporal and spatial processes when predicting multi-scale patterns of diversity.
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Affiliation(s)
- Nathan I Wisnoski
- Wyoming Geographic Information Science Center, University of Wyoming, Laramie, Wyoming, USA
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68
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Yokoi H, Takeuchi Y, Ichinose G, Kitade O, Tainaka KI. Microbial mutualism promoting the coexistence of competing species: Double-layer model for two competing hosts and one microbial species. Biosystems 2021; 211:104589. [PMID: 34896189 DOI: 10.1016/j.biosystems.2021.104589] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2021] [Revised: 12/05/2021] [Accepted: 12/05/2021] [Indexed: 11/24/2022]
Abstract
Gause's law of competitive exclusion holds that the coexistence of competing species is extremely unlikely when niches are not differentiated. This law is supported by many mathematical studies, yet the coexistence of competing species is nearly ubiquitous in real ecosystems. We pay attention to the fact that plants and animals usually contact with microbial species as mutualistic partners. The activity spaces of host species are different from those of micro-organisms. In the present study, we apply double-layer model to the association of two competing hosts and a microorganism. Two lattices are prepared: one is for hosts, and the other is for microorganism. The basic equation obtained by mean-field theory is an extension of Lotka-Volterra competition model. Both mathematical analysis and numerical simulations reveal that a shared microbial mutualist can permit the coexistence of competing hosts. From the derived condition of coexistence, we believe the microbial mutualism promotes biodiversity in many ecological systems.
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Affiliation(s)
- Hiroki Yokoi
- Fisheries Resources Institute, Japan Fisheries Research and Education Agency, 2-12-4, Fukuura, Kanazawa-ku, Yokohama, Kanagawa, 236-8648, Japan.
| | - Yasuhiro Takeuchi
- Department of Physics and Mathematics, Aoyama Gakuin University, Fuchinobe, ChuoKu, Sagamihara-shi, Kanagawa, 252-5258, Japan
| | - Genki Ichinose
- Department of Mathematical and Systems Engineering, Shizuoka University, 3-5-1 Johoku, Hamamatsu, 432-8561, Japan
| | - Osamu Kitade
- Faculty of Science, Ibaraki University, Bunkyo, Mito, 310-8512, Japan
| | - Kei-Ichi Tainaka
- Department of Mathematical and Systems Engineering, Shizuoka University, 3-5-1 Johoku, Hamamatsu, 432-8561, Japan.
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69
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Shah K, Sharma GP. A missing cog in the wheel: an Allee effects perspective in biological invasion paradigm. ENVIRONMENTAL MONITORING AND ASSESSMENT 2021; 194:7. [PMID: 34873668 DOI: 10.1007/s10661-021-09643-5] [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: 03/18/2021] [Accepted: 11/20/2021] [Indexed: 06/13/2023]
Abstract
Environmental stochasticity and invasive species demographical factors are considered to be fundamental aspects of species invasion. Population size, density, and intraspecific competition are the important determinants of species range expansion. Allee effects, interesting density-dependent phenomena, act as 'mechanism of population regulation' during species expansion. The study intends to understand the trend of published researches and identify research gaps pertaining to biological invasions and Allee effects with the help of bibliometric analysis. Content and citation analysis using key words 'Allee effects' AND 'biological invasion' was conducted on research articles published over a period of two and a half decades from Scopus database for global and Indian context. Understanding of Allee effects dynamics in context of biological invasion is limited, especially in India. Integrating the emerging trends pertaining to Allee effects in the biological invasion framework will strengthen the understanding on species range expansion. It is emphasized that Allee effects can emerge as an important tool to manage invasive species range expansion.
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Affiliation(s)
- Kanhaiya Shah
- Department of Environmental Studies, University of Delhi, Delhi, 110 007, India
| | - Gyan Prakash Sharma
- Department of Environmental Studies, University of Delhi, Delhi, 110 007, India
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70
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Shen S, Guo W, Li X. Above- and belowground herbivory alters the outcome of intra- and interspecific competition between invasive and native Alternanthera species. Biol Invasions 2021. [DOI: 10.1007/s10530-021-02694-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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71
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Adams AE, Besozzi EM, Shahrokhi G, Patten MA. A case for associational resistance: Apparent support for the stress gradient hypothesis varies with study system. Ecol Lett 2021; 25:202-217. [PMID: 34775662 DOI: 10.1111/ele.13917] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2021] [Revised: 09/07/2021] [Accepted: 10/18/2021] [Indexed: 11/30/2022]
Abstract
According to the stress gradient hypothesis (SGH), ecological interactions between organisms shift positively as environmental stress increases. In the case of associational resistance, habitat is modified to ameliorate stress, benefitting other organisms. The SGH is contentious due to conflicting evidence and theoretical perspectives, so we adopted a meta-analytic approach to determine if it is widely supported across a variety of contexts, including different kingdoms, ecosystems, habitats, interactions, stressors, and life history stages. We developed an extensive list of Boolean search criteria to search the published ecological literature and successfully detect studies that both directly tested the hypothesis, and those that were relevant but never mentioned it. We found that the SGH is well supported by studies that feature bacteria, plants, terrestrial ecosystems, interspecific negative interactions, adults, survival instead of growth or reproduction, and drought, fire, and nutrient stress. We conclude that the SGH is indeed a broadly relevant ecological hypothesis that is currently held back by cross-disciplinary communication barriers. More SGH research is needed beyond the scope of interspecific plant competition, and more SGH research should feature multifactor stress. There remains a need to account for positive interactions in scientific pursuits, such as associational resistance in tests of the SGH.
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Affiliation(s)
- Amy E Adams
- Department of Biology, University of Oklahoma, Norman, Oklahoma, USA
| | | | - Golya Shahrokhi
- Oklahoma Biological Survey, University of Oklahoma, Norman, Oklahoma, USA
| | - Michael A Patten
- Ecology Research Group, Faculty of Biosciences and Aquaculture, Nord University, Steinkjer, Norway
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72
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Ghedini G, Marshall DJ, Loreau M. Phytoplankton diversity affects biomass and energy production differently during community development. Funct Ecol 2021. [DOI: 10.1111/1365-2435.13955] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Affiliation(s)
- Giulia Ghedini
- Centre for Geometric Biology School of Biological Sciences Monash University Melbourne Vic Australia
| | - Dustin J. Marshall
- Centre for Geometric Biology School of Biological Sciences Monash University Melbourne Vic Australia
| | - Michel Loreau
- Centre for Biodiversity Theory and Modelling, Theoretical and Experimental Ecology Station CNRS Moulis France
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73
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Kinlock NL, Munch SB. Interaction network structure and spatial patterns influence invasiveness and invasibility in a stochastic model of plant communities. OIKOS 2021. [DOI: 10.1111/oik.08453] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Nicole L. Kinlock
- Dept of Ecology and Evolution, Stony Brook Univ. Stony Brook NY USA
- Southwest Fisheries Science Center, National Marine Fisheries Service, National Oceanic and Atmospheric Administration Santa Cruz CA USA
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74
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Nguyen VAT, Vural DC. Theoretical guidelines for editing ecological communities. J Theor Biol 2021; 534:110945. [PMID: 34717935 DOI: 10.1016/j.jtbi.2021.110945] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2020] [Revised: 10/21/2021] [Accepted: 10/22/2021] [Indexed: 11/18/2022]
Abstract
Having control over species abundances and community resilience is of great interest for experimental, agricultural, industrial and conservation purposes. Here, we theoretically explore the possibility of manipulating ecological communities by modifying pairwise interactions. Specifically, we establish which interaction values should be modified, and by how much, in order to alter the composition or resilience of a community towards a favorable direction. While doing so, we also take into account the experimental difficulties in making such modifications by including in our optimization process, a cost parameter, which penalizes large modifications. In addition to prescribing what changes should be made to interspecies interactions given some modification cost, our approach also serves to establish the limits of community control, i.e. how well can one approach an ecological goal at best, even when not constrained by cost.
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Affiliation(s)
- Vu A T Nguyen
- University of Notre Dame, South Bend, IN, United States
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75
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Xu W, Deng X, Xu B, Palta JA, Chen Y. Soil Water Availability Changes in Amount and Timing Favor the Growth and Competitiveness of Grass Than a Co-dominant Legume in Their Mixtures. FRONTIERS IN PLANT SCIENCE 2021; 12:723839. [PMID: 34745160 PMCID: PMC8569297 DOI: 10.3389/fpls.2021.723839] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/11/2021] [Accepted: 09/27/2021] [Indexed: 06/13/2023]
Abstract
The grasslands on the semi-arid Loess Plateau of China are expected to be particularly responsive to the size and frequency changes of extreme precipitation events because their ecological processes are largely driven by distinct soil moisture pulses. However, the plant growth and competitiveness of co-dominant species in response to the changes in the amount and timing of soil water are still unclear. Thus, two co-dominant species, Bothriochloa ischaemum and Lespedeza davurica, were grown in seven mixture ratios under three watering regimes [80 ± 5% pot soil capacity (FC) (high watering), 60 ± 5% FC (moderate watering), and 40 ± 5% FC (low watering)] in a pot experiment. The soil water contents were rapidly improved from low to moderate water and from moderate to high water, respectively, at the heading, flowering, and maturity stages of B. ischaemum, and were maintained until the end of the growing season of each species. The biomass production of both species increased significantly with the increased soil water contents, particularly at the heading and flowering periods, with a more pronounced increase in B. ischaemum in the mixtures. The root/shoot ratio of both species was decreased when the soil water availability increased at the heading or flowering periods. The total biomass production, water use efficiency (WUE), and relative yield total (RYT) increased gradually with the increase of B. ischaemum in the mixtures. The relative competition intensity was below zero in B. ischaemum, and above zero in L. davurica. The competitive balance index calculated for B. ischaemum was increased with the increase of the soil water contents. Bothriochloa ischaemum responded more positively to the periodical increase in soil water availability than L. davurica, indicating that the abundance of B. ischaemum could increase in relatively wet seasons or plenty-rainfall periods. In addition, the mixture ratio of 10:2 (B. ischaemum to L. davurica) was the most compatible combination for the improved biomass production, WUE, and RYTs across all soil water treatments.
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Affiliation(s)
- Weizhou Xu
- College of Life Sciences, Yulin University, Yulin, China
- State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau, Northwest A&F University, Yangling, China
| | - Xiping Deng
- State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau, Northwest A&F University, Yangling, China
- Institute of Soil and Water Conservation, Chinese Academy of Sciences and Ministry of Water Resources, Yangling, China
| | - Bingcheng Xu
- State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau, Northwest A&F University, Yangling, China
- Institute of Soil and Water Conservation, Chinese Academy of Sciences and Ministry of Water Resources, Yangling, China
| | - Jairo A. Palta
- School of Agriculture and Environment, The UWA Institute of Agriculture, The University of Western Australia, Perth, WA, Australia
- CSIRO Agriculture and Food, Wembley, WA, Australia
| | - Yinglong Chen
- School of Agriculture and Environment, The UWA Institute of Agriculture, The University of Western Australia, Perth, WA, Australia
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76
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Spaak JW, Carpentier C, De Laender F. Species richness increases fitness differences, but does not affect niche differences. Ecol Lett 2021; 24:2611-2623. [PMID: 34532957 DOI: 10.1111/ele.13877] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2021] [Revised: 06/21/2021] [Accepted: 08/20/2021] [Indexed: 11/30/2022]
Abstract
A key question in ecology is what limits species richness. Modern coexistence theory presents the persistence of species as a balance between niche differences and fitness differences that favour and hamper coexistence, respectively. With most applications focusing on species pairs, however, we know little about if and how this balance changes with species richness. Here, we apply recently developed definitions of niche and fitness differences, based on invasion analysis, to multispecies communities. We present the first mathematical proof that, for invariant average interaction strengths, the average fitness difference among species increases with richness, while the average niche difference stays constant. Extensive simulations with more complex models and analyses of empirical data confirmed these mathematical results. Combined, our work suggests that, as species accumulate in ecosystems, ever-increasing fitness differences will at some point exceed constant niche differences, limiting species richness. Our results contribute to a better understanding of coexistence multispecies communities.
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Affiliation(s)
- Jurg W Spaak
- University of Namur, Institute of Life-Earth-Environment, Namur Center for Complex Systems, Namur, Belgium.,Department of Ecology and Evolutionary Biology, Cornell University, Ithaca, New York, USA
| | - Camille Carpentier
- University of Namur, Institute of Life-Earth-Environment, Namur Center for Complex Systems, Namur, Belgium
| | - Frederik De Laender
- University of Namur, Institute of Life-Earth-Environment, Namur Center for Complex Systems, Namur, Belgium
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77
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Spaak JW, Godoy O, De Laender F. Mapping species niche and fitness differences for communities with multiple interaction types. OIKOS 2021. [DOI: 10.1111/oik.08362] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Affiliation(s)
- Jürg W. Spaak
- Univ. of Namur, Inst. of Life‐Earth‐Environment, Namur Center for Complex Systems Namur Rue de Bruxelles Belgium
| | - Oscar Godoy
- Depto de Biología, Inst. Universitario de Investigación Marina (INMAR), Univ. de Cádiz Puerto Real Spain
| | - Frederik De Laender
- Univ. of Namur, Inst. of Life‐Earth‐Environment, Namur Center for Complex Systems Namur Rue de Bruxelles Belgium
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78
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Waterman R, Sultan SE. Transgenerational effects of parent plant competition on offspring development in contrasting conditions. Ecology 2021; 102:e03531. [PMID: 34496058 DOI: 10.1002/ecy.3531] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/08/2021] [Revised: 06/13/2021] [Accepted: 07/08/2021] [Indexed: 12/15/2022]
Abstract
Conditions during a parent's lifetime can induce phenotypic changes in offspring, providing a potentially important source of variation in natural populations. Yet, to date, biotic factors have seldom been tested as sources of transgenerational effects in plants. In a greenhouse experiment with the generalist annual Polygonum persicaria, we tested for effects of parental competition on offspring by growing isogenic parent plants either individually or in competitive arrays and comparing their seedling progeny in contrasting growth environments. Offspring of competing vs. non-competing parents showed significantly altered development, resulting in greater biomass and total leaf area, but only when growing in neighbor or simulated canopy shade, rather than sunny dry conditions. A follow-up experiment in which parent plants instead competed in dry soil found that offspring in dry soil had slightly reduced growth, both with and without competitors. In neither experiment were effects of parental competition explained by changes in seed provisioning, suggesting a more complex mode of regulatory inheritance. We hypothesize that parental competition in moist soil (i.e., primarily for light) confers specific developmental effects that are beneficial for light-limited offspring, while parental competition in dry soil (i.e., primarily for belowground resources) produces offspring of slightly lower overall quality. Together, these results indicate that competitive conditions during the parental generation can contribute significantly to offspring variation, but these transgenerational effects will depend on the abiotic resources available to both parents and progeny.
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Affiliation(s)
- Robin Waterman
- Biology Department, Wesleyan University, Middletown, Connecticut, 06459, USA.,Department of Plant Biology, Michigan State University, East Lansing, Michigan, 48823, USA
| | - Sonia E Sultan
- Biology Department, Wesleyan University, Middletown, Connecticut, 06459, USA
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79
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Davrinche A, Haider S. Intra-specific leaf trait responses to species richness at two different local scales. Basic Appl Ecol 2021. [DOI: 10.1016/j.baae.2021.04.011] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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80
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Ulrich W, Olszewski P, Puchałka R, Sewerniak P, Koprowski M. Inter‐ and intraspecific spatial distributions, spatial segregation by dominants and emergent neutrality in understorey plants. OIKOS 2021. [DOI: 10.1111/oik.08269] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Werner Ulrich
- Dept of Ecology and Biogeography, Nicolaus Copernicus Univ.Toruń Poland
| | - Piotr Olszewski
- Dept of Ecology and Biogeography, Nicolaus Copernicus Univ.Toruń Poland
| | - Radosław Puchałka
- Dept of Ecology and Biogeography, Nicolaus Copernicus Univ.Toruń Poland
| | - Piotr Sewerniak
- Dept of Soil Science and Landscape Management, Nicolaus Copernicus Univ.Toruń Poland
| | - Marcin Koprowski
- Dept of Ecology and Biogeography, Nicolaus Copernicus Univ.Toruń Poland
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81
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Ferenc V, Merkert C, Zilles F, Sheppard CS. Native and alien species suffer from late arrival, while negative effects of multiple alien species on natives vary. Oecologia 2021; 197:271-281. [PMID: 34410489 PMCID: PMC8445876 DOI: 10.1007/s00442-021-05017-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2020] [Accepted: 08/11/2021] [Indexed: 11/29/2022]
Abstract
Ongoing globalisation and climate change are causing plant species to invade new habitats and thereby alter biodiversity and ecosystem functioning. Since numbers of plant invasions continue to increase globally, it is crucial to investigate the effects of multiple co-occurring alien species on native communities. Furthermore, priority effects due to the earlier emergence of certain species affecting fitness of later arriving species can shape community structure and affect native species performance. We investigate in a common garden pot experiment the interactions among five alien-native species pairs. First we focus on the effect of growing with either one or two alien neighbour species on a native plant, second we alter the arrival time of the alien or native neighbour by 3 weeks. Generally, native species performance decreased when surrounded by two alien species compared to only one, although the magnitude of this effect varied depending on species, with one species even performing better with alien neighbours than in monoculture. Species performance greatly decreased when arriving second in the pot, for both native and alien species. In contrast, alien species tended to benefit more from arriving early. Given that we studied annual ruderal species, their potentially lower competitive ability might explain why we detected negative effects of late arrival. We highlight the need to further elucidate underlying mechanisms of small-scale invasion dynamics to achieve generalisations concerning the response of multiple alien and native plants given their species-specific differences in response to neighbour species and arrival time.
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Affiliation(s)
- Viktoria Ferenc
- Institute of Landscape and Plant Ecology, University of Hohenheim, 70593, Stuttgart, Germany.
| | - Christian Merkert
- Institute of Landscape and Plant Ecology, University of Hohenheim, 70593, Stuttgart, Germany
| | - Frederik Zilles
- Institute of Landscape and Plant Ecology, University of Hohenheim, 70593, Stuttgart, Germany
| | - Christine S Sheppard
- Institute of Landscape and Plant Ecology, University of Hohenheim, 70593, Stuttgart, Germany
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82
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Freedberg S, Urban C, Cunniff BM. Dispersal reduces interspecific competitiveness by spreading locally harmful traits. J Evol Biol 2021; 34:1477-1487. [PMID: 34378272 DOI: 10.1111/jeb.13912] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2020] [Revised: 07/26/2021] [Accepted: 07/26/2021] [Indexed: 11/30/2022]
Abstract
Just as intraorganismal selection can produce "selfish" elements that lower individual fitness, selection at the organismal level can favour traits that reduce the fitness of conspecifics and potentially impact population survival. Because dispersal can affect how these traits are distributed within species, it may determine whether their negative consequences are restricted locally or spread throughout the species' range. We present an individual-based simulation model that explores the interaction between dispersal rate and traits that increase individual fecundity at the expense of conspecific fitness. We first modelled dispersal as a trait that varied within species and then fixed the within-species dispersal rates and modelled competition between species that differed only in dispersal rate. Reproductive isolation allowed species differences in dispersal rates to become associated with traits moulded by intraspecific competition, but this association did not occur when dispersal variation was distributed within species due to recombination between the dispersal and competition loci. Alleles that reduced the fitness of conspecifics were maintained at lower frequencies in low-dispersal species, resulting in a competitive advantage over high-dispersing species. Although high-dispersal species initially outcompeted low-dispersal species owing to enhanced colonization opportunities, low-dispersal species ultimately showed greater representation across a range of ecological and genetic scenarios. This process may shift the makeup of communities over time towards a greater representation of low-dispersal species.
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Affiliation(s)
| | - Caroline Urban
- Department of Biology, St. Olaf College, Northfield, MN, USA
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83
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Wisnoski NI, Lennon JT. Stabilising role of seed banks and the maintenance of bacterial diversity. Ecol Lett 2021; 24:2328-2338. [PMID: 34322982 DOI: 10.1111/ele.13853] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2021] [Revised: 04/19/2021] [Accepted: 07/07/2021] [Indexed: 01/09/2023]
Abstract
Coexisting species often exhibit negative frequency dependence due to mechanisms that promote population growth and persistence when rare. These stabilising mechanisms can maintain diversity through interspecific niche differences, but also through life-history strategies like dormancy that buffer populations in fluctuating environments. However, there are few tests demonstrating how seed banks contribute to long-term community dynamics and the maintenance of diversity. Using a multi-year, high-frequency time series of bacterial community data from a north temperate lake, we documented patterns consistent with stabilising coexistence. Bacterial taxa exhibited differential responses to seasonal environmental conditions, while seed bank dynamics helped maintain diversity over less-favourable winter periods. Strong negative frequency dependence in rare, but metabolically active, taxa suggested a role for biotic interactions in promoting coexistence. Together, our results provide field-based evidence that niche differences and seed banks contribute to recurring community dynamics and the long-term maintenance of diversity in nature.
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Affiliation(s)
- Nathan I Wisnoski
- Department of Biology, Indiana University, Bloomington, Indiana, USA
| | - Jay T Lennon
- Department of Biology, Indiana University, Bloomington, Indiana, USA
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84
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Zaiats A, Germino MJ, Serpe MD, Richardson BA, Caughlin TT. Intraspecific variation mediates density dependence in a genetically diverse plant species. Ecology 2021; 102:e03502. [PMID: 34314039 DOI: 10.1002/ecy.3502] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/22/2021] [Accepted: 05/06/2021] [Indexed: 11/06/2022]
Abstract
Interactions between neighboring plants are critical for biodiversity maintenance in plant populations and communities. Intraspecific trait variation and genome duplication are common in plant species and can drive eco-evolutionary dynamics through genotype-mediated plant-plant interactions. However, few studies have examined how species-wide intraspecific variation may alter interactions between neighboring plants. We investigate how subspecies and ploidy variation in a genetically diverse species, big sagebrush (Artemisia tridentata), can alter the demographic outcomes of plant interactions. Using a replicated, long-term common garden experiment that represents range-wide diversity of A. tridentata, we ask how intraspecific variation, environment, and stand age mediate neighbor effects on plant growth and survival. Spatially explicit models revealed that ploidy variation and subspecies identity can mediate plant-plant interactions but that the effect size varied in time and across experimental sites. We found that demographic impacts of neighbor effects were strongest during early stages of stand development and in sites with greater growth rates. Within subspecies, tetraploid populations showed greater tolerance to neighbor crowding compared to their diploid variants. Our findings provide evidence that intraspecific variation related to genome size and subspecies identity impacts spatial demography in a genetically diverse plant species. Accounting for intraspecific variation in studies of conspecific density dependence will improve our understanding of how local populations will respond to novel genotypes and biotic interaction regimes. As introduction of novel genotypes into local populations becomes more common, quantifying demographic processes in genetically diverse populations will help predict long-term consequences of plant-plant interactions.
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Affiliation(s)
- Andrii Zaiats
- Department of Biological Sciences, Boise State University, Boise, Idaho, 83725, USA
| | - Matthew J Germino
- U.S. Geological Survey, Forest and Rangeland Ecosystem Science Center, Boise, Idaho, 83706, USA
| | - Marcelo D Serpe
- Department of Biological Sciences, Boise State University, Boise, Idaho, 83725, USA
| | - Bryce A Richardson
- USDA Forest Service, Rocky Mountain Research Station, Moscow, Idaho, 83843, USA
| | - T Trevor Caughlin
- Department of Biological Sciences, Boise State University, Boise, Idaho, 83725, USA
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85
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Song C, Uricchio LH, Mordecai EA, Saavedra S. Understanding the emergence of contingent and deterministic exclusion in multispecies communities. Ecol Lett 2021; 24:2155-2168. [PMID: 34288350 DOI: 10.1111/ele.13846] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2021] [Revised: 04/21/2021] [Accepted: 06/23/2021] [Indexed: 12/11/2022]
Abstract
Competitive exclusion can be classified as deterministic or as historically contingent. While competitive exclusion is common in nature, it has remained unclear when multispecies communities formed by more than two species should be dominated by deterministic or contingent exclusion. Here, we take a fully parameterised model of an empirical competitive system between invasive annual and native perennial plant species to explain both the emergence and sources of competitive exclusion in multispecies communities. Using a structural approach to understand the range of parameters promoting deterministic and contingent exclusions, we then find heuristic theoretical support for the following three general conclusions. First, we find that the life-history of perennial species increases the probability of observing contingent exclusion by increasing their effective intrinsic growth rates. Second, we find that the probability of observing contingent exclusion increases with weaker intraspecific competition, and not with the level of hierarchical competition. Third, we find a shift from contingent exclusion to deterministic exclusion with increasing numbers of competing species. Our work provides a heuristic framework to increase our understanding about the predictability of species persistence within multispecies communities.
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Affiliation(s)
- Chuliang Song
- Department of Civil and Environmental Engineering, MIT, Cambridge, MA, USA.,Department of Biology, McGill University, Montreal, Canada.,Department of Ecology and Evolutionary Biology, University of Toronto, Toronto, ON, Canada
| | - Lawrence H Uricchio
- Department of Integrative Biology, University of California, Berkeley, Berkeley, CA, USA
| | | | - Serguei Saavedra
- Department of Civil and Environmental Engineering, MIT, Cambridge, MA, USA
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86
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Induced plasticity alters responses to conspecific interactions in seedlings of a perennial grass. Sci Rep 2021; 11:14581. [PMID: 34272406 PMCID: PMC8285392 DOI: 10.1038/s41598-021-93494-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2021] [Accepted: 06/25/2021] [Indexed: 11/13/2022] Open
Abstract
Plants can interact with different individuals in their lifetime which may lead to plastic response that affect performance. If conspecific interactions are altered through previous plastic responses that could affect stabilizing niche mechanisms, in which conspecifics compete more intensely to promote diversity and coexistence. Here, I show interactions between Pascopyrum smithii and conspecifics resulted in largely canalized traits, whereas P. smithii with an invasive grass, Bromus tectorum resulted in plastic responses for root mass (p = 0.02), shoot mass (p < 0.0001), root mass fraction (p = 0.003) and plant height (p < 0.0001). A subset of individuals transplanted from these two interaction treatments which were moved with new, same aged conspecifics showed that previous interactions led to differing trait relationships: increases in the number of leaves for the interspecific-induced plants were related to increases in non-focal leaf production, whereas increases in the number of leaves for the intraspecific-induced plants were related to decreases in the non-focal plants (R2 = 0.52, p = 0.006). These results suggest that previous intraspecific interactions intensify conspecific competition and stabilize subsequent interactions with conspecifics by imposing greater competition, and that invasive-interspecific interactions can weaken stabilizing niche mechanisms, thus negatively influencing species coexistence.
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87
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Zhang Z, Fu Y, Zhang Z, Zhang X, Chen S. A Comparative Study on Two Territorial Fishes: The Influence of Physical Enrichment on Aggressive Behavior. Animals (Basel) 2021; 11:ani11071868. [PMID: 34201637 PMCID: PMC8300207 DOI: 10.3390/ani11071868] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2021] [Revised: 06/11/2021] [Accepted: 06/18/2021] [Indexed: 11/19/2022] Open
Abstract
Simple Summary This study aimed to evaluate the effect of physical enrichment levels (i.e., the intensity of physical enrichment) on the aggressive behavior of two territorial fishes, black rockfish (Sebastes schlegelii) and fat greenling (Hexagrammos otakii). The main results show that with the increase in the enrichment level, the frequency of aggressive behavior of black rockfish gradually decreased. In contrast, a non-monotonous effect of the enrichment level on aggression was observed for fat greenling, with low and intermediate levels leading to no or more aggression, while a high enrichment level reduced aggression. After three days, the high-level enrichment groups in both rockfish and greenling reached social stability (i.e., a relatively stable social structure indicated by low aggression), while aggression in the other groups continued to increase. These results verify the regulatory effect of enrichment levels on the aggressive behavior in both black rockfish and fat greenling. This study may provide useful information for reducing fish aggression and improving fish welfare in aquaculture. Abstract Intraspecific aggression is detrimental to body/fin damage, physiological stress, and other problems in aquaculture. Environmental enrichment has been proposed to have positive effects on fish aggressive behavior, physiological stress, and fish welfare, but there are mixed results. Here, we examine the impact of physical enrichment levels (i.e., the intensity of physical enrichment) on aggression in black rockfish (Sebastes schlegelii) and fat greenling (Hexagrammos otakii). Generally, with the increase in the enrichment level, the frequency of the aggressive behavior of black rockfish gradually decreased. In contrast, a non-monotonous effect of the enrichment level on aggression was observed for fat greenling, with low and intermediate levels leading to no or more aggression, while a high enrichment level reduced aggression. After three days, the high-level enrichment groups in both rockfish and greenling reached social stability (i.e., a relatively stable social structure indicated by lower aggression), while aggression in the other groups continued increased. These results show the significant regulatory effect of enrichment levels on the aggressive behavior in both black rockfish and fat greenling. This study may promote the development of environmental enrichment measures, and it provides useful information for reducing fish aggression and improving fish welfare in aquaculture.
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Affiliation(s)
- Zonghang Zhang
- The Key Laboratory of Mariculture, Ministry of Education, Ocean University of China, Qingdao 266003, China; (Z.Z.); (Y.F.); (Z.Z.)
| | - Yiqiu Fu
- The Key Laboratory of Mariculture, Ministry of Education, Ocean University of China, Qingdao 266003, China; (Z.Z.); (Y.F.); (Z.Z.)
| | - Zhen Zhang
- The Key Laboratory of Mariculture, Ministry of Education, Ocean University of China, Qingdao 266003, China; (Z.Z.); (Y.F.); (Z.Z.)
| | - Xiumei Zhang
- Fisheries College, Zhejiang Ocean University, Zhoushan 316022, China
- Laboratory for Marine Fisheries Science and Food Production Processes, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266237, China
- Correspondence: or
| | - Shengcan Chen
- National Fisheries Technology Extension Center, Beijing 100125, China;
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88
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Engen S, Grøtan V, Sæther BE, Coste CFD. An Evolutionary and Ecological Community Model for Distribution of Phenotypes and Abundances among Competing Species. Am Nat 2021; 198:13-32. [PMID: 34143723 DOI: 10.1086/714529] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
AbstractHere, we propose a theory for the structure of communities of competing species. We include ecologically realistic assumptions, such as density dependence and stochastic fluctuations in the environment, and analyze how evolution caused by r- and K-selection will affect the packing of species in the phenotypic space as well as the species abundance distribution. Species-specific traits have the same matrix G of additive genetic variances and covariances, and evolution of mean traits is affected by fluctuations in population size of all species. In general, the model produces a shape of the distributions of log abundances that is skewed to the left, which is typical of most natural communities. Mean phenotypes of the species in the community are distributed approximately uniformly on the surface of a multidimensional sphere. However, environmental stochasticity generates selection that deviates species slightly from this surface; nonetheless, phenotypic distribution will be different from a random packing of species. This model of community evolution provides a theoretical framework that predicts a relationship between the structure of the phenotypic space and the form of species abundance distributions that can be compared against time series of variation in community structure.
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89
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Scharf I, Reshef MH, Avidov B, Ovadia O. Evidence for competition and cannibalism in wormlions. Sci Rep 2021; 11:12733. [PMID: 34140585 PMCID: PMC8211784 DOI: 10.1038/s41598-021-92154-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2020] [Accepted: 06/07/2021] [Indexed: 02/05/2023] Open
Abstract
Trap-building predators, such as web-building spiders and pit-building antlions, construct traps to capture their prey. These predators compete over sites that either enable the construction of suitable traps, are prey rich, or simply satisfy their abiotic requirements. We examined the effect of intraspecific competition over suitable space in pit-building wormlions. As expected, the ability of wormlions to select their favorable microhabitats-shaded or deep sand over lit or shallow sand-decreased with increasing density. Favorable microhabitats were populated more frequently by large than by small individuals and the density of individuals in the favorable microhabitat decreased with their increase in body mass. The advantage of large individuals in populating favorable microhabitats is nevertheless not absolute: both size categories constructed smaller pits when competing over a limited space compared to those constructed in isolation. The outcome of competition also depends on the type of habitat: deep sand is more important for large wormlions than small ones, while shade is similarly important for both size classes. Finally, in contrast to previous reports, cannibalism is shown here to be possible in wormlions. Its prevalence however is much lower compared to that documented in other trap-building predators. Our findings show that the advantage of large individuals over small ones should not be taken for granted, as it can depend on the environmental context. We present suggestions for the relative lack of competitive advantage of large wormlion individuals compared to other trap-building predators, which may stem from the absence of obvious weaponry, such as sharp mandibles.
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Affiliation(s)
- Inon Scharf
- grid.12136.370000 0004 1937 0546School of Zoology, Faculty of Life Sciences, Tel Aviv University, 69978 Tel Aviv, Israel
| | - May Hershkovitz Reshef
- grid.12136.370000 0004 1937 0546School of Zoology, Faculty of Life Sciences, Tel Aviv University, 69978 Tel Aviv, Israel
| | - Bar Avidov
- grid.12136.370000 0004 1937 0546School of Zoology, Faculty of Life Sciences, Tel Aviv University, 69978 Tel Aviv, Israel
| | - Ofer Ovadia
- grid.7489.20000 0004 1937 0511Department of Life Sciences, Ben-Gurion University of the Negev, Beer-Sheva, Israel
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90
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Tamura J, Ingram J, Martin AM, Burridge CP, Carver S. Contrasting population manipulations reveal resource competition between two large marsupials: bare-nosed wombats and eastern grey kangaroos. Oecologia 2021; 197:313-325. [PMID: 34095983 DOI: 10.1007/s00442-021-04959-y] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2021] [Accepted: 05/28/2021] [Indexed: 11/27/2022]
Abstract
Resource competition is an important interaction that can structure ecological communities, but is difficult to demonstrate in nature, and rarely demonstrated for large mammals including marsupials. We analysed 10 years of population survey data to investigate resource competition between bare-nosed wombats (Vombatus ursinus) and eastern grey kangaroos (Macropus giganteus) at two sites to assess whether resource competition is occurring. At one site, wombat abundance was reduced by increased mortality from mange disease, whereas at the other site, kangaroo abundance was reduced primarily by culling. We used the modified Lotka-Volterra competition (LVC) models to describe the mechanism of resource competition and fitted those models to the empirical data by maximum likelihood estimation. We found strong negative relationships between the abundance of wombats and kangaroos at each site, and resource competition was also mechanistically supported by the modified LVC models. The estimated competition coefficients indicate that bare-nosed wombats are a slightly superior competitor of eastern grey kangaroos than vice versa, and that intraspecific competition is almost twice as strong as interspecific competition. In addition, this study facilitated the calculation of the transmission rate associated with mange disease at one site (0.011), and the removal rate owing to culling, the introduction of a predator species, and drought at the other site (0.0006). Collectively, this research represents a rare empirical demonstration of resource competition between large mammals and contributes new insight into the ecology of two of Australia's largest grazing marsupials.
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Affiliation(s)
- Julie Tamura
- School of Natural Sciences, University of Tasmania, Sandy Bay, TAS, Australia.
| | - Janeane Ingram
- School of Geography, Planning and Spatial Sciences, University of Tasmania, Sandy Bay, TAS, Australia
| | - Alynn M Martin
- School of Natural Sciences, University of Tasmania, Sandy Bay, TAS, Australia
| | | | - Scott Carver
- School of Natural Sciences, University of Tasmania, Sandy Bay, TAS, Australia
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91
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Wang S, Callaway RM. Plasticity in response to plant-plant interactions and water availability. Ecology 2021; 102:e03361. [PMID: 33829488 DOI: 10.1002/ecy.3361] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/07/2020] [Revised: 12/02/2020] [Accepted: 01/13/2021] [Indexed: 01/13/2023]
Abstract
The plastic responses of plants to abiotic and biotic environmental factors have generally been addressed separately; thus we have a poor understanding of how these factors interact. For example, little is known about the effects of plant-plant interactions on the plasticity of plants in response to water availability. Furthermore, few studies have compared the effects of intra- and interspecific interactions on plastic responses to abiotic factors. To explore the effects of intraspecific and interspecific plant-plant interactions on plant responses to water availability, we grew Leucanthemum vulgare and Potentilla recta with a conspecific or the other species, and grew pairs of each species as controls in pots with the roots, but not shoots, physically separated. We subjected these competitive arrangements to mesic and dry conditions, and then measured shoot mass, root mass, total mass and root : shoot ratio and calculated plasticity in these traits. The total biomass of both species was highly suppressed by both intra- and interspecific interactions in mesic soil conditions. However, in drier soil, intraspecific interactions for both species and the effect of P. recta on L. vulgare were facilitative. For plasticity in response to water supply, when adjusted for total biomass, drought increased shoot mass, and decreased root mass and root : shoot ratios for both species in intraspecific interactions. When grown alone, there were no plastic responses in any trait except total mass, for either species. Our results suggested that plants interacting with other plants often show improved tolerance for drought than those grown alone, perhaps because of neighbor-induced shifts in plasticity in biomass allocation. Facilitative effects might also be promoted by plasticity to drought in root : shoot ratios.
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Affiliation(s)
- Shu Wang
- College of Forestry, Guizhou University, Guiyang, 550025, China.,Division of Biological Sciences and the Institute on Ecosystems, University of Montana, Missoula, Montana, 59812, USA
| | - Ragan M Callaway
- Division of Biological Sciences and the Institute on Ecosystems, University of Montana, Missoula, Montana, 59812, USA
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92
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Chalmandrier L, Hartig F, Laughlin DC, Lischke H, Pichler M, Stouffer DB, Pellissier L. Linking functional traits and demography to model species-rich communities. Nat Commun 2021; 12:2724. [PMID: 33976117 PMCID: PMC8113445 DOI: 10.1038/s41467-021-22630-1] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2019] [Accepted: 03/12/2021] [Indexed: 11/15/2022] Open
Abstract
It has long been anticipated that relating functional traits to species demography would be a cornerstone for achieving large-scale predictability of ecological systems. If such a relationship existed, species demography could be modeled only by measuring functional traits, transforming our ability to predict states and dynamics of species-rich communities with process-based community models. Here, we introduce a new method that links empirical functional traits with the demographic parameters of a process-based model by calibrating a transfer function through inverse modeling. As a case study, we parameterize a modified Lotka–Volterra model of a high-diversity mountain grassland with static plant community and functional trait data only. The calibrated trait–demography relationships are amenable to ecological interpretation, and lead to species abundances that fit well to the observed community structure. We conclude that our new method offers a general solution to bridge the divide between trait data and process-based models in species-rich ecosystems. Advances in process-based community ecology models are hindered by the challenge of linking functional traits to demography in species-rich systems, where a high number of parameters need to be estimated from limited data. Here the authors propose a new Bayesian framework to calibrate community models via functional traits, and validate it in a species-rich plant community.
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Affiliation(s)
- Loïc Chalmandrier
- Landscape Ecology, Institute of Terrestrial Ecosystems, ETH Zurich, Zürich, Switzerland. .,Landscape Ecology, Land Change Science, Swiss Federal Research Institute WSL, Birmensdorf, Switzerland. .,Department of Botany, University of Wyoming, Laramie, WY, USA. .,Theoretical Ecology, Faculty of Biology and Pre-Clinical Medicine, University of Regensburg, Regensburg, Germany. .,Centre for Integrative Ecology, University of Canterbury, School of Biological Sciences, Christchurch, Canterbury, New Zealand.
| | - Florian Hartig
- Theoretical Ecology, Faculty of Biology and Pre-Clinical Medicine, University of Regensburg, Regensburg, Germany
| | | | - Heike Lischke
- Dynamic Macroecology, Land Change Science, Swiss Federal Research Institute WSL, Birmensdorf, Switzerland
| | - Maximilian Pichler
- Theoretical Ecology, Faculty of Biology and Pre-Clinical Medicine, University of Regensburg, Regensburg, Germany
| | - Daniel B Stouffer
- Centre for Integrative Ecology, University of Canterbury, School of Biological Sciences, Christchurch, Canterbury, New Zealand
| | - Loïc Pellissier
- Landscape Ecology, Institute of Terrestrial Ecosystems, ETH Zurich, Zürich, Switzerland. .,Landscape Ecology, Land Change Science, Swiss Federal Research Institute WSL, Birmensdorf, Switzerland.
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93
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Disturbance Effects on Spatial Autocorrelation in Biodiversity: An Overview and a Call for Study. DIVERSITY 2021. [DOI: 10.3390/d13040167] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
The spatially autocorrelated patterns of biodiversity can be an important determinant of ecological processes, functions and delivery of services across spatial scales. Therefore, understanding disturbance effects on spatial autocorrelation in biodiversity is crucial for conservation and restoration planning but remains unclear. In a survey of disturbance versus spatial patterns of biodiversity literature from forests, grasslands and savannah ecosystems, we found that habitat disturbances generally reduce the spatial autocorrelation in species diversity on average by 15.5% and reduce its range (the distance up to which autocorrelation prevails) by 21.4%, in part, due to disturbance-driven changes in environmental conditions, dispersal, species interactions, or a combination of these processes. The observed effect of disturbance, however, varied markedly among the scale of disturbance (patch-scale versus habitat-scale). Surprisingly, few studies have examined disturbance effects on the spatial patterns of functional diversity, and the overall effect was non-significant. Despite major knowledge gaps in certain areas, our analysis offers a much-needed initial insights into the disturbance-driven changes in the spatial patterns of biodiversity, thereby setting the ground for informed discussion on conservation and promotion of spatial heterogeneity in managing natural systems under a changing world.
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94
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Sun Y, Zang H, Splettstößer T, Kumar A, Xu X, Kuzyakov Y, Pausch J. Plant intraspecific competition and growth stage alter carbon and nitrogen mineralization in the rhizosphere. PLANT, CELL & ENVIRONMENT 2021; 44:1231-1242. [PMID: 33175402 DOI: 10.1111/pce.13945] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/30/2020] [Revised: 10/29/2020] [Accepted: 10/29/2020] [Indexed: 06/11/2023]
Abstract
Plant roots interact with rhizosphere microorganisms to accelerate soil organic matter (SOM) mineralization for nutrient acquisition. Root-mediated changes in SOM mineralization largely depend on root-derived carbon (root-C) input and soil nutrient status. Hence, intraspecific competition over plant development and spatiotemporal variability in the root-C input and nutrients uptake may modify SOM mineralization. To investigate the effect of intraspecific competition on SOM mineralization at three growth stages (heading, flowering, and ripening), we grew maize (C4 plant) under three planting densities on a C3 soil and determined in situ soil C- and N-mineralization by 13 C-natural abundance and 15 N-pool dilution approaches. From heading to ripening, soil C- and N-mineralization rates exhibit similar unimodal trends and were tightly coupled. The C-to-N-mineralization ratio (0.6 to 2.6) increased with N availability, indicating that an increase in N-mineralization with N depletion was driven by microorganisms mining N-rich SOM. With the intraspecific competition, plants increased specific root lengths as an efficient strategy to compete for resources. Root morphologic traits rather than root biomass per se were positively related to C- and N-mineralization. Overall, plant phenology and intraspecific competition controlled the intensity and mechanisms of soil C- and N- mineralization by the adaptation of root traits and nutrient mining.
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Affiliation(s)
- Yue Sun
- Department of Agroecology, BayCEER, University of Bayreuth, Bayreuth, Germany
- Department of Agricultural Soil Science, University of Göttingen, Göttingen, Germany
| | - Huadong Zang
- College of Agronomy and Biotechnology, China Agricultural University, Beijing, China
| | - Thomas Splettstößer
- Department of Soil Science of Temperate and Boreal Ecosystems, University of Göttingen, Göttingen, Germany
| | - Amit Kumar
- Chair of Ecosystem Functioning and Services, Institute of Ecology, Leuphana University of Lüneburg, Lüneburg, Germany
| | - Xingliang Xu
- Key Laboratory of Ecosystem Network Observation and Modelling, Institute of Geographic Sciences and Natural Resources Research, CAS, Beijing, China
| | - Yakov Kuzyakov
- Department of Agricultural Soil Science, University of Göttingen, Göttingen, Germany
- Department of Soil Science of Temperate and Boreal Ecosystems, University of Göttingen, Göttingen, Germany
- Peoples Friendship University of Russia (RUDN University), Moscow, Russian Federation
| | - Johanna Pausch
- Department of Agroecology, BayCEER, University of Bayreuth, Bayreuth, Germany
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95
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Cope OL, Lindroth RL, Helm A, Keefover-Ring K, Kruger EL. Trait plasticity and trade-offs shape intra-specific variation in competitive response in a foundation tree species. THE NEW PHYTOLOGIST 2021; 230:710-719. [PMID: 33378548 DOI: 10.1111/nph.17166] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/28/2020] [Accepted: 12/15/2020] [Indexed: 06/12/2023]
Abstract
The ability to tolerate neighboring plants (i.e. degree of competitive response) is a key determinant of plant success in high-competition environments. Plant genotypes adjust their functional trait expression under high levels of competition, which may help explain intra-specific variation in competitive response. However, the relationships between traits and competitive response are not well understood, especially in trees. In this study, we investigated among-genotype associations between tree trait plasticity and competitive response. We manipulated competition intensity in experimental stands of trembling aspen (Populus tremuloides) to address the covariance between competition-induced changes in functional trait expression and aspects of competitive ability at the genotype level. Genotypic variation in the direction and magnitude of functional trait responses, especially those of crown foliar mass, phytochemistry, and leaf physiology, was associated with genotypic variation in competitive response. Traits exhibited distinct plastic responses to competition, with varying degrees of genotypic variation and covariance with other trait responses. The combination of genotypic diversity and covariance among functional traits led to tree responses to competition that were coordinated among traits yet variable among genotypes. Such relationships between tree traits and competitive success have the potential to shape stand-level trait distributions over space and time.
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Affiliation(s)
- Olivia L Cope
- Department of Integrative Biology, University of Wisconsin-Madison, Madison, WI, 53706, USA
| | - Richard L Lindroth
- Department of Entomology, University of Wisconsin-Madison, Madison, WI, 53706, USA
| | - Andrew Helm
- Department of Forest and Wildlife Ecology, University of Wisconsin-Madison, Madison, WI, 53706, USA
| | - Ken Keefover-Ring
- Departments of Botany and Geography, University of Wisconsin-Madison, Madison, WI, 53706, USA
| | - Eric L Kruger
- Department of Forest and Wildlife Ecology, University of Wisconsin-Madison, Madison, WI, 53706, USA
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96
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Fort H, Grigera TS. A method for predicting species trajectories tested with trees in barro colorado tropical forest. Ecol Modell 2021. [DOI: 10.1016/j.ecolmodel.2021.109504] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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97
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Trinder CJ, Brooker RW, Davidson H, Robinson D. Directly quantifying multiple interacting influences on plant competition. PLANT, CELL & ENVIRONMENT 2021; 44:1268-1277. [PMID: 33176015 DOI: 10.1111/pce.13944] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/30/2020] [Revised: 11/04/2020] [Accepted: 11/05/2020] [Indexed: 06/11/2023]
Abstract
When plants compete what influences that interaction? To answer this we measured belowground competition directly, as the simultaneous capture of soil ammonium and nitrate by co-existing herbaceous perennials, Dactylis glomerata and Plantago lanceolata, under the influence of: species identity; N uptake and biomass of focal and neighbour plants; location (benign lowland versus harsher upland site); N availability (low or high N fertilizer); N ion, ammonium or nitrate production (mineralisation) rate, and competition type (intra- or interspecific), as direct effects or pairwise interactions in linear models. We also measured biomass as an indirect proxy for competition. Only three factors influenced both competitive N uptake and biomass production: focal species identity, N ion and the interaction between N ion and neighbour N uptake. Location had little effect on N uptake but a strong influence on biomass production. N uptake increased linearly with biomass only in isolated plants. Our results support the view that measuring resource capture or biomass production tells you different things about how competitors interact with one another and their environment, and that biomass is a longer-term integrative proxy for the outcomes of multiple separate interactions-such as competition for N-occurring between plants.
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Affiliation(s)
- Clare J Trinder
- School of Biological and Environmental Sciences, University of Aberdeen, Aberdeen, UK
| | - Rob W Brooker
- Ecological Sciences, The James Hutton Institute, Aberdeen, UK
| | - Hazel Davidson
- School of Biological and Environmental Sciences, University of Aberdeen, Aberdeen, UK
| | - David Robinson
- School of Biological and Environmental Sciences, University of Aberdeen, Aberdeen, UK
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98
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Martyn TE, Stouffer DB, Godoy O, Bartomeus I, Pastore AI, Mayfield MM. Identifying "Useful" Fitness Models: Balancing the Benefits of Added Complexity with Realistic Data Requirements in Models of Individual Plant Fitness. Am Nat 2021; 197:415-433. [PMID: 33755538 DOI: 10.1086/713082] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
AbstractDirect species interactions are commonly included in individual fitness models used for coexistence and local diversity modeling. Though widely considered important for such models, direct interactions alone are often insufficient for accurately predicting fitness, coexistence, or diversity outcomes. Incorporating higher-order interactions (HOIs) can lead to more accurate individual fitness models but also adds many model terms, which can quickly result in model overfitting. We explore approaches for balancing the trade-off between tractability and model accuracy that occurs when HOIs are added to individual fitness models. To do this, we compare models parameterized with data from annual plant communities in Australia and Spain, varying in the extent of information included about the focal and neighbor species. The best-performing models for both data sets were those that grouped neighbors based on origin status and life form, a grouping approach that reduced the number of model parameters substantially while retaining important ecological information about direct interactions and HOIs. Results suggest that the specific identity of focal or neighbor species is not necessary for building well-performing fitness models that include HOIs. In fact, grouping neighbors by even basic functional information seems sufficient to maximize model accuracy, an important outcome for the practical use of HOI-inclusive fitness models.
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99
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Luskin MS, Johnson DJ, Ickes K, Yao TL, Davies SJ. Wildlife disturbances as a source of conspecific negative density-dependent mortality in tropical trees. Proc Biol Sci 2021; 288:20210001. [PMID: 33653133 DOI: 10.1098/rspb.2021.0001] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Large vertebrates are rarely considered important drivers of conspecific negative density-dependent mortality (CNDD) in plants because they are generalist consumers. However, disturbances like trampling and nesting also cause plant mortality, and their impact on plant diversity depends on the spatial overlap between wildlife habitat preferences and plant species composition. We studied the impact of native wildlife on a hyperdiverse tree community in Malaysia. Pigs (Sus scrofa) are abnormally abundant at the site due to food subsidies in nearby farmland and they construct birthing nests using hundreds of tree saplings. We tagged 34 950 tree saplings in a 25 ha plot during an initial census and assessed the source mortality by recovering tree tags from pig nests (n = 1672 pig-induced deaths). At the stand scale, pigs nested in flat dry habitats, and at the local neighbourhood scale, they nested within clumps of saplings, both of which are intuitive for safe and efficient nest building. At the stand scale, flat dry habitats contained higher sapling densities and higher proportions of common species, so pig nesting increased the weighted average species evenness across habitats. At the neighbourhood scale, pig-induced sapling mortality was associated with higher heterospecific and especially conspecific sapling densities. Tree species have clumped distributions due to dispersal limitation and habitat filtering, so pig disturbances in sapling clumps indirectly caused CNDD. As a result, Pielou species evenness in 400 m2 quadrats increased 105% more in areas with pig-induced deaths than areas without disturbances. Wildlife induced CNDD and this supported tree species evenness, but they also drove a 62% decline in sapling densities from 1996 to 2010, which is unsustainable. We suspect pig nesting is an important feature shaping tree composition throughout the region.
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Affiliation(s)
- Matthew Scott Luskin
- School of Biological Sciences, The University of Queensland, Brisbane, Queensland 4072, Australia.,Forest Global Earth Observatory, Smithsonian Tropical Research Institute, Washington, DC, USA.,Asian School of the Environment, Nanyang Technological University, Singapore, Singapore
| | - Daniel J Johnson
- School of Forest Resources and Conservation, University of Florida, Gainesville, FL, USA
| | - Kalan Ickes
- Department of Biological Sciences, Clemson University, Clemson, SC, USA
| | - Tze Leong Yao
- Forest Research Institute Malaysia (FRIM), Kepong, Selangor Darul Ehsan, Malaysia
| | - Stuart J Davies
- Forest Global Earth Observatory, Smithsonian Tropical Research Institute, Washington, DC, USA
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100
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Lamont BB, Witkowski ETF. Plant functional types determine how close postfire seedlings are from their parents in a species-rich shrubland. ANNALS OF BOTANY 2021; 127:381-395. [PMID: 33038222 PMCID: PMC7872127 DOI: 10.1093/aob/mcaa180] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/05/2020] [Accepted: 10/05/2020] [Indexed: 06/11/2023]
Abstract
BACKGROUND AND AIMS Fine-scale spatial patterns of the seedlings of co-occurring species reveal the relative success of reproduction and dispersal and may help interpret coexistence patterns of adult plants. To understand whether postfire community dynamics are controlled by mathematical, biological or environmental factors, we documented seedling-adult (putative parent) distances for a range of co-occurring species. We hypothesized that nearest-seedling-to-adult distances should be a function of the distance between the closest conspecific seedlings, closest inter-adult distances and seedling-to-parent ratios, and also that these should scale up in a consistent way from all individuals, to within and between species and finally between functional types (FTs). METHODS We assessed seedling-adult, seedling-seedling and adult-adult distances for 19 co-occurring shrub species 10 months after fire in a species-rich shrubland in south-western Australia. Species were categorized into 2 × 2 FTs: those that are killed by fire [non-(re)sprouters] vs. those that survive (resprouters) in nine taxonomically matched pairs, and those that disperse their seeds prefire (geosporous) vs. those that disperse their seeds postfire (serotinous). KEY RESULTS For the total data set and means for all species, seedling-adult distance was essentially a mathematical phenomenon, and correlated positively with seedling-seedling distance and adult-adult distance, and inversely with seedlings per adult. Among the four FTs, seedling-adult distance was shortest for geosporous non-sprouters and widest for serotinous resprouters. Why adults that produce few seedlings (resprouters) should be further away from them defies a simple mathematical or biological explanation at present. Ecologically, however, it is adaptive: the closest seedling was usually under the (now incinerated) parent crown of non-sprouters whereas those of resprouters were on average four times further away. CONCLUSIONS Our study highlights the value of recognizing four reproductive syndromes within fire-prone vegetation, and shows how these are characterized by marked differences in their seedling-adult spatial relations that serve to enhance biodiversity of the community.
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Affiliation(s)
- Byron B Lamont
- Ecology Section, School of Life and Molecular Sciences, Curtin University, Perth, WA, Australia
| | - Ed T F Witkowski
- School of Animal, Plant and Environmental Sciences, University of the Witwatersrand, PO Wits, Johannesburg, South Africa
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