Plant invasions research in Latin America: fast track to a more focused agenda.

Autores:

Gardener, M., Bustamante, R., Herrera, I., Durigan, G., Pivello, V., & Moro, M., Stoll, A., et al.

Resumen:

While many developed countries have invested heavily in research on plant invasions over the last 50 years, the immense region of Latin America has made little progress. Recognising this, a group of scientists working on plant invasions in Latin America met in Chile in late 2010 to develop a research agenda for the region based on lessons learned elsewhere. Our three main findings are as follows. (1) Globalisation is inevitable, but the resultant plant introductions can be slowed or prevented by effective quarantine and early intervention. Development of spatially explicit inventories, research on the invasion process and weed risk assessments can help prioritise and streamline action. (2) Eradication has limited application for plants and control is expensive and requires strict prioritisation and careful planning and evaluation. (3) Accepting the concept of novel ecosystems, new combinations of native and introduced species that no longer depend on human intervention, may help optimise invasive species management. Our vision of novel ecosystem management is through actions that: (a) maintain as much native biodiversity and ecosystem functionality as possible, (b) minimise management intervention to invasives with known impact, and (c) maximise the area of intervention. We propose the creation of a Latin American Invasive Plants Network to help focus the new research agenda for member countries. The network would coordinate research and training and establish funding priorities, develop and strengthen tools to share knowledge, and raise awareness at the community, governmental and intergovernmental levels about the social, economic and environmental costs of plant invasions.

Año: 2012

Palabras claves: control, eradication, globalisation, inventories, novel ecosystems, plant invasions, quarantine, Weed Risk Assessment,

Respuestas antioxidantes en dos ecotipos de Colobanthus quitensis (Caryophyllaceae) expuestos a alta radiación UV-B y baja temperatura.

Autores:

Navarrete-Gallegos, A., Bravo, L., Molina-Montenegro, M., & Corcuera, L.

Resumen:

Colobanthus quitensis (Kunth) Bartl. (Caryophyllaceae) está distribuida desde México hasta la Antártida Marítima formando poblaciones adaptadas a distintas condiciones microambientales a lo largo de su distribución. La Antártica Marítima se caracteriza por una estación de crecimiento más fría y breve, con crecientes niveles de radiación UV-B. Los Andes de Chile Central, en cambio, tienen oscilaciones térmicas más amplias y una elevada tasa de radiación UV-B. El objetivo de este estudio es conocer las estrategias y mecanismos antioxidantes adoptadas por los ecotipos Antártico y Andino para tolerar los efectos dañinos de la radiación UV-B y el frío bajo condiciones controladas de laboratorio. Postulamos que los individuos de C. quitensis provenientes de la cordillera de Los Andes de Chile Central, donde los niveles de radiación UV-B son mayores que en la Antártica, tendrían un conjunto de mecanismos antioxidantes más eficaces para contrarrestar los efectos del UV-B y sufrirían menos daño que el ecotipo Antártico. Plantas cultivadas en laboratorio del ecotipo Antártico y Andino fueron sometidas a tres intensidades de radiación UV-B (70, 35 y 3 µW cm-2), a 4 y 15 °C, respectivamente. En cada tratamiento se evaluaron las respuestas de la actividad antioxidante total (TAS), actividad de la enzima superóxido dismutasa (SOD) y características anatómicas foliares con un posible rol protector frente a UV-B. Finalmente, se evaluaron los efectos dañinos del UV-B, como son: acumulación de malonaldialdehido (MDA), eficiencia fotoquímica máxima del PSII y fotoinactivación. Ambos ecotipos mostraron reducción de área foliar y engrosamiento del parénquima. El ecotipo andino presentó mayores niveles de TAS con radiación UV-B media y alta. La actividad SOD máxima se midió en el ecotipo andino, encontrándose un aumento de hasta ocho veces el nivel basal a las cuatro horas de irradiación. El ecotipo antártico expuesto a UV-B y frío presentó un mayor daño a membranas (MDA), al igual que un mayor grado de fotoinactivación. Adicionalmente, se detectó la acumulación de una nueva isoforma Cu-Zn/SOD, insensible a H2O2, en plantas tratadas con UV-B. En conclusión, el ecotipo andino presenta una respuesta antioxidante más efectiva contra el UV-B que el ecotipo antártico.

Año: 2012

Palabras claves: Antártica, antioxidantes, daño oxidativo, UV-B.

The conquest of the South Pole: Importance and lessons for the present.

Autores:

Molina-Montenegro, M. & Corcuera, L.

Resumen:

On December 14, 1911, the Swedish Roald Amundsen, heading a group of explorers reached the South Pole. This date has become a symbol of all those great explorers that risking their lives in the most inhospitable continent in our planet, reached places that looked impossible to conquer. This date is also a symbol of the great difficulties that must be overcome to work in the Antarctic and of much that is yet to be known in the white continent. These are the reasons why Revista Chilena de Historia Natural is commemorating this important historic event with a Special Feature dedicated to Antarctic research.

The era of epic exploration in the Antarctic, such as those led by Roald Amundsen, Robert Scott, Ernest Shakleton, and many others has come to an end. This era had great unforgettable victories and defeats. The exciting race to conquer the South Pole among Amundsen and Scott left valuable lessons on the enormous difficulties to perform Antarctic exploration and the importance of planning and logistic design for any activity in the Antarctic. Perhaps, one of the best known expeditions for the magnitude of the encountered, adverse climatic conditions and importance of international cooperation is the Endurance Expedition, led by Ernest Shackleton in the period between 1914 and 1916. The loss of the Endurance, the courage of the explorers to reach Elephant Island, and the incredible determination of the leader of the expedition to achieve impress us even today. It was this determination that inspired the Chilean pilot Luis Pardo to risk the precarious ship Yelcho, performing one of the most celebrated rescue expeditions in Antarctic history. This era of great explorers, in addition to opening new routes, had the merit of drawing international attention on the great white continent and raised interest of many countries on the possible colonization, use of resources, and scientific research of Antarctic organisms, geological resources, climate, atmosphere, climatic change, and other aspects.

The difficulties and dangers of Antarctic research are still enormous in spite of the technology which is available today. Logistic costs to perform modern and safe Antarctic expeditions are very high. For this reason, the available budget is the main limitation for Antarctic research. However, in spite of the encountered difficulties, researchers have unveiled step by step the importance of Antarctic in the world's climate, ocean levels, availability of natural resources, and aspects of conservation and utilization of its flora and fauna.

Año: 2012

Palabras claves:

Rise And Decline Of Chinchorro Sacred Landscapes Along The Hyperarid Coast Of The Atacama Desert.

Autores:

Santoro, C., Rivadeneira, M., Latorre, C., Rothhammer, F., & Standen, V.

Resumen:

The study of complex funerary ritual development among hunters and gatherers societies should take into account how people made up for the continuity of their social system without the support of centralized organizations. This research integrates cultural and natural factors to explore how the Chinchorro carried on with their way of life isolated at geographically restricted perennial river mouths with fresh water along the Atacama Desert in the Pacific coast of South America. Within these rather crowded settlings, they created and maintained a social system catalyzed by a complex funerary tradition, embodied by a unique funerary ideological discourse that resulted in the creation of a sacred landscape or "spiritscape". We argue that the extreme hyperaridity of the coastal Atacama Desert (21° - 17.30° S), and the extraordinary biomass production of the marine littoral constituted a fundamental milieu for the maintenance of their long-term social system. The Chinchorro belief system lasted for several millennia (8,000-4,000 BP), but new ways of life and burial practices followed major changes in the coastal ecosystem they relied on, which would have influenced how the "old tradition" was manifested over time. Conversely, we sustain that these natural "constraints" faced by the Chinchorro along the coast of the Atacama Desert, were influential, in the course of their history or the way they socially organized themselves.

Año: 2012

Palabras claves: Chinchorro spiritscape, sacred landscape, hyperaridity, coastal Atacama Desert.

No evidence of a trade-off between drought and shade tolerance in seedlings of six coastal desert shrub species in north-central Chile.

Autores:

Martínez-Tillería, K., Loayza, A., Sandquist, D., & Squeo, F.

Resumen:

We found species-specific differences in the temporal pattern of mortality. Water and/or light levels affected seedling survival of all species, excluding C. chilensis. Relative growth rate (RGR) increased in low-light conditions in C. chilensis and P. revolutus, but otherwise did not vary in response to differences in either light or water, independently or to their interaction. Across species, the effect of water on specific leaf area (SLA) was inconsistent, increasing both in drought conditions (C. chilensis) and in treatments with supplemental water (S. cumingii). Additionally, SLA tended to increase with decreasing light levels for most species (F. thurifera, H. parvifolius, C. chilensis). In our study, only F. thrurifera and C. chilensis showed changes in leaf mass ratio (LMR) and only with respect to light levels; specifically, LMR tended to increase with decreasing light level. Biomass allocation was independent of light and water for all species except F. thurifera, which showed an increase in root biomass in drought conditions.

Año: 2012

Palabras claves: Atacama desert; Biomass allocation; Centaurea chilensis ; Encelia canescens ; Flourensia thurifera ; Haplopappus parvifolius ; LMR ; Pleocarphus revolutus ; RGR ; Seedling performance; Senna cumingii ; SLA

Leaf morphological and genetic divergence in populations of Drimys (Winteraceae) in Chile.

Autores:

Jara-Arancio, P., Carmona, M., Correa, C., Squeo, F., & Arancio, G.

Resumen:

The genus Drimys is distributed in Chile from semiarid zones to sub-Antarctic forests; there are three species of this tree, D. andina, D. confertifolia and D. winteri, the latter with varieties chilensis and winteri. Northern populations are found in small disjunct natural refuges, specifically mountain cloud forests and the bottom of ravines. The size and continuity of populations are greater in the south, where wetter conditions prevail. Morphological differences between populations have been observed, particularly between the northern populations of Fray Jorge and Talinay. This observation, led to the following questions: a) what is the level of morphological and genetic divergence among the populations of Drimys in Chile? and b) do the populations from Fray Jorge/Talinay, currently classified as D. winteri var. chilensis, differ genetically from the other populations of this variety? To answer these questions, we collected leaf samples from 37 populations of all Chilean Drimys, performed leaf morphology analysis and estimated genetic divergence using RAPD markers. We found a high degree of leaf morphological and genetic divergence between the populations of Fray Jorge/Talinay and the other Chilean species of Drimys. The morphological and genetic divergence among varieties of D. winteri was greater than that among the species of Drimys, which may indicate problems with their taxonomic classification.

Año: 2012

Palabras claves: Drimys; RAPD; Fray Jorge/Talinay; Divergence

Conservación de la biodiversidad en Chile: Nuevos desafíos y oportunidades en ecosistemas terrestres y marinos costeros

Autores:

Jorquera-Jaramillo, C., Vega, J., Aburto, J., Martínez-Tillería, K., F. Leon, M., & A. Pérez, M., Gaymer, C.F., & Squeo, F.A.

Resumen:

La pérdida de la biodiversidad producida por el crecimiento demográfico, la demanda por recursos y la actividad productiva es contradictoria con el reconocimiento de su importancia. En ecosistemas terrestres, el Sistema Nacional de Áreas Protegidas del Estado (SNASPE) contiene cerca del 19 % del territorio de Chile continental; aunque no representa todos los ecosistemas con especies amenazadas, puede ser complementado implementando nuevas áreas protegidas públicas (AP) y privadas (APP). El desarrollo de áreas marinas protegidas (AMP) es incipiente, y algunas iniciativas comparten la responsabilidad de conservación con los usuarios locales. En Chile, un conjunto de reglamentos, normas legales y tratados internacionales promueven distintas oportunidades de conservación en ecosistemas terrestres y marinos costeros, de las cuales emergen nuevos desafíos. Entre estos destacan, estandarizar la clasificación de especies según categorías de conservación en un protocolo internacional y optimizar las metodologías para seleccionar áreas prioritarias, ambos criterios indispensables para decidir qué y dónde conservar. Otro desafío es integrar el valor intrínseco de la biodiversidad con los servicios ecosistémicos que presta para instaurar una cultura participativa. Esto mejoraría la efectividad de las distintas estrategias de protección y uso sustentable de la biodiversidad al incorporar la educación y la participación ciudadana desde una perspectiva biocultural. La educación fomenta la conservación de la naturaleza al hacernos conscientes de nuestro entorno; mientras que la participación involucra a los ciudadanos como un actor más en la toma de decisiones, procurando la aplicación efectiva de las estrategias de conservación de la biodiversidad.

Año: 2012

Palabras claves: áreas marinas protegidas, áreas silvestres protegidas, conservación privada, participación ciudadana.

Latitudinal Patterns in Phenotypic Plasticity and Fitness-Related Traits: Assessing the Climatic Variability Hypothesis (CVH) with an Invasive Plant Species.

Autores:

Molina-Montenegro, M. & Naya, D.

Resumen:

Phenotypic plasticity has been suggested as the main mechanism for species persistence under a global change scenario, and also as one of the main mechanisms that alien species use to tolerate and invade broad geographic areas. However, contrasting with this central role of phenotypic plasticity, standard models aimed to predict the effect of climatic change on species distributions do not allow for the inclusion of differences in plastic responses among populations. In this context, the climatic variability hypothesis (CVH), which states that higher thermal variability at higher latitudes should determine an increase in phenotypic plasticity with latitude, could be considered a timely and promising hypothesis. Accordingly, in this study we evaluated, for the first time in a plant species (Taraxacum officinale), the prediction of the CVH. Specifically, we measured plastic responses at different environmental temperatures (5 and 20°C), in several ecophysiological and fitness-related traits for five populations distributed along a broad latitudinal gradient. Overall, phenotypic plasticity increased with latitude for all six traits analyzed, and mean trait values increased with latitude at both experimental temperatures, the change was noticeably greater at 20° than at 5°C. Our results suggest that the positive relationship found between phenotypic plasticity and geographic latitude could have very deep implications on future species persistence and invasion processes under a scenario of climate change.

Año: 2012

Palabras claves: Biogeography, Latitude, Invasive species, Phenotypes, Climate change, Seeds, Photosynthetic efficiency, Plants.

Estimating rat predation on Humboldt Penguin colonies in north-central Chile.

Autores:

Simeone, A. & Luna-Jorquera, G.

Resumen:

Rats (Rattus spp.) are among the most successful alien predators brought to islands by humans and have had devastating impacts on numerous seabird populations, but studies demonstrating rates of consumption and ecological impacts on penguins are scarce and mostly based on anecdotal evidence. We investigated the effects of rat predation on Humboldt Penguins (Spheniscus humboldti) by simulating unattended clutches with domestic Chicken eggs. Experiments were independently set at two Humboldt Penguin colonies in north (Pájaros Island, 29°S) and central Chile (Algarrobo Island, 33°S). At both colonies, eggs were primarily predated by rats (Rattus rattus = 70.8 % at Pájaros and Rattus norvegicus = 52.6 % at Algarrobo), and secondarily by Kelp Gulls (Larus dominicanus = 9.7 % at Pájaros and 15.8 % at Algarrobo). Significantly more eggs were predated at night. At both colonies, rates of rat and gull predation were highest within the first 12 h. Our study constitutes the first quantification of rats as important alien predators at Humboldt Penguin colonies. We suggest that rat presence at Humboldt Penguin colonies coupled with events that can cause temporary nest abandonment, such as human perturbation and El Niño events, may impact on the species’ breeding success. Eradication of rats is suggested to improve the nesting habitat of this and other threatened and endemic seabird species in the region.

Año: 2012

Palabras claves: Introduced species, Island conservation, Nest attendance, Alien predation, RattusPenguins

Progress in creating a joint research agenda that allows networked long-term socio-ecological research in southern South America: Addressing crucial technological and human capacity gaps limiting its application in Chile and Argentina.

Autores:

Anderson, C., Celis-Diez, J., Bond, B., Martínez Pastur, G., Little, C., & Armesto, J., Ghersa, C., Austin, A., Schlichter, T., Lara, A., Carmona, M., Chaneton, E.J., Gutierrez, J.R.,et al.

Resumen:

Since 1980, more than 40 countries have implemented long-term ecological research (LTER) programs, which have shown their power to affect advances in basic science to understand the natural world at meaningful temporal and spatial scales and also help link research with socially relevant outcomes. Recently, a disciplinary paradigmatic shift has integrated the human dimensions of ecosystems, leading to a long-term socio-ecological research (LTSER) framework to address the world's current environmental challenges. A global gap in LTER/LTSER only exists in the latitudinal range of 40–60°S, corresponding to Argentina and Chile's temperate/sub-Antarctic biome. A team of Chilean, Argentine and US researchers has participated in an ongoing dialogue to define not only conceptual, but also practical barriers limiting LTER/LTSER in southern South America. We have found a number of existing long-term research sites and platforms throughout the region, but at the same time it has been concluded an agenda is needed to create and implement further training courses for students, postdoctoral fellows and young scientists, particularly in the areas of data and information management systems. Since LTER/LTSER efforts in Chile and Argentina are incipient, instituting such courses now will enhance human and technical capacity of the natural science and resource community to improve the collection, storage, analysis and dissemination of information in emerging LTER/LTSER platforms. In turn, having this capacity, as well as the ongoing formalization of LTER/LTSER programs at national levels, will allow the enhancement of crucial collaborations and comparisons between long-term research programs within the region and between hemispheres and continents. For Spanish version of the entire article, see Online Supporting Information (Appendix S1).

Año: 2012

Palabras claves: environmental monitoring; information management; long-term ecological research; LTER; LTSER; science policy; socio-ecology