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Warneke CR, Caughlin TT, Damschen EI, Haddad NM, Levey DJ, Brudvig LA. Habitat fragmentation alters the distance of abiotic seed dispersal through edge effects and direction of dispersal. Ecology 2021; 103:e03586. [PMID: 34767277 DOI: 10.1002/ecy.3586] [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: 10/07/2020] [Revised: 06/03/2021] [Accepted: 07/16/2021] [Indexed: 11/11/2022]
Abstract
Habitat loss and fragmentation are leading causes of species declines, driven in part by reduced dispersal. Isolating the effects of fragmentation on dispersal, however, is daunting because the consequences of fragmentation are typically intertwined, such as reduced connectivity and increased prevalence of edge effects. We used a large-scale landscape experiment to separate consequences of fragmentation on seed dispersal, considering both distance and direction of local dispersal. We evaluated seed dispersal for five wind- or gravity-dispersed, herbaceous plant species that were planted at different distances from habitat edges, within fragments that varied in their connectivity and shape (edge-to-area ratio). Dispersal distance was affected by proximity and direction relative to the nearest edge. For four of five species, dispersal distances were greater further from habitat edges and when seeds dispersed in the direction of the nearest edge. Connectivity and patch edge-to-area ratio had minimal effects on local dispersal. Our findings illustrate how some, but not all, landscape changes associated with fragmentation can affect the key population process of seed dispersal.
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Affiliation(s)
- Christopher R Warneke
- Department of Plant Biology and Program in Ecology, Evolutionary Biology, and Behavior, Michigan State University, East Lansing, Michigan, 48824, USA
| | - T Trevor Caughlin
- Department of Biological Sciences and Program in Ecology, Evolution, and Behavior, Boise State University, Boise, Idaho, 83725, USA
| | - Ellen I Damschen
- Department of Integrative Biology, University of Wisconsin-Madison, 451 Birge Hall, 430 Lincoln Drive, Madison, Wisconsin, 53706, USA
| | - Nick M Haddad
- Kellogg Biological Station and Department of Integrative Biology, Michigan State University, Hickory Corners, Michigan, 49060, USA
| | - Douglas J Levey
- Division of Environmental Biology, National Science Foundation, Alexandria, Virginia, 22314, USA
| | - Lars A Brudvig
- Department of Plant Biology and Program in Ecology, Evolutionary Biology, and Behavior, Michigan State University, East Lansing, Michigan, 48824, USA
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2
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Liversage K. Experiments determining if habitat mosaics include the refugia from succession theorized to promote species coexistence. Oecologia 2020; 194:193-204. [PMID: 32954461 DOI: 10.1007/s00442-020-04751-4] [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: 03/05/2019] [Accepted: 09/08/2020] [Indexed: 11/28/2022]
Abstract
Refugia within successional mosaics where localized conditions inhibit successional replacement may support large abundances of early colonizing species and their coexistence with strongly competitive late colonizers. Numerous habitats have been hypothesized as refugia from succession with important landscape-scale consequences from export of propagules, but their commonness among ecological systems is unknown because tests to demonstrate their existence have not been formulated and applied. In this study on an intertidal model system, an early successional tubeworm was highly abundant in a hypothesized refuge habitat-type where late successional algae could not establish. In adjacent non-refuge habitat, a change in species dominance involving tubeworms shifting to algae occurred from early to late succession following experimentally induced disturbance. No such change occurred in refuges where early successional tubeworm populations steadily increased throughout succession. Tubeworm recruitment was reduced in the presence of late successional algae, likely from competition in the non-refuge. The presence of habitats providing refugia from succession may have important consequences, e.g. promoting low but consistent levels of local-scale coexistence of early and late successional taxa observed here even without disturbance. Experimental tests such as these to identify refugia from succession will be useful to apply to larger-scale land/seascapes if, as in this study, the scale of experimentation is optimized for the species and processes of interest. If the inferences from these results are extrapolated to larger-scale systems, they may inform our understanding of spread of early successional species such as weeds with large impacts that are potentially influenced by this landscape feature.
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Affiliation(s)
- K Liversage
- Centre for Research On Ecological Impacts of Coastal Cities, School of Life and Environmental Sciences, Marine Ecology Laboratories (A11), The University of Sydney, Sydney, NSW, 2006, Australia. .,Estonian Marine Institute, University of Tartu, Mäealuse 14, 12618, Tallinn, Estonia.
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3
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Chmielewski MW, Eppley SM. Forest passerines as a novel dispersal vector of viable bryophyte propagules. Proc Biol Sci 2019; 286:20182253. [PMID: 30963825 PMCID: PMC6408877 DOI: 10.1098/rspb.2018.2253] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2018] [Accepted: 12/04/2018] [Indexed: 11/12/2022] Open
Abstract
Animal dispersal influences the community structure and diversity of a wide variety of plant taxa, yet the potential effects of animal dispersal in bryophytes (hornworts, liverworts, and mosses) is poorly understood. In many communities, birds use bryophyte-abundant niche space for foraging and gathering nest material, suggesting that birds may play a role in bryophyte dispersal. As highly motile animals with long migratory routes, birds potentially provide a means for both local and long-distance bryophyte dispersal in a manner that differs greatly from passive, aerial spore dispersal. To examine this phenomenon, we collected and germinated bryophyte propagules from the legs, feet and tails of 224 birds from 34 species within a temperate forest community. In total we found 1512 spores, and were able to germinate 242 bryophyte propagules. In addition, we provide evidence that topical (externally-carried) spore load varies by bird species and behaviour. Tail feather spore abundance is highest in bark and foliage gleaning species and is positively correlated with tarsal length. Together, these data suggest that a variety of forest birds exhibit the potential to act as dispersal vectors for bryophyte propagules, including an abundance of spores, and that understanding the effects of animal behaviour on bryophyte dispersal will be key to further understanding this interaction.
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4
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Harvey E, Gounand I, Little CJ, Fronhofer EA, Altermatt F. Upstream trophic structure modulates downstream community dynamics via resource subsidies. Ecol Evol 2017; 7:5724-5731. [PMID: 29085622 PMCID: PMC5655794 DOI: 10.1002/ece3.3144] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2016] [Revised: 04/27/2017] [Accepted: 05/17/2017] [Indexed: 02/06/2023] Open
Abstract
In many natural systems, the physical structure of the landscape dictates the flow of resources. Despite mounting evidence that communities' dynamics can be indirectly coupled by reciprocal among ecosystem resource flows, our understanding of how directional resource flows might indirectly link biological communities is limited. We here propose that differences in community structure upstream should lead to different downstream dynamics, even in the absence of dispersal of organisms. We report an experimental test of the effect of upstream community structure on downstream community dynamics in a simplified but highly controlled setting, using protist microcosms. We implemented directional flows of resources, without dispersal, from a standard resource pool into upstream communities of contrasting interaction structure and then to further downstream communities of either one or two trophic levels. Our results demonstrate that different types of species interactions in upstream habitats may lead to different population sizes and levels of biomass in these upstream habitats. This, in turn, leads to varying levels of detritus transfer (dead biomass) to the downstream communities, thus influencing their population densities and trophic interactions in predictable ways. Our results suggest that the structure of species interactions in directionally structured ecosystems can be a key mediator of alterations to downstream habitats. Alterations to upstream habitats can thus cascade down to downstream communities, even without dispersal.
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Affiliation(s)
- Eric Harvey
- Department of Evolutionary Biology and Environmental Studies University of Zurich Zürich Switzerland.,Department of Aquatic Ecology Eawag, Swiss Federal Institute of Aquatic Science and Technology Dübendorf Switzerland
| | - Isabelle Gounand
- Department of Evolutionary Biology and Environmental Studies University of Zurich Zürich Switzerland.,Department of Aquatic Ecology Eawag, Swiss Federal Institute of Aquatic Science and Technology Dübendorf Switzerland
| | - Chelsea J Little
- Department of Evolutionary Biology and Environmental Studies University of Zurich Zürich Switzerland.,Department of Aquatic Ecology Eawag, Swiss Federal Institute of Aquatic Science and Technology Dübendorf Switzerland
| | - Emanuel A Fronhofer
- Department of Evolutionary Biology and Environmental Studies University of Zurich Zürich Switzerland.,Department of Aquatic Ecology Eawag, Swiss Federal Institute of Aquatic Science and Technology Dübendorf Switzerland
| | - Florian Altermatt
- Department of Evolutionary Biology and Environmental Studies University of Zurich Zürich Switzerland.,Department of Aquatic Ecology Eawag, Swiss Federal Institute of Aquatic Science and Technology Dübendorf Switzerland
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5
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Caughlin TT, Elliott S, Lichstein JW. When does seed limitation matter for scaling up reforestation from patches to landscapes? ECOLOGICAL APPLICATIONS : A PUBLICATION OF THE ECOLOGICAL SOCIETY OF AMERICA 2016; 26:2437-2448. [PMID: 27862619 DOI: 10.1002/eap.1410] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/08/2016] [Revised: 05/17/2016] [Accepted: 05/25/2016] [Indexed: 06/06/2023]
Abstract
Restoring forest to hundreds of millions of hectares of degraded land has become a centerpiece of international plans to sequester carbon and conserve biodiversity. Forest landscape restoration will require scaling up ecological knowledge of secondary succession from small-scale field studies to predict forest recovery rates in heterogeneous landscapes. However, ecological field studies reveal widely divergent times to forest recovery, in part due to landscape features that are difficult to replicate in empirical studies. Seed rain can determine reforestation rate and depends on landscape features that are beyond the scale of most field studies. We develop mathematical models to quantify how landscape configuration affects seed rain and forest regrowth in degraded patches. The models show how landscape features can alter the successional trajectories of otherwise identical patches, thus providing insight into why some empirical studies reveal a strong effect of seed rain on secondary succession, while others do not. We show that seed rain will strongly limit reforestation rate when patches are near a threshold for arrested succession, when positive feedbacks between tree canopy cover and seed rain occur during early succession, and when directed dispersal leads to between-patch interactions. In contrast, seed rain has weak effects on reforestation rate over a wide range of conditions, including when landscape-scale seed availability is either very high or very low. Our modeling framework incorporates growth and survival parameters that are commonly estimated in field studies of reforestation. We demonstrate how mathematical models can inform forest landscape restoration by allowing land managers to predict where natural regeneration will be sufficient to restore tree cover. Translating quantitative forecasts into spatially targeted interventions for forest landscape restoration could support target goals of restoring millions of hectares of degraded land and help mitigate global climate change.
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Affiliation(s)
- T Trevor Caughlin
- Department of Biology, University of Florida, Gainesville, Florida, 32601, USA
| | - Stephen Elliott
- Forest Restoration Research Unit, Department of Biology, Science Faculty, Chiang Mai University Huaykaew Rd, Chiang Mai, 50200, Thailand
| | - Jeremy W Lichstein
- Department of Biology, University of Florida, Gainesville, Florida, 32601, USA
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6
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Holt G, Chesson P. Scale-Dependent Community Theory for Streams and Other Linear Habitats. Am Nat 2016; 188:E59-73. [DOI: 10.1086/687525] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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7
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Crawford M, Davies S, Griffith A. Predicting metapopulation responses of a tidal wetland annual to environmental stochasticity and water dispersal through an individual-based model. Ecol Modell 2015. [DOI: 10.1016/j.ecolmodel.2015.08.019] [Citation(s) in RCA: 3] [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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8
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Wang S, Haegeman B, Loreau M. Dispersal and metapopulation stability. PeerJ 2015; 3:e1295. [PMID: 26557427 PMCID: PMC4636407 DOI: 10.7717/peerj.1295] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2015] [Accepted: 09/15/2015] [Indexed: 11/20/2022] Open
Abstract
Metapopulation dynamics are jointly regulated by local and spatial factors. These factors may affect the dynamics of local populations and of the entire metapopulation differently. Previous studies have shown that dispersal can stabilize local populations; however, as dispersal also tends to increase spatial synchrony, its net effect on metapopulation stability has been controversial. Here we present a simple metapopulation model to study how dispersal, in interaction with other spatial and local processes, affects the temporal variability of metapopulations in a stochastic environment. Our results show that in homogeneous metapopulations, the local stabilizing and spatial synchronizing effects of dispersal cancel each other out, such that dispersal has no effect on metapopulation variability. This result is robust to moderate heterogeneities in local and spatial parameters. When local and spatial dynamics exhibit high heterogeneities, however, dispersal can either stabilize or destabilize metapopulation dynamics through various mechanisms. Our findings have important theoretical and practical implications. We show that dispersal functions as a form of spatial intraspecific mutualism in metapopulation dynamics and that its effect on metapopulation stability is opposite to that of interspecific competition on local community stability. Our results also suggest that conservation corridors should be designed with appreciation of spatial heterogeneities in population dynamics in order to maximize metapopulation stability.
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Affiliation(s)
- Shaopeng Wang
- Centre for Biodiversity Theory and Modelling, Station d'Ecologie Expérimentale du CNRS , Moulis , France
| | - Bart Haegeman
- Centre for Biodiversity Theory and Modelling, Station d'Ecologie Expérimentale du CNRS , Moulis , France
| | - Michel Loreau
- Centre for Biodiversity Theory and Modelling, Station d'Ecologie Expérimentale du CNRS , Moulis , France
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9
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A mathematical biologist's guide to absolute and convective instability. Bull Math Biol 2013; 76:1-26. [PMID: 24272387 DOI: 10.1007/s11538-013-9911-9] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2013] [Accepted: 10/08/2013] [Indexed: 10/26/2022]
Abstract
Mathematical models have been highly successful at reproducing the complex spatiotemporal phenomena seen in many biological systems. However, the ability to numerically simulate such phenomena currently far outstrips detailed mathematical understanding. This paper reviews the theory of absolute and convective instability, which has the potential to redress this inbalance in some cases. In spatiotemporal systems, unstable steady states subdivide into two categories. Those that are absolutely unstable are not relevant in applications except as generators of spatial or spatiotemporal patterns, but convectively unstable steady states can occur as persistent features of solutions. The authors explain the concepts of absolute and convective instability, and also the related concepts of remnant and transient instability. They give examples of their use in explaining qualitative transitions in solution behaviour. They then describe how to distinguish different types of instability, focussing on the relatively new approach of the absolute spectrum. They also discuss the use of the theory for making quantitative predictions on how spatiotemporal solutions change with model parameters. The discussion is illustrated throughout by numerical simulations of a model for river-based predator-prey systems.
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10
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Sarhad J, Carlson R, Anderson KE. Population persistence in river networks. J Math Biol 2013; 69:401-48. [PMID: 23846242 DOI: 10.1007/s00285-013-0710-6] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2012] [Revised: 06/28/2013] [Indexed: 11/28/2022]
Affiliation(s)
- Jonathan Sarhad
- Department of Biology, University of California, Riverside, Riverside, CA, USA,
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11
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Yearsley JM, Viard F, Broquet T. THE EFFECT OF COLLECTIVE DISPERSAL ON THE GENETIC STRUCTURE OF A SUBDIVIDED POPULATION. Evolution 2013; 67:1649-59. [DOI: 10.1111/evo.12111] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2012] [Accepted: 03/07/2013] [Indexed: 11/29/2022]
Affiliation(s)
- Jonathan M. Yearsley
- School of Biology & Environmental Science; University College Dublin; Belfield Dublin 4 Ireland
| | - Frédérique Viard
- CNRS, UMR 7144, Team Div& Co; Lab. Adaptation et Diversité en Milieu Marin, Station Biologique de Roscoff; 29682 Roscoff France
- UPMC Univ Paris; 06, UMR 7144 AD2M; Station Biologique de Roscoff; 29682 Roscoff France
| | - Thomas Broquet
- CNRS, UMR 7144, Team Div& Co; Lab. Adaptation et Diversité en Milieu Marin, Station Biologique de Roscoff; 29682 Roscoff France
- UPMC Univ Paris; 06, UMR 7144 AD2M; Station Biologique de Roscoff; 29682 Roscoff France
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12
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13
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Anderson KE, Hilker FM, Nisbet RM. Directional biases and resource-dependence in dispersal generate spatial patterning in a consumer-producer model. Ecol Lett 2012; 15:209-17. [PMID: 22248081 DOI: 10.1111/j.1461-0248.2011.01727.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
Directional dispersal plays a large role in shaping ecological processes in diverse systems such as rivers, coastlines and vegetation communities. We describe an instability driven by directional dispersal in a spatially explicit consumer-producer model where spatial patterns emerge in the absence of external environmental variation. Dispersal of the consumer has both undirected and directed components that are functions of producer biomass. We demonstrate that directional dispersal is required for the instability, while undirected diffusive dispersal sets a lower bound to the spatial scale of emerging patterns. Furthermore, instability requires indirect feedbacks affecting consumer per capita dispersal rates, and not activator-inhibitor dynamics affecting production and mortality as is described in previous theory. This novel and less-restrictive mechanism for generating spatial patterns can arise over realistic parameter values, which we explore using an empirically inspired model and data on stream macroinvertebrates.
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Affiliation(s)
- Kurt E Anderson
- Department of Biology, University of California, Riverside CA 92521, USA.
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14
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Merritt DM, Nilsson C, Jansson R. Consequences of propagule dispersal and river fragmentation for riparian plant community diversity and turnover. ECOL MONOGR 2010. [DOI: 10.1890/09-1533.1] [Citation(s) in RCA: 84] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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15
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Goldberg EE, Lynch HJ, Neubert MG, Fagan WF. Effects of branching spatial structure and life history on the asymptotic growth rate of a population. THEOR ECOL-NETH 2009. [DOI: 10.1007/s12080-009-0058-0] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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16
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Transient Responses to Spatial Perturbations in Advective Systems. Bull Math Biol 2008; 70:1480-502. [DOI: 10.1007/s11538-008-9309-2] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2007] [Accepted: 01/25/2008] [Indexed: 10/22/2022]
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17
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Muneepeerakul R, Bertuzzo E, Rinaldo A, Rodriguez-Iturbe I. Patterns of vegetation biodiversity: the roles of dispersal directionality and river network structure. J Theor Biol 2008; 252:221-9. [PMID: 18343409 DOI: 10.1016/j.jtbi.2008.02.001] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2007] [Revised: 01/31/2008] [Accepted: 02/01/2008] [Indexed: 11/20/2022]
Abstract
This paper investigates the importance of dispersal directionality and river network structure to biodiversity patterns. Our model results suggest that dispersal directionality plays a crucial role in determining biodiversity patterns, even more so than dispersal rates. Dispersal directionality heterogenizes the spatial distribution of abundance, which results in higher extinction rates of rare species and higher beta diversity. It induces a few species with very high abundances at the expense of many species with intermediate abundances, thereby lowering alpha and gamma diversities. The river network structure also increases beta diversity, i.e., more heterogeneous ecosystems, in comparison to typical two-dimensional landscapes. We find that the interplay between the dispersal directionality and network topology has important consequences on relative species abundance patterns and the distribution of alpha diversity.
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Affiliation(s)
- Rachata Muneepeerakul
- Department of Civil and Environmental Engineering, E-Quad, Princeton University, Princeton, NJ 08544, USA.
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18
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Westcott DA, Setter M, Bradford MG, McKeown A, Setter S. Cassowary dispersal of the invasive pond apple in a tropical rainforest: the contribution of subordinate dispersal modes in invasion. DIVERS DISTRIB 2007. [DOI: 10.1111/j.1472-4642.2007.00416.x] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
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19
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Sousa WP, Kennedy PG, Mitchell BJ, Ordóñez L BM. SUPPLY-SIDE ECOLOGY IN MANGROVES: DO PROPAGULE DISPERSAL AND SEEDLING ESTABLISHMENT EXPLAIN FOREST STRUCTURE? ECOL MONOGR 2007. [DOI: 10.1890/05-1935] [Citation(s) in RCA: 104] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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20
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Abstract
1. We examine the relationship between immigration rate and patch area for different types of movement behaviours and detection modes. Theoretical models suggest that the scale dependence of the immigration rate per unit area (I/A) can be described by a power model I/A = i*Area(zeta), where zeta describes the strength of the scale dependence. 2. Three types of scaling were identified. Area scaling (zeta = 0) is expected for passively dispersed organisms that have the same probability of landing anywhere in the patch. Perimeter scaling (-0.30 > zeta > -0.45) is expected when patches are detected from a very short distance and immigrants arrive over the patch boundary, whereas diameter scaling (zeta = -0.5) is expected if patches are detected from a long distance or if search is approximately linear. 3. A meta-analysis of published empirical studies of the scale dependence of immigration rates in terrestrial insects suggests that butterflies show diameter scaling, aphids show area scaling, and the scaling of beetle immigration is highly variable. We conclude that the scaling of immigration rates in many cases can be predicted from search behaviour and the mode of patch detection.
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Affiliation(s)
- Göran Englund
- Department of Ecology and Environmental Science, Umeå Marine Science Center, Umeå University, SE-901 87 Umeå, Sweden.
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21
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Muneepeerakul R, Weitz JS, Levin SA, Rinaldo A, Rodriguez-Iturbe I. A neutral metapopulation model of biodiversity in river networks. J Theor Biol 2006; 245:351-63. [PMID: 17109896 DOI: 10.1016/j.jtbi.2006.10.005] [Citation(s) in RCA: 77] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2006] [Revised: 09/27/2006] [Accepted: 10/05/2006] [Indexed: 11/15/2022]
Abstract
In this paper, we develop a stochastic, discrete, structured metapopulation model to explore the dynamics and patterns of biodiversity of riparian vegetation. In the model, individual plants spread along a branched network via directional dispersal and undergo neutral ecological drift. Simulation results suggest that in comparison to 2-D landscapes with non-directional dispersal, river networks with directional dispersal have lower local (alpha) and overall (gamma) diversities, but higher between-community (beta) diversity, implying that riparian species are distributed in a more localized pattern and more vulnerable to local extinction. The relative abundance patterns also change, such that higher percentages of species are in low-abundance, or rare, classes, accompanied by concave rank-abundance curves. In contrast to existing theories, the results suggest that in river networks, increased directional dispersal reduces alpha diversity. These altered patterns and trends result from the combined effects of directionality of dispersal and river network structure, whose relative importance is in need of continuing study. In addition, riparian communities obeying neutral dynamics seem to exhibit abrupt changes where large tributaries confluence; this pattern may provide a signature to identify types of interspecific dynamics in river networks.
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Affiliation(s)
- Rachata Muneepeerakul
- Department of Civil and Environmental Engineering, E-Quad, Princeton University, Princeton, NJ 08544, USA.
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22
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Anderson KE, Nisbet RM, Diehl S. Spatial scaling of consumer-resource interactions in advection-dominated systems. Am Nat 2006; 168:358-72. [PMID: 16947111 DOI: 10.1086/506916] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2005] [Accepted: 03/14/2006] [Indexed: 11/04/2022]
Abstract
Ecologists studying consumer-resource interactions in advection-dominated systems such as streams and rivers frequently seek to link the results of small-scale experiments with larger-scale patterns of distribution and abundance. Accomplishing this goal requires determining the characteristic scale, termed the response length, at which there is a shift from local dynamics dominated by advective dispersal to larger-scale dynamics dominated by births and deaths. Here, we model the dynamics of consumer-resource systems in a spatially variable, advective environment and show how consumer-resource interactions alter the response length relative to its single-species value. For one case involving a grazer that emigrates in response to high predator density, we quantify the changes using published data from small-scale experiments on aquatic invertebrates. Using Fourier analysis, we describe the responses of advection-dominated consumer-resource systems to spatially extended environmental variability in a way that involves explicit consideration of the response length. The patterns we derive for different consumer-resource systems exhibit important similarities in how component populations respond to spatial environmental variability affecting dispersal as opposed to demographic parameters.
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Affiliation(s)
- Kurt E Anderson
- Department of Ecology, Evolution, and Marine Biology, University of California, Santa Barbara, California 93106, USA.
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24
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Östman Ö, Kneitel JM, Chase JM. Disturbance alters habitat isolation's effect on biodiversity in aquatic microcosms. OIKOS 2006. [DOI: 10.1111/j.2006.0030-1299.14521.x] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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25
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Anderson KE, Nisbet RM, Diehl S, Cooper SD. Scaling population responses to spatial environmental variability in advection‐dominated systems. Ecol Lett 2005; 8:933-943. [DOI: 10.1111/j.1461-0248.2005.00797.x] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Kurt E. Anderson
- Department of Ecology, Evolution, and Marine Biology, University of California, Santa Barbara, CA‐93106‐9610, USA
| | - Roger M. Nisbet
- Department of Ecology, Evolution, and Marine Biology, University of California, Santa Barbara, CA‐93106‐9610, USA
| | - Sebastian Diehl
- Department Biologie II, Aquatische Ökologie, Ludwig‐Maximilians‐Universität München, Großhaderner Str. 2, D‐82152 Planegg‐Martinsried, Germany
| | - Scott D. Cooper
- Department of Ecology, Evolution, and Marine Biology, University of California, Santa Barbara, CA‐93106‐9610, USA
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26
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Nilsson C, Reidy CA, Dynesius M, Revenga C. Fragmentation and flow regulation of the world's large river systems. Science 2005; 308:405-8. [PMID: 15831757 DOI: 10.1126/science.1107887] [Citation(s) in RCA: 745] [Impact Index Per Article: 39.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
A global overview of dam-based impacts on large river systems shows that over half (172 out of 292) are affected by dams, including the eight most biogeographically diverse. Dam-impacted catchments experience higher irrigation pressure and about 25 times more economic activity per unit of water than do unaffected catchments. In view of projected changes in climate and water resource use, these findings can be used to identify ecological risks associated with further impacts on large river systems.
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Affiliation(s)
- Christer Nilsson
- Landscape Ecology Group, Department of Ecology and Environmental Science, Umeå University, SE-901 87 Umeå, Sweden.
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Levine JM, Murrell DJ. The Community-Level Consequences of Seed Dispersal Patterns. ANNUAL REVIEW OF ECOLOGY EVOLUTION AND SYSTEMATICS 2003. [DOI: 10.1146/annurev.ecolsys.34.011802.132400] [Citation(s) in RCA: 329] [Impact Index Per Article: 15.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Jonathan M. Levine
- Department of Ecology, Evolution, and Marine Biology, University of California, Santa Barbara, California 93106;
- Center for Population Biology, Imperial College at Silwood Park, Ascot, Berkshire SL5 7PY, United Kingdom;
| | - David J. Murrell
- Department of Ecology, Evolution, and Marine Biology, University of California, Santa Barbara, California 93106;
- Center for Population Biology, Imperial College at Silwood Park, Ascot, Berkshire SL5 7PY, United Kingdom;
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