Browsing by Author "Celis-Diez, Juan L."

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    A Sarcocystid Misidentified as Hepatozoon didelphydis: Molecular Data from a Parasitic Infection in the Blood of the Southern Mouse Opossum (Thylamys elegans) from Chile
    (2008) Merino, Santiago; Vasquez, Rodrigo A.; Martinez, Javier; Celis-Diez, Juan L.; Martinez-De La Puente, Josue; Marin-Vial, Paula; Sanchez-Monsalvez, Inocencia; Peirce, Michael A.
    The blood of 21 adult South American mouse opossums (Thylamys elegans) captured from April through August of 2005 in central Chile was examined for parasites. Light microscopic analysis of blood smears initially suggested that a highly pleomorphic Hepatozoon species typical of American opossums was infecting erythrocytes. Unexpectedly, amplification by PCR and sequencing of a DNA fragment of the small subunit rDNA combined with phylogenetic analyses indicated that the parasite is not a member of the suborder Adeleorina, which includes the Haemogregarina and Hepatozoon species, but that it is a clearly distinct member of the suborder Eimeriorina, which includes the cyst-forming family Sarcocystidae. Therefore, a reclassification of this unusual intraerythrocytic apicomplexan will require additional life cycle, microscopic, and molecular analyses.
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    Assessing Ecological Indicators for Remnant Vegetation Strips as Functional Biological Corridors in Chilean Vineyards
    (2021) Diaz-Forestier, Javiera; Abades, Sebastian; Pohl, Nelida; Barbosa, Olga; Godoy, Karina; Svensson, Gabriella L.; Undurraga, Maria, I; Bravo, Camila; Garcia, Camila; Root-Bernstein, Meredith; Armesto, Juan J.; Celis-Diez, Juan L.
    Mediterranean central Chile is globally recognized as a hotspot for terrestrial biodiversity due to its high endemism and massive habitat loss. However, within the rural landscape of central Chile, significant extents of natural areas remain, especially on less productive, steep slopes, and vegetation strips extending from the surrounding hills to agricultural areas. Accordingly, vegetation strips or corridors, within lowland farms, constitute key elements to support the conservation of biodiversity in rural landscapes. To assess the ecological performance of corridors in 22 commercials vineyards in central Chile, we characterized them in terms of width-, length-, area-, and perimeter-to-area ratios, as well as the number of connections with natural areas. Based on a set of previously defined ecological indicators (species, functional groups, and structural components), we compared their occurrence in corridors within vineyards and in the surrounding natural areas. We evaluated the effects of corridor attributes on the occurrence of the selected ecological indicators, using a generalized linear mixed model with each vineyard as a random factor. The area, width, and length of vegetation corridors varied widely (1.2-86.3 ha, 10.5-95 m, and 380-5000 m, respectively). We found significant differences in the occurrence of indicators between corridors and natural areas. All sampled ecological indicators in corridors showed a negative relationship with the distance to the nearest natural area. Vegetation strips within vineyards represent important opportunities for biodiversity conservation that significantly enhance habitat quality in the agricultural landscape for biodiversity and habitat connectivity.
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    Bird Communities in Coastal Areas. Effects of Anthropogenic Influences and Distance From the Coast
    (2022) Graells, Giorgia; Celis-Diez, Juan L.; Corcoran, Derek; Gelcich, Stefan
    Urbanization effects have been studied all over the world, documenting impact in species richness, abundances and changes in species communities. Birds have been broadly used as study models. In general, urbanization affects birds, reducing species richness, especially in the urban core, and increasing species richness in areas with intermediate levels of disturbance, such as suburbs. Urbanization also changes species assemblages depending on urban characteristics and resources available, creating habitats for different species. Even when more than half of the cities in the world are on the coast, the effects of urbanization on habitat use of terrestrial and marine birds in coastal urban environments has received little attention. We hypothesized that coastal cities would present different bird diversity in modified marine areas and modified inland areas as terrestrial and marine ecosystems coexist. We predict that modified marine areas will have higher species richness than modified inland areas and natural marine areas. For bird assemblages, we expect to find similar species compositions between sites with similar habitat characteristics more than closeness. We compare habitat use of marine and terrestrial avifauna in the human-modified coastal city of Valparaiso, Chile, characterized by a range of urban developments within city boundaries. We specifically compare corrected bird abundance in six different possible habitats for birds, according to distance to the coast, and human influence. Bird counts (50 m fixed radius) were conducted in winter and spring of 2019. Bird species richness and abundances, corrected by the probability of detection, were estimated. Additionally, species composition and occupancy of bird species in those habitats were calculated. Results show that coastal urban cities can provide different habitats for bird species. Modified inland habitats differ from semi-natural inland habitats and from the modified beaches in species richness and species composition. Environmental heterogeneity in coastal cities seems to allow the coexistence of marine and terrestrial bird species, showing differences in species richness and bird assemblages for marine-inland environments and natural- modified habitats. Results highlight the need to consider these factors for urban planning in order to conserve bird diversity in coastal urban areas.
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    Comparison of carbon and water fluxes and the drivers of ecosystem water use efficiency in a temperate rainforest and a peatland in southern South America
    (2024) Perez-Quezada, Jorge F.; Trejo, David; Lopatin, Javier; Aguilera, David; Osborne, Bruce; Galleguillos, Mauricio; Zattera, Luca; Celis-Diez, Juan L.; Armesto, Juan J.
    The variability and drivers of carbon and water fluxes and their relationship to ecosystem water use efficiency (WUE) in natural ecosystems of southern South America are still poorly understood. For 8 years (2015-2022), we measured carbon dioxide net ecosystem exchange (NEE) and evapotranspiration (ET) using eddy covariance towers in a temperate rainforest and a peatland in southern Chile. NEE was partitioned into gross primary productivity (GPP) and ecosystem respiration ( R eco ), while ET was partitioned into evaporation ( E ) and transpiration ( T ) and used to estimate different expressions of ecosystem WUE. We then used the correlation between detrended time series and structural equation modelling to identify the main environmental drivers of WUE, GPP, ET, E and T . The results showed that the forest was a consistent carbon sink ( - 486 +/- 23 g C m - 2 yr - 1 ), while the peatland was, on average, a small source (33 +/- 21 g C m - 2 yr - 1 ). WUE is low in both ecosystems and likely explained by the high annual precipitation in this region ( similar to 2100 mm). Only expressions of WUE that included atmospheric water demand showed seasonal variation. Variations in WUE were related more to changes in ET than to changes in GPP, while T remained relatively stable, accounting for around 47 % of ET for most of the study period. For both ecosystems, E increased with higher global radiation and higher surface conductance and when the water table was closer to the surface. Higher values for E were also found with increased wind speeds in the forest and higher air temperatures in the peatland. The absence of a close relationship between ET and GPP is likely related to the dominance of plant species that either do not have stomata (i.e. mosses in the peatland or epiphytes in the forest) or have poor stomatal control (i.e. anisohydric tree species in the forest). The observed increase in potential ET in the last 2 decades and the projected drought in this region suggests that WUE could increase in these ecosystems, particularly in the forest, where stomatal control may be more significant.
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    Genetic variability and structure of the Olive Field Mouse: a sigmodontine rodent in a biodiversity hotspot of southern Chile
    (2019) Zepeda, Paulo S.; Rodriguez-Serrano, Enrique; Torres-Perez, Fernando; Celis-Diez, Juan L.; Eduardo Palma, R.
    The temperate rainforests of southern Chile, a recognized biodiversity hotspot, were significantly affected by Pleistocene glacial cycles in their southern portion and have been severely disrupted mainly due to recent human activities. Additionally, the landscape is characterized by a series of potential barriers to gene flow, such as the Chacao Channel, Cordillera de Piuche in Chiloe and both the Ancud and the Corcovado gulfs. We used mitochondrial DNA sequences and microsatellite data across several populations to evaluate the genetic variability and structure of the sigmodontine rodent Abrothrix olivacea brachiotis, one of the most common species of small mammals and an inhabitant of these biodiverse forests. Sequencing data showed that along with the recovery of high haplotype variation for this species, there was a low nucleotide diversity between haplotypes, showing no genetic differences between the Chiloe Island and continental populations in southern Chile or through any other geographic barrier in the study area. However, microsatellite data exhibited some level of population structuring. The most evident clusterings were those of the Chiloe Island and that of North Patagonia. These findings are corroborated by a barrier analysis that showed a genetic barrier in the latter areas, whereas the Chacao Channel was not a significant barrier for this rodent. Overall, the genetic variability and structure of A. o. brachiotis was concordant with historical factors, such as the Last Glacial Maximum and the presence of geographic elements that isolate populations.
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    Habitat use of remnant forest habitats by the threatened arboreal marsupial Dromiciops gliroides (Microbiotheria) in a rural landscape of southern Chile
    (2010) Smith-Ramirez, Cecilia; Celis-Diez, Juan L.; von Jenstchyk, Erik; Jimenez, Jaime E.; Armesto, Juan J.
    Context. Remnant forest patches in rural landscapes may be important sites for maintaining viable populations of restricted forest species, especially when these remnant habitats maintain some connectivity, for instance through riparian vegetation strips and other forest patches.
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    Presence of Ixodes neuquenensis Ringuelet, 1947 (Acari: Ixodidae) on the endangered Neotropical marsupial Monito del Monte (Dromiciops gliroides Thomas, 1894, Microbiotheria: Microbiotheriidae) at Chiloe Island, Chile
    (2007) Marin-Vial, Paula; Gonzalez-Acuna, Daniel; Celis-Diez, Juan L.; Cattan, Pedro E.; Guglielmone, Alberto A.
    The presence of Ixodes neuquenensis (Ringuelet, Notas Mus la Plata 12:207-216, 1947) (Acari: Ixodidae) parasitizing populations of Dromiciops gliroides Thomas, 1894 (Microbiotheria: Microbiotheriidae) at Chiloe Island confirms that this tick species is established in Chile. No preference of the ticks for sex or age of the host was observed.
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    Residents' valuation of ecosystem services in a Mediterranean coastal dune ecosystem: The case of the Ritoque dunes in central Chile
    (2023) Diaz-Siefer, Pablo; Weishaupt, Paulina; Pozo, Rocio A.; Huenchuleo, Carlos; Guerrero-Rojas, Rodrigo; Gelcich, Stefan; Celis-Diez, Juan L.
    Coastal dunes provide a variety of cultural and ecological ecosystem services to local communities. However, most of these ecosystems are globally threatened by anthropic factors. Chile is home to important dune eco-systems such as the emblematic Ritoque coastal dunes located in the hotspot for biodiversity conservation in central Chile where there is a delicate relationship between conservation and human development interests, among local communities and authorities. Here, we performed a choice experiment study to determined will-ingness to implement conservation measures in the Ritoque dunes. In particular, we assessed residents' prefer-ences for improvements of the current state of local ecosystem services such as scenic beauty, biodiversity and archaeological sites. Residents showed preferences for improvements in Ritoque coastal dunes' ecosystem ser-vices, and a high willingness to pay for protecting biodiversity and archeological sites, rather than for recrea-tional infrastructure. Our study highlights the importance of place-based research that specifically addresses residents and stakeholders' conservation priorities, which could be used to design and implement effective conservation management strategies for coastal ecosystems and coastal cities near them.
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    Social-environmental conflicts in Chile: Is there any potential for an ecological constitution?
    (MDPI, 2021) Berasaluce, Maite; Diaz-Siefer, Pablo; Rodríguez-Diaz, Paulina; Mena-Carrasco, Marcelo; Ibarra Eliessetch, José Tomás; Celis-Diez, Juan L.; Mondaca, Pedro
    © 2021 by the authors. Licensee MDPI, Basel, Switzerland.Social unrest is on the rise worldwide amid deepening inequalities, environmental degradation, and job crises worsened by increasing social-environmental conflicts. In Chile, a social revolt in 2019 resulted in a national referendum in 2020. An ample majority (78.3% vs. 21.7%) voted to draft a new constitution to replace the current constitution drawn up under dictatorship. The result led to the emergence and empowerment of several organizations demanding an “ecological constitution”. In this context, we aim to analyze: (1) the main social-environmental conflicts in Chile and how they are related to the country’s current constitution, and (2) the potential drafting of an ecological constitution that addresses these conflicts. Across different industries in Chile, we observed common problems that are intrinsically related to the current constitution. This relationship seems to be perceived by Chilean citizens since a survey carried out in May 2021 found 79% support for an ecological constitution. Moreover, 105 of the 155 delegates to the constitutional convention proposed three or more environmental principles to be included in the new constitution. A potential ecological constitution entails principles that would improve the current situation of social-environmental conflicts in Chile. Based on our analysis, we recommend the establishment of watershed-based “territorial rights” in the new Chilean constitution to improve sustainability and environmental justice.
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    The biogeography of Dromiciops in southern South America: Middle Miocene transgressions, speciation and associations with Nothofagus
    (2021) Quintero-Galvis, Julian F.; Saenz-Agudelo, Pablo; Celis-Diez, Juan L.; Amico, Guillermo C.; Vazquez, Soledad; Shafer, Aaron B. A.; Nespolo, Roberto F.
    The current distribution of the flora and fauna of southern South America is the result of drastic geological events that occurred during the last 20 million years, including marine transgressions, glaciations and active vulcanism. All these have been associated with fragmentation, isolation and subsequent expansion of the biota, south of 35 degrees S, such as the temperate rainforest. This forest is mostly dominated by Nothofagus trees and is the habitat of the relict marsupial monito del monte, genus Dromiciops, sole survivor of the order Microbiotheria. Preliminary analyses using mtDNA proposed the existence of three main Dromiciops lineages, distributed latitudinally, whose divergence was initially attributed to recent Pleistocene glaciations. Using fossil-calibrated dating on nuclear and mitochondrial genes, here we reevaluate this hypothesis and report an older (Miocene) biogeographic history for the genus. We performed phylogenetic reconstructions using sequences from two mitochondrial DNA and four nuclear DNA genes in 159 specimens from 31 sites across Chile and Argentina. Our phylogenetic analysis resolved three main clades with discrete geographic distributions. The oldest and most differentiated clade corresponds to that of the northern distribution (35.2 degrees S to 39.3 degrees S), which should be considered a distinct species (D. bozinovici, sensu D'Elia et al. 2016). According to our estimations, this species shared a common ancestor with D. gliroides (southern clades) about similar to 13 million years ago. Divergence time estimates for the southern clades (39.6 degrees S to 42.0 degrees S) ranged from 9.57 to 6.5 Mya. A strong genetic structure was also detected within and between clades. Demographic analyses suggest population size stability for the northern clade (D. bozinovici), and recent demographic expansions for the central and southern clades. All together, our results suggest that the diversification of Dromiciops were initiated by the Middle Miocene transgression (MMT), the massive marine flooding that covered several lowlands of the western face of Los Andes between 37 and 48 degrees S. The MMT resulted from an increase in global sea levels at the Miocene climatic optimum, which shaped the biogeographic origin of several species, including Nothofagus forests, the habitat of Dromiciops.
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    The Future of Rurality: Place Attachment among Young Inhabitants of Two Rural Communities of Mediterranean Central Chile
    (2022) Rodriguez-Diaz, Paulina; Almuna, Rocio; Marchant, Carla; Heinz, Sally; Lebuy, Roxana; Celis-Diez, Juan L.; Diaz-Siefer, Pablo
    Rural livelihoods are under threat, not only from climate change and soil erosion but also because young people in rural areas are increasingly moving to urbanized areas, seeking employment and education opportunities. In the Valparaiso region of Chile, megadrought, soil degradation, and industrialization are driving young people to leave agricultural and livestock activities. In this study, our main objective was to identify the factors influencing young people living in two rural agricultural communities (Valle Hermoso and La Vega). We conducted 90 online surveys of young people aged 13-24 to evaluate their interest in living in the countryside (ILC). We assessed the effect of community satisfaction, connectedness to nature, and social valuation of rural livelihoods on the ILC. The results show that young people were more likely to stay living in the countryside when they felt satisfied and safe in their community, felt a connection with nature, and were surrounded by people who enjoyed the countryside. These results highlight the relevance of promoting place attachment and the feeling of belonging within the rural community. Chilean rural management and local policies need to focus on rural youth and highlight the opportunities that the countryside provides for them.