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Meneses R.I.,Campus Universitario | Meneses R.I.,Campus Universitario Cota Cota | Beck S.,Campus Universitario | Beck S.,Higher University of San Andres | And 5 more authors.
Rodriguesia | Year: 2015

The botanical exploration of Bolivia during the last two centuries did not leave a botanical legacy in the country. Only towards the end of the 20th century Bolivia saw the start of the biology careers at its universities and the development of its own herbaria. Nowadays there are important herbaria in La Paz, Santa Cruz, Cochabamba and Sucre with collections ranging between 40,000 and 350,000 specimens. In 2014 a catalogue of the vascular flora of Bolivia was published under the auspices of the Missouri Botanical Garden, recording 15,345 species, of which 12,165 are native and 2,343 are endemic, while 694 are cultivated, 267 adventitious and 221 are naturalized. Endemic species of vascular plants add up to 2,343 species. The 286 families listed follow the APG III classification system. There are about 150 botanists in Bolivia interested in studying the country's rich flora. During a workshop organized in 2013 to promote a Flora of Bolivia, the participants established jointly a preliminary format for the taxonomic treatments. The Flora of Bolivia is planned to be an electronic, open access publication with international participation. The World Flora represents a challenge that must be tackled by circumscribing, verifying and recording all species known within our territory, and it is expected that it will have positive repercussions from and towards the ongoing Flora of Bolivia, in a similar way as the long running series of the Flora Neotropica has provided a wider picture that can be adapted and modified to fit our particular country.

Thibert E.,IRSTEA | Thibert E.,University Grenoble alpes | Bellot H.,IRSTEA | Bellot H.,University Grenoble alpes | And 27 more authors.
Cold Regions Science and Technology | Year: 2015

The full-scale avalanche test site at Lautaret Pass in the southern French Alps has been used by IRSTEA-Cemagref Research Institute since 1972. Over recent years, two avalanche paths have been used routinely to release avalanches and study avalanche dynamics and interactions between avalanches and obstacles. Avalanche flows are generally dense and dry, sometimes with a powder cloud on top. Main avalanche path no. 2 is dedicated to studies on avalanche dynamics. Within the flow of the avalanche, flow height and vertical profiles of pressure and velocity are measured along a 3.5m tripod. The snow volume released in the release zone is quantified by differential analysis of laser scanning measurements performed before and after triggering. High-speed positioning of the avalanche front along the track is carried out by terrestrial oblique photogrammetry. Above the dense layer, the upper layer of the avalanche is characterized by particle and air flux measurements. Avalanche path no. 1 is smaller in size and particularly well-suited to experiments on structures exposed to small to medium-size avalanches (<1000m3). A macroscopic sensor structure consisting of a one square-meter plate supported by a 3.5m high steel cantilever beam is fixed in the ground, facing the avalanche. Impact pressures are reconstructed from the beam deformations and avalanche velocity is measured by optical sensors. For these experimental devices dedicated to improving our understanding of avalanche physics, a national and international partnership has been developed over the years, including INSA de Lyon, CNRS and Université Joseph Fourier (France), Aalto University (Finland), Nagoya University (Japan), Boku University (Austria) and IGEMA (Bolivia). © 2015.

Tello J.S.,Missouri Botanical Garden | Tello J.S.,Pontifical Catholic University of Ecuador | Myers J.A.,Washington University in St. Louis | Macia M.J.,Autonomous University of Madrid | And 9 more authors.
PLoS ONE | Year: 2015

Despite long-standing interest in elevational-diversity gradients, little is known about the processes that cause changes in the compositional variation of communities (β-diversity) across elevations. Recent studies have suggested that β-diversity gradients are driven by variation in species pools, rather than by variation in the strength of local community assembly mechanisms such as dispersal limitation, environmental filtering, or local biotic interactions. However, tests of this hypothesis have been limited to very small spatial scales that limit inferences about how the relative importance of assembly mechanisms may change across spatial scales. Here, we test the hypothesis that scale-dependent community assembly mechanisms shape biogeographic β-diversity gradients using one of the most well-characterized elevational gradients of tropical plant diversity. Using an extensive dataset on woody plant distributions along a 4,000-m elevational gradient in the Bolivian Andes, we compared observed patterns of β-diversity to null-model expectations. β-deviations (standardized differences from null values) were used to measure the relative effects of local community assembly mechanisms after removing sampling effects caused by variation in species pools. To test for scale-dependency, we compared elevational gradients at two contrasting spatial scales that differed in the size of local assemblages and regions by at least an order of magnitude. Elevational gradients in β-diversity persisted after accounting for regional variation in species pools. Moreover, the elevational gradient in β-deviations changed with spatial scale. At small scales, local assembly mechanisms were detectable, but variation in species pools accounted for most of the elevational gradient in β-diversity. At large spatial scales, in contrast, local assembly mechanisms were a dominant force driving changes in β-diversity. In contrast to the hypothesis that variation in species pools alone drives β-diversity gradients, we show that local community assembly mechanisms contribute strongly to systematic changes in β-diversity across elevations.We conclude that scale-dependent variation in community assembly mechanisms underlies these iconic gradients in global biodiversity. © 2015 Tello et al.

Arellano G.,Autonomous University of Madrid | Tello J.S.,Missouri Botanical Garden | Tello J.S.,Pontifical Catholic University of Ecuador | Jorgensen P.M.,Missouri Botanical Garden | And 5 more authors.
Oikos | Year: 2016

Understanding patterns and mechanisms of variation in the compositional structure of communities across spatial scales is one of the fundamental challenges in ecology and biogeography. In this study, we evaluated the effects of spatial extent (i.e. size of study region) on: 1) whether community composition can be better explained by environmental (i.e. niche-based) or spatial (e.g. dispersal-based) processes; and 2) how climate and soils contribute to the influence of environment on plant community composition. We surveyed community composition across a network of 398 forest plots spanning a ∼4000 m elevational gradient in the Madidi region in northwestern Bolivia. Using redundancy analyses and hierarchical variation partitioning, we disentangled the effects of environmental and spatial predictors on species composition, further decomposing the environmental effect between its climatic and soil components. We repeated analyses for 200 sub-regions ranging in spatial extent from ∼250 to ∼17 500 km2. Our analyses show a high degree of idiosyncrasy in results that come from different sub-regions. Despite this variability, we were able to identify various important patterns in the structure of tropical plant communities in our study system. First, even though sub-regions varied in size by nearly two orders of magnitude, the total amount of explained variation in community composition was scale independent; at all spatial scales, environment and space accounted for about 25% of the differences in community composition among plots. Second, the measured environmental effect was higher than the spatial effect on average and in the vast majority of sub-regions. This was true regardless of the spatial extent of analysis. Finally, we found that both climatic and soil variables accounted for significant fractions of variation, but climate was always more important than soils. © 2016 Nordic Society Oikos.

Arellano G.,Autonomous University of Madrid | Arellano G.,University of Missouri-St. Louis | Arellano G.,Missouri Botanical Garden | Arellano G.,Campus Universitario Cota Cota | And 16 more authors.
Biodiversity and Conservation | Year: 2015

The aim of this work is to examine whether there exists a link between local and landscape patterns of species commonness, and if these are related to morphological traits in tropical plant communities. The Madidi region (Bolivian tropical Andes) is selected as study location. We estimated local and landscape commonness, rarity classes, height, diameter, number of stems, and habit for >2,300 species. We employed correlations to evaluate the relationship between local scale commonness and landscape scale commonness. We performed ANCOVA and multinomial logistic regressions to predict commonness and rarity variables from the morphological traits. We repeated the analyses for six different forest types, including dry forests and wet forests along a 3,477 m elevation gradient. We found a positive relationship between local and landscape commonness in all forest types. Additionally, we found that, plant height influences the local and landscape commonness, and that the apportioning of species into rarity classes depends greatly on the species habit and, at lesser degree, on the number of stems. Our main conclusions are: (1) Approaches to commonness and rarity based on abundance only or occurrence only could summarize most of the relevant information to characterize commonness and rarity patterns: both approaches, in practice, do not supply independent information. (2) The species traits determine which species are rare and which ones are common, which indicates that commonness and rarity patterns are the result of non-neutral trait-based community assembly processes. © 2014, Springer Science+Business Media Dordrecht.

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