Examinando por Autor "Cayuela, Luis"

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A method to incorporate the effect of taxonomic uncertainty on multivariate analyses of ecological data
(Wiley, 2011) Cayuela, Luis; Cruz, Marcelino de la; Ruokolainen, Kalle
Researchers in ecology commonly use multivariate analyses (e.g. redundancy analysis, canonical correspondence analysis, Mantel correlation, multivariate analysis of variance) to interpret patterns in biological data and relate these patterns to environmental predictors. There has been, however, little recognition of the errors associated with biological data and the influence that these may have on predictions derived from ecological hypotheses. We present a permutational method that assesses the effects of taxonomic uncertainty on the multivariate analyses typically used in the analysis of ecological data. The procedure is based on iterative randomizations that randomly re-assign non identified species in each site to any of the other species found in the remaining sites. After each re-assignment of species identities, the multivariate method at stake is run and a parameter of interest is calculated. Consequently, one can estimate a range of plausible values for the parameter of interest under different scenarios of re-assigned species identities. We demonstrate the use of our approach in the calculation of two parameters with an example involving tropical tree species from western Amazonia: 1) the Mantel correlation between compositional similarity and environmental distances between pairs of sites, and; 2) the variance explained by environmental predictors in redundancy analysis (RDA). We also investigated the effects of increasing taxonomic uncertainty (i.e. number of unidentified species), and the taxonomic resolution at which morphospecies are determined (genus-resolution, family-resolution, or fully undetermined species) on the uncertainty range of these parameters. To achieve this, we performed simulations on a tree dataset from southern Mexico by randomly selecting a portion of the species contained in the dataset and classifying them as unidentified at each level of decreasing taxonomic resolution. An analysis of covariance showed that both taxonomic uncertainty and resolution significantly influence the uncertainty range of the resulting parameters. Increasing taxonomic uncertainty expands our uncertainty of the parameters estimated both in the Mantel test and RDA. The effects of increasing taxonomic resolution, however, are not as evident. The method presented in this study improves the traditional approaches to study compositional change in ecological communities by accounting for some of the uncertainty inherent to biological data. We hope that this approach can be routinely used to estimate any parameter of interest obtained from compositional data tables when faced with taxonomic uncertainty.
Colecciones de ejercicios de la asignatura de Biología de la Conservación
(2023-02) Cayuela, Luis; Iriondo, José María
Colección de ejercicios (prácticas) de la asignatura de Biología de la Conservación del Grado en Biología. El material recogido incluye los guiones de las cinco prácticas realizadas en la asignatura.
Guía de la asignatura Biología de la Conservación
(2023-01-19) Cayuela, Luis
Guía de estudio de la asignatura de Biología de la Conservación del Grado en Biología, que incluye información de los objetivos, el temario, el cronograma, el programa docente detallado y la bibliografía más relevante para la asignatura.
Is insecticide spraying a viable and cost-efficient management practice to control pine processionary moth in Mediterranean woodlands?
(Elsevier, 2011) Cayuela, Luis; Hódar, José A.; Zamora, Regino
Insect pests are a major threat to many forests worldwide, from boreal to tropical forest ecosystems. Some pests exhibit periodical outbreaks, after which their populations often crash as a result of natural biological control. To offset such outbreaks, several management techniques are used, including aerial spraying of insecticides. The question remains whether pest decline following an outbreak is the result of management practices or a natural consequence of the insect¿s population cycle. In this study, we assessed the performance of aerial spraying of insecticides on pine woodland stands to control pine processionary moth Thaumetopoea pityocampa (PPM) outbreaks in southern Spain. To achieve this, we compared the degree to which a forest stand recovers from defoliation from one year of severe damage by PPM to the following year (infestation index) in stands that were treated (i.e. subjected to aerial spraying) and untreated using a 4-years database from the Regional Environmental Council. The results revealed a significant similar recovery from infestation after a PPM outbreak of both sprayed and non sprayed pine woodland stands, for the four most representative pine species (black, Aleppo, maritime, and stone pine). It is concluded that insecticide spraying cannot be considered a prevention for outbreaks if it is applied once the outbreak explodes. Management practices that can help control PPM outbreaks include promoting spatial heterogeneity at the landscape level, fostering biodiversity in pine plantations, and reinforcing parasitoid insect and predatory bird populations that negatively affect the PPM. This study illustrates how simple sampling designs and statistical tests can be useful decision-making tools and can help improve the environmental viability and cost-efficiency of forest management practices.
Presentaciones de la asignatura Biología de la conservación
(2023-02) Cayuela, Luis
Presentaciones de 10 de los 11 temas de la asignatura de Biología de la Conservación del Grado en Biología de la Universidad Rey Juan Carlos. Las presentaciones adjuntas cubren la práctica totalidad del temario de la asignatura. Las presentaciones están hechas en Prezi, no en PowerPoint, y están en acceso abierto configurados de tal forma que todo el mundo puede encontrar las presentaciones a través de motores de búsqueda y que cualquier persona con acceso pueda hacer una copia y reutilizar el contenido de las mismas. El temario que se cubre es el siguiente (los enlaces a las presentaciones de Prezi se muestran entre paréntesis): - Tema 1. ¿Qué es la biología de la conservación? (https://prezi.com/view/fbdlbxLRtxSnisbAvSso/). - Tema 2. ¿Por qué conservar? El valor de la biodiversidad (https://prezi.com/view/HVeq4lpGcOhKJIyG3ITp/) - Tema 3. Causas de la extinción de especies (https://prezi.com/view/LW4qiTc4ZBEXQDkzIk3N/). - Tema 4. ¿Qué especies conservar? Introducción a los criterios de la UICN (https://prezi.com/view/xUwezXyzxszGe6kU9lVP/). - Tema 5. Genética de la conservación (https://prezi.com/view/SvIdu62NKvcbojSwckgk/). - Tema 6. Seguimiento y conservación de poblaciones (https://prezi.com/view/YTSt87zj01Kd81tQi3c3/). - Tema 7. Conservación ex-situ (https://prezi.com/view/Wrv73lYdU0MCm0rrb4sk/). - Tema 8. Conservación in-situ. Planes de gestión de especies amenazadas (https://prezi.com/view/Ze99XtyBDavASnVx0kvi/). - Tema 9. Introducción a los espacios naturales protegidos. Normativa (sin presentación). - Tema 10. Categorías UICN de espacios naturales protegidos (https://prezi.com/view/730lC8vqOXjjuP8HK2Ig/). - Tema 11. Categorías internacionales de espacios naturales protegidos (https://prezi.com/view/Q0Mrh9t0tSevOjXvpRmh/).
The effects of human population density on trophic interactions are contingent upon latitude
(Wiley, 2024-04-23) Hernández-Agüero, Juan A.; Ruiz-Tapiador, Ildefonso; Garibaldi, Lucas A.; Kozlov, Mikhail V.; Mäntylä, Elina; Nacif, Marcos E.; Salinas, Norma; Cayuela, Luis
Aim Global-scale studies are necessary to draw general conclusions on how trophic interactions vary with urbanization and to explore how the effects of urbanization change along latitudinal gradients. We predict that the intensity of trophic interactions decreases in response to urbanization (quantified by human population density). Since trophic interactions are more intense at lower latitudes, we also expect major impacts of urbanization at higher latitudes, where base levels are essentially lower. Location Global (881 study sites). Time period 2000–2021. Major taxa studied Birds, arthropods and woody plants. Methods We compiled global data on insect herbivory and bird predation from studies that employed similar methods and fitted generalized linear mixed models to test how these trophic interactions vary with human population density, latitude and their interactions. Results The intensity of herbivory and predation decreased with an increase in human population density at lower latitudes. Surprisingly, it remained unaffected at intermediate latitudes and even increased at higher latitudes. Main conclusions The observed patterns may be attributed to local climate changes in urban areas, such as the Urban Heat Island effect, which disrupts thermal stability in the tropics while increasing niche availability at polar latitudes