Contributions of carbon and nitrogen from the Andes Mountains to the Amazon River: Evidence from an elevational gradient of soils, plants, and river material

ABSTRACTThe tropical and subtropical Andes have among the highest levels of biodiversity in the world. Understanding the forces that underlie speciation and diversification in the Andes is a major focus of research. Here we tested two hypotheses of species origins in the Andes: 1. Vicariance mediated by orogenesis or shifting habitat distribution. 2. Parapatric diversification along elevational environmental gradients. We also sought insights on the factors that impacted the phylogeography of co-distributed taxa, and the influences of divergent species ecology on population genetic structure. We used phylogeographic and coalescent analyses of nuclear and mitochondrial DNA sequence data to compare genetic diversity and evolutionary history of two frog species: Pleurodema borellii (Family: Leiuperidae, 130 individuals; 20 sites), and Hypsiboas riojanus (Family: Hyllidae, 258 individuals; 23 sites) across their shared range in northwestern Argentina. The two showed concordant phylogeographic structuring, and our analyses support the vicariance model over the elevational gradient model. However, Pleurodema borellii exhibited markedly deeper temporal divergence (≥4 Ma) than H. riojanus (1-2 Ma). The three main mtDNA lineages of P. borellii were nearly allopatric and diverged between 4-10 Ma. At similar spatial scales, differentiation was less in the putatively more habitat-specialized H. riojanus than in the more generalist P. borellii. Similar allopatric distributions of major lineages for both species implies common causes of historical range fragmentation and vicariance. However, different divergence times among clades presumably reflect different demographic histories, permeability of different historical barriers at different times, and/or difference in life history attributes and sensitivities to historical environmental change. Our research enriches our understanding of the phylogeography of the Andes in northwestern Argentina.

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10. Mercury Biomagnification in the Food Web of Tropical Andean Stream

Inquiry@Queen's Undergraduate Research Conference Proceedings ◽

10.24908/iqurcp.7593 ◽

2017 ◽

Author(s):

Sae Yun Kwon

Keyword(s):

Food Web ◽

Gold Mining ◽

Nitrogen Isotope ◽

Andes Mountains ◽

Reproductive Capacity ◽

The Andes ◽

Fish Mucus ◽

13C Isotopes ◽

Natural Emission ◽

Aquatic Food

Increasing release of mercury (Hg) through gold amalgamation, and deforestation have been major concerns in South America. Volcanic sources have also contributed to the natural emission of Hg from the Andes Mountains. Hg not only exhibits biomagnification through aquatic food webs, but it is also neurotoxic and impacts the reproductive capacity of fish. Many studies have assessed Hg biomagnification from areas of gold mining and erosion, but ours is one of the first to examine Hg contamination in a relatively undisturbed area. We used stable nitrogen () and carbon (13C) isotopes to characterize the food web of Río Las Marías, Venezuela, and examine Hg biomagnification trends. Representative fish species from Río Las Marías were collected during January‐February 2004, including detritivores, herbivores, invertivores, parasites, piscivores, and carnivores. Nitrogen isotope results indicate that parasitic catfish (Ochmancanthus alternus) ( = 12.2‰), carnivorous stingrays (Potamotrygon orbignyi) ( =11.4‰) and piscivorous redeye piranhas (Serrasalmus rhombeus) ( =10.9‰) act as top consumers in the web. Detritivorous characins (Steindachnerina argentae) (=6.8‰), and invertivorous knifefish (Apteronotus albifrons) ( =7.9‰) were located at the bottom of the food web. Although the highest value was observed from Ochmancanthus alternus due to its unusual diet of fish mucus, we predict that piscivorous species will exhibit higher Hg concentrations by consuming the muscle tissue where Hg is stored. Our assessment of Hg patterns in Río Las Marías will clarify the extent of Hg contamination in undisturbed areas, and will offer a valuable comparison to rivers that are influenced by gold mining activities.3

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Black carbon transport between Santiago de Chile and glaciers in the Andes Mountains

Atmospheric Environment ◽

10.1016/j.atmosenv.2020.117546 ◽

2020 ◽

Vol 232 ◽

pp. 117546 ◽

Cited By ~ 1

Author(s):

Ernesto Gramsch ◽

Alicia Muñoz ◽

Joakim Langner ◽

Luis Morales ◽

Cristian Soto ◽

...

Keyword(s):

Black Carbon ◽

Andes Mountains ◽

Santiago De Chile ◽

The Andes ◽

Carbon Transport

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Altavelia, a new genus of Neotropical Veliinae (Heteroptera: Gerromorpha: Veliidae), with a key to species and descriptions of four new species from Colombia

Zootaxa ◽

10.11646/zootaxa.4585.2.4 ◽

2019 ◽

Vol 4585 (2) ◽

pp. 295 ◽

Cited By ~ 2

Author(s):

DAN A. POLHEMUS ◽

FREDY MOLANO ◽

IRINA MORALES ◽

FELIPE FERRAZ FIGUEIREDO MOREIRA ◽

CARLA FERNANDA BURGUEZ FLORIANO

Keyword(s):

New Species ◽

Body Shape ◽

New Genus ◽

Antennal Segment ◽

Andes Mountains ◽

Key To Species ◽

The Andes ◽

High Elevations ◽

Female Abdomen

The new genus Altavelia Polhemus & Moreira (Heteroptera: Gerromorpha: Veliidae) includes seven species previously contained in the inveruglas group of Paravelia Breddin, 1898 and four new species from Colombia: A. altoandina Molano & Morales, A. antioquia Molano & Morales, A. montana Molano & Morales, and A. quindiana Molano & Morales. Additionally, A. amoena (Drake, 1957) is synonymized with A. flavomarginata (Hungerford, 1930). The genus is characterized by prominent setal tufts or sclerotized wing-like processes on the male proctiger; elongate body shape with long, slender legs; uniformly blackish forewings; antennal segment I longest; and the female abdomen with tergum VIII deflexed. Species in this genus occur at high elevations in the Andes Mountains with records from 1500 to 3600 m. A key is provided to all 11 species in the genus and new distributional records are presented for A. boliviana (Breddin, 1898), A. columbiensis (Hungerford, 1930), and A. flavomarginata.

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Comparison of 20th century and pre-industrial climate over South America in regional model simulations

Climate of the Past ◽

10.5194/cp-8-1599-2012 ◽

2012 ◽

Vol 8 (5) ◽

pp. 1599-1620 ◽

Cited By ~ 6

Author(s):

S. Wagner ◽

I. Fast ◽

F. Kaspar

Keyword(s):

South America ◽

Greenhouse Gas ◽

Atmospheric Circulation ◽

20Th Century ◽

Climate Model ◽

Regional Climate ◽

Regional Model ◽

Andes Mountains ◽

Southern South America ◽

The Andes

Abstract. In this study, we assess how the anthropogenically induced increase in greenhouse gas concentrations affects the climate of central and southern South America. We utilise two regional climate simulations for present day (PD) and pre-industrial (PI) times. These simulations are compared to historical reconstructions in order to investigate the driving processes responsible for climatic changes between the different periods. The regional climate model is validated against observations for both re-analysis data and GCM-driven regional simulations for the second half of the 20th century. Model biases are also taken into account for the interpretation of the model results. The added value of the regional simulation over global-scale modelling relates to a better representation of hydrological processes that are particularly evident in the proximity of the Andes Mountains. Climatic differences between the simulated PD minus PI period agree qualitatively well with proxy-based temperature reconstructions, albeit the regional model overestimates the amplitude of the temperature increase. For precipitation the most important changes between the PD and PI simulation relate to a dipole pattern along the Andes Mountains with increased precipitation over the southern parts and reduced precipitation over the central parts. Here only a few regions show robust similarity with studies based on empirical evidence. However, from a dynamical point-of-view, atmospheric circulation changes related to an increase in high-latitude zonal wind speed simulated by the regional climate model are consistent with numerical modelling studies addressing changes in greenhouse gas concentrations. Our results indicate that besides the direct effect of greenhouse gas changes, large-scale changes in atmospheric circulation and sea surface temperatures also exert an influence on temperature and precipitation changes in southern South America. These combined changes in turn affect the relationship between climate and atmospheric circulation between PD and PI times and should be considered for the statistical reconstruction of climate indices calibrated within present-day climate data.

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New lectotypifications and new synonyms in Festuca (Poaceae, Pooideae, Loliinae) from the Central Andes

Phytotaxa ◽

10.11646/phytotaxa.247.4.2 ◽

2016 ◽

Vol 247 (4) ◽

pp. 247 ◽

Cited By ~ 4

Author(s):

JUAN C. OSPINA

Keyword(s):

Morphological Characters ◽

Central Andes ◽

Andes Mountains ◽

Valid Species ◽

Second Step ◽

New Synonyms ◽

The Andes ◽

New Synonym ◽

Differential Characters ◽

Anatomical Characters

New lectotypifications and new synonyms are provided as a result of a systematic study of the genus Festuca from the Central Andes. In the Andes mountains of Argentina, Bolivia, and Chile, several species of Festuca are dominant components of the grasslands and high Andean steppes. Festuca circinata and F. dissitiflora occur in this area and were described based on morphological characters. Some authors have considered F. circinata as a valid species while others have treated it as a synonym of F. dissitiflora, together with F. dissitiflora var. loricata , F. dissitiflora var. villipalea, and F. erecta var. aristulata. In this study, a review of the taxonomy and nomenclature of F. castilloniana, F. circinata, and F. potosiana was performed, and their morphological and anatomical characters were compared with F. dissitiflora. Based on morphoanatomical and epidermal characters, this study contributes to the delimitation of F. circinata and F. dissitiflora. Nomenclatural notes and new anatomical and epidermal descriptions are included for these species. Differential characters between F. circinata and F. dissitiflora are discussed and F. circinata is restored as a valid species for Argentina. Festuca castilloniana and F. potosiana are synonymised under F. dissitiflora. Festuca dissitiflora var. loricata, F. dissitiflora var. villipalea, and F. erecta var. aristulata are excluded from the synonymy of F. dissitiflora and it is suggested that these names should be subordinate under F. fiebrigii. Festuca stuckertii is proposed as a new synonym of F. uninodis. Lectotypes are designated for the names F. argentinensis, F. dissitiflora, F. nemoralis and F. parodii, and second-step lectotypes are designated for the names F. circinata and F. ampliflora.

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