scholarly journals Distribution and habitat use of Neotropical migrant landbirds in the Amazon basin and Andes

1995 ◽  
Vol 5 (2-3) ◽  
pp. 305-323 ◽  
Author(s):  
S. K. Robinson ◽  
J. W. Fitzpatrick ◽  
J. Terborgh
Keyword(s):  
South America ◽  
Amazon Basin ◽  
Migratory Birds ◽  
Primary Forest ◽  
Western Slope ◽  
Neotropical Migrant ◽  
Dendroica Cerulea ◽  
The Andes ◽  
Negative Effect ◽  
The Impact

SummaryWe documented the geographical distributions and habitat selection of Neotropical migrants in South America along a successional gradient in the lowlands of Amazonian Peru, and along elevational gradients in the Andes of south-eastern Peru and of eastern and western Ecuador. Most of the 30 species of northern migrants that regularly winter in South America appear to be concentrated in the western edge of the Amazon basin and on the lower slopes (2,000 m) of the Andes. Migrants in a lowland site were documented more often in early successional habitats than in primary forest, and no species were confined to mature forest habitats. The number of species and relative abundance of migrants in primary forest, however, increased with elevation up to about 1,200 m and decreased above that elevation. Several species (Contopus borealis, Dendroica cerulea and Wilsonia canadensis) were largely confined to primary forest in the 1,000-2,000 m elevational zones in both Peru and Ecuador. Migrants on the western slope of the Ecuadorean Andes included several species that primarily winter further north. In general, the species richness of migrants and residents was inversely correlated, both on a biogeographical and a local scale. Migratory birds are most likely to be adversely affected by deforestation of the lower slopes of the Andes, which is proceeding at a rapid pace. The impact of human alterations of Amazonian forests will be greater on resident than on migratory birds. The loss of mid-successional lowland forests, however, might have a negative effect on several species.

scholarly journals Future climate change will impact the size and location of breeding and wintering areas of migratory thrushes in South America

The Condor ◽  
2021 ◽  
Author(s):  
Natália Stefanini Da Silveira ◽  
Maurício Humberto Vancine ◽  
Alex E Jahn ◽  
Marco Aurélio Pizo ◽  
Thadeu Sobral-Souza
Keyword(s):  
Climate Change ◽  
South America ◽  
Migratory Birds ◽  
Global Climate ◽  
Future Climate ◽  
Future Climate Change ◽  
Ecological Niche Models ◽  
Global Climate Changes ◽  
The Andes ◽  
Wintering Areas

Abstract Bird migration patterns are changing worldwide due to current global climate changes. Addressing the effects of such changes on the migration of birds in South America is particularly challenging because the details about how birds migrate within the Neotropics are generally not well understood. Here, we aim to infer the potential effects of future climate change on breeding and wintering areas of birds that migrate within South America by estimating the size and elevations of their future breeding and wintering areas. We used occurrence data from species distribution databases (VertNet and GBIF), published studies, and eBird for 3 thrush species (Turdidae; Turdus nigriceps, T. subalaris, and T. flavipes) that breed and winter in different regions of South America and built ecological niche models using ensemble forecasting approaches to infer current and future potential distributions throughout the breeding and wintering periods of each species. Our findings point to future shifts in wintering and breeding areas, mainly through elevational and longitudinal changes. Future breeding areas for T. nigriceps, which migrates along the Andes Mountains, will be displaced to the west, while breeding displacements to the east are expected for the other 2 species. An overall loss in the size of future wintering areas was also supported for 2 of the species, especially for T. subalaris, but an increase is anticipated for T. flavipes. Our results suggest that future climate change in South America will require that species shift their breeding and wintering areas to higher elevations in addition to changes in their latitudes and longitude. Our findings are the first to show how future climate change may affect migratory birds in South America throughout the year and suggest that even closely related migratory birds in South America will be affected in different ways, depending on the regions where they breed and overwinter.

Impact of strong El Niño events on river discharge in South America

2021 ◽  
Author(s):  
Markus Deppner ◽  
Bedartha Goswami
Keyword(s):  
Machine Learning ◽  
Missing Data ◽  
South America ◽  
River Discharge ◽  
Amazon Basin ◽  
Missing Values ◽  
Southern Oscillation ◽  
Enso Events ◽  
Streamflow Data ◽  
The Impact

<p>The impact of the El Niño Southern Oscillation (ENSO) on rivers are well known, but most existing studies involving streamflow data are severely limited by data coverage. Time series of gauging stations fade in and out over time, which makes hydrological large scale and long time analysis or studies of rarely occurring extreme events challenging. Here, we use a machine learning approach to infer missing streamflow data based on temporal correlations of stations with missing values to others with data. By using 346 stations, from the “Global Streamflow Indices and Metadata archive” (GSIM), that initially cover the 40 year timespan in conjunction with Gaussian processes we were able to extend our data by estimating missing data for an additional 646 stations, allowing us to include a total of 992 stations. We then investigate the impact of the 6 strongest El Niño (EN) events on rivers in South America between 1960 and 2000. Our analysis shows a strong correlation between ENSO events and extreme river dynamics in the southeast of Brazil, Carribean South America and parts of the Amazon basin. Furthermore we see a peak in the number of stations showing maximum river discharge all over Brazil during the EN of 1982/83 which has been linked to severe floods in the east of Brazil, parts of Uruguay and Paraguay. However EN events in other years with similar intensity did not evoke floods with such magnitude and therefore the additional drivers of the 1982/83  floods need further investigation. By using machine learning methods to infer data for gauging stations with missing data we were able to extend our data by almost three-fold, revealing a possible heavier and spatially larger impact of the 1982/83 EN on South America's hydrology than indicated in literature.</p>

scholarly journals Parallel diversifications of Cremastosperma and Mosannona (Annonaceae), tropical rainforest trees tracking Neogene upheaval of the South American continent

2017 ◽  
Author(s):  
Michael D. Pirie ◽  
Paul J. M. Maas ◽  
Rutger A. Wilschut ◽  
Heleen Melchers-Sharrott ◽  
Lars W. Chatrou
Keyword(s):  
South America ◽  
Biological Diversity ◽  
Molecular Dating ◽  
Niche Modelling ◽  
Apparent Contradiction ◽  
Independent Evidence ◽  
Humid Forest ◽  
The Andes ◽  
High Dispersal ◽  
The Impact

AbstractThis preprint has been reviewed and recommended by Peer Community In Evolutionary Biology (http://dx.doi.org/10.24072/pci.evolbiol.100033). Much of the immense present day biological diversity of Neotropical rainforests originated from the Miocene onwards, a period of geological and ecological upheaval in South America. We assess the impact of the Andean orogeny, drainage of lake Pebas, and closure of the Panama Isthmus on two clades of trees (Cremastosperma, c. 31 spp.; and Mosannona, c. 14 spp.; both Annonaceae) found in humid forest distributed across the transition zones between the Andes and Western (lowland) Amazonia and between Central and South America. We inferred phylogenies based on c. 80% of recognised species of each clade using plastid and nuclear encoded sequence markers, revealing similar patterns of geographically restricted clades. Using molecular dating we showed that diversifications in the different areas occurred in parallel, with timing consistent with Andean vicariance and Central American geodispersal. In apparent contradiction of high dispersal abilities of rainforest trees, Cremastosperma clades within Amazonia are also geographically restricted, with a southern/montane clade that appears to have diversified along the foothills of the Andes sister to one of more northern/lowland species that diversified in a region once inundated by lake Pebas. Ecological niche modelling approaches show phylogenetically conserved niche differentiation, particularly within Cremastosperma. Niche similarity and recent common ancestry of Amazon and Guianan Mosannona species contrasts with dissimilar niches and more distant ancestry of Amazon, Venezuelan and Guianan species of Cremastosperma suggesting that this element of the similar patterns of disjunct distributions in the two genera is instead a biogeographic parallelism, with differing origins. The results provide further independent evidence for the importance of the Andean orogeny, the drainage of Lake Pebas, and the formation of links between South and Central America in the evolutionary history of Neotropical lowland rainforest trees.

scholarly journals On the ability of a global atmospheric inversion to constrain variations of CO<sub>2</sub> fluxes over Amazonia

2015 ◽  
Vol 15 (2) ◽  
pp. 1915-1952
Author(s):  
L. Molina ◽  
G. Broquet ◽  
P. Imbach ◽  
F. Chevallier ◽  
B. Poulter ◽  
...  
Keyword(s):  
South America ◽  
Amazon Basin ◽  
Transport Model ◽  
Net Ecosystem Exchange ◽  
Extreme Rainfall ◽  
Atmospheric Composition ◽  
Interannual Variations ◽  
The Impact ◽  
Seasonal And Interannual Variations ◽  
Atmospheric Inversion

Abstract. The exchanges of carbon, water, and energy between the atmosphere and the Amazon Basin have global implications for current and future climate. Here, the global atmospheric inversion system of the Monitoring of Atmospheric Composition and Climate service (MACC) was used to further study the seasonal and interannual variations of biogenic CO2 fluxes in Amazonia. The system assimilated surface measurements of atmospheric CO2 mole fractions made over more than 100 sites over the globe into an atmospheric transport model. This study added four surface stations located in tropical South America, a region poorly covered by CO2 observations. The estimates of net ecosystem exchange (NEE) optimized by the inversion were compared to independent estimates of NEE upscaled from eddy-covariance flux measurements in Amazonia, and against reports on the seasonal and interannual variations of the land sink in South America from the scientific literature. We focused on the impact of the interannual variation of the strong droughts in 2005 and 2010 (due to severe and longer-than-usual dry seasons), and of the extreme rainfall conditions registered in 2009. The spatial variations of the seasonal and interannual variability of optimized NEE were also investigated. While the inversion supported the assumption of strong spatial heterogeneity of these variations, the results revealed critical limitations that prevent global inversion frameworks from capturing the data-driven seasonal patterns of fluxes across Amazonia. In particular, it highlighted issues due to the configuration of the observation network in South America and the lack of continuity of the measurements. However, some robust patterns from the inversion seemed consistent with the abnormal moisture conditions in 2009.

Atmospheric Circulation and Climatic Variability

2007 ◽  
Author(s):  
René D. Garreaud ◽  
Patricio Aceituno
Keyword(s):  
South America ◽  
Atmospheric Circulation ◽  
Amazon Basin ◽  
Southern Oscillation ◽  
Climatic Variability ◽  
Climatic Conditions ◽  
The West ◽  
The Andes ◽  
Weather And Climate ◽  
Atmospheric Phenomena

Regional variations in South America’s weather and climate reflect the atmospheric circulation over the continent and adjacent oceans, involving mean climatic conditions and regular cycles, as well as their variability on timescales ranging from less than a few months to longer than a year. Rather than surveying mean climatic conditions and variability over different parts of South America, as provided by Schwerdtfeger and Landsberg (1976) and Hobbs et al. (1998), this chapter presents a physical understanding of the atmospheric phenomena and precipitation patterns that explain the continent’s weather and climate. These atmospheric phenomena are strongly affected by the topographic features and vegetation patterns over the continent, as well as by the slowly varying boundary conditions provided by the adjacent oceans. The diverse patterns of weather, climate, and climatic variability over South America, including tropical, subtropical, and midlatitude features, arise from the long meridional span of the continent, from north of the equator south to 55°S. The Andes cordillera, running continuously along the west coast of the continent, reaches elevations in excess of 4 km from the equator to about 40°S and, therefore, represents a formidable obstacle for tropospheric flow. As shown later, the Andes not only acts as a “climatic wall” with dry conditions to the west and moist conditions to the east in the subtropics (the pattern is reversed in midlatitudes), but it also fosters tropical-extratropical interactions, especially along its eastern side. The Brazilian plateau also tends to block the low-level circulation over subtropical South America. Another important feature is the large area of continental landmass at low latitudes (10°N–20°S), conducive to the development of intense convective activity that supports the world’s largest rain forest in the Amazon basin. The El Niño–Southern Oscillation phenomenon, rooted in the ocean-atmosphere system of the tropical Pacific, has a direct strong influence over most of tropical and subtropical South America. Similarly, sea surface temperature anomalies over the Atlantic Ocean have a profound impact on the climate and weather along the eastern coast of the continent. In this section we describe the long-term annual and monthly mean fields of several meteorological variables.

Extreme Summer Convection in South America

2010 ◽  
Vol 23 (14) ◽  
pp. 3761-3791 ◽  
Author(s):  
Ulrike Romatschke ◽  
Robert A. Houze
Keyword(s):  
South America ◽  
Amazon Basin ◽  
Three Dimensional ◽  
Tropical Rainfall Measuring Mission ◽  
Central Andes ◽  
South Atlantic Convergence Zone ◽  
Reanalysis Data ◽  
The North ◽  
The Andes ◽  
Environmental Prediction

Abstract Tropical Rainfall Measuring Mission (TRMM) Precipitation Radar (PR) and National Centers for Environmental Prediction–National Center for Atmospheric Research (NCEP–NCAR) reanalysis data are used to indicate mechanisms responsible for extreme summer convection over South America. The three-dimensional reflectivity field is analyzed to define three types of extreme echo, deep convective cores, wide convective cores, and broad stratiform regions. The location and timing of these echoes are sensitive to midlatitude synoptic disturbances crossing the Andes. At the leading edges of these disturbances the nocturnal South American low-level jet (SALLJ) transports moisture along the eastern edge of the Andes from the tropical to the subtropical part of the continent. Where the SALLJ rises over lower but steep mountains on the east side of the southern central Andes, deep and wide convective cores are triggered in the evening. When the SALLJ withdraws to the north as the disturbance passes, nocturnal triggering occurs in the northeastern foothills of the central Andes. Extreme convection over the Amazon basin takes the form of broad stratiform regions that evolve from systems with wide convective cores moving into the center of the region from both the southwest and northeast. The systems from the northeast form at the northeast coast and are likely squall lines. Along the coast of the Brazilian Highlands, diurnal/topographic forcing leads to daytime maxima of deep convective cores followed a few hours later by wide convective cores. Wide convective cores and broad stratiform regions form in the South Atlantic convergence zone (SACZ) with a diurnal cycle related to continental heating.

scholarly journals Impacts of Atmospheric Rivers on Precipitation in Southern South America

2018 ◽  
Vol 19 (10) ◽  
pp. 1671-1687 ◽  
Author(s):  
Maximiliano Viale ◽  
Raúl Valenzuela ◽  
René D. Garreaud ◽  
F. Martin Ralph
Keyword(s):  
South America ◽  
West Coast ◽  
Detection Algorithm ◽  
Water Vapor Transport ◽  
The South ◽  
Southern South America ◽  
Atmospheric Rivers ◽  
The Andes ◽  
Hourly Data ◽  
The Impact

Abstract This study quantifies the impact of atmospheric rivers (ARs) on precipitation in southern South America. An AR detection algorithm was developed based on integrated water vapor transport (IVT) from 6-hourly CFSR reanalysis data over a 16-yr period (2001–16). AR landfalls were linked to precipitation using a comprehensive observing network that spanned large variations in terrain along and across the Andes from 27° to 55°S, including some sites with hourly data. Along the Pacific (west) coast, AR landfalls are most frequent between 38° and 50°S, averaging 35–40 days yr−1. This decreases rapidly to the south and north of this maximum, as well as to the east of the Andes. Landfalling ARs are more frequent in winter/spring (summer/fall) to the north (south) of ~43°S. ARs contribute 45%–60% of the annual precipitation in subtropical Chile (37°–32°S) and 40%–55% along the midlatitude west coast (37°–47°S). These values significantly exceed those in western North America, likely due to the Andes being taller. In subtropical and midlatitude regions, roughly half of all events with top-quartile precipitation rates occur under AR conditions. Median daily and hourly precipitation in ARs is 2–3 times that of other storms. The results of this study extend knowledge of the key roles of ARs on precipitation, weather, and climate in the South American region. They enable comparisons with other areas globally, provide context for specific events, and support local nowcasting and forecasting.

Vulnerability of Patagonian planktonic copepods to fluctuations in temperature and UV radiation

Crustaceana ◽  
2014 ◽  
Vol 87 (3) ◽  
pp. 291-304 ◽  
Author(s):  
Patricia Elizabeth Garcia ◽  
María C. Dieguez
Keyword(s):  
South America ◽  
Effect Of Temperature ◽  
Limiting Factor ◽  
South American ◽  
The Andes ◽  
High Solar Radiation ◽  
Set Up ◽  
Solar Radiation Exposure ◽  
Increasing Temperature ◽  
The Impact

The aim of this investigation is to address the impact of fluctuations in temperature and ultraviolet radiation (UVR) on three species of South American copepods, Boeckella antiqua, B. gracilis and B. brevicaudata. These copepods are cold stenotherm and occur in high latitude lakes of South America and in mountain lakes in the Andes. The forecast scenarios for climate change in southern South America anticipate raising temperature and UVR levels. These changes may have the potential to impact high altitude and latitude ecosystems, including lakes and their cold adapted biota, such as those in Patagonia. Laboratory experiments, consisting of 10 day and 2 day incubations, were set up to analyse copepod mortality in relation with: (i) temperature, and (ii) the combined effect of temperature (5, 8, 12, 16, 20°C) and UV-B dose (61, 194 and 324 J m−2). The results obtained showed up that temperature is a limiting factor for B. brevicaudata that did not survive above 12°C. B. antiqua and B. gracilis withstood the temperature range although their mortality was higher at 12-16°C. The survivorship of these copepod species to radiation was found to depend on the UV-B dose, resulting in higher mortality at the highest UV-B dose. Overall, at least one Boeckella species showed an acute sensitivity to increasing temperature, and the three species studied proved tolerant to the UV-B experimental exposure. The survivorship patterns observed in Boeckella species reflect clearly their adaptation to high solar radiation exposure and to temperate to cold environmental conditions.

scholarly journals Cacao Diseases—The Trilogy Revisited

2007 ◽  
Vol 97 (12) ◽  
pp. 1640-1643 ◽  
Author(s):  
Harry C. Evans
Keyword(s):  
Amazon Basin ◽  
Control Strategies ◽  
Phytophthora Species ◽  
The North ◽  
Molecular Approaches ◽  
The Andes ◽  
Black Pod ◽  
Fallen Fruit ◽  
The Impact ◽  
Frosty Pod Rot

This paper reviews the significant advances by the diseases themselves, as well as by the scientists, in the intervening period since the disease trilogy was first delimited in 1989. The impact of these diseases, black pod, witches' broom, and frosty pod rot, has increased dramatically. In addition, there have been radical changes in the taxonomic profiles of these pathogens, which have been based on both traditional (morphological, cytological) and modern (molecular) approaches. Black pod is caused by a complex of Phytophthora species, in which P. palmivora still is the most important worldwide. However, recent invasion of the principal cacao-growing countries of West Africa by the more virulent P. megakarya has been cause for concern. The latter evolved in the ancient forests straddling the Cameroon-Nigerian border as a primary coloniser of fallen fruit. Conversely, frosty pod rot, caused by Moniliophthora roreri, and witches' broom, caused by M. (Crinipellis) perniciosa, both neotropical diseases, are hemibiotrophic, coevolved pathogens. Respectively, M. roreri arose on Theobroma gileri in submontane forests on the north-western slopes of the Andes, whereas M. perniciosa developed as a complex of pathotypes with a considerably wider geographic and host range within South America; the cacao pathotype evolved on that host in the Amazon basin. The inter-relationships of these vicariant species and their recent spread are discussed, together with control strategies.

scholarly journals Role of atmospheric horizontal resolution in simulating tropical and subtropical South American precipitation in HadGEM3-GC31

2020 ◽  
Author(s):  
Paul-Arthur Monerie ◽  
Amulya Chevuturi ◽  
Peter Cook ◽  
Nick Klingaman ◽  
Christopher E. Holloway
Keyword(s):  
South America ◽  
Amazon Basin ◽  
Climate Model ◽  
Spatial Scales ◽  
Moisture Flux ◽  
Horizontal Resolution ◽  
South American ◽  
North East ◽  
The Andes ◽  
Simulated Precipitation

Abstract. We assess the effect of increasing horizontal resolution on simulated precipitation over South America in a climate model. We use atmosphere-only simulations, performed with HadGEM3-GC31 at three horizontal resolutions: N96 (~ 130 km, 1.88° × 1.25°), N216 (~ 60 km, 0.83° × 0.56°), and N512 (~25 km, 0.35° × 0.23°). We show that all simulations have systematic biases in annual mean and seasonal mean precipitation over South America (e.g. too wet over the Amazon and too dry in northeast). Increasing horizontal resolution improves simulated precipitation over the Andes and north-east Brazil. Over the Andes, improvements from horizontal resolution continue to ~ 25 km, while over north-east Brazil, there are no improvements beyond ~ 60 km resolution. These changes are primarily related to changes in atmospheric dynamics and moisture flux convergence. Over the Amazon basin, precipitation variability increases at higher resolution. We show that some spatial and temporal features of daily South American precipitation are improved at high resolution, including the intensity spectra of rainfall. Spatial scales of daily precipitation features are also better simulated, suggesting that higher resolution may improve the representation of South American mesoscale convective systems.

Sign in / Sign up

Export Citation Format

Share Document