Peruvian Desert Research Articles

The South American Biogeographic Transition Zone: An analysis from Asteraceae

AbstractIn order to elucidate the biotic diversification of Asteraceae inhabiting the South American Transition Zone, we undertook a panbiogeographic analysis (based on a parsimony analysis of endemicity) and a cladistic biogeographic analysis. The study units were the six biogeographic provinces of this zone plus the seven subregions of the Neotropical and Andean regions, considered as “outgroups”. Species analyzed belonged to the generaArnaldoa, Barnadesia, Belloa, Berroa, Chevreulia, Chuquiraga, Cuatrecasiella, Dasyphyllum, Doniophyton, Duseniella, Facellis, Fulcaldea, Gamochaetopsis, Huarpea, Hypochaeris, Jalcophila, Lucilia, Luciliocline, andSchlechtendalia. A parsimony analysis of endemicity, based on presence/absence data of the 66 individual tracks ranged on two or more areas, allowed to identify four generalized tracks: (1) Coastal Peruvian Desert and Puna provinces; (2) Central Chilean, Patagonian, and Subantarctic subregions; (3) Amazonian, Chacoan, and Parana subregions; and (4) Puna province and Parana and Chacoan subregions. The Puna and Parana provinces, connected with two different generalized tracks each, constitute nodes. A cladistic biogeographic analysis, based on the paralogy–free subtrees extracted from the taxonomic area cladograms ofBarnadesia, Chuquiraga, Dasyphyllum, Hypochaeris, and the Lucilia group, allowed obtaining a general area cladogram, which indicates a basic separation between the Atacama, Monte, and Prepuna provinces closely related to the Andean region, and the North Andean Paramo, Coastal Peruvian Desert, and Puna provinces closely related to the Neotropical region. Our results corroborate once again the transitional character of the provinces assigned to the South American Transition Zone, and allow speculating on their close affinities with the Andean and Neotropical regions.

Biogeographic diversification inNolana(Solanaceae), a ubiquitous member of the Atacama and Peruvian Deserts along the western coast of South America

Abstract The present paper reconstructs the biogeographic diversification forNolanaL.f. (Solanaceae), a genus of 89 endemic species largely restricted to fog‐dependent desertlomasformations of coastal Peru and Chile. Previous efforts have reconstructed a phylogenetic estimate forNolanausing a combination of molecular markers. Herein, we expand on those results to examine hypotheses of biogeographic origins and diversification patterns.Nolanaoccupies habitats within a continuous coastal desert and forms a terrestrial archipelago of discrete “islands” unique in size, topography, and species composition. Each locality contains at least oneNolanaspecies and many contain multiple species in sympatry. The genus has a Chilean origin, with the basal clades confined to Chile with wide geographic and ecological distributions. Peru contains two strongly supported clades, suggesting two introductions with subsequent radiation. A Chilean clade of shrubby, small‐flowered species appears to have had its origins from the same ancestors of the second line that radiated in Peru and northern Chile.Nolana galapagensisis endemic to the Islas Galápagos, with origins traced to Peruvian taxa with a divergence time of 0.35 mya. Rates of diversification over the past 4.02 mya inNolana, in one of the driest habitats on Earth, suggest rapid adaptive radiation in several clades. Success inNolanamay be attributed to characters that confer a competitive advantage in unpredictable and water‐dependent environments, such as succulent leaf anatomy and ecophysiology, and the reproductive mericarp unique toNolana. The processes affecting or shaping the biota of western South America are discussed.

Dieta de la lagartija de las playas Microlophus peruvianus (Reptilia: Tropiduridae) en la playa Santo Domingo, Ica, Perú

Even the beach lizard Microlophus peruvianus is one of the most conspicuous saurian species in the Peruvian desert, however there is almost none information about its diet. Here we reported important evident about the diet differences of both M. peruvianus adult and juvenile in Santo Domingo beach, Ica, which could be reduced the intraspecific competition between them.

Phylogeny of Nolana (Solanaceae) of the Atacama and Peruvian deserts inferred from sequences of four plastid markers and the nuclear LEAFY second intron

The phylogeny of Nolana (Solanaceae), a genus primarily distributed in the coastal Atacama and Peruvian deserts with a few species in the Andes and one species endemic to the Galápagos Islands, was reconstructed using sequences of four plastid regions ( ndhF, psbA-trnH, rps16-trnK and trnC-psbM) and the nuclear LEAFY second intron. The monophyly of Nolana was strongly supported by all molecular data. The LEAFY data suggested that the Chilean species, including Nolana sessiliflora, the N. acuminata group and at least some members of the Alona group, are basally diverged, supporting the Chilean origin of the genus. Three well-supported clades in the LEAFY tree were corroborated by the SINE (short interspersed elements) or SINE-like insertions. Taxa from Peru are grouped roughly into two clades. Nolana galapagensis from the Galápagos Island is most likely to have derived from a Peruvian ancestor. The monophyly of the morphologically well-diagnosed Nolana acuminata group ( N. acuminata, N. baccata, N. paradoxa, N. parviflora, N. pterocarpa, N. rupicola and N. elegans) was supported by both plastid and LEAFY data. Incongruence between the plastid and the LEAFY data was detected concerning primarily the positions of N. sessiliflora, N. galapagensis, taxa of the Alona group and the two Peruvian clades. Such incongruence may be due to reticulate evolution or in some cases lineage sorting of plastid DNA. Incongruence between our previous GBSSI trees and the plastid– LEAFY trees was also detected concerning two well-supported major clades in the GBSSI tree. Duplication of the GBSSI gene may have contributed to this incongruence.

Distribution of geckos in northern Peru: Long-term effect of strong ENSO events?

Arid ecosystems of western South America that are affected by ENSO events experience short-term pulses in precipitation that trigger changes in the recruitment and growth of vegetation. We hypothesized that strong ENSO events, such as those of 1982/83 and 1997/98, could influence animal communities over several decades. We surveyed populations of three sympatric species of geckos ( Phyllodactylus spp.) at the Illescas Peninsula, northern Peru, in 2004, and compared our results with those collected by Huey [1979. Parapatry and niche complementarity of Peruvian desert geckos ( Phyllodactylus): the ambiguous role of competition. Oecologia 38, 249–259] in 1968. We found that the number of mesquite trees was much higher in 2004 than it was in 1968. The frequency of the most arboreal species of gecko, Phyllodactylus reissi, was higher in 2004 than it was in 1968. P. reissi was also more likely to be associated with mesquite trees in 2004 than in 1968. Carbon and nitrogen stable isotopes could not be used to identify the most important source of primary productivity for the diet of geckos, because the values of mesquite trees and Capparis shrubs were similar. However, nitrogen isotopic values suggested that one species of gecko was incorporating marine-derived nutrients in its diet.

Mega‐Yardangs: A Global Analysis

AbstractYardangs, analogues of which occur on Mars and possibly on Venus, are wind moulded landforms that develop in the world's drylands. Mega‐yardangs (wind‐abraded, ridge, and swale features of regional extent) are easily identified on satellite images and these have been employed to map their global distribution. Areas where they are present include Central Asia, the Lut Desert of Iran, northern Saudi Arabia, Bahrain, the Libyan Desert in Egypt, the central Sahara, the Namib Desert, the high Andes and the Peruvian Desert. These features develop in a wide range of rock types, including sandstones, ignimbrites, limestones and basement rocks, occur in hyper‐arid areas, form where winds tend to be unimodal in direction, are best developed in areas of sand transport rather than sand accumulation, and occur in plains rather than in mountainous areas.

BIOGEOGRAPHIC AREAS AND TRANSITION ZONES OF LATIN AMERICA AND THE CARIBBEAN ISLANDS BASED ON PANBIOGEOGRAPHIC AND CLADISTIC ANALYSES OF THE ENTOMOFAUNA

Track and cladistic biogeographic analyses based on insect taxa are used as a framework to interpret patterns of the Latin American and Caribbean entomofauna by identifying biogeographic areas on the basis of endemicity and arranging them hierarchically in a system of regions, subregions, dominions, and provinces. The Nearctic region, inhabited by Holarctic insect taxa, comprises five provinces: California, Baja California, Sonora, Mexican Plateau, and Tamaulipas. The Mexican transition zone comprises five provinces: Sierra Madre Occidental, Sierra Madre Oriental, Transmexican Volcanic Belt, Balsas Basin, and Sierra Madre del Sur. The Neotropical region, which harbors many insect taxa with close relatives in the tropical areas of the Old World, comprises four subregions: Caribbean, Amazonian, Chacoan, and Parana. The South American transition zone comprises five provinces: North Andean Paramo, Coastal Peruvian Desert, Puna, Atacama, Prepuna, and Monte. The Andean region, which harbors insect taxa with close relatives in the Austral continents, comprises three subregions: Central Chilean, Subantarctic, and Patagonian.

Dating the geometric Nasca lines in the Peruvian desert

The Nasca lines are geoglyphs – arrays of stones forming geometric shapes constructed by ancient humans, the largest ones occupying areas of more than 1km2. The authors used optically stimulated luminescence dating of quartz buried when the stone lines were constructed to give new dates for contexts associated with geoglyphs on high mesetas near Palpa. They conclude that the stone lines at sites at San Ignacio and Sacramento were constructed between AD 400 and 650. This suggests that they were made in the later part of the Early Intermediate Period by people of the Nasca culture.

Irrigation and Society in the Peruvian Desert. The Puquios of Nasca

Irrigation and Society in the Peruvian Desert. The Puquios of Nasca

Irrigation and Society in the Peruvian Desert. The Puquios of Nasca

Irrigation and Society in the Peruvian Desert. The Puquios of Nasca

Geoarchaeological insights gained from surficial geologic mapping, middle Moche Valley, Peru

AbstractWe present the results of detailed surficial geologic mapping for a 10 km2 area of alluvial (quebrada) deposits located in the middle Moche Valley of Peru, where archaeological features and deposits provide cross‐cutting relationships and numerical age control for late Holocene erosion and deposition associated with El Niño. Despite surfaces containing clasts that are heavily pitted and cracked due to salt weathering, archaeological and 14C dates indicate that most quebrada landforms in the study area are late Holocene in age and may reflect enhanced alluviation associated with increased El Niño activity beginning ca. 6000 cal yr B.P. Our study provides criteria for correlative dating of other Holocene landforms in the Moche Valley area but urges caution in long‐distance (>100 km) correlation because of geographic variability in surface weathering. Surficial geologic mapping aided by archaeological age control allows improved understanding of the rates of landscape change important to the development of complex irrigation‐based societies in the Peruvian Desert. © 2003 Wiley Periodicals, Inc.

A formal definition of the biogeographic Paramo-Punan subregion and its provinces, based mainly on animal taxa

The Paramo-Punan subregion comprises the Andean highlands between western Venezuela and central western Argentina. It comprises five provinces: North Andean Paramo (high peaks of Venezuela, Colombia, Ecuador, and northern Peru, above 3000 m), Coastal Peruvian Desert (narrow strip along the Pacific Ocean coast, from northern Peru to northern Chile), Puna (southern Bolivia, northern Chile, northern Argentina, and southern Peru), Atacama (northern Chile), and Prepuna (central western Argentina, from Jujuy to northern Mendoza). The subregion and its provinces are defined and characterized by endemic taxa, specially animals

Impacts of heavy rainfalls in El Niño 1997/98 on the vegetation of Sechura Desert in Northern Peru (A preliminary report)

Impacts of heavy rainfalls in El Niño 1997/98 on the vegetation of Sechura Desert in Northern Peru (A preliminary report)

Holocene coevolution of the physical landscape and human settlement in northern coastal Peru

Humans are constrained by the hyperarid environment of the Peruvian Desert, which they have occupied throughout the Holocene Epoch. Habitats amenable to human occupation are limited to the riparian oases and the high-productivity coastal zone. Dramatic cultural and technological evolution was coincident with landscape evolution that responded to climatic and sea level variability. Occupation sites of hunter-gatherers older than 8,000 years are rarely found, as much of the landscape from this period is drowned and unexplored. Seven-thousand years ago, sea level stabilized and coastal middens of this age attest to exploitation of the now stationary marine resource. In response, rivers backfilled and the population became progressively more dependent upon terrestrial resources. The shift to an agricultural economy resulted in a migration of settlements inland along the river valleys. Extreme events (sea level stabilization, droughts, El Niño floods) have likely facilitated periods of rapid technological and cultural innovation. © 1999 John Wiley & Sons, Inc.

Near-infrared Fourier transform Raman spectroscopy of the mummified skin of the Alpine iceman, Qilakitsoq Greenland mummies and Chiribaya mummies from Peru

Near-infrared Fourier transform (NIR-FT) Raman spectroscopy was employed to compare archaeological skin samples of a late Neolithic man (5200 BP) preserved in a glacial field in the Alps (the Iceman), skin of fifteenth century mummies preserved at low temperature and dry air in stone graves in Qilakitsoq, Greenland, and skin samples from mummified bodies from the Chiribaya culture from the Southern Peruvian desert (1000 BP). In all the spectra of mummified skin, a progressive loss of protein amide I (1640–1680 cm−1) and amide III (1220–1290 cm−1) band intensities was found, indicating either loss of protein or changes in the secondary protein structure. Thus, the observed changes or degradation in protein structure in the samples of the 500-year-old skin of the Qilakitsoq mummy and the 1000-year-old skin of Chiribaya mummies have been observed to be broadly similar to those found in the 5200-year-old Iceman. This implies that most changes in the molecular structure of the skin take place in a relatively short time interval during the natural mummification process. The spectra of lightly pigmented Peruvian mummies showed a relatively strong peak near 1300 cm−1 and an increased intensity of the ν(CH) peak at 2850 cm−1. The band near 1300 cm−1 is characteristic of twisting and wagging CH2 vibrations in lipids and the 2850 cm−1 band represents lipid CH stretching vibrations. These spectral changes suggest an increased lipid content in lightly pigmented Peruvian mummy skin compared with contemporary skin and the skin of the mummies preserved in ice. We ascribe this increased lipid intensity in the skin of the Peruvian mummies to embalming, by which means a better preservation is achieved. In conclusion, NIR-FT-Raman spectroscopy has potential use for the non-destructive chemical analysis of archaeological biomaterial. By using this technique it is possible to assess the degree of protein degradation and also to provide an analysis of embalming materials employed for the mummification processes. Copyright © 1999 John Wiley & Sons, Ltd.

Ecological patterns in theBromeliaceae of the lomas formations of Coastal Chile and Peru

Studies of geographic distribution and physiological adaptations in theBromeliaceae of coastal Chile and Peru provide insights into the ecological patterns of habit selection and speciation. The hyperarid coastal Atacama and Peruvian Deserts along the Pacific coast of South America contain a surprisingly rich flora of bromeliad species. These include representatives of all threeBromeliaceae subfamilies: two terrestrialBromelioideae and two terrestialPitcairnioideae, all with rooted growth morphologies, and 14 species ofTillandsioideae (allTillandsia) with epiphytic and unrooted, terrestraial representatives. TheBromelioideae are represented by two species ofPuyaMolina, one each in Peru and Chile. ThePitcairnioideae are represented by two genera,Deuterocohnia andPitcairnia, with one species each. The 14Tillandsia species are distributed in five subgenera which have successfully invaded the coastal deserts, and include both widespread and local endemics with xeromorphic adaptations. All theTillandsia species are epiphytic in the broad sense, but in addition to growing on plants, they are found growing on rocks (i.e. saxicolous or epilithic). Six species (T. purpurea, T. latifolia, T. capillaris, T. marconae, T. werdermanii, andT. landbeckii) have evolved a highly specialized substrate ecology where they grow essentially unrooted on sand (i.e. epiarenic). Nowhere in the world are bromeliads more dominant or have more biomass than in these coastal species growing on sand. Many of these species grow at the absolute limits of vascular plant tolerance, with the entire community consisting of a singleTillandsia species. Rooted, terrestrial bromeliads in the coastal lomas formations (allPitcairnioideae) include CAM, C3, and C3-CAM flexible taxa in their metabolic systems, the CAM species growing in the most arid sites along the coast and C3 species growing in the most mesic habitats within the center of the coastal fog belt where fog moisture input is highest. All of the epiphyticTillandsia species of the coastal desert region utilize CAM metabolism entirely or in part. At least two species,T. latifolia andT. tragophoba, utilize a flexible C3-CAM mode of carbon fixation. Whereas most of the desert-inhabitingTillandsia species have relatively narrow leaves covered by water absorbing trichomes on their surface,T. multiflora in northern Peru andT. tragophoba in northern Chile are tank-forming species where the bases of the leaves form a water-containing reservoir. The occurrence of the latter as a local endemic in hyperarid northern Chile is remarkable since it occurs thousands of kilometers south of its closest potential relatives in the central Andes.

Southern Oscillation Signal in South American Palaeoclimatic Data of the Last 7000 Years

During strong El Niño events, rainfall anomalies and changes in wind patterns are observed in different regions of South America. Along the central Brazilian coast, during the 1983 El Niño year, the frontal systems were blocked to the south, provoking a reversal of the longshore sand transport. Long-duration reversals of longshore transport were also recorded in Holocene beach-ridge terraces from the Rio Doce coastal plain. This led to the formulation of a model relating these reversals of longshore transport to El Niño-like conditions. El Niño-like conditions are past average climate situations that generate the same perturbations as the strong El Niño events observed during the last decade. They are likely to correspond to the long-duration low phase of the Southern Oscillation. To confirm this hypothesis we compared the Holocene beach-ridge record with other palaeoenvironmental records from regions where strong El Niño events would have a substancial signal as well: (1) water-level fluctuations of Lake Titicaca, (2) a pollen and sediment record in an eastern Amazonian lake, (3) changes of the Rio Xingu discharge in eastern Amazonia, and (4) variations of sand supply at the Rio Piura and Rio Chira outlets in the Sechura Desert. The occurrences of El Niño-like conditions were numerous before 3900-3600 yr B.P., absent between 39003600 and 2800-2500 yr B.P., and infrequent after 2800-2500 yr B.P.

GENETIC DIVERGENCE IN GALVEZIA (SCROPHULARIACEAE): EVOLUTIONARY AND BIOGEOGRAPHIC RELATIONSHIPS AMONG SOUTH AMERICAN AND GALÁPAGOS SPECIES

Nineteen populations representing all species of Galvezia were examined for electrophoretic differentiation at 23 loci. Allozyme variation within G. leucantha is minimal, suggesting that a genetic bottleneck, possibly resulting from a single colonization event, accompanied establishment of Galvezia in the Galàpagos Islands less than 1.5 million years ago. South American species have higher levels of genetic polymorphism. Interspecific divergence patterns in Galvezia are characterized by many qualitative allelic differences, including one to six marker alleles for each species. Isozyme data support delimitation of four species. Geographic modes of speciation predominate. Allozyme data indicate that the Galàpagos endemic is not a recent derivative from a continental progenitor; rather, it is most likely the sister species to G. fruticosa or to a lineage of G. fruticosa and an undescribed species from southern Peru. It is hypothesized that the presence of six fixed, unique alleles in G. leucantha identifies a relictual genotype from an extinct South American progenitor. Biogeographic patterns and the presence of an allele shared between G. leucantha and two populations from the Sechura Desert indicate that northern Peru is the probable source region for the Galàpagos introduction. Estimates of elapsed divergence times and paleoecological data suggest that continental species diverged in the late Pliocene or during the Pleistocene as a result of geographic isolation caused by climatic and vegetational change.

Genetic Divergence in Galvezia (Scrophulariaceae): Evolutionary and Biogeographic Relationships Among South American and Galapagos Species

Nineteen populations representing all species of Galvezia were examined for electrophoretic differentiation at 23 loci. Allozyme variation within G. leucantha is minimal, suggesting that a genetic bottleneck, possibly resulting from a single colonization event, accompanied establishment of Galvezia in the Galàpagos Islands less than 1.5 million years ago. South American species have higher levels of genetic polymorphism. Interspecific divergence patterns in Galvezia are characterized by many qualitative allelic differences, including one to six marker alleles for each species. Isozyme data support delimitation of four species. Geographic modes of speciation predominate. Allozyme data indicate that the Galàpagos endemic is not a recent derivative from a continental progenitor; rather, it is most likely the sister species to G. fruticosa or to a lineage of G. fruticosa and an undescribed species from southern Peru. It is hypothesized that the presence of six fixed, unique alleles in G. leucantha identifies a relictual genotype from an extinct South American progenitor. Biogeographic patterns and the presence of an allele shared between G. leucantha and two populations from the Sechura Desert indicate that northern Peru is the probable source region for the Galàpagos introduction. Estimates of elapsed divergence times and paleoecological data suggest that continental species diverged in the late Pliocene or during the Pleistocene as a result of geographic isolation caused by climatic and vegetational change.

The Phytogeography and Ecology of the Coastal Atacama and Peruvian Deserts

The Atacama and Peruvian Deserts form a continuous belt for more than 3500 km along the western escarpment of the Andes from northern Peru to northernmost Chile. These arid environments are due to a climatic regime dominated by the cool, north-flowing Humboldt (Peruvian) Current. Atmospheric conditions influenced by a stable, subtropical anticyclone result in a mild, uniform coastal climate nearly devoid of rain, but with the regular formation of thick stratus clouds below I 000 m during the winter months. Where coastal topography is low and flat, the clouds dissipate inward over broad areas with little biological impact. However, where isolated mountains or steep coastal slopes intercept the clouds, a fog-zone develops. This moisture allows the development of plant communities termed lomas formations. These floristic assemblages function as islands separated by hyperarid habitat devoid of plant life. Since growth is dependent upon available moisture, an understanding of climatic patterns is essential in efforts to interpret present-day plant distributions. Topography and substrate combine to influence patterns of moisture availability. The ecological requirements and tolerances of individual species ultimately determines community composition. Species endemism exceeds 40% and suggests that the lomas formations have evolved in isolation from their nearest geographic neighbors in the Andes. While the arid environment is continuous, there appears to be a significant barrier to dispersal between 18° and 22°S latitude in extreme northern Chile. Less than 7% of a total flora, estimated at nearly 1000 species, occur on both sides ofthis region. Viable hypotheses concerning the age and origins of these desert floras will require continued study of the ecology and biogeography of their component species.