Browsing by Author "Perez, Fernanda"

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    Calceolaria flavida (Calceolariaceae) a new endemic species to central Chile
    (2021) Lavandero, Nicolas; Santilli, Ludovica; Perez, Fernanda
    A new species of Calceolaria sect. Cheiloncos endemic to central Chile is described. A comparison with the morphologically similar species Calceolaria asperula and Calceolaria petioalaris is made, and a key as well as detailed images to differentiate them is provided. The species is only known from the Natural Sanctu-ary Cerro El Roble, which is part of the coastal mountain range of central Chile and can be considered as Critically Endangered (CR) under the IUCN categories and criteria.
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    Decoupled evolution of foliar freezing resistance, temperature niche and morphological leaf traits in Chilean Myrceugenia
    (2014) Perez, Fernanda; Hinojosa, Luis F.; Ossa, Carmen G.; Campano, Francisca; Orrego, Fabiola
    1. Phylogenetic conservatism of tolerance to freezing temperatures has been cited to explain the tendency of plant lineages to grow in similar climates. However, there is little information about whether or not freezing resistance is conserved across phylogenies, and whether conservatism of physiological traits could explain conservatism of realized climatic niches. Here, we compared the phylogenetical lability of realized climatic niche, foliar freezing resistance and four morphological leaf traits that are generally considered to be adaptations to frost resistance in the Chilean species of Myrceugenia, which grows in a wide range of habitats.
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    EVOLUTION OF AUTONOMOUS SELFING ACCOMPANIES INCREASED SPECIALIZATION IN THE POLLINATION SYSTEM OF SCHIZANTHUS (SOLANACEAE)
    (2009) Perez, Fernanda; Arroyo, Mary T. K.; Armesto, Juan J.
    The co-occurrence of elaborate flowers visited by specific groups of pollinators and capacity for autonomous selfing in the same plant species has puzzled evolutionary biologists since the time of Charles Darwin. To examine whether autonomous selfing and floral specialization evolved in association, we quantified the autofertility level (AFI) in nine Schizanthus species characterized by a wide range of pollination specialization, revealing AFI values of 0.02 to complete selfing. An independent contrasts analysis conducted on AFIs and number of functional pollinator groups showed that autonomous selfing evolved from an ancestral out-crossing system is plants became increasingly specialized (r = -0.82). To assess whether autonomous selfing together with specialization acts as a reproductive assurance mechanism, we estimated spatial and interannual variation in fruit set due to pollinator failure in two closely related high Andean Schizanthus species differing in their specialization levels. Variation in pollinator failure rate was more pronounced and autonomous selfing increased fruit production over biotically assisted pollination in the more specialized species. Our study suggests that specialized pollination deems species more vulnerable to pollinator fluctuation thus promoting the evolution of delayed autonomous selfing.
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    Floral integration and pollinator diversity in the generalized plant-pollinator system of Alstroemeria ligtu (Alstroemeriaceae)
    (2015) Gonzalez, Alejandra V.; Murua, Maureen M.; Perez, Fernanda
    Floral integration may result from the combined effects of pollinator-mediated selection, genetic correlations and abiotic factors. Thus, by sampling a set of populations in the field and examining their variation of floral correlations in relation to pollinators and abiotic factors, we intended to shed light on the ecological factors underlying the evolution of floral integration. In this study, floral integration patterns and the composition of pollinator assemblage were characterized across ten populations of Alstroemeria ligtu to test the following: (1) Whether the patterns of floral integration estimated at population level covary with the composition of local pollinator assemblage, climate and/or geographic distance. (2) Whether the magnitude of floral integration decreases with the number or the morphological variability of pollinators. (3) Whether the behavior of the three most widespread pollinators is affected by floral integration. Our results indicated that populations with similar patterns of integration showed greater similitude in pollinator assemblages, but that this was not related to climate or geographic distance. We also found that the most widespread pollinator, Centris nigerrima, invested lower handling time in populations with higher levels of floral integration. The magnitude of floral integration was not related to taxonomical diversity, yet, unexpectedly, correlated positively with the variability of pollinator proboscis length. We suggest that variation in the magnitude and pattern of floral integration across the species range was related to the composition of pollinator assemblage, and not to pollinator diversity per se, nor to climatic variables. A. ligtu was visited by numerous pollinators, but floral integration patterns are likely shaped by only a subset of them, such as C. nigerrima, which is sensitive to variations in floral architecture.
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    Flower meristematic size correlates with heterostylous morphs in two Chilean Oxalis (Oxalidaceae) species
    (2016) Bull Herenu, Kester John; De Craene, L.; Perez, Fernanda
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    Functional traits variation explains the distribution of Aextoxicon punctatum (Aextoxicaceae) in pronounced moisture gradients within fog-dependent forest fragments
    (2015) Salgado-Negret, Beatriz; Canessa, Rafaella; Valladares, Fernando; Armesto, Juan J.; Perez, Fernanda
    Climate change and fragmentation are major threats to world forests. Understanding how functional traits related to drought tolerance change across small-scale, pronounced moisture gradients in fragmented forests is important to predict species' responses to these threats. In the case of Aextoxicon punctatum, a dominant canopy tree in fog-dependent rain forest patches in semiarid Chile, we explored how the magnitude, variability and correlation patterns of leaf and xylem vessel traits and hydraulic conductivity varied across soil moisture (SM) gradients established within and among forest patches of different size, which are associated with differences in tree establishment and mortality patterns. Leaf traits varied across soil-moisture gradients produced by fog interception. Trees growing at drier leeward edges showed higher leaf mass per area, trichome and stomatal density than trees from the wetter core and windward zones. In contrast, xylem vessel traits (vessels diameter and density) did not vary producing loss of hydraulic conductivity at drier leeward edges. We also detected higher levels of phenotypic integration and variability at leeward edges. The ability of A. puncta turn to modify leaf traits in response to differences in SM availability established over short distances (<500 m) facilitates its persistence in contrasting microhabitats within forest patches. However, xylem anatomy showed limited plasticity, which increases cavitation risk at leeward edges. Greater patch fragmentation, together with fluctuations in irradiance and SM in small patches, could result in higher risk of drought-related tree mortality, with profound impacts on hydrological balances at the ecosystem scale.
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    Genetic Patterns of Myrceugenia correifolia, a Rare Species of Fog-Dependent Forests of Mediterranean Chile: Is It a Climatic Relict?
    (2017) Perez, Fernanda; Hinojosa, L.; Peralta, G.; Montenegro, P.; Irarrazabal, C.; Cossio, M.
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    How variable is delayed selfing in a fluctuating pollinator environment? A comparison between a delayed selfing and a pollinator-dependent Schizanthus species of the high Andes
    (2013) Perez, Fernanda; Leon, Constanza; Munoz, Thais
    Delayed selfing has been considered the best-of-both-worlds response to pollinator unpredictability because it can provide reproductive assurance without decreasing outcrossing potential. According to this hypothesis, selfing rates in delayed selfing species should be highly variable in fluctuating pollinator environments. To test this prediction, as well to explore the consequences of delayed selfing on genetic patterns, we compared two sister species that grow in the high Andes of Chile: Schizanthus grahamii that exhibits delayed selfing and Schizanthus hookeri, which is self-compatible but requires pollinators for seed set. We estimated genetic diversity within and among five populations of each species using six shared microsatellites. Our results indicated that selfing rates in S. grahamii (range 0.07-0.81) were significantly more variable than in S. hookeri (range 0-0.26). The highest levels of selfing were found in the populations of S. grahamii located at highest altitudes (r = 0.78) and at northern margin range, where pollinators are probably more scarce. These populations also showed the lowest allelic richness and heterozygosity values. Southern populations of S. grahamii had mixed mating, and showed heterozygosity and diversity values close to those detected for S. hookeri along all the sampled range. Selfing in this species results from geitonogamy, and did not covary with altitude. Schizanthus grahamii showed greater population differentiation than S. hookeri. Overall, our results indicated that selfing rates were widely variable in S. grahamii, with some populations predominantly selfing and others showing mixed mating. This pattern may be associated with the strong fluctuations in pollinator service that typically occur in the high Andes of Chile.
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    Leucheria peteroana (Nassauvieae, Asteraceae), a new species of Leucheria endemic to the Andes of Central Chile, and insights into the systematics of Nassauviae
    (2024) Lavandero, Nicolas; Perez, Fernanda; Pinilla, Nicolas
    A new species, Leucheria peteroana sp. nov., endemic to a restricted area of the Andes of Central Chile, is here described. Using newly sequenced nDNA and cpDNA data, the phylogenetic affinities of Leucheria and closely related taxa within Nassauvieae are revisited. This new species shows a unique set of characters that clearly distinguish it from other species of Leucheria. Phylogenetic analyses place this perennial species close to annual species found in the pre-Andean environments of Central Chile. A detailed description, distribution map, insights about its habitat, conservation status, and photographs are provided.
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    Nicotiana rupicola sp. nov. and Nicotiana knightiana (sect. Paniculatae, Solanaceae), a new endemic and a new record for the flora of Chile
    (2022) Santilli, Ludovica; Perez, Fernanda; De Schrevel, Claire; Dandois, Philippe; Mondaca, Hector; Lavandero, Nicolas
    Nicotiana knightiana is recorded for the first time for the flora of Chile. A new species of Nicotiana, endemic to the coast of the Coquimbo region is described and illustrated. Molecular analysis placed the new species within the N. sect. Paniculatae, as sister to N. cordifolia, an endemic to Juan Fernandez islands. The new species can be considered critically endangered (CR) according to the IUCN categories due to its restricted and fragmented distribution, small population number, and the threat that urbanization and mining activities represent for the conservation of the biodiversity of the area.
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    Nitrogen overfertilization: Impact on ecological interactions and floral morphology in a peri-urban environment
    (2024) Vera, Gabriel A. Brito; Calderon, Ximena; Perez, Fernanda
    Nitrogen is a crucial element that affects plant metabolic processes and indirectly influences the structure and dynamics of ecological interactions in terrestrial ecosystems. Since the invention of the Haber-Bosch process, human activity has significantly influenced the amount of nitrogen released into the environment. However, how do these overfertilization processes affect flora and fauna in urban ecosystems? In our experiments, we used elevated nitrogen concentrations to simulate terrestrial eutrophication processes in Nicotiana tabacum L. We evaluated reproductive traits such as floral morphology using geometric morphometrics. Additionally, nectar volume and solute concentration, along with other vegetative traits, were quantified. Subsequently, the impacts of these modifications on herbivory and pollination interactions in a peri-urban environment were measured. Overfertilization resulted in notable modifications to the floral shape of the lobes, as well as a significant increase in percentage of herbivory by chewing insects, without affecting floral visitation rates. We also observed that elevated herbivory on fertilised plants did not show a direct correlation with overall pollination rates per plant or seed set. In contrast, the reduction in leaf size during the second phase of the experiment, owing to overfertilization effects, affected seed production. The roles of potential pollinators and their influence on seed quantity in control plants are discussed. Nitrogen is a crucial element not only for plants in natural terrestrial ecosystems but also plays a fundamental role in the modification and shaping of reproductive and vegetative structures. Moreover, it affects the functionality of ecological interactions of pollination and herbivory in anthropogenic environments, such as peri-urban areas.
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    Non-congruent fossil and phylogenetic evidence on the evolution of climatic niche in the Gondwana genus Nothofagus
    (2016) Hinojosa, L.; Gaxiola Alcantar, Aurora; Perez, Fernanda; Carvajal, F.; Campano, M.; Quattrocchio, M.; Nishida, H.; Uemura, K.; Yabe, A.; Bustamante, R.; Arroyo, M.
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    Phylogeography of two closely related species of Nolana from the coastal Atacama Desert of Chile: post-glacial population expansions in response to climate fluctuations
    (2013) Ossa, Paulina G.; Perez, Fernanda; Armesto, Juan J.
    AimTo investigate the impact of Quaternary climate cycles on the coastal Atacama Desert flora by assessing phylogeographical patterns of the desert shrub Nolana crassulifolia (Solanaceae) and its congener Nolanaincana.
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    Speciation and evolution of growth form in Adesmia D. C. (Dalbergieae, Fabaceae): the relevance of Andean uplift and aridification
    (2024) Perez, Fernanda; Lavandero, Nicolas; Hinojosa, Luis Felipe; Cisternas, Mauricio; Araneda, Daniela; Pinilla, Nicolas; Moraga, Valeska
    The Andean uplift and the concomitant aridification drove the rapid diversification of several plant lineages that were able to colonize warmer and drier habitats at low elevations and wetter and colder habitats at high elevations. These transitions may be facilitated by shifts in plant strategies to cope with drought and cold, which in turn can trigger episodes of accelerated species diversification. Here, we used four nuclear DNA markers to infer phylogenetic relationships of 80 Adesmia species of annuals, perennial herbs, shrubs and small shrubs that occur in Chile and Argentina. We reconstructed ancestral states for area, climatic niche and growth form to explore how Andean uplift and aridification promoted Adesmia diversification. We also performed logistic and linear regression analyses between different components of growth form (life span, woodiness and plant height) and climate. Finally, we estimated speciation rates across the phylogeny. Our results suggest that the ancestor of Chilean Adesmia was a perennial herb that probably originated in the high Andes of northern and central Chile. The low elevations of Central Chile were colonized in the late Miocene, whereas the high latitudes of Patagonia and the hyperarid coastal Atacama Desert were colonized repeatedly since Pliocene by lineages with different growth forms. Multiple and bidirectional transitions between annual and perennial habits and between herbaceous and woody habits were detected. These shifts were not correlated with climate, suggesting that the different growth forms are alternative and successful strategies to survive unfavorable seasons of both desert and high Andes. Net diversification analysis indicated a constant rate of diversification, suggesting that the high species diversity of Adesmia that occur in Chile is due to a uniform speciation process rather than to accelerated episodes of speciation.
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    The Physiological Effect of a Holoparasite Over a Cactus Along an Environmental Gradient
    (2021) Ossa, Carmen Gloria; Aros-Mualin, Daniela; Mujica, Maria Isabel; Perez, Fernanda
    Echinopsis chiloensis is an endemic cactus from Chile, distributed in a temperature and rainfall gradient between 30 degrees and 35 degrees South latitude, with mean temperatures increasing and precipitation decreasing toward the north. It is the main host of the mistletoe Tristerix aphyllus, a holoparasite completely dependent on the cactus for water, carbon, and minerals. In this study, we investigated the consequences of parasitism over the fitness and physiology of this cactus throughout its distribution range and how it is affected by the environment. We measured five functional traits in eight populations latitudinally distributed, the first three only for the host: reproductive fitness, stomatal traits (density and size), and photosynthesis (during winter and summer); and the last two for the host and parasite: stable isotopes ( partial differential C-13 and partial differential N-15), and nutrients (carbon and nitrogen content). The results showed a negative effect of parasitism over fitness of infected cacti. However, the higher nitrogen concentrations in cactus tissues toward the south improved overall fitness. Regarding photosynthesis, we only observed a negative effect of parasitism during the dry season (summer), which is also negatively affected by the increase in summer temperatures and decrease in winter rainfall toward the north. There were no differences in nutrient concentration or in the isotopic signature of healthy and infected cacti. Conversely, we observed a higher carbon and lower nitrogen concentration in mistletoes than in cacti regardless of latitude. The loss of temperature seasonality toward the north increases the C:N ratio, and the values between the parasite and its host diverge. partial differential N-15 was similar between parasites and hosts while partial differential C-13 of the parasite was enriched when compared to its host. Overall, the infection by T. aphyllus affects Echinopsis chiloensis fitness but showed no strong effects over the cactus physiology, except for the summer photosynthesis. Therefore, our data revealed that E. chiloensis response to T. aphyllus infection is sensitive to environmental changes in a way that could be strongly impacted by the desertification projected for this area due to climate change.