Edgar Chávez González is visiting our lab

edgar_chavez-gonzalezThis week we received the visit of Edgar Chávez González, master’s student at the Institute of Ecology in Xalapa, México. He will be with us until early August, collaborating with Diego in the study of the temporal dynamics of plant-hummingbird networks.

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Third annual group retreat

Recently we had our third annual group retreat, following the success of the retreats in previous years (see here and here). This year, each participant had to give a talk on our research, with no visual aids (no PowerPoint) and targeted to the general public. It was a fun exercise, as it forced us to focus on the essentials and forget about the bells and whistles of electronic media. We also had discussions on how to make our research more relevant for society, an introduction to the world of drones (led by Nati Schroeder) and of course a walk to the nearby Mendoza river. All in the great setting in the mountains of Colonia Suiza in Mendoza. A great experience we’ll surely repeat in future years.


The retreat’s participants viewed from Nati’s drone. Clockwise from the top: Natalia Schroeder, Hugo Marrero, Nydia Vitale, Micaela Santos, Jimena Dorado, Diego Vázquez, Laura Dällenbach.


Listening to Mica’s talk on fragmentation and food web structure.

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Back from workshop on temporal mutualistic networks

I just came back from the workshop Adding the temporal scale to plant-animal mutualistic networks, which I organized with Tiffany Knight. The attendees included colleagues from Germany, the USA, China and Argentina (see group photo below). Our goal was to start work towards conceptual and data-based syntheses involving the inclusion of the temporal dimension in the study of plant-animal mutualistic networks. And we made good progress towards this goal! The workshop was generously sponsored by the Freiburg Institute for Advanced Studies and the Humboldt Foundation, and was held at the Waldhof, in Freiburg im Breisgau, Germany.

Participants of workshop on temporal mutualistic networks

Participants of workshop on temporal mutualistic networks, November 5-10, Freiburg im Breisgau, Germany. From left to right: Benoit Gauzens, Qiang Fang, Julian Resasco, Nico Blüthgen, Benjamin Schwarz, Jochen Fründ, Rachael Winfree, Tiffany Knight, Carsten Dormann, Paul CaraDonna, Christopher Kaiser-Bunbury, Laura Burkle, Gita Benadi and Diego Vázquez. The broom at the far right of the picture represents the sweeping influence of the temporal scale on the structure and dynamics of plant-animal mutualistic networks.

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Oportunidades para estudiantes de grado en nuestro laboratorio

Estamos buscando estudiantes de grado altamente motivados para realizar investigación en ecología y en condiciones de empezar con su tesina. También hay posibilidades de realizar voluntariados de investigación (pasantías cortas no rentadas) para participar de los proyectos del laboratorio. Los posibles temas de investigación son los siguientes:

  1. Trampas-nido utilizadaspara estudiar las abejas solitarias en Villavicencio.

    Ecología de abejas solitarias. Se trata de un estudio a largo plazo que los integrantes del laboratorio están realizando desde 2006 en la Reserva Natural Villavicencio para estudiar la demografía y la dinámica poblacional de varias especies de abejas solitarias que nidifican en orificios de la madera y su relación con sus recursos florales y el clima. El trabajo de tesina consistirá en el estudio de las poblaciones de abejas y sus recursos florales durante la primavera-verano de 2017-2018 y la comparación de tendencias en la demografía (fecundidad, abundancia, tasa de crecimiento poblacional) con las de años anteriores. Los interesados deben contactarse con Diego Vázquez (dvazquez [arroba] mendoza-conicet.gob.ar).

  2. Estudiando interacciones planta-polinizador en Ñacuñán.

    Impacto de las abejas melíferas sobre las interacciones planta-polinizador. Se trata de un proyecto para evaluar el impacto de las colmenas de la abeja de la miel (Apis mellifera) sobre las interacciones planta-polinizador en la Reserva de Biósfera Ñacuñán y alrededores. La motivación del estudio es que recientemente se ha introducido numerosas colmenas en las inmediaciones de la reserva, pero se desconoce el impacto que esta actividad está teniendo sobre los ecosistemas naturales en esta región. Responder esta pregunta es importante para generar recomendaciones de manejo concretas sobre la carga máxima de colmenas recomendable para minimizar el impacto sobre los ecosistemas naturales. El trabajo de tesina consistirá en estudiar y comparar las tasas de visitas de A. mellifera y de los polinizadores nativos antes y después de la introducción de las colmenas, utilizando datos nuevos tomados en el campo y datos preexistentes. Los interesados deben contactarse con Jimena Dorado (jdorado [arroba] mendoza-conicet.gob.ar).

  3. Red planta-polinizador de Villavicencio (datos acumulados de seis años).

    Estructura y dinámica temporal de redes de interacción planta-polinizador. Esta es una línea de investigación que miembros del laboratorio desarrollan desde hace años. Las oportunidades para tesinas incluyen un estudio sobre el impacto de una planta invasora sobre la estructura de la red de interacciones planta-polinizador comunidades de alta montaña, y un estudio sobre la dinámica temporal de una red planta-polinizador en la Reserva Natural Villavicencio. En el primer caso el trabajo de tesina consistirá en estudios experimentales de remoción de la planta invasora y el muestro de las interacciones planta-polinizador, mientras que en el segundo caso el trabajo consistirá en una combinación de estudios de campo y simulaciones en computadora para evaluar predicciones sobre la estabilidad de las interacciones según su posición en la red, en ambos casos durante la primavera-verano de 2017-2018. Los interesados deben contactarse con Diego Vázquez (dvazquez [arroba] mendoza-conicet.gob.ar).

Además de estos temas, hay oportunidades para colaborar y eventualmente realizar tesinas en otros temas desarrollados por los integrantes del laboratorio. Las puertas del laborarotorio están abiertas para que nos visiten y así conocer lo que hacemos y conversar sobre oportunidades para realizar investigación.

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Three new doctors in the group!

Recently, Belén, Ana and Nydia have successfully defended their doctoral theses. Congratulations to the trio!

Belén, celebrating with a bottle of sparkling wine.

Belén Maldonado studied the ecological functions of dung beetles in an aridity gradient in the Monte desert. With a series of observational and experimental studies, she investigated how these beetles can influence the seed dispersal of a key tree species in the Monte, the algarrobo dulce Prosopis flexuosa. She also studied the role dung beetles in nutrient cycling. She is now starting a post-doctoral fellowship to study eco-phisiological aspects of dung beetles, in collaboration with researchers in Mendoza and Lund, Sweden.

Ana, with one of the presents received on the occassion.

Ana Mazzolari’s doctoral thesis is a study of the ecological factors that contribute to the invasion of two rose species in Mendoza, Rosa canina and R. rubiginosa. Ana studied the reproductive strategies of these roses and how they may contribute to the invasion process (see our paper in Biological Invasions), the functional traits of the roses and how they compare to those of native species, and the habitat suitability for invasion of these species in the study region. The information generated in Ana’s thesis may be extremely useful for the management of these two invasive plant species. Ana is now starting a post-doc to work in conservation biology in collaboration with Gustavo Zuleta’s group in Buenos Aires.

Nydia, starting to relax after the defense.

Finally, Nydia Vitale studied the ecology of several species of wood-nesting solitary bees and their potential response to climate change. Nydia’s thesis is a great example of how a lot of detailed natural history information on a group of species (see for example our recent paper in Apidologie) can lead to important insights on the functioning of ecological interactions and on the species’ potential to cope with a changing climate. Nydia is now continuing with a post-doc under the combined supervision of Víctor González (University of Kansas, USA) and myself  to pursue further studies on the response of bees to climate change.

Best wishes to the three in this new stage in their careers!

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Juan Manuel Drack defended his thesis on cement pollution and cactus morphology

Juan with our colleague Jimena Dorado after the defense.

Last Monday, 13 March, 2017, Juan defended his undergraduate thesis on the morphological response of a cactus to cement dust pollution. The thesis examiners agreed in that Juan had done a great job in this project, producing interesting results that are relevant for our understanding of how human activities are influencing natural species and ecosystems. Bravo Juan!

Here’s the story of Juan’s thesis project. While helping me with my bee work in the field, he noticed that the individuals of the cactus Tephrocactus aoracanthus around a cement factory presented some unusual features: longer and more numerous spines, thicker cladodia (stems). His research project was an attempt to understand whether these morphological features were related to the cement dust produced by the factory. In a series of field observational and experimental studies, Juan was able to show that this cactus species does in fact respond to cement dust deposition by growing larger and spinier. We have just submitted this work for publication in an international journal, so stay tuned for more news on this project.

This is a drawing that our colleague Cecilia Scoones kindly prepared for us as a graphical abstract for the journal publication of the thesis. It illustrates the essence of Juan’s results: cacti in the proximity of the cement factory grown larger and spinier cacti growing far from the factory. Thanks Cecilia for sharing your superb art with us!

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Jimena Dorado visited Germany to attend a workshop


Jimena in Oberlinden, in the old city of Freiburg.

Jimena was recently in Freiburg im Breisgau, Germany, attending a workshop on trap-nest food webs (host-parasite interaction networks involving wood-nesting hymenopterans). The workshop, organized by Jochen Fründ, Alex Klein and Teja Tscharnkte, involved colleagues from Germany, Switzerland, Canada, the US and Argentina. It was held at the Waldhof, a quiet place ideal for this kind of activities in the Littenweiler area of Freiburg. Jimena also spent a few days as a guest researcher at the Freiburg Institute of Advanced Studies (FRIAS) at the University of Freiburg, where we worked together on a couple of manuscripts. It was really nice to have her here!

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Exotic plants and pollination niche overlap in an agroecosystem

Post contributed by Hugo Marrero


Some of the many pollen grains transported by pollinators that were observed during the study.

A paper on the influence of exotic plants on the pollination niche overlap among plants in an agroecosystem was just published in Agriculture, Ecosystems and Environment. The study, which is part of my PhD thesis, focuses on pollinator-mediated interactions among plants. The idea was to evaluate the transport of pollen by pollinators in agricultural and restored ecosystems, and how exotic plant species can disrupt such transport by increasing niche overlap among coexisting plant species. In doing so, we described for the first time a community-wide pollen transport network in an agroecosystem. The study involved many hours of laboratory work due to the difficulty of determining and counting the pollen grains carried by pollinators. But it was worth the effort, as the results were very interesting: we found that the diversity of pollen transported by pollinators and the overlap in the pollination niche among plants were greater in agricultural sites than in restored sites. Exotic plant species contributed positively to an increase in niche overlap, while native species contributed negatively, promoting decreased overlap. These results may be useful to improve our understanding of the ecology of pollinator-mediated interactions among plants, and of how alien species may disrupt the functioning of interactions among native species.

You can find the final version of the manuscript in the journal`s web site, or send me an email at hugomarrero[_at_]gmail.com to request the pdf.

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Guadalupe Peralta is in New Zealand collaborating with Daniel Stouffer’s group

Student profile, Guadalupe Peralta, PhD Ecology, 16.4.13

Guadalupe Peralta

Taking advantage of the great flexibility of CONICET’s post-doctoral fellowships, Lupe is spending several months in New Zealand collaborating with Daniel Stouffer and his group at the University of Canterbury, Christchurch. She will continue with her work on dynamic models of mutualistic networks that include not only benefits but also costs of interactions, and is starting other collaborations with some of Daniel’s group members. Good luck Lupe in this new Kiwi adventure!


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Hugo Marrero will become a CONICET Assistant Researcher


Hugo Marrero

We heard last week that Hugo’s application to become an Assistant CONICET Researcher has been approved. He will be working at the Center for Natural Renewable Resources of the Semi-Arid Zone (CERZOS), in Bahía Blanca, in the south of Buenos Aires Province. During the first several years as a CONICET researcher, Hugo is planning to focus on the management of floral and nesting resources for native bees in agro-ecosystems to enhance crop pollination. Congratulations Hugo!

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