Central Bolivia Research Articles

Human Disturbance affects a Deciduous Forest Bird Community in the Andean Foothills of Central Bolivia

Neotropical deciduous forests are threatened by anthropogenic activities and only a small area is protected against exploitation. In contrast to other Neotropical forest types, not much is known about the effect of habitat disturbance on deciduous forest bird communities. In the present study, we examine the effects of human disturbance on a deciduous forest bird community in the Andean foothills of Bolivia. Bird community composition was determined by means of point count surveys in three forest types, i.e. undisturbed deciduous and semi-deciduous forest, and disturbed forest habitat. Habitat disturbance was estimated indirectly by measuring vegetation structure variables in these forests. The effect of habitat disturbance was subsequently examined at bird community level (species richness, species abundance and diversity indices) and functional group level (habitat preference categories and foraging guild). Differences in community composition and reduced species abundance could clearly be related to habitat disturbance. However, results also indicated that sensitivity to disturbance varied among functional groups. Humid forest specialists showed the strongest response to habitat disturbance, predominantly bark-gleaning insectivores, canopy insectivores, understorey insectivores and ground-dwelling species, whereas dry forest specialists were not affected by disturbance. The present study suggests that anthropogenic disturbance negatively influenced the forest bird community in the investigated deciduous forest in Bolivia. This may indicate that conservation of both deciduous and semi-deciduous forest remnants is relevant for a diverse montane bird community in South America. Because various bird species typical of deciduous forests may also be able to survive in partly disturbed forests, conservation strategies should not only be focussed on the protection of pristine remnants but should also include secondary forest edge zones.

Non-woody life-form contribution to vascular plant species richness in a tropical American forest

We provide total vascular plant species counts for three 1-ha plots in deciduous, semi-deciduous and evergreen forests in central Bolivia. Species richness ranged from 297 species and 22,360 individuals/ha in the dry deciduous forest to 382 species and 31,670 individuals/ha in the evergreen forest. Orchidaceae, Pteridophyta and Leguminosae were among the most species-rich major plant groups in each plot, and Peperomia (Piperaceae), Pleurothallis (Orchidaceae) and Tillandsia (Bromeliaceae), all epiphytes, were the most species-rich genera. This dominance of a few but very diverse and/or widespread taxa contrasted with the low compositional similarity between plots. In a neotropical context, these Central Bolivian forest plots are similar in total species richness to other dry deciduous and humid montane forests, but less rich than most Amazonian forests. Nevertheless, lianas, terrestrial herbs and especially epiphytes proved to be of equal or higher species richness than most other neotropical forest inventories from which data are available. We therefore highlight the importance of non-woody life-forms (especially epiphytes and terrestrial herbs) in Andean foothill forest ecosystems in terms of species richness and numbers of individuals, representing in some cases nearly 50% of the species and more than 75% of the individuals. These figures stress the need for an increased inventory effort on non-woody plant groups in order to accurately direct conservation actions.

Electrical conductivity beneath the Bolivian Orocline and its relation to subduction processes at the South American continental margin

A long‐period magnetotelluric data set was obtained during 2002 and 2004 in the central Andes to study the deep electrical conductivity structure in the region of the Bolivian Orocline between latitudes 17°S and 19°S. The profile extends from the Coastal Cordillera in northernmost Chile, crosses the volcanic arc and the Altiplano high plateau in central Bolivia, and ends in the Eastern Cordillera. Two‐dimensional inversion revealed several well‐defined conductivity anomalies: in upper crustal levels the conductive sedimentary basins of the central Altiplano and the resistive Arequipa block beneath the western Altiplano are imaged. Earlier seismological and magnetotelluric investigations on the southern Altiplano inferred a large, highly conductive (partially molten) body in the mid to deep crust. It was assumed that this structure would be underlying the entire plateau, but this is not the case according to the new models. Instead, the most prominent feature in the new investigation area is a high‐conductivity zone at upper mantle depths below the high plateau, which may be interpreted as an image of partial melts and fluids triggered by water supply from the subducting Nazca slab. This conductor would be in accordance with the standard subduction scenario; it is, however, laterally offset by almost 100 km from the volcanic arc. In contrast, the deep crust and upper mantle beneath the arc is moderately resistive. Both observations may hint at an emerging shift of the magmatic/fluid system in the central Andes.

Taxonomy of Koeberlinia (Koeberliniaceae)

Koeberlinia has a natural amphitropical distribution that includes the deserts of central Bolivia, northern Mexico, and the southwestern United States. Despite the long recognition of only one species, K. spinosa, field, herbarium, and SEM studies support the recognition of two species. Koeberlinia spinosa of northern Mexico and adjacent United States is recognized to consist of three varieties: K. spinosa var. spinosa of northeastern Mexico and the adjacent United States, K. spinosa var. tenuispina of the Sonoran Desert of southwestern Arizona, adjacent California, and northwestern Mexico, and K. spinosa var. wivaggii from south central Texas and northern Mexico to Arizona, which is described as new. Koeberlina holacantha, endemic to the deserts of Bolivia, is proposed as new.

Matelea sartago-diaboli, a new species of Apocynaceae: Asclepiadoideae from the inter-Andean dry valleys of Bolivia

Matelea sartago-diaboli is described from the Rio Grande inter-Andean dry valley system of central Bolivia, and compared with the recently described Argentinian endemic M. calchaquina. The new species is illustrated, and its conservation status discussed.

Distributional patterns of the Neotropical humid montane forest avifaunas

The study of biogeographical patterns of the Neotropical humid montane forest avifauna has been prevented due to the lack of phylogenetic hypotheses for most taxa, and to the paucity of detailed studies about the geographical distribution for most of the species. Distributional patterns of this avifauna were explored by integrating predictive distributional models and Parsimony Analysis of Endemicity (PAE). Distributional maps were generated using the Genetic Algorithms for Rule Set Prediction for 442 species; this information was transformed into a data matrix for analysis with PAE. Hierarchical information corresponding to the genus level was incorporated to help resolve the relationships between areas. A strict consensus cladogram showed a clear separation between the Mesoamerican and South American avifaunas. Within the Mesoamerican clade, three geographically structured groups were obtained, whereas the South American clade showed a polytomy of three groups, with two of them, the South Andean Yungas and the Tepuis, located outside the main clade. The third group is a well resolved clade, including areas from eastern Panama and northern Venezuela to central Bolivia. Area relationships suggest a mixed history of dispersal and vicariant events, with the latter being the most important for explaining the biogeographical patterns found. © 2008 The Linnean Society of London, Biological Journal of the Linnean Society, 2008, 94, 175–194.

Systematics of Oreobates and the Eleutherodactylus discoidalis species group (Amphibia, Anura), based on two mitochondrial DNA genes and external morphology

We present morphological and molecular (mitochondrial DNA, mtDNA) evidence supporting the validity and monophyly of the genus Oreobates. This genus also includes members of the former Eleutherodactylus discoidalis species group plus Eleutherodactylus heterodactylus. The presence of prominent conical subarticular tubercles and prominent supernumerary tubercles associated with the axis of fingers and toes, the presence of glandular axillary pads, and the absence of vocal sacs are proposed as morphological synapomorphies. Species of this taxon form a well-supported crown clade in a phylogeny including members of the genera Craugastor and Eleutherodactylus s.l. The sister taxon to Oreobates is the Eleutherodactylus martinicensis series; Oreobates does not appear to be closely related to the Eleutherodactylus binotatus series or to members of the Eleutherodactylus dolops and Eleutherodactylus nigrovittatus species groups. The taxonomic status of all species of Oreobates is reassessed. Hylodes philippi and Hylodes verrucosus are removed from the synonymy of Oreobates quixensis. We redescribe Oreobates cruralis on the basis of the holotype and new material from Bolivia and Peru, and restrict its distribution to the humid forests of the lowlands and adjacent foothills of the Andes, from southern Peru to central Bolivia. Oreobates granulosus is rediscovered, redescribed, and resurrected, on the basis of the examination of the holotype and additional material from Peru. Phylogenetic analyses of partial 16S mtDNA are used to test the independence of lineages (species). The 14 species of Oreobates are distributed from southern Ecuador to northern Argentina. © 2008 The Linnean Society of London, Zoological Journal of the Linnean Society, 2008, 152, 737–773.

A new species of Coprophanaeus Olsoufieff (Coleoptera: Scarabaeidae) from Bolivia

Coprophanaeus caroliae Edmonds, new species, is described. This species occurs in the cloud forests (yungas) of the department of Cochabamba in central Bolivia. It is illustrated and compared with the similar species Coprophanaeus ignecinctus (Felsche) and Coprophanaeus ohausi (Felsche).

A Morphometric Study of Species Boundaries of the Wild Potato Solanum Series Conicibaccata: a Replicated Field Trial in Andean Peru

Abstract Solanum series Conicibaccata contains about 40 wild potato (section Petota) species distributed from southern Mexico to central Bolivia. It contains diploids (2n = 2x = 24), tetraploids (2n = 4x = 48) and hexaploids (2n = 6x = 72) and some polyploids are likely allopolyploids. Our morphological phenetic study in an Andean site in central Peru (12°S, 3200 m altitude) is a replicated study from one done in the north central United States (45°N, 180 m elevation) but uses more species (28 vs. 25), accessions (173 vs. 100), and morphological characters (72 vs. 45) and also includes members of related series Piurana. Both US and Peruvian studies provide phenetic support with Canonical Discriminant Analyses (but poorly if at all with Principal Components Analyses) to distinguish the following species or species groups in series Conicibaccata: 1) S. agrimonifolium and S. oxycarpum as a possible single species, and 2) S. longiconicum (tetraploids from Mexico and Central America), 3) the South American Con...

Assessing the taxonomic status of tropical frogs through bioacoustics: geographical variation in the advertisement calls in the Eleutherodactylus discoidalis species group (Anura)

The taxonomic status of a very poorly known group of Andean frogs (the Eleutherodactylus discoidalis group) is assessed through acoustic and statistical analyses of differences in temporal parameters of advertisement calls, such as the number of pulses and the call duration, and also in a spectral parameter, dominant frequency. As these species are usually misidentified or ignored because of their taxonomic complexity in both ecological and biodiversity studies, we provide a bioacoustical diagnosis for each species in order to facilitate identification in the field. Differences in acoustic parameters support the specific status of Eleutherodactylus cruralis, E. discoidalis, Eleutherodactylus ibischi, and Eleutherodactylus madidi. The name E. cruralis is probably applied to three different species: the nominal form from Amazonian forests of the Andean slopes and adjacent lowlands, and two cryptic species restricted to inter-Andean dry valleys and cloud forests from central Bolivia. Moreover, the distribution of energy through the call and the aggregation of pulses seem to be useful meristic characters for detecting interspecific differences. Populations from each macrohabitat can be recognized by distinctive advertisement calls, usually corresponding to a recognized species. For the whole group, pulse rate is significantly correlated to latitude, which could indicate a speciation process along the Andes in relation to habitat changes and isolation. © 2008 The Linnean Society of London, Zoological Journal of the Linnean Society, 2008, 152, 353–365.

Host Occurrence and Geographical Distribution of Dipetalonema spp. (Nematoda: Onchocercidae) in Neotropical Monkeys and the First Record of Dipetalonema gracile in Ecuador

Abstract Here we summarize the geographical distribution and host occurrence of Dipetalonema spp. in Central and South American primates, and report the first record of Dipetalonema gracile in Ecuador from a squirrel monkey Saimiri sciureus. We also provide additional data on the morphology of D. gracile including scanning electron microscope (SEM) photographs. The 6 species of Dipetalonema are known from 19 species, representing 9 genera of Platyrrhini monkeys. Dipetalonema spp. are widespread both geographically and in time, starting in 1809 and ranging from southern Mexico to central Bolivia and subtropical Brazil. Dipetalonema freitasi, Dipetalonema yatesi, Dipetalonema robini, and Dipetalonema graciliformis are known from only a few records from 1 or 2 localities, whereas Dipetalonema caudispina and D. gracile are known from multiple localities. Dipetalonema caudispina seems to be an Amazonian species, in contrast to D. gracile, which is widespread from 20°N (Mexico) to 24°S (Paraguay and Brazil). Sp...

Andean aquatic vegetation in central Bolivia

Andean aquatic vegetation in central Bolivia

The use and limits of AFLP data in the taxonomy of polyploid wild potato species in Solanum series Conicibaccata

Solanum sect. Petota (tuber-bearing wild and cultivated potatoes) are a group of approximately 190 wild species distributed throughout the Americas from the southwestern United States south to Argentina, Chile, and Uruguay. Solanum series Conicibaccata are a group of approximately 40 species within sect. Petota, distributed from central Mexico to central Bolivia, composed of diploids (2n = 2x = 24), tetraploids (2n = 4x = 48) and hexaploids (2n = 6x = 64); the polyploids are thought to be polysomic polyploids. This study initially was designed to address species boundaries of the four Mexican and Central American species of series Conicibaccata with AFLP data with the addition of first germplasm collections of one of these four species, Solanum woodsonii, as a follow-up to prior morphological, chloroplast DNA, and RAPD studies; and additional species of series Conicibaccata from South America. AFLP data from 12 primer combinations (1722 polymorphic bands) are unable to distinguish polyploid species long thought to be distinct. The data suggest a complex reticulate history of the tetraploids or the need for a broad downward reevaluation of the number of species in series Conicibaccata, a trend seen in other series of sect. Petota. Separately, through flow cytometry, we report the first ploidy level of S. woodsonii, as tetraploid (2n = 48).

Shallow-marine massive sandstone sheets as indicators of palaeoseismic liquefaction — An example from the Ordovician shelf of Central Bolivia

The Middle to Upper Ordovician siliciclastic succession in Central Bolivia provides excellent exposures of up to 1 m thick massive sandstone beds produced by liquefaction-induced sediment remobilisation. These fine-grained massive sandstones occur in shallow-marine nearshore facies that were deposited above storm wave base. Vertical to steeply inclined clastic dykes, which penetrate up to 1.5 m of the overlying sediment pile, feed into the basal parts of massive sandstone sheets. These dykes are interpreted as pathways used by liquefied sediment during upward-directed escape from a subsurface horizon. The relatively short lateral spacing of 5 to 25 m between the individual dykes initiated lateral coalescence of ejected individual sediment bodies. As a result, massive sandstone sheets formed and can be traced laterally over several kilometres. While undeformed sandy deposits contain between 5 to 10% dispersed clay the average clay content in massive sandstone sheets is ∼ 15%. The elongated, sometimes S-shaped form of the sandy, laminated fragments reflects squeezing during movement showing that they have been deformed under shear stress during flow. The axis of maximum elongation of the fragments indicates local flow direction. As the massive sandstone sheets are likely the products of seismic shocks they provide the first evidence of tectonic activity in this part of the basin during the Middle to Late Ordovician.

Biostratigraphic precision of the Cruziana rugosa group: a study from the Ordovician succession of southern and central Bolivia

Cruziana ichnospecies have been repeatedly reported to have biostratigraphic significance. This study presents a re-evaluation of the arthropod ichnotaxa of the Cruziana rugosa Group from bio- and/or lithostratigraphically well-defined Lower to Upper Ordovician siliciclastic sections of southern and central Bolivia. With the exception of Cruziana rouaulti, the ichnofaunas contain all the members of the Cruziana rugosa Group throughout the Ordovician (Arenig to Caradoc) successions in Bolivia. The Bolivian material therefore indicates that these arthropod ichnofossil assemblages are suitable for recognizing Ordovician strata in Bolivia. These findings cast doubt on their use as reliable indicators for a global intra-Ordovician (Arenig to Caradoc) biozonation of Peri-Gondwanan sedimentary successions.

Ichnology, palaeoecology and taphonomy of a Gondwanan early vertebrate habitat: Insights from the Ordovician Anzaldo Formation, Bolivia

Sacabambaspis janvieri is the most completely known pteraspidomorph fish from the Ordovician in terms of its morphology, histology and palaeogeographical range. Restricted to Gondwana, Sacabambaspis has assumed a role as the text-book Ordovician fish as it is known from a large number of articulated specimens recovered from within the mid-late Ordovician Anzaldo Formation of central Bolivia. The research presented here provides insights into the nature of the habitats of this early vertebrate, utilising new palaeoecological, ichnological and taphonomic field data. The Anzaldo Formation is interpreted as having been deposited in a number of shoreface and offshore transition environments that can be divided into four ichnofacies containing thirteen ichnotaxa: ?Arenicolites isp., Cruziana furcifera, C. goldfussi, C. rugosa, Curvolithus isp., Monocraterion isp., Palaeophycus striatus, Phycodes curvipalmatum, Planolites montanus, Rusophycus isp., R. latus, Skolithos linearis, and Teichichnus isp. Two of the ichnofacies are bathymetrically-controlled (the Cruziana and Skolithos ichnofacies) and two are controlled by localised depositional and salinity conditions (a mixed Skolithos– Cruziana and restricted Skolithos ichnofacies). Articulated specimens of Sacabambaspis are confined to the restricted Skolithos ichnofacies where they have been found in association with concentrations of lingulid brachiopods. Other brachiopod concentrations are found within the archetypal Skolithos ichnofacies. Data is presented that suggests that both the fish and brachiopods were killed by a combination of freshwater inundations and influxes of terrigenous sediment that buried and preserved the organisms within nearshore obrution deposits. Subsequent colonization of these obrution deposits was then initially limited to opportunistic Skolithos tracemakers.

Evaluation of the potential of various spectral indices and textural features derived from satellite images for surficial deposits mapping

The present paper deals with the relevance of spectral and textural indices to surficial deposits identification and mapping. The study area is located in the Cochabamba valley in central Bolivia. Potential of SPOT‐4, Landsat‐7 and Radarsat‐1 data were compared for surficial deposits mapping. Different spectral indices including NDVI (normalized difference vegetation index) and TSAVI (transformed soil adjusted vegetation index) and textural features (mean, standard deviation, angular second moment, entropy, etc.) were extracted from these datasets and used in the mapping process. The results showed that indices exhibit different level of sensitivities according to surficial deposit types. A discriminant analysis was conducted to extract the most significant indices, which were then used in a three‐step linear combination mathematical model to map surficial deposits. We achieved an overall classification rate of 74% using spectral data of land use map in step 1. By adding information on vegetation and soils obtained from evaluation of spectral indices, this rate was improved to 82% during step 2. Finally, it was further slightly improved to 83% by adding textural data in the final step.

Genetic analysis of the cultivated potato Solanum tuberosum L. Phureja Group using RAPDs and nuclear SSRs

The Solanum tuberosum L. Phureja Group consists of potato landraces widely grown in the Andes from western Venezuela to central Bolivia, and forms an important breeding stock due to their excellent culinary properties and other traits for developing modern varieties. They have been distinguished by short-day adaptation, diploid ploidy (2n = 2x = 24), and lack of tuber dormancy. This nuclear simple sequence repeat (nSSR or microsatellite) study complements a prior random amplified polymorphic DNA (RAPD) study to explore the use of these markers to form a core collection of cultivar groups of potatoes. Like this prior RAPD study, we analyzed 128 accessions of the Phureja Group using nuclear microsatellites (nSSR). Twenty-six of the 128 accessions were invariant for 22 nSSR markers assayed. The nSSR data uncovered 25 unexpected triploid and tetraploid accessions. Chromosome counts of the 102 accessions confirmed these nSSR results and highlighted seven more triploids or tetraploids. Thus, these nSSR markers (except 1) are good indicators of ploidy for diploid potatoes in 92% of the cases. The nSSR and RAPD results: (1) were highly discordant for the remaining 70 accessions that were diploid and variable in nSSR, (2) show the utility of nSSRs to effectively uncover many ploidy variants in cultivated potato, (3) support the use of a cultivar-group (rather than a species) classification of cultivated potato, (4) fail to support a relationship between genetic distance and geographic distance, (5) question the use of any single type of molecular marker to construct core collections.

Palaeogeographical implications of the Miocene Quendeque Formation (Bolivia) and tidally-influenced strata in southwestern Amazonia

The Miocene palaeogeography of the western Amazonian Foreland Basin (Venezuela, Colombia, Ecuador, Peru and western Brazil) and the Paraná Basin (mainly Argentina) are contentious. Several studies have hypothesized for and against a possible connection of these epicontinental depositional systems during Miocene. However, the lack of well defined palaeoenvironmental data, especially from the Bolivian lowlands, has hindered the delineation of the Miocene palaeogeography in these areas. The objective of this study is to provide new data concerning this problem. This paper presents sedimentological and ichnological data from the Quendeque Formation in the northern Subandean zone of Bolivia (lat. 15°S). This virtually unstudied formation relates the marine-influenced Paranan (northernmost reported occurrence lat. 18°S) and western Amazonian (southernmost reported occurrence lat. 13°S) depositional systems and is contemporaneous with them. The palaeogeographical significance of the new data and recently discovered tidal deposits from southern Peru (Madre de Dios) and western Brazil (Acre) is discussed. New palaeocurrent and rhythmite data from the Madre de Dios and Acre Sub-basins are presented. The studied deposits are interpreted as alluvial, deltaic and estuarine coastal plain. These data coupled with recently published data from south and central Bolivia indicate that thin Miocene tidally/marine influenced levels are present throughout the Bolivian forelands. The distal–proximal facies relations between the Late Miocene Chaco and Madre de Dios strata, and the south–southwest oriented palaeocurrent directions collected from the Madre de Dios Sub-basin suggest at least South Atlantic source for the marine influence in these areas. The episodically open hydrodynamic connection between the southwestern Amazonia and Paranan Sea may have provided a dispersal route, especially for fresh-water and euryhaline aquatic taxa. Thus, the results may explain the reported fossil faunal similarities between these areas and the modern biogeography of certain aquatic species.

Distribution and morphological variation of Eleutherodactylus mercedesae Lynch & McDiarmid, 1987 (Amphibia, Anura, Leptodactylidae) with first record for Peru

We report new distributional information for Eleutherodactylus mercedesae in Bolivia, and provide the first record for Peru based on an adult female. This species, previously endemic to Bolivia, now ranges across about 1000 km in cloud forests on the Amazonian slopes of the Andes from southern Peru to central Bolivia. We provide the first morphological description of females based on two specimens, compare them with the male type and paratype, add some observations to the original description, and comment on variation in the species.