49 research outputs found
Insectos de importancia económica y sanitaria: La cuncuna espinuda, una oruga defoliadora en los bosques de Patagonia
No full textLa cuncuna espinuda es una polilla nativa del sur de Argentina y Chile que, en su estado de oruga y ante eventos de crecimiento poblacional exponencial, causa las defoliaciones más extensas documentadas en los bosques Andino Patagónicos. Si bien actualmente no causa mortalidad masiva de los árboles que ataca, esta situación podría cambiar debido al calentamiento global.Fil: Paritsis, Juan. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Instituto de Investigaciones en Biodiversidad y Medioambiente. Universidad Nacional del Comahue. Centro Regional Universidad Bariloche. Instituto de Investigaciones en Biodiversidad y Medioambiente; Argentina. Universidad Nacional del Comahue. Centro Regional Universitario Bariloche. Laboratorio de Ecotono; Argentin
Ormiscodes outbreaks dynamics: Impacts and perspectives in a warming world
No full textChanges in the frequency and magnitude of insect outbreak appear to be occurring worldwide, but research has been mainly focused on northern hemisphere forests. In the temperate forests of the southern Andes, Nothofagus tree species experience severe defoliation caused by Ormiscodes caterpillars (Lepidoptera: Saturniidae). Current impacts of defoliation on tree health are relatively low and short term. Although relationships between Ormiscodes outbreaks and climate proved to be complex, defoliation events are generally associated with drier and warmer than average growing seasons. However, these probable climatic influences on outbreak occurrence are contingent on the sensitivity of Nothofagus and Ormiscodes to temperature and precipitation along environmental gradients. Relationships between Ormiscodes outbreaks and climate suggest that under predicted warmer and drier climates in the twenty-first century, these defoliator outbreaks may become more frequent and contribute to future forest decline in Nothofagus forests.Fil: Paritsis, Juan. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Instituto de Investigaciones en Biodiversidad y Medioambiente. Universidad Nacional del Comahue. Centro Regional Universidad Bariloche. Instituto de Investigaciones en Biodiversidad y Medioambiente; Argentin
Cambio climático e insectos herbívoros
No full textFil: Garibaldi, Lucas Alejandro. Universidad Nacional de Río Negro. Sede Andina. Río Negro. Argentina. - Universidad de Buenos Aires. Facultad de Agronomía. Buenos Aires, Argentina.Fil: Paritsis, Juan. Universidad Nacional del Comahue. Instituto de Investigaciones en Biodiversidad y Medioambiente. Laboratorio Ecotono. Argentina. - CONICET - Universidad Nacional del Comahue. Instituto de Investigaciones en Biodiversidad y Medioambiente. Laboratorio Ecotono. Argentina.El aumento de la temperatura del planeta asociado con el cambio climático global afecta a los insectos que se alimentan de plantas en los bosques de todo el mundo, entre ellos los andino - patagónicos, pero hay diferencias entre las regiones templadas y los trópicos.tbls., grafs., fot., mapa
Guía de Identificación de Insectos de la Patagonia: Zona Andina y alrededores
No full textEn la Patagonia habitan numerosas especies de insectos únicas en el mundo. Esta guía será una ayuda indispensable para el reconocimiento de más de 110 especies comunes o llamativas en esta región. Mediante fotografías y descripciones de las especies y sus hábitos aprenderás a disfrutar del increíble mundo de los insectos de la Patagonia.Fil: Paritsis, Juan. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Instituto de Investigaciones en Biodiversidad y Medioambiente. Universidad Nacional del Comahue. Centro Regional Universidad Bariloche. Instituto de Investigaciones en Biodiversidad y Medioambiente; ArgentinaFil: Kun, Marcelo Eduardo. Universidad Nacional del Comahue. Centro Regional Universitario Bariloche; ArgentinaFil: Quintero, Carolina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Instituto de Investigaciones en Biodiversidad y Medioambiente. Universidad Nacional del Comahue. Centro Regional Universidad Bariloche. Instituto de Investigaciones en Biodiversidad y Medioambiente; Argentin
Cambio climático e insectos herbívoros
No full textFil: Garibaldi, Lucas Alejandro. Universidad Nacional de Río Negro (UNRN). Sede Andina; Argentina.Fil: Paritsis, Juan. Universidad Nacional del Comahue. Centro Regional Universitario Bariloche. INIBIOMA-CONICET. Laboratorio Ecotono; Argentina.trueLos insectos y las plantas ocupan un lugar central en el funcionamiento de los ecosistemas terrestres. Los insectos conforman la mayoría de las especies de animales del planeta, y ascienden aproximadamente a la mitad de todas las especies conocidas de seres vivos, incluidas las plantas y los microorganismos. Las plantas, por su lado, aunque menos diversas, representan en peso la mayor cantidad de la biomasa viva de la Tierra. Aproximadamente la mitad de las especies de insectos dependen de tejidos vegetales vivos para su supervivencia, y en los ecosistemas silvestres consumen en promedio alrededor del 10% de la producción anual de biomasa vegetal, proporción que es mucho más alta en los ambientes agrícolas, a pesar del uso de plaguicidas y de otras medidas habituales de control. Sin embargo, esos valores medios ocultan grandes variaciones, tanto entre sitios como entre años, y lo mismo en ambientes silvestres que en agrícolas. ¿Por qué en algunos sitios prácticamente no hay insectos herbívoros mientras que en otros son extremadamente abundantes? ¿Por qué en algunos años hay plagas que destruyen íntegramente las cosechas, o consumen todas las hojas de bosques, mientras que en otros años, en los mismos sitios, esas plagas están ausentes? ¿Afecta el cambio climático global la actividad de esos organismos? ¿Cómo lo hace
Spatiotemporal variability of horsefly abundance and richness in northwestern Patagonia = Variabilidad espaciotemporal de abundancia y riqueza de tábanos en el noroeste de la Patagonia
No full textHorseflies (Diptera: Tabanidae) are a nuisance to humans and livestock in many regions around the world including Patagonia, Argentina. Although in this region there are no records of Tabanidae species as vectors of disease-causing microorganisms to livestock, it is suspected that they are disease vectors in other Argentinean regions adjacent to Patagonia. There are several studies on the taxonomy and morphology of Tabanidae in Patagonia, but little is known on their ecology and behavior in this region. An initial assessment was conducted aimed at describing the fluctuations in horsefly populations/activity throughout the flight season and among different locations in northwestern Patagonia using Nzi traps. Four species were captured throughout the sampling season totalling 483 individuals and most individuals (87 %) belonged to the species Dasybasis antilope Brèthes. Species phenology, abundance and composition were strongly influenced by site characteristics (e.g. vegetation, livestock) and less clearly by ambient temperature. The current study is an initial contribution toward understanding spatiotemporal fluctuations in horsefly populations and activity in the Argentinean Patagonia.Los tábanos (Diptera: Tabanidae) son una molestia para los humanos y el ganado en muchas regiones del mundo, incluida la Patagonia Argentina. Aunque en esta región no hay registros de especies de Tabanidae como vectores de microorganismos patógenos al ganado, se sospecha que éstos son vectores de enfermedades en otras regiones argentinas adyacentes a la Patagonia. Existen varios estudios sobre la taxonomía y morfología de Tabanidae en la Patagonia, pero poco se sabe sobre su ecología y comportamiento en esta región. Se realizó una evaluación inicial destinada a describir las fluctuaciones en las poblaciones/actividad de tábanos a lo largo de la temporada de vuelo y entre
diferentes sitios en el noroeste de la Patagonia utilizando trampas Nzi. Se capturaron cuatro especies a lo largo de la temporada de muestreo con un total de 483 individuos. La mayoría de los individuos (87 %)
pertenecían a la especie Dasybasis antilope Brèthes. La fenología, abundancia y composición de las especies estuvieron fuertemente influenciadas por las características del sitio (e.g. vegetación, ganado) y
menos claramente por la temperatura ambiente. El presente estudio es una contribución inicial hacia la comprensión de las fluctuaciones espaciotemporales en las poblaciones y la actividad de tábanos en la Patagonia Argentina.EEA BarilocheFil: Paritsis, Juan. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones en Biodiversidad y Medioambiente. Laboratorio de Investigación en Ecología de Bosques; ArgentinaFil: Paritsis, Juan. Universidad Nacional del Comahue. Instituto de Investigaciones en Biodiversidad y Medioambiente. Laboratorio de Investigación en Ecología de Bosques; ArgentinaFil: Martinez Von Ellrich, Andres Santiago. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Bariloche. Instituto de Investigaciones Forestales y Agropecuarias Bariloche; ArgentinaFil: Martinez Von Ellrich, Andres Santiago. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones Forestales y Agropecuarias Bariloche; Argentin
How are monospecific stands of invasive trees formed? Spatio-temporal evidence from Douglas fir invasions
No full textInvasive plant species can produce many impacts on native communities. Impacts can be especially important when the non-natives reach high densities, producing monospecific stands where little grows besides the non-native species. We propose three basic pathways by which monospecific stands of invasive tree species are formed: (i) gradually from the propagule source, (ii) via synchronous establishment and (iii) following several pulses of synchronous establishment. Different patterns can produce different impacts through time and may require different management techniques. This study aims to further our understanding of how monotypic stands of invasive species arise. We documented how monospecific stands are formed during invasion processes by studying patterns of spatio-temporal establishment of several monospecific stands of Douglas fir in Patagonia. We obtained data on tree density, year of establishment, size, distance to the seed source and other related measurements for this tree species along transects from the original seed source (80-year-old plantations) to the edge of the monospecific stand. We found that these monospecific stands arose in a more complex way than expected. While individuals established on average simultaneously over all distances from the seed source, there was substantial variation in time of establishment at all distances. Also, tree density was higher near the source than far from it. Different factors can account for the observed pattern of tree establishment, including seed dispersal, mycorrhizal facilitation and herbivory. Our results elucidate the complexities of spatio-temporal pattern of formation in monospecific stands. This understanding can improve management strategies and techniques for this invasion and other plant invasions in different regions.Fil: Nuñez, Martin Andres. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Instituto de Investigaciones en Biodiversidad y Medioambiente. Universidad Nacional del Comahue. Centro Regional Universidad Bariloche. Instituto de Investigaciones en Biodiversidad y Medioambiente; ArgentinaFil: Paritsis, Juan. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Instituto de Investigaciones en Biodiversidad y Medioambiente. Universidad Nacional del Comahue. Centro Regional Universidad Bariloche. Instituto de Investigaciones en Biodiversidad y Medioambiente; Argentin
Positive fire feedbacks contribute to shifts from Nothofagus pumilio forests to fire-prone shrublands in Patagonia
No full textQuestion: Under climate change and increased ignitions by humans, burning of forests in which severe fires were naturally infrequent may result in environmental changes that increase the probability that they will burn again. On the eastern slopes of the northern Patagonian Andes, after fire-resistant Nothofagus pumilio forests burn they are typically replaced by fire-prone shrublands dominated by resprouting shrubs. We examine fuel properties and microclimatic conditions at the community level as potential fire feedback mechanisms mediating switches from fire-resistant N. pumilio forests to fire-prone shrublands.
Location: Northwestern Chubut province, Patagonia, Argentina.
Methods: We characterized the volume and vertical distribution of fine fuels, understorey woody and semi-woody plant composition, stand structure and microclimatic conditions in unburned and burned N. pumilio forest and shrublands 14–29 yr after severe fire.
Results: Fuel amount and arrangement in unburned N. pumilio forests are unfavourable for fire activity compared with post-fire N. pumilio forests and shrublands. Unburned N. pumilio forests presented vertical discontinuities in fine fuel distribution and lesser amounts of fine fuels near the ground in comparison to fuels in shrublands. Floristic understorey composition of unburned and burned shrublands was very similar, while composition of unburned and burned N. pumilio forests showed clear differences. Additionally, microclimatic conditions following burning of N. pumilio forests and shrublands were signifi- cantly warmer and drier than in the unburned forest, and more frequently exceeded thresholds associated with fire activity in this region.
Conclusions: Positive feedbacks from initial burning of otherwise fire-resistant N. pumilio forest will accelerate the rate of fire-induced conversion of forests to non-forest assemblages. Once transformed to the alternative state of shrublands, return to a forest cover is unlikely due to increased probability of burning in shrublands, as well as the unfavourable effects of warmer and drier conditions on tree establishment.Fil: Paritsis, Juan. Universidad Nacional del Comahue. Centro Regional Universitario Bariloche. Laboratorio de Ecotono; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Patagonia Norte. Instituto de Investigación en Biodiversidad y Medioambiente; ArgentinaFil: Veblen, Thomas T.. State University Of Colorado-boulder; Estados UnidosFil: Holz, Andrés. University Of Tasmania; Australia. Portland State University; Estados Unido
Temperature and host plant species affect the performance and immunocompetence of an outbreak defoliator in northwestern Patagonia
No full text1. Rising temperature has been associated with increased occurrence of herbivorous insect outbreaks, explained by several direct and indirect mechanisms. Whereas natural enemies are known key drivers of forest-defoliating insect cycles, indirect effects of temperature on insect’s ability to defend against pathogens and parasitoids (e.g., immunocompetence), as well as the interaction with other mechanisms (e.g., diet), remain less explored. The aim of this study is to evaluate the effect of temperature and diet on the performance and immune response of the model lepidopteran system Ormiscodes amphimone (Saturniidae) and its host plants Nothofagus spp. (Nothofagaceae).
2. Larvae of O. amphimone were reared under two temperature conditions (ambient 18:6 C and warmed, 21:6 C; light: dark, 14:10 h) and on leaves of two of their preferred Nothofagus host plants, which vary in quality (lower N. antarctica–higher N. pumilio). We measured developmental time, female pupal weight as a proxy of fitness, relative growth rate, nutritional indices and melanisation of a monofilament as a proxy of immune response.
3. Results showed that an average rise of 2 C favours larval immunocompetence, potentially decreasing mortality exerted by parasitoids. Moreover, depending on diet, an increase in temperature can either maintain (on more nutritious N. pumilio leaves) or enhance (on less nutritious N. antarctica leaves) larval nutritional efficiency, performance and female pupal weight.
4. Hence, an increase in temperature could enhance O. amphimone population growth, through attenuating differences caused by diet and enhancing immunocompetence, favouring outbreak frequency, severity and area.Estación Experimental Agropecuaria BarilocheFil: Serra, Maria Noel. Universidad Nacional del Comahue; ArgentinaFil: Serra, Maria Noel. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Instituto de Investigaciones en Biodiversidad y Medioambiente. Laboratorio Ecotono; ArgentinaFil: Quintero, Carolina. Universidad Nacional del Comahue; ArgentinaFil: Quintero, Carolina. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Instituto de Investigaciones en Biodiversidad y Medioambiente. Laboratorio Ecotono; ArgentinaFil: Rodriguez Cabal, Mariano Alberto. Universidad Nacional del Comahue; ArgentinaFil: Rodriguez Cabal, Mariano Alberto. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Instituto de Investigaciones en Biodiversidad y Medioambiente. Grupo de Ecología de Invasiones; ArgentinaFil: Martinez Von Ellrich, Andres Santiago. Instituto Nacional de Tecnologia Agropecuaria (INTA). Estacion Experimental Agropecuaria Bariloche; ArgentinaFil: Martinez Von Ellrich, Andres Santiago. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Instituto de Investigaciones Forestales y Agropecuarias Bariloche; ArgentinaFil: Paritsis, Juan. Universidad Nacional del Comahue; ArgentinaFil: Paritsis, Juan. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Instituto de Investigaciones en Biodiversidad y Medioambiente. Laboratorio Ecotono; Argentin
Habitat distribution modeling reveals vegetation flammability and land use as drivers of wildfire in SW Patagonia
No full textDespite important recent advances in modeling current and future global fire activity in relation to biophysical predictors there remain important uncertainties about finer-scale spatial heterogeneity of fire and especially about human influences which are typically assessed at coarse-spatial resolutions. The purpose of the current study is to quantify the influence of biophysical and anthropogenic variables on the spatial distribution of wildfire activity between 1984 and 2010 over an extensive southern Patagonian-Andean region from ca. 43° to 53° S extending from coastal rainforests to xeric woodland and steppe.
We used satellite imagery to map all detectable fires > 5 ha from 1984 to 2010 in four study areas (each of 13,100 to 36,635 km2) and field checked 65 of these burns for accuracy of burned vegetation class and fire perimeters. Then, we used the MaxEnt modeling technique to assess the relationships of wildfire distributions to biophysical and human environmental variables in each of the four regions. The 232 fires > 5 ha mapped in the four study areas accounted for an area of 1,314 km2 indicating that at least 1.8% of the total area burned between 1984 and 2010. In general, areas with intermediate productivity levels (e.g. shrublands) have higher fire probability compared with areas of low and high productivity levels, such as steppe and wet forests, respectively. There is a marked contrast in the flammability of broad vegetation classes in determining fire activity at a regional scale, as well as a strong spatial relationship of wildfires to anthropogenic variables. The juxtaposition of fire-resistant tall forests with fire-prone shrublands and woodlands creates the potential for positive feedbacks from human-set fires to gradually increase the flammability of extensive landscapes through repeated burning. Distance to roads and settlements were also strong predictors, suggesting that fire in all regions is ignition-limited. However, these anthropogenic predictors influenced probability of fire differently among study regions depending on their main land-use practices and their past and present socioeconomic contexts.Fil: Paritsis, Juan. State University Of Colorado-boulder; Estados Unidos. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Patagonia Norte. Instituto de Investigación en Biodiversidad y Medioambiente; ArgentinaFil: Holz, Andrés. State University Of Colorado-boulder; Estados UnidosFil: Veblen, Thomas T.. State University Of Colorado-boulder; Estados UnidosFil: Kitzberger, Thomas. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Patagonia Norte. Instituto de Investigación en Biodiversidad y Medioambiente; Argentin
