Consequences of habitat fragmentation on the reproductive success of two Tillandsia species with contrasting life history strategies

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.Fil: Sáyago, Roberto. Universidad Nacional Autónoma de México; México. Universidad Autonoma de Guerrero; MéxicoFil: Quesada, Mauricio. Universidad Autonoma de Guerrero; México. Universidad Nacional Autónoma de México; MéxicoFil: Aguilar, Ramiro. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; ArgentinaFil: Ashworth, Lorena. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; ArgentinaFil: Lopezaraiza-Mikel, Martha. Universidad Nacional Autónoma de México; México. Universidad Autonoma de Guerrero; MéxicoFil: Martén-Rodríguez, Silvana. Universidad Nacional Autónoma de México; Méxic

The stained-glass palm, geonoma epetiolata

Geonoma epetiolata is the only neotropical palm that exhibits substantial leaf mottling. This article provides a summary of its biology and conservation, some observations of natural populations and a discussion of the ecological role of leaf mottling.National Science Foundation/[DEB-0234064]/NSF/Estados UnidosUCR::Vicerrectoría de Investigación::Unidades de Investigación::Ciencias Agroalimentarias::Jardín Botánico Lankester (JBL

Appendix A. Growth habit and floral characteristics and pollinator visitation frequency for 13 species of Gesneria and Rhytidophyllum from Puerto Rico and the Dominican Republic.

Growth habit and floral characteristics and pollinator visitation frequency for 13 species of Gesneria and Rhytidophyllum from Puerto Rico and the Dominican Republic

Appendix B. Sites and geographic coordinates of studied populations of 13 Gesneria and Rhytidophyllum surveyed in Puerto Rico and the Dominican Republic in 2006 and 2007.

Sites and geographic coordinates of studied populations of 13 Gesneria and Rhytidophyllum surveyed in Puerto Rico and the Dominican Republic in 2006 and 2007

Hummingbirds in high alpine habitats of the tropical Mexican mountains: new elevational records and ecological considerations

Most hummingbird species are distributed in tropical lowlands and mountains with few species reaching the alpine environments of high mountain peaks. Field surveys were conducted in nine alpine sites across four of the highest volcanoes in central Mexico for three years to document hummingbird occurrence, habitat use, and some aspects of behavior. We also searched through historical museum collections and online databases to document early records of hummingbirds in Mexican alpine habitats. In addition, we conducted a search through historical herbarium collections of ornithophilous plant species in alpine habitats, and a literature search on glacier retreats in Mexico to establish past and present elevational limits of alpine vegetation. We recorded the presence of four hummingbird species using floral resources across the nine study sites: Cynanthus latirostris (Broad-billed Hummingbird), Hylocharis leucotis (White-eared Hummingbird), Lampornis clemenciae (Blue-throated Hummingbird), and Selasphorus platycercus (Broad-tailed Hummingbird). The latter two species were recorded frequently throughout the growing season (May-October), whereas C. latirostris was observed on one day in July, and H. leucotis on two days in April and May. Three of the four species were observed foraging from Castilleja tolucensis, an alpine Mexican endemic herb, at 4428 m above sea level, and all four species foraged from Penstemon gentianoides at the lower alpine sites 3900-4100. At the highest elevations, we observed hummingbirds hovering and perching on rocks while feeding from flowers at ground level. Both male and female of L. clemenciae and S. platycercus were present at patches of P. gentianoides; however, with S. platycercus, males accounted for more than 80% of the individuals observed and more than 95% of individuals observed at the highest elevations. Additionally, a survey of historical records from museum collections and bird sightings from e-databases revealed only three early records of hummingbirds in alpine sites, with only one observed earlier than 1987. This suggests that hummingbirds were not recorded earlier in alpine habitats because of a lack of sampling. Nevertheless, evidence from glacial retreats and plant distributions along an elevational gradient also indicate that hummingbirds have expanded their elevational range as new habitats have opened up for colonization associated with global climate change. The results reported here are the first records of the four hummingbird species in the Mexican alpine grassland and one of the highest altitudinal records for hummingbirds in North America. We discuss the importance and conservation implications of alpine ecosystems in Mexico as habitats for hummingbirds

Elevational and seasonal patterns of plant pollinator networks in two highland tropical ecosystems in Costa Rica.

Many plant species in high montane ecosystems rely on animal pollination for sexual reproduction, however, our understanding of plant-pollinator interactions in tropical montane habitats is still limited. We compared species diversity and composition of blooming plants and floral visitors, and the structure of plant-floral visitor networks between the Montane Forest and Paramo ecosystems in Costa Rica. We also studied the influence of seasonality on species composition and interaction structure. Given the severe climatic conditions experienced by organisms in habitats above treeline, we expected lower plant and insect richness, as well as less specialized and smaller pollination networks in the Paramo than in Montane Forest where climatic conditions are milder and understory plants are better protected. Accordingly, we found that blooming plants and floral visitor species richness was higher in the Montane Forest than in the Paramo, and in both ecosystems species richness of blooming plants and floral visitors was higher in the rainy season than in the dry season. Interaction networks in the Paramo were smaller and more nested, with lower levels of specialization and modularity than those in the Montane Forest, but there were no seasonal differences within either ecosystem. Beta diversity analyses indicate that differences between ecosystems are likely explained by species turnover, whereas within the Montane Forest differences between seasons are more likely explained by the rewiring of interactions. Results indicate that the decrease in species diversity with elevation affects network structure, increasing nestedness and reducing specialization and modularity

Habitat fragmentation reduces plant progeny quality: a global synthesis

Most of the world’s land surface is currently under human use and natural habitats remain as fragmented samples of the original landscapes. Measuring the quality of plant progeny sired in these pervasive environments represents a fundamental endeavour for predicting the evolutionary potential of plant populations remaining in fragmented habitats and thus their ability to adapt to changing environments. By means of hierarchical and phylogenetically independent meta-analyses we reviewed habitat fragmentation effects on the genetic and biological characteristics of progenies across 179 plant species. Progeny sired in fragmented habitats showed overall genetic erosion in contrast with progeny sired in continuous habitats, with the exception of plants pollinated by vertebrates. Similarly, plant progeny in fragmented habitats showed reduced germination, survival and growth. Habitat fragmentation had stronger negative effects on the progeny vigour of outcrossing- than mixed-mating plant species, except for vertebrate-pollinated species. Finally, we observed that increased inbreeding coefficients due to fragmentation correlated negatively with progeny vigour. Our findings reveal a gloomy future for angiosperms remaining in fragmented habitats as fewer sired progeny of lower quality may decrease recruitment of plant populations, thereby increasing their probability of extinction.UCR::Vicerrectoría de Docencia::Ciencias Básicas::Facultad de Ciencias::Escuela de Biologí

Ecological network metrics for rainy and dry seasons in Paramo and Montane Forest in Costa Rican highlands.

Ecological network metrics for rainy and dry seasons in Paramo and Montane Forest in Costa Rican highlands.</p