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The magnitude and extent of edge effects on vascular epiphytes across the Brazilian Atlantic Forest. Sci Rep 2020; 10:18847. [PMID: 33139836 PMCID: PMC7606527 DOI: 10.1038/s41598-020-75970-1] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2018] [Accepted: 08/12/2020] [Indexed: 11/20/2022] Open
Abstract
Edge effects are ubiquitous landscape processes influencing over 70% of forest cover worldwide. However, little is known about how edge effects influence the vertical stratification of communities in forest fragments. We combined a spatially implicit and a spatially explicit approach to quantify the magnitude and extent of edge effects on canopy and understorey epiphytic plants in the Brazilian Atlantic Forest. Within the human-modified landscape, species richness, species abundance and community composition remained practically unchanged along the interior-edge gradient, pointing to severe biotic homogenisation at all strata. This is because the extent of edge effects reached at least 500 m, potentially leaving just 0.24% of the studied landscape unaffected by edges. We extrapolated our findings to the entire Atlantic Forest and found that just 19.4% of the total existing area is likely unaffected by edge effects and provide suitable habitat conditions for forest-dependent epiphytes. Our results suggest that the resources provided by the current forest cover might be insufficient to support the future of epiphyte communities. Preserving large continuous ‘intact’ forests is probably the only effective conservation strategy for vascular epiphytes.
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Sáyago R, Quesada M, Aguilar R, Ashworth L, Lopezaraiza-Mikel M, Martén-Rodríguez S. Consequences of habitat fragmentation on the reproductive success of two Tillandsia species with contrasting life history strategies. AOB PLANTS 2018; 10:ply038. [PMID: 30018757 PMCID: PMC6041750 DOI: 10.1093/aobpla/ply038] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/05/2017] [Accepted: 06/18/2018] [Indexed: 06/08/2023]
Abstract
Fragmentation of natural habitats generally has negative effects on the reproductive success of many plant species; however, little is known about epiphytic plants. We assessed the impact of forest fragmentation on plant-pollinator interactions and female reproductive success in two epiphytic Tillandsia species with contrasting life history strategies (polycarpic and monocarpic) in Chamela, Jalisco, Mexico, over three consecutive years. Hummingbirds were the major pollinators of both species and pollinator visitation rates were similar between habitat conditions. In contrast, the composition and frequency of floral visitors significantly varied between habitat conditions in polycarpic and self-incompatible T. intermedia but not in monocarpic self-compatible T. makoyana. There were no differences between continuous and fragmented habitats in fruit set in either species, but T. makoyana had a lower seed set in fragmented than in continuous forests. In contrast, T. intermedia had similar seed set in both forest conditions. These results indicate that pollinators were effective under both fragmented and continuous habitats, possibly because the major pollinators are hummingbird species capable of moving across open spaces and human-modified habitats. However, the lower seed set of T. makoyana under fragmented conditions suggests that the amount and quality of pollen deposited onto stigmas may differ between habitat conditions. Alternatively, changes in resource availability may also cause reductions in seed production in fragmented habitats. This study adds to the limited information on the effects of habitat fragmentation on the reproductive success of epiphytic plants, showing that even related congeneric species may exhibit different responses to human disturbance. Plant reproductive systems, along with changes in pollinator communities associated with habitat fragmentation, may have yet undocumented consequences on gene flow, levels of inbreeding and progeny quality of dry forest tillandsias.
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Affiliation(s)
- Roberto Sáyago
- Facultad de Desarrollo Sustentable, Campus Costa Grande, Universidad Autónoma de Guerrero, Carretera Nacional Acapulco Zihuatanejo Km, Colonia Las Tunas, Tecpan de Galeana, Guerrero, México
- Laboratorio Nacional de Análisis y Síntesis Ecológica (LANASE), Escuela Nacional de Estudios Superiores (ENES), Universidad Nacional Autónoma de México, Antigua Carretera a Pátzcuaro, Morelia, Michoacán, C.P., México
- Instituto de Investigaciones en Ecosistemas y Sustentabilidad, Universidad Nacional Autónoma de México, Antigua Carretera a Pátzcuaro, Morelia, Michoacán, C.P., México
| | - Mauricio Quesada
- Laboratorio Nacional de Análisis y Síntesis Ecológica (LANASE), Escuela Nacional de Estudios Superiores (ENES), Universidad Nacional Autónoma de México, Antigua Carretera a Pátzcuaro, Morelia, Michoacán, C.P., México
- Instituto de Investigaciones en Ecosistemas y Sustentabilidad, Universidad Nacional Autónoma de México, Antigua Carretera a Pátzcuaro, Morelia, Michoacán, C.P., México
| | - Ramiro Aguilar
- Laboratorio Nacional de Análisis y Síntesis Ecológica (LANASE), Escuela Nacional de Estudios Superiores (ENES), Universidad Nacional Autónoma de México, Antigua Carretera a Pátzcuaro, Morelia, Michoacán, C.P., México
- Instituto Multidisciplinario de Biología Vegetal (CONICET), Universidad Nacional de Córdoba, C.P. X5000JJC, Argentina
| | - Lorena Ashworth
- Laboratorio Nacional de Análisis y Síntesis Ecológica (LANASE), Escuela Nacional de Estudios Superiores (ENES), Universidad Nacional Autónoma de México, Antigua Carretera a Pátzcuaro, Morelia, Michoacán, C.P., México
- Instituto Multidisciplinario de Biología Vegetal (CONICET), Universidad Nacional de Córdoba, C.P. X5000JJC, Argentina
| | - Martha Lopezaraiza-Mikel
- Facultad de Desarrollo Sustentable, Campus Costa Grande, Universidad Autónoma de Guerrero, Carretera Nacional Acapulco Zihuatanejo Km, Colonia Las Tunas, Tecpan de Galeana, Guerrero, México
- Laboratorio Nacional de Análisis y Síntesis Ecológica (LANASE), Escuela Nacional de Estudios Superiores (ENES), Universidad Nacional Autónoma de México, Antigua Carretera a Pátzcuaro, Morelia, Michoacán, C.P., México
| | - Silvana Martén-Rodríguez
- Laboratorio Nacional de Análisis y Síntesis Ecológica (LANASE), Escuela Nacional de Estudios Superiores (ENES), Universidad Nacional Autónoma de México, Antigua Carretera a Pátzcuaro, Morelia, Michoacán, C.P., México
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Gentili R, Solari A, Diekmann M, Duprè C, Monti GS, Armiraglio S, Assini S, Citterio S. Genetic differentiation, local adaptation and phenotypic plasticity in fragmented populations of a rare forest herb. PeerJ 2018; 6:e4929. [PMID: 29915689 PMCID: PMC6004105 DOI: 10.7717/peerj.4929] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2018] [Accepted: 05/18/2018] [Indexed: 12/04/2022] Open
Abstract
Background Due to habitat loss and fragmentation, numerous forest species are subject to severe population decline. Investigating variation in genetic diversity, phenotypic plasticity and local adaptation should be a prerequisite for implementing conservation actions. This study aimed to explore these aspects in ten fragmented populations of Physospermum cornubiense in view of translocation measures across its Italian range. Methods For each population we collected environmental data on landscape (habitat size, quality and fragmentation) and local conditions (slope, presence of alien species, incidence of the herbivorous insect Metcalfa pruinosa and soil parameters). We measured vegetative and reproductive traits in the field and analysed the genetic population structure using ISSR markers (STRUCTURE and AMOVA). We then estimated the neutral (FST) and quantitative (PST) genetic differentiation of populations. Results The populations exhibited moderate phenotypic variation. Population size (range: 16–655 individuals), number of flowering adults (range: 3–420 individuals) and inflorescence size (range: 5.0–8.4 cm) were positively related to Mg soil content. Populations’ gene diversity was moderate (Nei-H = 0.071–0.1316); STRUCTURE analysis identified five different clusters and three main geographic groups: upper, lower, and Apennine/Western Po plain. Fragmentation did not have an influence on the local adaptation of populations, which for all measured traits showed PST < FST, indicating convergent selection. Discussion The variation of phenotypic traits across sites was attributed to plastic response rather than local adaptation. Plant translocation from suitable source populations to endangered ones should particularly take into account provenance according to identified genetic clusters and specific soil factors.
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Affiliation(s)
- Rodolfo Gentili
- Department of Earth and Environmental Sciences, University of Milan-Bicocca, Milan, Italy
| | - Aldo Solari
- Department of Economics, Management and Statistics, University of Milan-Bicocca, Milan, Italy
| | | | - Cecilia Duprè
- Institute of Ecology, University of Bremen, Bremen, Germany
| | - Gianna Serafina Monti
- Department of Economics, Management and Statistics, University of Milan-Bicocca, Milan, Italy
| | | | - Silvia Assini
- Department of Earth and Environmental Sciences, University of Pavia, Pavia, Italy
| | - Sandra Citterio
- Department of Earth and Environmental Sciences, University of Milan-Bicocca, Milan, Italy
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Magrach A, Laurance WF, Larrinaga AR, Santamaria L. Meta-analysis of the effects of forest fragmentation on interspecific interactions. CONSERVATION BIOLOGY : THE JOURNAL OF THE SOCIETY FOR CONSERVATION BIOLOGY 2014; 28:1342-1348. [PMID: 24725007 DOI: 10.1111/cobi.12304] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/17/2013] [Accepted: 01/26/2014] [Indexed: 06/03/2023]
Abstract
Forest fragmentation dramatically alters species persistence and distribution and affects many ecological interactions among species. Recent studies suggest that mutualisms, such as pollination and seed dispersal, are more sensitive to the negative effects of forest fragmentation than antagonisms, such as predation or herbivory. We applied meta-analytical techniques to evaluate this hypothesis and quantified the relative contributions of different components of the fragmentation process (decreases in fragment size, edge effects, increased isolation, and habitat degradation) to the overall effect. The effects of fragmentation on mutualisms were primarily driven by habitat degradation, edge effects, and fragment isolation, and, as predicted, they were consistently more negative on mutualisms than on antagonisms. For the most studied interaction type, seed dispersal, only certain components of fragmentation had significant (edge effects) or marginally significant (fragment size) effects. Seed size modulated the effect of fragmentation: species with large seeds showed stronger negative impacts of fragmentation via reduced dispersal rates. Our results reveal that different components of the habitat fragmentation process have varying impacts on key mutualisms. We also conclude that antagonistic interactions have been understudied in fragmented landscapes, most of the research has concentrated on particular types of mutualistic interactions such as seed dispersal, and that available studies of interspecific interactions have a strong geographical bias (arising mostly from studies carried out in Brazil, Chile, and the United States).
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Affiliation(s)
- Ainhoa Magrach
- Center for Tropical Environmental and Sustainability Science (TESS) and School of Marine and Tropical Biology, James Cook University, Cairns, QLD 4878, Australia.
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Robledo-Arnuncio JJ, Klein EK, Muller-Landau HC, Santamaría L. Space, time and complexity in plant dispersal ecology. MOVEMENT ECOLOGY 2014; 2:16. [PMID: 25709828 PMCID: PMC4337469 DOI: 10.1186/s40462-014-0016-3] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/05/2014] [Accepted: 07/24/2014] [Indexed: 05/09/2023]
Abstract
Dispersal of pollen and seeds are essential functions of plant species, with far-reaching demographic, ecological and evolutionary consequences. Interest in plant dispersal has increased with concerns about the persistence of populations and species under global change. We argue here that advances in plant dispersal ecology research will be determined by our ability to surmount challenges of spatiotemporal scales and heterogeneities and ecosystem complexity. Based on this framework, we propose a selected set of research questions, for which we suggest some specific objectives and methodological approaches. Reviewed topics include multiple vector contributions to plant dispersal, landscape-dependent dispersal patterns, long-distance dispersal events, spatiotemporal variation in dispersal, and the consequences of dispersal for plant communities, populations under climate change, and anthropogenic landscapes.
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Affiliation(s)
- Juan J Robledo-Arnuncio
- />Department of Forest Ecology & Genetics, INIA-CIFOR, Ctra. de la Coruña km 7.5, 28040 Madrid, Spain
| | - Etienne K Klein
- />INRA, UR546 Biostatistique et Processus Spatiaux (BioSP), Avignon, France
| | - Helene C Muller-Landau
- />Smithsonian Tropical Research Institute, Apartado Postal 0843-03092 Panamá, Republica de Panamá
| | - Luis Santamaría
- />Spatial Ecology Group, Doñana Biological Station (EBD-CSIC), Sevilla, Spain
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