Tuesday, June 6, 2017
14:00 - 15:45

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14:15 - 14:30: / 306B EXPERIMENTAL STREAM WARMING EFFECTS ON MAYFLY GROWTH RATES ACROSS ELEVATION GRADIENTS: A TEMPERATE-TROPICAL COMPARISON

6/06/2017  |   14:15 - 14:30   |  306B

EXPERIMENTAL STREAM WARMING EFFECTS ON MAYFLY GROWTH RATES ACROSS ELEVATION GRADIENTS: A TEMPERATE-TROPICAL COMPARISON Climate change is anticipated to impact ecosystems worldwide, yet there is little consensus about how this impact will differ across temperate and tropical ecosystems. The Climate Variability Hypothesis predicts that organisms in temperate regions, which experience seasonal temperature fluctuations, will be less vulnerable to warming compared to their tropical counterparts, where temperatures are more stable. To understand how aquatic organisms respond to stream warming, we used streamside mesocosms to measure growth rates in Baetidae mayflies under elevated temperatures (relative to ambient) in both the Colorado Rockies and the Ecuadorian Andes. Warming effects followed expectations, temperate populations showed faster growth rates at higher temperatures in low elevation, while high elevation Baetidae had the fastest growth rates at low temperature. Overall mayfly growth rates were higher in Colorado than in Ecuador (at similar temperatures). In tropical populations increasing temperature of high elevation Baetidae did not lead to faster growth rates, but did increase mortality rates. These results suggest differential metabolic thresholds for tropical vs temperate mayflies and suggest that tropical populations may be more vulnerable to climate change than their temperate counterparts.

Andrea Landeira-Dabarca (Primary Presenter/Author), Universidad San Francisco de Quito, andrealandab@gmail.com;


Amanda Rugenski ( Co-Presenter/Co-Author), Cornell University , atrugenski@gmail.com;


Andrea C. Encalada ( Co-Presenter/Co-Author), Instituto BIOSFERA, Universidad San Francisco de Quito, Cumbayá, Ecuador Biológicas y Ambientales, Universidad San Francisco de Quito, Cumbaya, Ecuador, aencalada@usfq.edu.ec;


Carla L. Atkinson ( Co-Presenter/Co-Author), University of Alabama, carlalatkinson@gmail.com;


Steven Thomas ( Co-Presenter/Co-Author), School of Natural Resources, University of Nebraska-Lincoln, Lincoln, sthomas5@unl.edu;


LeRoy Poff ( Co-Presenter/Co-Author), Colorado State University, poff@lamar.colostate.edu;


Alexander Flecker ( Co-Presenter/Co-Author), Cornell University, asf3@cornell.edu;


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14:30 - 14:45: / 306B ALTITUDINAL GRADIENTS OF AQUATIC MACROINVERTEBRATE DIVERSITY IN THE CHOCO-ANDEAN REGION OF ECUADOR

6/06/2017  |   14:30 - 14:45   |  306B

ALTITUDINAL GRADIENTS OF AQUATIC MACROINVERTEBRATE DIVERSITY IN THE CHOCO-ANDEAN REGION OF ECUADOR The Choco bioregion is a biodiversity hotspot. However, the status of aquatic populations in this area is poorly understood. In Ecuador, the Andean-Choco area is one of the most modified regions due to deforestation. Environmental gradients and their relationships with aquatic communities are of major importance to understand how human activities affect rivers and the natural processes that sustain biodiversity in these streams. However, these aspects have not been studied in streams of these areas. Our objective was establish the macroinvertebrate diversity along an elevation gradient and the relationships of these with environmental variables in streams of the Ecuadorian Choco. We conducted our study at Mashpi Protected Forest in streams at 3 different altitudes: 1200, 800 and 600 m asl. We sampled all habitats of 3 streams at each altitude. We found both, a strong relationship of assemblages with habitat and strong altitudinal variations for several groups. Our findings show that composition and diversity of aquatic communities change from high and mid elevations to lower elevations. Currently the protected areas concentrate in higher, steeper areas of the basin leaving low gradient streams and its biodiversity out of protection.

Blanca Rios-Touma (Primary Presenter/Author), 1_.Universidad de las Américas- Quito, Ecuador. Facultad de Ingenierías y Ciencias Agropecuarias. Ingeniería Ambiental. Unidad de Biotecnología y Medio Ambiente -BIOMA-Campus Queri, Calle José Queri y Av. Granados. Edificio #8, PB. Quito, Ecuador., briostouma@gmail.com;


Andres Morabowen ( Co-Presenter/Co-Author), 1._Escuela de Ciencias Biológicas, Facultad de Ciencias Exactas y Naturales, Pontificia Universidad Católica del Ecuador, Av. 12 de Octubre 1076 y Roca, Quito, Ecuador. 2._Centro de Investigación de la Biodiversidad y el Cambio Climático, Universidad Tecnológica Indoamérica, Av. Machala y Sabanilla, Quito, Ecuador 170103., andresmorabowen@gmail.com;


Ibon Tobes ( Co-Presenter/Co-Author), Centro de Investigación de la Biodiversidad y el Cambio Climático, Universidad Tecnológica Indoamérica, Av. Machala y Sabanilla, Quito, Ecuador 170103, ibontobes@gmail.com;


Carlos Morochz ( Co-Presenter/Co-Author), Reserva Mashpi, morochz@mashpi.com;


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14:45 - 15:00: / 306B DOES CHIRONOMID SPECIES DIVERSITY DIFFER ACROSS A LAND USE GRADIENT OF ESTUARIES ON THE CARIBBEAN COAST OF COSTA RICA?

6/06/2017  |   14:45 - 15:00   |  306B

Does chironomid species diversity differ across a land use gradient of estuaries on the Caribbean coast of Costa Rica? Sediments and nutrients transported from watersheds converted from forested to agricultural landscapes have consequences on productive estuarine environments. Species-rich and abundant midges are widely used as bioindicators of water quality, since their community composition is influenced by different watershed land uses. We analyzed chironomid species diversity in nine estuaries from watersheds representing a land use gradient from mostly primary and secondary tropical rainforest to largely covered with monoculture plantation agriculture (e.g. banana and/or pineapple). We made Chironomidae surface-floating pupal exuviae collections during July 2012, January 2013, July 2013, and January 2014. We identified 229 species and 69 genera from 17,778 specimens. Estero Negro had the lowest relative abundance (n=474), while Rio Estrella had the highest relative abundance (n=3802). We investigated Chironomidae species diversity through simultaneous univariate analyses of species richness, species evenness, species dominance, species diversity, and generic pollution tolerance. The results of this study will be useful for conservation and management of tropical watersheds and monitoring long-term water quality trends of estuarine and coastal ecosystems.

Petra Kranzfelder (Primary Presenter/Author), University of Minnesota, kranz081@umn.edu;


Leonard C. Ferrington, Jr. ( Co-Presenter/Co-Author), University of minnesota, ferri016@umn.edu;


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15:00 - 15:15: / 306B ECOLOGICAL RESPONSES ALONG A TROPICAL GEOTHERMAL STREAM GRADIENT: EXPLORING POTENTIAL IMPACTS OF CLIMATE CHANGE

6/06/2017  |   15:00 - 15:15   |  306B

ECOLOGICAL RESPONSES ALONG A TROPICAL GEOTHERMAL STREAM GRADIENT: EXPLORING POTENTIAL IMPACTS OF CLIMATE CHANGE Understanding ecological responses to global warming in aquatic environments is an important and urgent challenge. Experimental manipulation of stream temperature under realistic conditions is difficult, consequently our comprehension of the impacts of these changes is still limited. However, using natural temperature gradients could capture the actual complexity of streams while allowing us to assess their ecological responses to contrasting temperature regimes. We used a ‘natural temperature gradient experiment’ in eight high altitude (3900m) tropical geothermal stream sites in northern Ecuador, ranging in temperatures from 5C to 57C, to test the influence of temperature across multiple levels of organization. At each site, we characterized mayfly (Andesiops sp.) body size, invertebrate community composition and litter decomposition rates. Temperature affected mayfly size, with smaller individuals occurring at higher temperatures. Similarly, community evenness was negatively related to temperature with a strong decline in species similarity as temperature differences increase. Higher temperatures lead to higher decomposition rates, except at the very high temperature sites. Our results suggest that higher temperatures will have overarching effects on the structure, composition and function of tropical stream ecosystems.

Andrea C. Encalada (Primary Presenter/Author), Instituto BIOSFERA, Universidad San Francisco de Quito, Cumbayá, Ecuador Biológicas y Ambientales, Universidad San Francisco de Quito, Cumbaya, Ecuador, aencalada@usfq.edu.ec;


Valeria Ochoa-Herrera ( Co-Presenter/Co-Author), Instituto BIOSFERA, Universidad San Francisco de Quito, Cumbayá, Ecuador Biológicas y Ambientales, Universidad San Francisco de Quito, Cumbaya, Ecuador, vochoa@usfq.edu.ec;


Juan M. Guayasamin ( Co-Presenter/Co-Author), Instituto BIOSFERA, Universidad San Francisco de Quito, Cumbayá, Ecuador Biológicas y Ambientales, Universidad San Francisco de Quito, Cumbaya, Ecuador, jmguayasamin@usfq.edu.ec;


Adrian Robalino ( Co-Presenter/Co-Author), Instituto BIOSFERA, Universidad San Francisco de Quito, Cumbayá, Ecuador Biológicas y Ambientales, Universidad San Francisco de Quito, Cumbaya, Ecuador, adrian.robalino@estud.usfq.edu.ec;


Diego Andrade ( Co-Presenter/Co-Author), Instituto BIOSFERA, Universidad San Francisco de Quito, Cumbayá, Ecuador Biológicas y Ambientales, Universidad San Francisco de Quito, Cumbaya, Ecuador, dandradeb@estud.usfq.edu.ec;


Nataly Guevara ( Co-Presenter/Co-Author), Massachusetts Institute of Technology, nguevara@mit.edu;


Olivier Dangles ( Co-Presenter/Co-Author), IRD, Institut de Recherche pour le Développement, UMR EGCE, IRD-247 CNRS-UP Sud-9191, 91198 Gif-sur-Yvette cedex, France, olivier.dangles@ird.fr;


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15:15 - 15:30: / 306B LIFE HISTORIES ALTER DECAPOD DISTRIBUTIONS AND FOODWEB STRUCTURAL CHANGES ALONG ENVIRONMENTAL GRADIENTS IN THE LUQUILLO MOUNTAINS, PUERTO RICO

6/06/2017  |   15:15 - 15:30   |  306B

LIFE HISTORIES ALTER DECAPOD DISTRIBUTIONS AND FOODWEB STRUCTURAL CHANGES ALONG ENVIRONMENTAL GRADIENTS IN THE LUQUILLO MOUNTAINS, PUERTO RICO Differences among decapod species in their life histories influence how many species occur along a gradient from sea level to 1000 m within the Espiritu Santo-Sonadora River network. All the shrimp species migrate as post larvae from estuaries to reproduce in inland rivers. Changes in salinity, water temperature, water depths, slope, and riparian forest composition can affect how many species co-occur. Omnivores include 5 species of Macrobrachium that differ in the distances they move to upslope. Only M. carcinus and M. crenulatum move as high as 450 masl. The most abundant detritivores, Atya lanipes and Xiphocaris elongata, can migrate along the entire gradient but fewer individuals of these species occur at the highest elevations. The reasons for their low numbers and the absence of Macrobrachium at the highest elevations is likely due to a combination of colder water, highly variable pool depths, and the risks associated with longer distance for larvae to travel downstream to the estuaries to complete their development to post larvae. In contrast, non-migratory, omnivorous freshwater crabs (Epilobocera sinuatifrons) carry their young and occur along the entire gradient.

Alan Covich ( Co-Presenter/Co-Author), University of Georgia, alanc@uga.edu;


Todd Crowl ( Co-Presenter/Co-Author), Florida International University, facrowl@gmail.com;


Omar Perez-Reyes (Primary Presenter/Author), University of Puerto Rico- Rio Piedras, macrobrachium@gmail.com;


John Bithorn ( Co-Presenter/Co-Author), University of Puerto Rico, fambithorn@yahoo.com;


Samuel Matta ( Co-Presenter/Co-Author), University of Puerto Rico, samuelmattapr@yahoo.com ;


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