1
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Nelson AS, Gelambi M, Estefania Morales M, Whitehead SR. Fruit secondary metabolites alter the quantity and quality of a seed dispersal mutualism. Ecology 2023; 104:e4032. [PMID: 36932996 DOI: 10.1002/ecy.4032] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/19/2022] [Revised: 01/30/2023] [Accepted: 03/08/2023] [Indexed: 03/19/2023]
Abstract
Plant secondary metabolites are key mechanistic drivers of species interactions. These metabolites have primarily been studied for their role in defense, but they can also have complex consequences for mutualisms, including seed dispersal. Although the primary function of fleshy fruits is to attract seed-dispersing animals, fruits often contain complex mixtures of toxic or deterrent secondary metabolites that can reduce the quantity or quality of seed dispersal mutualisms. Furthermore, because seeds are often dispersed across multiple stages by several dispersers, the net consequences of fruit secondary metabolites for the effectiveness of seed dispersal and ultimately plant fitness are poorly understood. Here, we tested the effects of amides, nitrogen-based defensive compounds common in fruits of the neotropical plant genus Piper (Piperaceae), on seed dispersal effectiveness (SDE) by ants, which are common secondary seed dispersers. We experimentally added amide extracts to Piper fruits both in the field and lab, finding that amides reduced the quantity of secondary seed dispersal by reducing ant recruitment (87%) and fruit removal rates (58% and 66% in the field and lab, respectively). Moreover, amides not only reduced dispersal quantity but also altered seed dispersal quality by shifting the community composition of recruiting ants (notably by reducing the recruitment of the most effective disperser by 90% but having no detectable effect on the recruitment of a cheater species that removes fruit pulp without dispersing seeds). Although amides did not affect the distance ants initially carried seeds, they altered the quality of seed dispersal by reducing the likelihood of ants cleaning seeds (67%) and increasing their likelihood of redispersing seeds outside of the nest (200%). Overall, these results demonstrate that secondary metabolites can alter the effectiveness of plant mutualisms, by both reducing mutualism quantity and altering mutualism quality through multiple mechanisms. These findings present a critical step in understanding the factors mediating the outcomes of seed dispersal and, more broadly, demonstrate the importance of considering how defensive secondary metabolites influence the outcomes of mutualisms surrounding plants.
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Affiliation(s)
- Annika S Nelson
- Department of Biological Sciences, Virginia Polytechnic Institute and State University, Derring Hall Room 2125, 926 West Campus Drive, Mail Code 0406, Blacksburg, Virginia, 24061, United States.,La Selva Biological Station, Organization for Tropical Studies, Puerto Viejo de Sarapiquí, Heredia Province, Costa Rica
| | - Mariana Gelambi
- Department of Biological Sciences, Virginia Polytechnic Institute and State University, Derring Hall Room 2125, 926 West Campus Drive, Mail Code 0406, Blacksburg, Virginia, 24061, United States.,La Selva Biological Station, Organization for Tropical Studies, Puerto Viejo de Sarapiquí, Heredia Province, Costa Rica
| | - -M Estefania Morales
- Ingenería en Ciencias Forestales y Vida Silvestre, Universidad Técnica Nacional, Barrio Lourdes, Provincia de Alajuela, Cd Quesada, Costa Rica.,La Selva Biological Station, Organization for Tropical Studies, Puerto Viejo de Sarapiquí, Heredia Province, Costa Rica
| | - Susan R Whitehead
- Department of Biological Sciences, Virginia Polytechnic Institute and State University, Derring Hall Room 2125, 926 West Campus Drive, Mail Code 0406, Blacksburg, Virginia, 24061, United States.,La Selva Biological Station, Organization for Tropical Studies, Puerto Viejo de Sarapiquí, Heredia Province, Costa Rica
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2
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Quintero E, Rodríguez-Sánchez F, Jordano P. Reciprocity and interaction effectiveness in generalised mutualisms among free-living species. Ecol Lett 2023; 26:132-146. [PMID: 36450595 PMCID: PMC10099531 DOI: 10.1111/ele.14141] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2022] [Revised: 09/12/2022] [Accepted: 10/24/2022] [Indexed: 12/02/2022]
Abstract
Mutualistic interactions among free-living species generally involve low-frequency interactions and highly asymmetric dependence among partners, yet our understanding of factors behind their emergence is still limited. Using individual-based interactions of a super-generalist fleshy-fruited plant with its frugivore assemblage, we estimated the Resource Provisioning Effectiveness (RPE) and Seed Dispersal Effectiveness (SDE) to assess the balance in the exchange of resources. Plants were highly dependent on a few frugivore species, while frugivores interacted with most individual plants, resulting in strong asymmetries of mutual dependence. Interaction effectiveness was mainly driven by interaction frequency. Despite highly asymmetric dependences, the strong reliance on quantity of fruit consumed determined high reciprocity in rewards between partners (i.e. higher energy provided by the plant, more seedlings recruited), which was not obscured by minor variations in the quality of animal or plant service. We anticipate reciprocity will emerge in low-intimacy mutualisms where the mutualistic outcome largely relies upon interaction frequency.
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Affiliation(s)
- Elena Quintero
- Integrative Ecology Group, Estación Biológica de Doñana, Sevilla, Spain
| | - Francisco Rodríguez-Sánchez
- Integrative Ecology Group, Estación Biológica de Doñana, Sevilla, Spain.,Departamento de Biología Vegetal y Ecología, Facultad de Biología, Universidad de Sevilla, Sevilla, Spain
| | - Pedro Jordano
- Integrative Ecology Group, Estación Biológica de Doñana, Sevilla, Spain.,Departamento de Biología Vegetal y Ecología, Facultad de Biología, Universidad de Sevilla, Sevilla, Spain
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3
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Rehling F, Schlautmann J, Jaroszewicz B, Schabo DG, Farwig N. Forest degradation limits the complementarity and quality of animal seed dispersal. Proc Biol Sci 2022; 289:20220391. [PMID: 35611541 PMCID: PMC9130786 DOI: 10.1098/rspb.2022.0391] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
Forest degradation changes the structural heterogeneity of forests and species communities, with potential consequences for ecosystem functions including seed dispersal by frugivorous animals. While the quantity of seed dispersal may be robust towards forest degradation, changes in the effectiveness of seed dispersal through qualitative changes are poorly understood. Here, we carried out extensive field sampling on the structure of forest microhabitats, seed deposition sites and plant recruitment along three characteristics of forest microhabitats (canopy cover, ground vegetation and deadwood) in Europe's last lowland primeval forest (Białowieża, Poland). We then applied niche modelling to study forest degradation effects on multi-dimensional seed deposition by frugivores and recruitment of fleshy-fruited plants. Forest degradation was shown to (i) reduce the niche volume of forest microhabitat characteristics by half, (ii) homogenize the spatial seed deposition within and among frugivore species, and (iii) limit the regeneration of plants via changes in seed deposition and recruitment. Our study shows that the loss of frugivores in degraded forests is accompanied by a reduction in the complementarity and quality of seed dispersal by remaining frugivores. By contrast, structure-rich habitats, such as old-growth forests, safeguard the diversity of species interactions, forming the basis for high-quality ecosystem functions.
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Affiliation(s)
- Finn Rehling
- Department of Biology, Conservation Ecology, University of Marburg, Karl-von-Frisch-Str. 8, D-35043 Marburg, Germany
| | - Jan Schlautmann
- Department of Biology, Conservation Ecology, University of Marburg, Karl-von-Frisch-Str. 8, D-35043 Marburg, Germany
| | - Bogdan Jaroszewicz
- Faculty of Biology, University of Warsaw, Białowieża Geobotanical Station, PL-17-230 Białowieża, Poland
| | - Dana G. Schabo
- Department of Biology, Conservation Ecology, University of Marburg, Karl-von-Frisch-Str. 8, D-35043 Marburg, Germany
| | - Nina Farwig
- Department of Biology, Conservation Ecology, University of Marburg, Karl-von-Frisch-Str. 8, D-35043 Marburg, Germany
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4
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Cao L, Jansen PA, Wang B, Yan C, Wang Z, Chen J. Mutual cheating strengthens a tropical seed dispersal mutualism. Ecology 2021; 103:e03574. [PMID: 34706058 DOI: 10.1002/ecy.3574] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/30/2020] [Revised: 04/16/2021] [Accepted: 07/07/2021] [Indexed: 11/07/2022]
Abstract
While cheating can cause the degradation or collapse of mutualisms, mutualisms may theoretically stabilize or strengthen if the cheating is mutual. Here, we present an asymmetric two-player game model to explore the evolutionary dynamics of mutual cheating in a mutualistic interaction. We found that the interaction evolved towards mutual cheating if cheating can help both partners obtain higher benefits or if counter-cheating yields more benefits to victims than simply tolerating exploitation by partners. Then, we present empirical evidence for such mutual cheating strengthening a seed dispersal mutualism in which rodents disperse seeds by scatter hoarding, rodents sabotage seed germination by pruning radicles, and seeds escape rodents by resprouting. By tracking >8000 Pittosporopsis kerrii seeds throughout the dispersal process in a tropical forest in southwest China, we found that rodents provided better dispersal to seeds that they pruned, i.e., pruned seeds were dispersed farther and were more likely to establish seedlings than unpruned seeds. Compared to unpruned seeds, pruned seeds retained more of their nutrients, i.e., dry mass of pruned seeds was greater than that of unpruned seeds, and were stored for longer by rodents. These findings indicate that mutual cheating benefited both partners. Payoffs estimated from the field experiments indicated that mutual cheating was indeed favored in rodents and plants P. kerrii, and that neither partner was enslaved by the other under mutual cheating. Rather, the mutualism remained stable because the partners were able to exploit each other, and each partner attempted to gain the maximum benefits from the interaction. Our findings indicate that mutual cheating between two mutualists can enhance and stabilize mutualisms.
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Affiliation(s)
- Lin Cao
- School of Ecology and Environmental Science, Yunnan University, Kunming, 650091, China.,Center for Integrative Conservation, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Mengla, Yunnan, 666303, China.,State Key Laboratory of Integrated Management of Pest Insects and Rodents in Agriculture, Institute of Zoology, Chinese Academy of Sciences (CAS), Beijing, 100101, China
| | - Patrick A Jansen
- Department of Environmental Sciences, Wageningen University, PO Box 47, 6700 AA, Wageningen, The Netherlands.,Smithsonian Tropical Research Institute, Apartado, 0843-03092, Republic of Panama
| | - Bo Wang
- Center for Integrative Conservation, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Mengla, Yunnan, 666303, China.,School of Resources and Environmental Engineering, Anhui University, Hefei, 230601, China
| | - Chuan Yan
- State Key Laboratory of Integrated Management of Pest Insects and Rodents in Agriculture, Institute of Zoology, Chinese Academy of Sciences (CAS), Beijing, 100101, China.,State Key Laboratory of Grassland Agro-ecosystem, Institute of Innovation Ecology & College of Life Sciences, Lanzhou University, Lanzhou, 730000, China
| | - Zhenyu Wang
- College of Life Sciences, Jiangxi Normal University, Nanchang, 330022, China
| | - Jin Chen
- Center for Integrative Conservation, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Mengla, Yunnan, 666303, China
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5
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Nelson AS, Whitehead SR. Fruit secondary metabolites shape seed dispersal effectiveness. Trends Ecol Evol 2021; 36:1113-23. [PMID: 34509316 DOI: 10.1016/j.tree.2021.08.005] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2021] [Revised: 08/05/2021] [Accepted: 08/09/2021] [Indexed: 11/22/2022]
Abstract
Plant secondary metabolites (PSMs) play a central role in seed dispersal and fruit defense, with potential for large impacts on plant fitness and demography. Yet because PSMs can have multiple interactive functions across seed dispersal stages, we must systematically study their effects to determine the net consequences for plant fitness. To tackle this issue, we integrate the role of fruit PSMs into the seed dispersal effectiveness (SDE) framework. We describe PSM effects on the quantity and quality of animal-mediated seed dispersal, both in pairwise interactions and diverse disperser communities, as well as trade-offs that occur across dispersal stages. By doing so, this review provides structure to a rapidly growing field and yields insights into a critical process shaping plant populations.
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6
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Schupp EW, Zwolak R, Jones LR, Snell RS, Beckman NG, Aslan C, Cavazos BR, Effiom E, Fricke EC, Montaño-Centellas F, Poulsen J, Razafindratsima OH, Sandor ME, Shea K. Intrinsic and extrinsic drivers of intraspecific variation in seed dispersal are diverse and pervasive. AoB Plants 2019; 11:plz067. [PMID: 31857875 PMCID: PMC6914678 DOI: 10.1093/aobpla/plz067] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/25/2019] [Accepted: 10/09/2019] [Indexed: 05/23/2023]
Abstract
There is growing realization that intraspecific variation in seed dispersal can have important ecological and evolutionary consequences. However, we do not have a good understanding of the drivers or causes of intraspecific variation in dispersal, how strong an effect these drivers have, and how widespread they are across dispersal modes. As a first step to developing a better understanding, we present a broad, but not exhaustive, review of what is known about the drivers of intraspecific variation in seed dispersal, and what remains uncertain. We start by decomposing 'drivers of intraspecific variation in seed dispersal' into intrinsic drivers (i.e. variation in traits of individual plants) and extrinsic drivers (i.e. variation in ecological context). For intrinsic traits, we further decompose intraspecific variation into variation among individuals and variation of trait values within individuals. We then review our understanding of the major intrinsic and extrinsic drivers of intraspecific variation in seed dispersal, with an emphasis on variation among individuals. Crop size is the best-supported and best-understood intrinsic driver of variation across dispersal modes; overall, more seeds are dispersed as more seeds are produced, even in cases where per seed dispersal rates decline. Fruit/seed size is the second most widely studied intrinsic driver, and is also relevant to a broad range of seed dispersal modes. Remaining intrinsic drivers are poorly understood, and range from effects that are probably widespread, such as plant height, to drivers that are most likely sporadic, such as fruit or seed colour polymorphism. Primary extrinsic drivers of variation in seed dispersal include local environmental conditions and habitat structure. Finally, we present a selection of outstanding questions as a starting point to advance our understanding of individual variation in seed dispersal.
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Affiliation(s)
- Eugene W Schupp
- Department of Wildland Resources and Ecology Center, Utah State University, Logan, UT, USA
| | - Rafal Zwolak
- Department of Systematic Zoology, Adam Mickiewicz University, Poznań, Poland
| | - Landon R Jones
- Department of Forestry and Natural Resources, Purdue University, West Lafayette, IN, USA
| | - Rebecca S Snell
- Environmental and Plant Biology, Ohio University, Athens, OH, USA
| | - Noelle G Beckman
- Department of Biology and Ecology Center, Utah State University, Logan, UT, USA
| | - Clare Aslan
- Landscape Conservation Initiative, Northern Arizona University, Flagstaff, AZ, USA
| | - Brittany R Cavazos
- Department of Ecology, Evolution and Organismal Biology, Iowa State University, Ames, IA, USA
| | - Edu Effiom
- REDD & Biodiversity Unit, Cross River State Forestry Commission, Calabar, Nigeria
| | - Evan C Fricke
- National Socio-Environmental Synthesis Center, University of Maryland, Annapolis, MD, USA
| | | | - John Poulsen
- Nicholas School of the Environment, Duke University, Durham, NC, USA
| | - Onja H Razafindratsima
- Department of Natural Resource Management, South Dakota State University, Brookings, SD, USA
| | - Manette E Sandor
- Department of Ecology, Evolution, and Environmental Biology, Columbia University, New York, NY, USA
- Center for Biodiversity and Conservation, American Museum of Natural History, New York, NY, USA
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7
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Yang X, Yan C, Gu H, Zhang Z. Interspecific synchrony of seed rain shapes rodent-mediated indirect seed-seed interactions of sympatric tree species in a subtropical forest. Ecol Lett 2019; 23:45-54. [PMID: 31631473 PMCID: PMC6916184 DOI: 10.1111/ele.13405] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2019] [Accepted: 09/23/2019] [Indexed: 11/30/2022]
Abstract
Animal‐mediated indirect interactions play a significant role in maintaining the biodiversity of plant communities. Less known is whether interspecific synchrony of seed rain can alter the indirect interactions of sympatric tree species. We assessed the seed dispersal success by tracking the fates of 21 600 tagged seeds from six paired sympatric tree species in both monospecific and mixed plots across 4 successive years in a subtropical forest. We found that apparent mutualism was associated with the interspecific synchrony of seed rain both seasonally and yearly, whereas apparent competition or apparent predation was associated with interspecific asynchrony of seed rain either seasonally or yearly. We did not find consistent associations of indirect interactions with seed traits. Our study suggests that the interspecific synchrony of seed rain plays a key role in the formation of animal‐mediated indirect interactions, which, in turn, may alter the seasonal or yearly seed rain schedules of sympatric tree species.
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Affiliation(s)
- Xifu Yang
- State Key Laboratory of Integrated Management of Pest Insects and Rodents in Agriculture Institute of Zoology, Chinese Academy of Sciences, Beijing, 100101, China
| | - Chuan Yan
- State Key Laboratory of Integrated Management of Pest Insects and Rodents in Agriculture Institute of Zoology, Chinese Academy of Sciences, Beijing, 100101, China
| | - Haifeng Gu
- State Key Laboratory of Integrated Management of Pest Insects and Rodents in Agriculture Institute of Zoology, Chinese Academy of Sciences, Beijing, 100101, China
| | - Zhibin Zhang
- State Key Laboratory of Integrated Management of Pest Insects and Rodents in Agriculture Institute of Zoology, Chinese Academy of Sciences, Beijing, 100101, China.,CAS Center for Excellence in Biotic Interactions, University of Chinese Academy of Sciences, Beijing, 100049, China
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8
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Rogers HS, Beckman NG, Hartig F, Johnson JS, Pufal G, Shea K, Zurell D, Bullock JM, Cantrell RS, Loiselle B, Pejchar L, Razafindratsima OH, Sandor ME, Schupp EW, Strickland WC, Zambrano J. The total dispersal kernel: a review and future directions. AoB Plants 2019; 11:plz042. [PMID: 31579119 PMCID: PMC6757349 DOI: 10.1093/aobpla/plz042] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/23/2018] [Accepted: 07/18/2019] [Indexed: 05/22/2023]
Abstract
The distribution and abundance of plants across the world depends in part on their ability to move, which is commonly characterized by a dispersal kernel. For seeds, the total dispersal kernel (TDK) describes the combined influence of all primary, secondary and higher-order dispersal vectors on the overall dispersal kernel for a plant individual, population, species or community. Understanding the role of each vector within the TDK, and their combined influence on the TDK, is critically important for being able to predict plant responses to a changing biotic or abiotic environment. In addition, fully characterizing the TDK by including all vectors may affect predictions of population spread. Here, we review existing research on the TDK and discuss advances in empirical, conceptual modelling and statistical approaches that will facilitate broader application. The concept is simple, but few examples of well-characterized TDKs exist. We find that significant empirical challenges exist, as many studies do not account for all dispersal vectors (e.g. gravity, higher-order dispersal vectors), inadequately measure or estimate long-distance dispersal resulting from multiple vectors and/or neglect spatial heterogeneity and context dependence. Existing mathematical and conceptual modelling approaches and statistical methods allow fitting individual dispersal kernels and combining them to form a TDK; these will perform best if robust prior information is available. We recommend a modelling cycle to parameterize TDKs, where empirical data inform models, which in turn inform additional data collection. Finally, we recommend that the TDK concept be extended to account for not only where seeds land, but also how that location affects the likelihood of establishing and producing a reproductive adult, i.e. the total effective dispersal kernel.
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Affiliation(s)
- Haldre S Rogers
- Department of Ecology, Evolution, and Organismal Biology, Iowa State University, Ames, IA, USA
- Corresponding author’s e-mail address:
| | - Noelle G Beckman
- Department of Biology and Ecology Center, Utah State University, Logan, UT, USA
| | - Florian Hartig
- Theoretical Ecology, Faculty of Biology and Preclinical Medicine, University of Regensburg, Regensburg, Germany
| | - Jeremy S Johnson
- School of Forestry, Northern Arizona University, Flagstaff, AZ, USA
| | - Gesine Pufal
- Department of Nature Conservation and Landscape Ecology, University of Freiburg, Freiburg, Germany
| | - Katriona Shea
- Department of Biology, The Pennsylvania State University, University Park, PA, USA
| | - Damaris Zurell
- Geography Department, Humboldt-University Berlin, Berlin, Germany
- Dynamic Macroecology, Department of Landscape Dynamics, Swiss Federal Research Institute WSL, Birmensdorf, Switzerland
| | - James M Bullock
- Centre for Ecology and Hydrology, Benson Lane, Wallingford, Oxfordshire, UK
| | | | - Bette Loiselle
- Department of Wildlife Ecology and Conservation & Center for Latin American Studies, University of Florida, Gainesville, FL, USA
| | - Liba Pejchar
- Department of Fish, Wildlife and Conservation Biology, Colorado State University, Fort Collins, CO, USA
| | | | - Manette E Sandor
- School of Earth Sciences and Environmental Sustainability, Northern Arizona University, Flagstaff, AZ, USA
| | - Eugene W Schupp
- Department of Wildland Resources and Ecology Center, Utah State University, Logan, UT, USA
| | - W Christopher Strickland
- Department of Mathematics and Department of Ecology & Evolutionary Biology, University of Tennessee, Knoxville, TN, USA
| | - Jenny Zambrano
- Department of Biology, University of Maryland, College Park, MD, USA
- School of Biological Sciences, Washington State University, Pullman WA, USA
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9
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HervÍas-Parejo S, Heleno R, Rumeu B, Guzmán B, Vargas P, Olesen JM, Traveset A, Vera C, Benavides E, Nogales M. Small size does not restrain frugivory and seed dispersal across the evolutionary radiation of Galápagos lava lizards. Curr Zool 2019; 65:353-361. [PMID: 31413708 PMCID: PMC6688575 DOI: 10.1093/cz/zoy066] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2018] [Accepted: 08/06/2018] [Indexed: 11/13/2022] Open
Abstract
Frugivory in lizards is often assumed to be constrained by body size; only large individuals are considered capable of consuming fruits, with the potential of acting as seed dispersers. However, only one previous study has tested the correlation of frugivory with body and head size at an archipelago scale across closely related species. All nine lava lizards (Microlophus spp.) were studied on the eleven largest Galápagos islands from 2010 to 2016 to investigate whether frugivory is related to body and head size. We also tested whether fruit abundance influences fruit consumption and explored the effect of seed ingestion on seedling emergence time and percentage. Our results showed that across islands, lava lizards varied considerably in size (64-102 mm in mean snout-vent length) and level of frugivory (1-23%, i.e., percentage of droppings with seeds). However, level of frugivory was only weakly affected by size as fruit consumption was also common among small lizards. Lava lizards consumed fruits throughout the year and factors other than fruit abundance may be more important drivers of fruit selection (e.g., fruit size, energy content of pulp). From 2,530 droppings, 1,714 seeds of at least 61 plant species were identified, 76% of the species being native to the Galápagos. Most seeds (91%) showed no external structural damage. Seedling emergence time (44 versus 118 days) and percentage (20% versus 12%) were enhanced for lizard-ingested seeds compared to control (uningested) fruits. De-pulping by lizards (i.e., removal of pulp with potential germination inhibitors) might increase the chances that at least some seeds find suitable recruitment conditions. We concluded that lizards are important seed dispersers throughout the year and across the whole archipelago, regardless of body size.
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Affiliation(s)
- Sandra HervÍas-Parejo
- Institut Mediterrani d’Estudis Avançats (CSIC-UIB), Global Change Research Group, Mallorca, Balearic Islands, Spain
| | - Ruben Heleno
- Centre for Functional Ecology, Department of Life Sciences, University of Coimbra, Portugal
| | - Beatriz Rumeu
- Institut Mediterrani d’Estudis Avançats (CSIC-UIB), Global Change Research Group, Mallorca, Balearic Islands, Spain
| | | | | | - Jens M Olesen
- Department of Bioscience, Aarhus University, Denmark
| | - Anna Traveset
- Institut Mediterrani d’Estudis Avançats (CSIC-UIB), Global Change Research Group, Mallorca, Balearic Islands, Spain
| | - Carlos Vera
- Galápagos National Park, Puerto Ayora, Santa Cruz, Galápagos, Ecuador
| | - Edgar Benavides
- Department of Ecology and Evolutionary Biology, Yale University, USA
| | - Manuel Nogales
- Instituto de Productos Naturales y Agrobiología (CSIC-IPNA), Island Ecology and Evolution Research Group, Canary Islands, Spain
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10
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Aslan C, Beckman NG, Rogers HS, Bronstein J, Zurell D, Hartig F, Shea K, Pejchar L, Neubert M, Poulsen J, HilleRisLambers J, Miriti M, Loiselle B, Effiom E, Zambrano J, Schupp G, Pufal G, Johnson J, Bullock JM, Brodie J, Bruna E, Cantrell RS, Decker R, Fricke E, Gurski K, Hastings A, Kogan O, Razafindratsima O, Sandor M, Schreiber S, Snell R, Strickland C, Zhou Y. Employing plant functional groups to advance seed dispersal ecology and conservation. AoB Plants 2019; 11:plz006. [PMID: 30895154 PMCID: PMC6420810 DOI: 10.1093/aobpla/plz006] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/15/2018] [Accepted: 02/05/2019] [Indexed: 05/06/2023]
Abstract
Seed dispersal enables plants to reach hospitable germination sites and escape natural enemies. Understanding when and how much seed dispersal matters to plant fitness is critical for understanding plant population and community dynamics. At the same time, the complexity of factors that determine if a seed will be successfully dispersed and subsequently develop into a reproductive plant is daunting. Quantifying all factors that may influence seed dispersal effectiveness for any potential seed-vector relationship would require an unrealistically large amount of time, materials and financial resources. On the other hand, being able to make dispersal predictions is critical for predicting whether single species and entire ecosystems will be resilient to global change. Building on current frameworks, we here posit that seed dispersal ecology should adopt plant functional groups as analytical units to reduce this complexity to manageable levels. Functional groups can be used to distinguish, for their constituent species, whether it matters (i) if seeds are dispersed, (ii) into what context they are dispersed and (iii) what vectors disperse them. To avoid overgeneralization, we propose that the utility of these functional groups may be assessed by generating predictions based on the groups and then testing those predictions against species-specific data. We suggest that data collection and analysis can then be guided by robust functional group definitions. Generalizing across similar species in this way could help us to better understand the population and community dynamics of plants and tackle the complexity of seed dispersal as well as its disruption.
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Affiliation(s)
- Clare Aslan
- Landscape Conservation Initiative, Northern Arizona University, Flagstaff, AZ, USA
- Corresponding author’s e-mail address:
| | | | - Haldre S Rogers
- Department of Ecology, Evolution, and Organismal Biology, Iowa State University, Ames, IA, USA
| | - Judie Bronstein
- Department of Ecology and Evolutionary Biology, University of Arizona, Tucson, AZ, USA
| | - Damaris Zurell
- Dynamic Macroecology, Landscape Dynamics, Swiss Federal Research Institute WSL, Zürcherstrasse, Birmensdorf, Switzerland
| | - Florian Hartig
- Faculty of Biology and Pre-Clinical Medicine, University of Regensburg, Universitätsstraße, Regensburg, Germany
| | - Katriona Shea
- Department of Biology, Pennsylvania State University, 208 Mueller Laboratory, University Park, PA, USA
| | - Liba Pejchar
- Department of Fish, Wildlife and Conservation Biology, Colorado State University, Fort Collins, CO, USA
| | - Mike Neubert
- Biology Department, Woods Hole Oceanographic Institution, Woods Hole, MA, USA
| | - John Poulsen
- Nicholas School of the Environment, Duke University, Durham, USA
| | | | - Maria Miriti
- Department of Evolution, Ecology and Organismal Biology, The Ohio State University, Columbus, OH, USA
| | - Bette Loiselle
- Department of Wildlife Ecology and Conservation, University of Florida, Gainesville, FL, USA
| | - Edu Effiom
- CRS Forestry Commission, Calabar, Nigeria
| | - Jenny Zambrano
- National Socio-Environmental Synthesis Center, 1 Park Place, Annapolis, MD, USA
| | - Geno Schupp
- Department of Biology, Utah State University, Logan, UT, USA
| | - Gesine Pufal
- Naturschutz & Landschaftsökologie, Albert-Ludwigs-Universität Freiburg, Freiburg, Germany
| | - Jeremy Johnson
- Department of Geography, Texas A&M University, College Station, TX, USA
| | | | - Jedediah Brodie
- Wildlife Biology Program, University of Montana, Missoula, MT, USA
| | - Emilio Bruna
- Department of Wildlife Ecology and Conservation, University of Florida, Gainesville, FL, USA
| | | | | | - Evan Fricke
- Department of Ecology, Evolution, and Organismal Biology, Iowa State University, Ames, IA, USA
| | - Katie Gurski
- Department of Mathematics, Howard University, Washington, DC, USA
| | | | - Oleg Kogan
- Physics Department, California Polytechnic State University, San Luis Obispo, CA, USA
| | | | - Manette Sandor
- Department of Ecology and Evolutionary Biology, University of Connecticut, Storrs, CT, USA
| | | | - Rebecca Snell
- Environmental and Plant Biology, Ohio University, Athens, OH, USA
| | | | - Ying Zhou
- Department of Mathematics, Lafayette College, Easton, PA, USA
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11
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Thibault M, Masse F, Pujapujane A, Lannuzel G, Bordez L, Potter MA, Fogliani B, Vidal É, Brescia F. "Liaisons dangereuses": The invasive red-vented bulbul ( Pycnonotus cafer), a disperser of exotic plant species in New Caledonia. Ecol Evol 2018; 8:9259-9269. [PMID: 30377498 PMCID: PMC6194277 DOI: 10.1002/ece3.4140] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2018] [Revised: 03/28/2018] [Accepted: 04/03/2018] [Indexed: 11/10/2022] Open
Abstract
The biodiversity hotspot of New Caledonia hosts high levels of endemism (74% of flora) that is threatened increasingly by climate change, habitat reduction, and invasive species. The fruit-eating red-vented bulbul (Pycnonotus cafer) is currently invading the main island of the archipelago, and its recent dispersal out of urbanized habitats raises questions about its potential to disperse noxious plant seeds along urban corridors and beyond. Indeed, the red-vented bulbul is considered a vector of several introduced plant species in its alien range including Miconia calvescens, Lantana camara, and Schinus terebinthifolius. We conducted a quantitative assessment of the bulbul's fruits consumption by analyzing the gut contents of shot birds. We estimated gut passage times for four species of fruit found in gut contents (S. terebinthifolius, Myrtastrum rufopunctatum, Passiflora suberosa, and Ficus prolixa) and tested the effects of bird digestion on seed germination rates for two species. Finally, we monitored the movements of individual VHF radio-tagged red-vented bulbuls. All of the consumed fruit species we identified here have red fleshy diaspore, including fruit of the shrub M. rufopunctatum that occurred frequently (9.6%) in bulbul gut samples. Median gut passage times were short (15-41 min), corresponding to short-distance seed transportation (77-92 m). The effect of gut passage was positive for the germination of the invasive S. terebinthifolius and negative for the endemic M. rufopunctatum, suggesting a potential bias in the contribution to the dispersal toward alien species. This study provides the first integrated assessment of mechanisms involved in the seed dispersal effectiveness of this high-concern invasive bird species that is expected to face similar plant communities in most of its alien range in tropical islands. More generally, our results enhance knowledge of synergies between non-native frugivores and plant species dispersal.
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Affiliation(s)
- Martin Thibault
- Institut Agronomique néo‐Calédonien (IAC)Equipe ARBOREAL (AgricultuRe BiOdiveRsité Et vAlorisation)PaïtaNew Caledonia
- Wildlife and Ecology GroupSchool of Agriculture and EnvironmentMassey UniversityPalmerston NorthNew Zealand
| | - Felix Masse
- Institut Agronomique néo‐Calédonien (IAC)Equipe ARBOREAL (AgricultuRe BiOdiveRsité Et vAlorisation)PaïtaNew Caledonia
- Faculté des arts et des sciencesUniversité de MontréalMontréalQCCanada
| | - Aurore Pujapujane
- Institut Agronomique néo‐Calédonien (IAC)Equipe ARBOREAL (AgricultuRe BiOdiveRsité Et vAlorisation)PaïtaNew Caledonia
| | - Guillaume Lannuzel
- Institut Agronomique néo‐Calédonien (IAC)Equipe ARBOREAL (AgricultuRe BiOdiveRsité Et vAlorisation)PaïtaNew Caledonia
| | - Laurent Bordez
- Institut Agronomique néo‐Calédonien (IAC)Equipe ARBOREAL (AgricultuRe BiOdiveRsité Et vAlorisation)PaïtaNew Caledonia
| | - Murray A. Potter
- Wildlife and Ecology GroupSchool of Agriculture and EnvironmentMassey UniversityPalmerston NorthNew Zealand
| | - Bruno Fogliani
- Institut Agronomique néo‐Calédonien (IAC)Equipe ARBOREAL (AgricultuRe BiOdiveRsité Et vAlorisation)PaïtaNew Caledonia
| | - Éric Vidal
- Institut Méditerranéen de Biodiversité et d'Ecologie marine et continentale (IMBE)Aix Marseille UniversitéCNRS, IRD, Avignon Université Centre IRD NouméaNouméa CedexNew Caledonia
| | - Fabrice Brescia
- Institut Agronomique néo‐Calédonien (IAC)Equipe ARBOREAL (AgricultuRe BiOdiveRsité Et vAlorisation)PaïtaNew Caledonia
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