Biology subjects

Estay, S. A.

Publications and source records attributed to Estay, S. A..

6 recordsLinked to original sources

bioRxiv2026

Species traits shape the intercontinental introduction patterns of bark and ambrosia beetles

O_LIA negative consequence of international trade is the accidental transport of non-native insect species to non-native regions, but our understanding of how this risk varies among species and how it relates to species traits remains incomplete. C_LIO_LIWe conducted a multi-continental analysis of historical border interception records for bark and ambrosia beetles (Coleoptera: Curculionidae: Scolytinae and Platypodinae), integrating 13,124 interception events (353 species) from Canada, Chile, Japan, New Zealand, and the United States. We estimated an intercontinental propagule pressure index and tested how species characteristics influence transport likelihood. C_LIO_LIInterception assemblages showed low similarity among countries, with 64% of species recorded in only one nation, indicating strong geographic structuring linked to trade pathways. Interceptions were taxonomically and biogeographically non-random: species native to the Palearctic Nearctic and Indo-Malayan regions were overrepresented, whereas Neotropical, Austro-Pacific and Afrotropical taxa were underrepresented. C_LIO_LIHost tree taxa emerged as the strongest predictor of propagule pressure. Species associated with conifers--particularly Pinaceae--exhibited approximately twice the propagule pressure of species restricted to broadleaved hosts. Ambrosia beetles showed higher propagule pressure than bark and twig/seed feeders. Propagule pressure also increased with the number of regions where species have already invaded, consistent with bridgehead dynamics. C_LIO_LISynthesis and applications: Our findings demonstrate that intercontinental transport of bark and ambrosia beetles is strongly structured by host associations, feeding guild, and biogeographic origin, reflecting the composition of traded commodities and historical trade networks. Identifying taxa with consistently high propagule pressure provides a basis for prioritizing surveillance and strengthening global forest biosecurity. C_LI

ecology↗

bioRxiv2022

Disentangling the spread dynamics of insect invasions using spatial networks

Describing and understanding spatiotemporal spread patterns in invasive species remains a longstanding 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. To do so, we apply theoretical graph methods to calculate the minimum cost arborescence graph (MCA) to reconstruct and understand the invasion dynamics of D. suzukii since the first detection in 2017. This method estimates a directed rooted weighted graph by minimizing the total length of the resulting graph. To describe the temporal pattern of spread, we estimate three metrics of spread: the median dispersal rate, the median coefficient of diffusion, and the median dispersal acceleration. The estimated MCA shows that over four years, D. suzukii colonized a ~1,000 km long strip in the central valley of Chile, with an initial phase with long paths and connections and no clear direction pattern, folowed by a clearer north-east propagation pattern. The median dispersal rate for the entire period was 8.8 [7.4 - 10.6,95% CI], while the median diffusion coefficient was 19.6 meters2/day [13.6 - 27.9, 95% CI]. The observed spread dynamics and the log-normal distribution of accelerations are consistent with longdistance dispersal events. The complexities of real landscapes cannot be summarized in any model, but this study shows how an alternative top-down approach based on graph theory can facilitate the ecological analysis of the spread of an invasive species in a new territory.

ecology↗

bioRxiv2022

Can suitability indices predict plant growth in the invaded range? The case of Acacias species

Forestry 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. Here, we used climatic and edaphic variables to predict the potentially 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. Our 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. This 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.

plant biology↗

bioRxiv2022

1000 years of population, warfare, and climate change in pre-Columbian societies of the Central Andes

Different Andean societies underwent processes of expansion and collapse during propitious or adverse climate conditions, resource boost or depletion along with population variations. Previous studies have emphasized that demographic collapses of polities in the Central Andes Area were triggered by warfare and the negative impacts of fluctuating climate (droughts) on crop productivity. Nevertheless, the interactions between climatic variability, demography and warfare have been less thoroughly evaluated. We develop population dynamic models to test feedback relationships between population growth, climate change and warfare in the Central Andes, where considerable regional hydroclimate variations have occurred over a millennium. Through population models, we found out that the rise and demise of social polities in the northern coast of the Central Andes appear to be a consequence of climate change. In contrast, for the highlands of Peru and the Titicaca basin, population models suggest that warfare intensity has a negative effect on population growth rates.

ecology↗

bioRxiv2022

A bug's tale: revealing the history, biogeography and ecological patterns of 500 years of insect introductions

The arrival of Europeans to the Americas triggered a massive exchange of organisms on a continental scale. This exchange was accelerated by the amazing increase in the movement of people and goods during the 20th century. In Chile, scientific and technical literature contains hundreds of records of exotic insect species in different parts of the territory, from the hyperarid Atacama Desert to the Magallanes Region. Here, we analyze the biological patterns obtained from the database of introductions of exotic insects to Chile from the European arrival to the present. Our task includes a review of old records in museums, libraries, collections, expedition records and catalogs. Almost 600 species of exotic insects have been reported in Chile. Introductions started at the very arrival of Europeans to the central valley of Chile and underwent a huge acceleration in the second half of the 20th century. The order Hemiptera was the most prevalent among introduced insects. Most species are linked to agriculture and forestry. Species are of Palearctic origin in more than 50% of the records. In terms of temporal trends, the rate of introduced species shows an abrupt increase at the beginning of the 1950s. This change may be associated with the strong development in agriculture and forestry in Chile after World War II and the increase in intercontinental air traffic. We believe that the understanding of past patterns of introductions is an important component in the design of current policies to minimize the impact of invasive insects.

ecology↗

bioRxiv2018

npphen: an R-package for non-parametric reconstruction of vegetation phenology and anomaly detection using remote sensing

For ecologists, the challenge at using remote sensing tools is to convert spectral data into ecologically relevant information like abundance, productivity or traits distribution. Among these features, plant phenology is one of the most used variables in any study applying remote sensing to plant ecology and it has formally considered as one of the Essential Biodiversity Variables. Currently, satellite imagery make possible cost-efficient monitoring of land surface phenology (LSP), but methods applicable to different ecosystems are not available. Here, we introduce the npphen R-package developed for remote sensing LSP reconstruction and anomaly detection using non-parametric techniques. The package implements basic and high-level functions for manipulating vector and raster data to obtain high resolution spatial and temporal LSP reconstructions. Advantages of npphen are: its flexibility to describe any LSP pattern (suitable for any ecosystem), it handles time series or raster stacks with and without gaps, and it provides confidence interval for the expected LSP at yearly basis, useful to judge anomaly magnitudes. We present two study cases to show how npphen can successfully reconstruct and map LSP and anomalies for contrasting ecosystems.

ecology↗