Pontifical Catholic University of Ecuador

Quito, Ecuador
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Agency: European Commission | Branch: FP7 | Program: CP-FP | Phase: ENV.2007. | Award Amount: 4.20M | Year: 2009

Tropical forests harbour thousands of useful plants which are harvested and used in subsistence economies or traded in local, regional or international markets. The effect on the ecosystem is little known, and the forests resilience is badly understod. Palms are the most useful group of plants in tropical American forests and we will study the effect of extraction and trade of palms on forest in the western Amazon, the Andes and the Pacific lowlands. We will determine the size of the resource by making palm community studies in the different forest formations and determine the number of species and individuals of all palm species. The genetic structure of useful palm species will be studied to determine how much harvesting of the species contributes to genetic erosion of its populations, and whether extraction can be made without harm. We then determine how much palms are used for subsistence purposes by carrying out quantitative, ethnobotanical research in different forest types and then we study trade patterns for palm products from local markets to markets which involve export to other countries and continents. Palm populations are managed in various ways from sustainable ones to destructive harvesting; we will study different ways in which palms are managed and propose sustainable methods to local farmers, local governments, NGOs and other interested parties. Finally we will study national level mechanism that governs extraction, trade and commercialization of palm products, to identify positive and negative policies in relation to resilience of ecosystems and use this to propose sustainable policies to the governments. The results will be diseminated in a variety of ways, depending on need and stake holders, from popular leaflets and videos for farmers, reports for policy makers to scientific publication for the research community. The team behind the proposal represents 10 universities and research institutions in Europe and northwestern South America.

Elinson R.P.,Duquesne University | del Pino E.M.,Pontifical Catholic University of Ecuador
Wiley Interdisciplinary Reviews: Developmental Biology | Year: 2012

The current model amphibian, Xenopus laevis, develops rapidly in water to a tadpole which metamorphoses into a frog. Many amphibians deviate from the X. laevis developmental pattern. Among other adaptations, their embryos develop in foam nests on land or in pouches on their mother's back or on a leaf guarded by a parent. The diversity of developmental patterns includes multinucleated oogenesis, lack of RNA localization, huge non-pigmented eggs, and asynchronous, irregular early cleavages. Variations in patterns of gastrulation highlight the modularity of this critical developmental period. Many species have eliminated the larva or tadpole and directly develop to the adult. The wealth of developmental diversity among amphibians coupled with the wealth of mechanistic information from X. laevis permit comparisons that provide deeper insights into developmental processes. © 2011 Wiley Periodicals, Inc.

Jacobsen D.,Copenhagen University | Dangles O.,Pontifical Catholic University of Ecuador | Dangles O.,French National Center for Scientific Research | Dangles O.,University Paris - Sud
Global Ecology and Biogeography | Year: 2012

Aim To test for a possible effect of environmental harshness on large-scale latitudinal and elevational patterns in taxon richness of macrofauna in arctic and alpine glacier-fed streams. Location Svalbard (79°N), Iceland (65°N), Norway (62°N), Switzerland and Italy (46°N), France (43°N), New Zealand (43°S) and Ecuador (0°), covering an elevational gradient from sea level to 4800m a.s.l. Methods We gathered data from 63 sites along 13 streams and created an index of glacial influence (the glacial index, GI) as an integrative proxy for environmental harshness. The explicative power of the GI, environmental variables, latitude and elevation on taxon richness was tested in generalized linear models. Taxon richness along geographical gradients was analysed at standardized levels of GI in contour plots. Beta diversity and assemblage similarity was calculated at different GI intervals and compared with a null-model. Results Overall, taxon richness decreased exponentially with increased GI (r 2= 0.64), and of all included factors, GI had the highest explicative power. At low values of GI we found that local taxon richness varied along the coupled gradients of latitude and elevation in a hump-shaped manner. However, this pattern disappeared at high values of GI, i.e. when environmental harshness increased. Beta diversity increased, while similarity among assemblages decreased towards high GI values. Main conclusions In our study system, the number of taxa able to cope with the harshest conditions was largely independent of the regional taxon pool, and environmental harshness constituted a 'fixed' constraint for local richness, irrespective of latitude and elevation. Contrary to expectations, we found that beta diversity was highest and similarity lowest among the harshest sites, suggesting that taxon richness was not solely driven by niche selection based on environmental tolerances, but also stochastic ecological drift, leading to dispersal-limited communities. © 2011 Blackwell Publishing Ltd.

Agency: European Commission | Branch: FP7 | Program: CP-SICA | Phase: HEALTH-2007-2.3.4-1 | Award Amount: 3.75M | Year: 2009

The focus of this multidisciplinary proposal is to elucidate the epidemiology of the genetic lineages of T. cruzi, for improved understanding and prevention of Chagas disease. The project will unite skills in genotyping, genomics, genetics and pathogenesis in Europe with considerable compatible skills in South America, and with key research in endemic areas that have distinct characteristics. The proposal is intended to be high impact in terms of both research progress and fostering of collaborative networks. Aim: Elucidate the epidemiology of the genetic lineages of T. cruzi, for improved understanding and prevention of Chagas disease. Technology development: 1. Develop further and apply MLST; PCR-RFLP and MLMT to the analysis of genetic populations of T. cruzi, 2. Sequence the unresolved genome of T. cruzi I, 3. Develop lineage specific diagnosis, 4. Develop an oligochromatography PCR-dipstick procedure for detection of T. cruzi. Molecular epidemiology: 5. Pilot studies of association between genetic lineage, clinical outcome, and prevalence of congenital infection, 6. Map the silvatic vector, silvatic mammal, human and ecological associations of the T. cruzi genotypes IId,e,b,a. 7. Compare lineage specific pathogenesis and transmissibility of congenital infection in a mouse model, and compare lineage susceptibility to drugs in vitro. Population genetics and phylogenetics: 8. Re-evaluate the population genetics and evolution of T. cruzi lineages. International cryobank and database: 9. Establish in South America an accessible, expanded, international cryobank for T. cruzi, 10. Establish a website and database for outputs of the project. The project encompasses the desirable characteristics prescribed by the call, in that they include: genomics/proteomics; effective, innovative relevance to disease, pathogenesis, drugs, interventions; an integrated multidisciplinarity, and capacity building, networking and training in endemic regions.

Tello J.S.,Louisiana State University | Tello J.S.,Pontifical Catholic University of Ecuador | Stevens R.D.,Louisiana State University
Global Ecology and Biogeography | Year: 2012

Aim Richness gradients are frequently correlated with environmental characteristics at broad geographic scales. In particular, richness is often associated with energy and climate, while environmental heterogeneity is rarely its best correlate. These correlations have been interpreted as evidence in favour of environmental determinants of diversity gradients, particularly energy and climate. This interpretation assumes that the expected-by-random correlation between richness and environment is zero, and that this is equally true for all environmental characteristics. However, these expectations might be unrealistic. We investigated to what degree basic evolutionary/biogeographical processes occurring independently of environment could lead to richness gradients that correlate with environmental characteristics by chance alone. Location Africa, Australia, Eurasia and the New World. Methods We produced artificial richness gradients based on a stochastic simulation model of geographic diversification of clades. In these simulations, species speciate, go extinct and expand or shift their distributions independently of any environmental characteristic. One thousand two hundred repetitions of this model were run, and the resulting stochastic richness gradients were regressed against real-world environmental variables. Stochastic species-environment relationships were then compared among continents and among three environmental characteristics: energy, environmental heterogeneity and climate seasonality. Results Simulations suggested that a significant degree of correlation between richness gradients and environment is expected even when clades diversify and species distribute stochastically. These correlations vary considerably in strength; but in the best cases, environment can spuriously account for almost 80% of variation in stochastic richness. Additionally, expected-by-chance relationships were different among continents and environmental characteristics, producing stronger spurious relationships with energy and climate than with heterogeneity. Main conclusions We conclude that some features of empirical species-environment relationships can be reproduced just by chance when taking into account evolutionary/biogeographical processes underlying the construction of species richness gradients. Future tests of environmental effects on richness should consider structure in richness-environment correlations that can be produced by simple evolutionary null models. Research should move away from the naive non-biological null hypotheses that are implicit in traditional statistical tests. © 2011 Blackwell Publishing Ltd.

Menendez-Guerrero P.A.,Pontifical Catholic University of Ecuador | Graham C.H.,State University of New York at Stony Brook
Ecography | Year: 2013

Amphibians are declining at alarming rates worldwide; however, the causes of these declines remain somewhat elusive. Here we evaluated three major threats implicated in declines of populations and disappearance of Ecuadorian amphibians: chytridiomicosis, climate change, and habitat loss. We assessed spatial patterns of these key threats to Ecuadorian amphibians using a multi-species database of endemic frogs along with information on the pathogen's distribution and environmental requirements, species sensitivity to climate change (indirectly based on species geographical distribution and ecological properties) and habitat loss. Our results show that amphibians display a non-random pattern of extinction risk, both geographically and taxonomically. Further, climate change, chytridiomicosis, and their synergetic effects, are likely currently exerting the greatest impact on amphibians in Ecuador, while habitat loss does not seem to be causing precipitous declines. The most threatened species under the IUCN extinction risk categories are exactly those that appear to be the most affected by these threats. By examining multiple potential causes of amphibian threat level in a spatially explicit framework our study provides new insights about what combination of factors are most important in amphibian declines in a tropical diversity hotspot. Further, our approach and conclusions are useful for studying declines in other regions of the world. © 2013 The Authors.

Chris Funk W.,Colorado State University | Caminer M.,Pontifical Catholic University of Ecuador | Ron S.R.,Pontifical Catholic University of Ecuador
Proceedings of the Royal Society B: Biological Sciences | Year: 2012

One of the greatest challenges for biodiversity conservation is the poor understanding of species diversity. Molecular methods have dramatically improved our ability to uncover cryptic species, but the magnitude of cryptic diversity remains unknown, particularly in diverse tropical regions such as the Amazon Basin. Uncovering cryptic diversity in amphibians is particularly pressing because amphibians are going extinct globally at an alarming rate. Here, we use an integrative analysis of two independent Amazonian frog clades, Engystomops toadlets and Hypsiboas treefrogs, to test whether species richness is underestimated and, if so, by how much. We sampled intensively in six countries with a focus in Ecuador (Engystomops: 252 individuals from 36 localities; Hypsiboas: 208 individuals from 65 localities) and combined mitochondrial DNA, nuclear DNA, morphological, and bioacoustic data to detect cryptic species.We found that in both clades, species richness was severely underestimated, with more undescribed species than described species. In Engystomops, the two currently recognized species are actually five to seven species (a 150- 250% increase in species richness); in Hypsiboas, two recognized species represent six to nine species (a 200-350% increase). Our results suggest that Amazonian frog biodiversity is much more severely underestimated than previously thought. © 2012 The Royal Society.

Hietz P.,University of Natural Resources and Life Sciences, Vienna | Valencia R.,Pontifical Catholic University of Ecuador | Joseph Wright S.,Smithsonian Tropical Research Institute
Functional Ecology | Year: 2013

Wood density (WD) affects plant biomechanics, drought and decay resistance. As a consequence, WD is an important functional trait related to plant demography and ecosystem processes, which is also used to estimate tree biomass. Radial variation in WD (changes from the centre of the stem to the cambium) affects the strength of the entire stem, but also reflects any changes in wood functional properties that might occur during a tree's lifetime. To understand how WD and radial WD gradients, which were defined as the slope of the relationship between WD and distance to the centre, are related to demographic traits of species, we investigated WD in 335 tree species from a Panamanian moist forest and 501 species from an Ecuadorian rain forest and radial density gradients in 118 and 186 species, respectively, and compared WD with tree growth, mortality and size. WD was negatively related to tree growth and mortality. WD tended to increase towards the outside in trees with low initial density and to decrease towards the outside in trees with high initial density. Radial WD gradients were largely unrelated to tree size and demographic traits, but some families had higher or lower WD gradients at a given inner WD. Inner WD was by far the best predictor of radial WD gradients (r2 = 0·39 for Panama and 0·45 for Ecuador) and this relationship was indistinguishable between the two rain forests. This suggests a broadly uniform function of WD variation, likely responding to mechanical requirements during ontogeny. We discuss the factors potentially driving radial increases or decreases in WD and suggest ways to elucidate the relative importance of tree mechanics, hydraulic safety or decay resistance. We also discuss that not accounting for radial WD gradients may result in substantial errors in WD of the whole stem and consequently biomass estimates, and recommend sampling density gradients when obtaining density data from tree cores. © 2013 The Authors. Functional Ecology © 2013 British Ecological Society.

Ocana-Mayorga S.,Pontifical Catholic University of Ecuador
PLoS neglected tropical diseases | Year: 2010

Molecular epidemiology at the community level has an important guiding role in zoonotic disease control programmes where genetic markers are suitably variable to unravel the dynamics of local transmission. We evaluated the molecular diversity of Trypanosoma cruzi, the etiological agent of Chagas disease, in southern Ecuador (Loja Province). This kinetoplastid parasite has traditionally been a paradigm for clonal population structure in pathogenic organisms. However, the presence of naturally occurring hybrids, mitochondrial introgression, and evidence of genetic exchange in the laboratory question this dogma. Eighty-one parasite isolates from domiciliary, peridomiciliary, and sylvatic triatomines and mammals were genotyped across 10 variable microsatellite loci. Two discrete parasite populations were defined: one predominantly composed of isolates from domestic and peridomestic foci, and another predominantly composed of isolates from sylvatic foci. Spatial genetic variation was absent from the former, suggesting rapid parasite dispersal across our study area. Furthermore, linkage equilibrium between loci, Hardy-Weinberg allele frequencies at individual loci, and a lack of repeated genotypes are indicative of frequent genetic exchange among individuals in the domestic/peridomestic population. These data represent novel population-level evidence of an extant capacity for sex among natural cycles of T. cruzi transmission. As such they have dramatic implications for our understanding of the fundamental genetics of this parasite. Our data also elucidate local disease transmission, whereby passive anthropogenic domestic mammal and triatomine dispersal across our study area is likely to account for the rapid domestic/peridomestic spread of the parasite. Finally we discuss how this, and the observed subdivision between sympatric sylvatic and domestic/peridomestic foci, can inform efforts at Chagas disease control in Ecuador.

Metz M.R.,University of California at Berkeley | Sousa W.P.,University of California at Berkeley | Valencia R.,Pontifical Catholic University of Ecuador
Ecology | Year: 2010

Negative density-dependent mortality can promote species coexistence through a spacing mechanism that prevents species from becoming too locally abundant. Negative density-dependent seedling mortality can be caused by interactions among seedlings or between seedlings and neighboring adults if the density of neighbors affects the strength of competition or facilitates the attack of natural enemies. We investigated the effects of seedling and adult neighborhoods on the survival of newly recruited seedlings for multiple cohorts of known age from 163 species in Yasuní National Park, Ecuador, an ever-wet, hyper-diverse lowland Amazonian rain forest. At local scales, we found a strong negative impact on firstyear survival of conspecific seedling densities and adult abundance in multiple neighborhood sizes and a beneficial effect of a local tree neighborhood that is distantly related to the focal seedling. Once seedlings have survived their first year, they also benefit from a more phylogenetically dispersed seedling neighborhood. Across species, we did not find evidence that rare species have an advantage relative to more common species, or a community compensatory trend. These results suggest that the local biotic neighborhood is a strong influence on early seedling survival for species that range widely in their abundance and life history. These patterns in seedling survival demonstrate the role of density-dependent seedling dynamics in promoting and maintaining diversity in understory seedling assemblages. The assemblage-wide impacts of species abundance distributions may multiply with repeated cycles of recruitment and density-dependent seedling mortality and impact forest diversity or the abundance of individual species over longer time scales. © 2010 by the Ecological Society of America.

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