Browsing by Author "Labra, Fabio A."

Now showing 1 - 8 of 8
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    Disentangling the spread dynamics of insect invasions using spatial networks
    (2023) Estay, Sergio A.; Silva, Carmen P.; Lopez, Daniela N.; Labra, Fabio A.
    Introduction: Describing and understanding spatiotemporal spread patterns in invasive species remains a long-standing interdisciplinary research goal. Here we show how a network-based top-down approach allows the efficient description of the ongoing invasion by Drosophila suzukii in Chile.
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    DNA barcoding of marine polychaetes species of southern Patagonian fjords
    (2011) Maturana, Claudia S.; Moreno, Rodrigo A.; Labra, Fabio A.; Gonzalez-Wevar, Claudio A.; Rozbaczylo, Nicolas; Carrasco, Franklin D.; Poulin, Elie
    Accurate species identification remains a basic first step in any study of biodiversity, particularly for global changes and their consequences. Thus, there is a pressing need for taxonomic expertise in a broad range of taxa. DNA barcoding has proved to be a powerful alternative method to traditional morphological approaches, allowing to complement identification techniques for living organisms. In this study, we assess intraspecific and interspecific genetic divergence among marine polychaetes from Patagonian fjords of southern Chile, using mitochondrial Cytochrome c Oxidase Subunit I (COI) gene. Our results showed that a total of 13 polychaetes species identified in this study exhibited high levels of interspecific variation among 31 analyzed sequences. Mean pairwise sequence distances comparisons based on K2P within species ranged from 0.2 to 0.4%. In contrast, interspecific comparisons were much higher and ranged between 18 to 47%, with the exception of the congeneric species Asychis chilensis and Asychis amphiglypta that showed high levels of genetic similarities and absence of reciprocal monophyly. This study presents the first information on DNA barcoding for polychaetes species in the southern Chile, and it establishes the effectiveness of DNA barcoding for identification of marine polychaetes species from Patagonian Fjords, thus making it available to a much broader range of scientists.
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    Ecosystem processes, management and human dimension of tectonically-influenced wetlands along the coast of central and southern Chile
    (2019) Lagos, Nelson A.; Labra, Fabio A.; Jaramillo, Eduardo; Marin, Andres; Miguel Farina, JosE; Camano, Andres
    A Workshop on Coastal Wetlands of Chile was held at Universidad Austral de Chile (Valdivia. november 2017). It was discussed the impact of earthquakes and tsunamis along this coast and their implication for wetlands. These events produce major modifications associated with variable rates of resilience. Emphasis was placed on social dimensions of such disturbances considering their impact on ecosystem services. Societal resilience must be included within the scales of wetland recovery, and incorporated in conservation and management strategies.
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    Functional biogeography of coastal marine invertebrates along the south-eastern Pacific coast reveals latitudinally divergent drivers of taxonomic versus functional diversity
    (John Wiley and Sons Inc, 2023) Herrera Paz, David Leonardo; Navarrete Campos, Sergio Andrés; Labra, Fabio A.; Castillo, Simón P.; Opazo Mella, Luis Felipe
    Characterizing the spatial structure of taxonomic and functional diversity (FD) of marine organisms across regional and latitudinal scales is essential for improving our understanding of the processes driving species richness and those that may constrain or enhance the set of species traits that define the functional structure of communities. Here, we present the functional diversity of coastal invertebrate macrofaunal species along the south-eastern Pacific from 7°N to 56°S, describe spatial variation of species traits, and examine the relationship with environmental variables. For that, we defined the functional traits and distribution ranges of 2350 marine macroinvertebrates calculated eight metrics of FD. Random forest regression was applied to identify significant relationships between FD and six environmental variables. Finally, functional β-turnover was estimated to detect alongshore shifts in functional structure and their coincidence with biogeographical domains. Our results show, in contrast with taxonomic richness that measures of trait differences, functional space and functional specialisation increase with latitude, while functional evenness exhibits a non-linear shape, peaking at mid latitudes. Functional redundancy decreased significantly poleward, while indicators of vulnerability increase. In contrast to taxonomic richness, FD was tightly connected to variables indicative of stress and productivity, such as dissolved oxygen and nutrients. Sea surface temperature and coastal area best explained the increased FD redundancy and richness towards the tropics. The high spatial correlation between taxonomic and functional turnover suggests environmental filters play an important role in the functional structure of the seascape. Our findings suggest that processes favouring taxonomic richness are latitudinally divergent from those favouring functional diversity. Correlations with environmental variables suggest that increased sea surface temperature and measures of stability increase redundancy, while variations in dissolved oxygen and nutrients positively affect functional diversification. Moreover, the functional diversity patterns suggest low resilience of high latitude coastal ecosystems, which are heavily exploited and threatened by climate change, hence highlighting the urgent need for effective conservation policies.
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    Geographic variation in trace-element signatures in the statoliths of near-hatch larvae and recruits of Concholepas concholepas (loco)
    (2012) Manriquez, Patricio H.; Galaz, Sylvana P.; Opitz, Tania; Hamilton, Scott; Paradis, George; Warner, Robert R.; Carlos Castilla, Juan; Labra, Fabio A.; Lagos, Nelson A.
    Spatial variation of trace elements in calcified structures (otoliths, statoliths, and shells) has been used to track the movements of individuals among habitats, and connectivity between marine populations. In the present study, we used laser ablation-inductively coupled plasma mass spectrometry to quantify the concentrations of trace elements in statoliths of prehatch larvae and recruits of the gastropod Concholepas concholepas from 3 regions in Chile. We also examined spatial variation in chemical signatures deposited during larval life and at the time of settlement in intertidal habitats. We found significant differences between 3 geographic regions in the trace element concentrations recorded in natal statoliths of near-hatch larvae and in natal core and edge areas of recruit statoliths. Discriminant function analysis indicates that natal signatures of near-hatch larvae and the cores and edges of recruit statoliths show spatial segregation among regions. High levels of reclassification success of larvae to the origin region suggest potential for assigning recruits to the corresponding matching region. Concentrations of trace elements in the natal cores of recruit statoliths fell relatively close but did not overlap with the discriminant space occupied by larvae, and at regional scales the pattern of geographic variation of recruit statoliths resembles that of larval statoliths. This suggests population grouping and little population interchange at this regional scale. Assessing population stocks and connectivity of this species at smaller scales along the Chilean coast will only be possible with more finely structured sampling and a better understanding of temporal variation in the chemical environment.
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    Ocean acidification alters anti-predator responses in a competitive dominant intertidal mussel
    (2022) Jahnsen-Guzman, Nicole; Lagos, Nelson A.; Quijon, Pedro A.; Manriquez, Patricio H.; Lardies, Marco A.; Fernandez, Carolina; Reyes, Miguel; Zapata, Javier; Roberto Garcia-Huidobro, M.; Labra, Fabio A.; Duarte, Cristian
    Widespread intertidal mussels are exposed to a variety of natural and anthropogenic stressors. Even so, our understanding of the combined influence of stressors such as predation risk and ocean acidification (OA) on these species remains limited. This study examined the response of the purple mussel (Perumytilus purpuratus), a species distributed along Pacific southeastern rocky shores, to the effects of predation risk and OA. Using a laboratory 2 x 2 cross design, purple mussels were either devoid or exposed to predator cues from the muricid snail Acanthina monodon, while simultaneously exposing them to current (500 ppm) or projected OA conditions (1500 ppm). The response of purple mussels to these factors was assessed using growth, calcification, clearance, and metabolic rates, in addition to byssus production. After 60 d, the presence of predator cues reduced mussel growth in width and length, and in the latter case, OA enhanced this response making the effects of predator cues more severe. Calcification rates were driven by the interaction between the two stressors, whereas clearance rates increased only in response to OA, likely explaining some of the growth results. Mussel byssus production also increased with pCO(2) but interacted with predation risk: in the absence of predator cues, byssus production increased with OA. These results suggest that projected levels of OA may alter and in some cases prevail over the natural response of purple mussels to predation risk. Considering the role played by this mussel as a dominant competitor and ecosystem engineer in rocky shores, these results have community-wide implications.
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    The relative role of ecological interactions and environmental variables on the population dynamics of marine benthic polychaetes
    (2018) Labra, Fabio A.; Moreno, Rodrigo A.; Alvarado, Sergio A.; Carrasco, Franklin D.; Estay, Sergio A.; Rivadeneira V., Marcelo M.