Browsing by Author "Silva, Carmen P."
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- ItemA modeling approach to estimate the historical population size of the Patagonian Kawesqar people(2022) Estay, Sergio A.; Lopez, Daniela N.; Silva, Carmen P.; Gayo, Eugenia M.; McRostie, Virginia; Lima, MauricioThe study of human-gatherers societies' demography used to be a difficult task due to the lack of direct evidence to support the estimations. This is the case of several human groups from Pacific Patagonia whose historical population size estimations are controversial. This study estimated the historical population size for the Kawesqar people using direct and indirect evidence. Thus, we collated past estimations from experts and encounter rates distribution in time and space to generate a statistical approximation for population size. We used weights to include the reliability of such past estimations under three modeling scenarios. Our results indicate that the historical population ranged roughly between 3700 and 3900 individuals before the massive contact with Chileans and European people. The approach developed here for combining and integrating different evidence for estimating population in Kawesqar people, emerges as a promising and valuable tool to study the demography of other hunter-gatherer societies in South America.
- ItemCan suitability indices predict plant growth in the invaded range? The case of Acacias species(2023) Silva, Carmen P.; Lopez, Daniela N.; Naulin, Paulette I.; Estay, Sergio A.IntroductionForestry in many parts of the world depends on exotic species, making this industry a source of invasions in some countries. Among others, plantations of the genus Pinus, Eucalyptus, Acacia, Populus, and Pseudotsuga underpin the forestry industry and are a vital component of many countries economies. Among woody plants, the cosmopolitan genus Acacia includes some of the most commonly planted trees worldwide. In order to prevent, manage and control invasive plant species, one of the most used tools is species distribution models. The output of these models can also be used to obtain information about population characteristics, such as spatial abundance patterns or species performance. Although ecological theory suggests a direct link between fitness and suitability, this link is often absent. The reasons behind the lack of this relationship are multiple. Chile is one of the countries where Acacia species, in particular, A. dealbata and A. melanoxylon, have become invaders. MethodsHere, we used climatic and edaphic variables to predict thepotentially suitable habitats for A. dealbata and A. melanoxylon in continental Chile and evaluate if the suitability indices obtained from these models are associated with the observed performance of the trees along the country. ResultsOur models show that variable importance showed significant similarities between the variables that characterize each species' niche. However, despite the high accuracy of our models, we did not observe an association between suitability and tree growth. DiscussionThis disconnection between suitability and performance can result from multiple causes, from structural limitations, like the lack of biotic interactions in the models, to methodological issues, like the usefulness of the performance metric used. Whatever the scenario, our results suggest that plans to control invasive species should be cautious in assuming this relationship in their design and consider other indicators such as species establishment success.
- ItemDisentangling 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.