Browsing by Autor "Rosa Isela Meneses"

Now showing 1 - 20 of 30

Biodiversity Patterns and Continental Insularity in the Tropical High Andes
(Institute of Arctic and Alpine Research, 2014) Fabien Anthelme; Dean Jacobsen; Petr Macek; Rosa Isela Meneses; Pierre Moret; Stephan Beck; Olivier Dangles
Alpine areas of the tropical Andes constitute the largest of all tropical alpine regions worldwide. They experience a particularly harsh climate, and they are fragmented into tropical alpine islands at various spatial scales. These factors generate unique patterns of continental insularity, whose impacts on biodiversity remain to be examined precisely. By reviewing existing literature and by presenting unpublished data on beta-diversity and endemism for a wide array of taxonomic groups, we aimed at providing a clear, overall picture of the isolation-biodiversity relationship in the tropical alpine environments of the Andes. Our analyses showed that (1) taxa with better dispersal capacities and wider distributions (e.g., grasses and birds) were less restricted to alpine areas at local scale; (2) similarity among communities decreased with spatial distance between isolated alpine areas; and (3) endemism reached a peak in small alpine areas strongly isolated from main alpine islands. These results pinpoint continental insularity as a powerful driver of biodiversity in the tropical High Andes. A combination of human activities and warming is expected to increase the effects of continental insularity in the next decades, especially by amplifying the resistance of the lowland matrix that surrounds tropical alpine islands.
Carbon dynamics in high‐<scp>A</scp>ndean tropical cushion peatlands: A review of geographic patterns and potential drivers
(Wiley, 2024) Mary Carolina García Lino; Simon Pfanzelt; Alejandra I. Domic; Isabell Hensen; Karsten Schittek; Rosa Isela Meneses; Maaike Y. Bader
Abstract Peatlands store large amounts of carbon (C), a function potentially threatened by climate change. Peatlands composed of vascular cushion plants are widespread in the northern and central high Andes (páramo, wet and dry puna), but their C dynamics are hardly known. To understand the interplay of the main drivers of peatland C dynamics and to infer geographic patterns across the Andean regions, we addressed the following question: How do topography, hydrology, temperature, past climate variability, and vegetation influence the C dynamics of these peatlands? We summarize the available information on observed spatial and inferred temporal patterns of cushion peatland development in the tropical and subtropical Andes. Based on this, we recognize the following emerging patterns, which all need testing in further studies addressing spatial and temporal patterns of C accumulation: (1) Peatlands in dry climates and those in larger catchments receive higher sediment inputs than peatlands from wet puna and páramo and in small catchments. This results in peat stratigraphies intercalated with mineral layers and affects C accumulation by triggering vegetation changes. (2) High and constant water tables favor C accumulation. Seasonal water level fluctuations are higher in wet and dry puna, in comparison with páramo, leading to more frequent episodes of C loss in puna. (3) Higher temperatures favor C gain under high and constant water availability but also increase C loss under low and fluctuating water levels. (4) C accumulation has been variable through the Holocene, but several peatlands show a recent increase in C accumulation rates. (5) Vegetation affects C dynamics through species‐specific differences in productivity and decomposition rate. Because of predicted regional differences in global climate change manifestations (seasonality, permafrost behavior, temperature, precipitation regimes), cushion peatlands from the páramo are expected to mostly continue as C sinks for now, whereas those of the dry puna are more likely to turn to C sources as a consequence of increasing aridification.
Comparación de modelos de distribución de especies para predecir la distribución potencial de vida silvestre en Bolivia
(2006) Kazuya Naoki; María Isabel Vargas; Ramiro Pablo López; Rosa Isela Meneses; Julieta Vargas
Comparación de modelos de distribución de especies para predecir la distribución potencial de vida silvestre en Bolivia Naoki, Kazuya Gómez, M. Isabel López, Ramiro P. Meneses, Rosa 1. Vargas, Julieta
(2006) Kazuya Naoki; María Isabel Vargas; Ramiro Pablo López; Rosa Isela Meneses; Julieta Vargas
Comunidades vegetales de los bofedales de la Cordillera Real (Bolivia) bajo el calentamiento global
(2015) Susi Loza Herrera; Rosa Isela Meneses; Fabien Anthelme
High-Andean wetlands (bofedales) are one of the most threatened ecosystems in the face of global warming. Given the close relationship between bofedales and water, it is expected that glacial retreat will cause their gradual shrinkage. With three proxies of climate change (bofedal area, glacier influence and elevation) we inferred how these changes may affect plant communities. The hypotheses were 1) that loss in the area of bofedales should reduce plant diversity - the glacier influence and elevation could affect this relationship through effect on environmental heterogeneity and diversity – and 2) glacial retreat may indirectly affect diversity through changes in dominant species. We measured α and β additive diversity of plants in 20 bofedales (>4.400 m) in the Cordillera Real (Bolivia). Sixty three species were found (species richness: 5-22 /plot 1m²). Variations in bofedales area and glacial influence weren’t correlated with vegetation changes whereas diversity reduced at higher elevation. In reference to our second hypothesis, leaves of Oxychloe andina were shown more resistant to drought stress because of its higher leaf dry mass content (LDMC) than the other cushions, indicating that the bofedales dominated by O. andina may be drier and the communities are dominated by species that also can be found in drier environments. In contrast, communities of Distichia spp. are less tolerant to water deficit. If glacial retreat reduces water availability in the coming decades, the bofedales of O. andina may be more abundant at the expense of Distichia spp. creating challenges for the biodiversity conservation.
Cushion-plant protection determines guild-dependent plant strategies in high-elevation peatlands of the Cordillera Real, Bolivian Andes
(Elsevier BV, 2017) Valérie Raevel; Fabien Anthelme; Rosa Isela Meneses; François Munoz
Ecotypic differentiation under farmers' selection: Molecular insights into the domestication of Pachyrhizus Rich. ex <scp>DC</scp>. (Fabaceae) in the Peruvian Andes
(Wiley, 2017) Marc Delêtre; Beatriz Soengas; Prem Jai Vidaurre; Rosa Isela Meneses; Octavio Delgado Vásquez; Isabel Oré Balbín; Monica Santayana; Bettina Heider; Marten Sørensen
Understanding the distribution of crop genetic diversity in relation to environmental factors can give insights into the eco-evolutionary processes involved in plant domestication. Yam beans (Pachyrhizus Rich. ex DC.) are leguminous crops native to South and Central America that are grown for their tuberous roots but are seed-propagated. Using a landscape genetic approach, we examined correlations between environmental factors and phylogeographic patterns of genetic diversity in Pachyrhizus landrace populations. Molecular analyses based on chloroplast DNA sequencing and a new set of nuclear microsatellite markers revealed two distinct lineages, with strong genetic differentiation between Andean landraces (lineage A) and Amazonian landraces (lineage B). The comparison of different evolutionary scenarios for the diversification history of yam beans in the Andes using approximate Bayesian computation suggests that Pachyrhizus ahipa and Pachyrhizus tuberosus share a progenitor-derivative relationship, with environmental factors playing an important role in driving selection for divergent ecotypes. The new molecular data call for a revision of the taxonomy of Pachyrhizus but are congruent with paleoclimatic and archeological evidence, and suggest that selection for determinate growth was part of ecophysiological adaptations associated with the diversification of the P. tuberosus-P. ahipa complex during the Mid-Holocene.
Effects of grazing pressure on plant species composition and water presence on bofedales in the Andes mountain range of Bolivia
(International Mire Conservation Group and International Peat Society, 2018) N. Cochi Machaca; Bruno Condori; Adara Pardo; Fabien Anthelme; Rosa Isela Meneses; C.E. Weeda; Humberto L. Perotto‐Baldivieso; UMR AMAP, IRD, CIRAD, CNRS, INRA, Université de Montpellier, Montpellier, France; Herbario Nacional de Bolivia, Universidad Mayor de San Andrés, La Paz, Bolivia; Museo Nacional de Historia Natural, La Paz, Bolivia
Bofedales are high-Andean peatland plant communities with high capacity for water retention, which are regarded as oases of biodiversity. These areas have great social and economic value for livestock grazing, which plays an important role in their vegetation dynamics. However, the effects of increased livestock pressure on vegetation composition and surface water have not yet been clarified. The goal of this study was to assess the impact of current grazing practices on bofedal vegetation, species diversity and function. Specifically, the study aimed to (1) quantify carrying capacity and stocking rate in grazed bofedales and (2) quantify the effects of grazing pressure on plant composition and the extents of bare soil and surface water. Biomass and stocking rate estimates for 25 bofedales along the Cordillera Real (Tropical Andes, Bolivia) showed that all bofedales were overgrazed (carrying capacity/stocking rate (CC/SR) <1). Regression analyses showed significant decreases in number of plant species, species dominance, diversity and percent surface water as CC/SR declined (p < 0.05). Bofedales are negatively affected by increased grazing pressure and potentially affected by changes in livestock species. These pressures, combined with land use changes and climate change, could result in long-term negative effects for the ecological functioning and sustainability of bofedales.
El uso del método de puntos de intercepción para cuantificar los tipos de vegetación y hábitats abióticos en los bofedales altoandinos
(2014) Kazuya Naoki; Rosa Isela Meneses; María Isabel Vargas; Carlos Miguel Landivar
Facilitation vs. competition: divergent plant-plant interactions in tropical and temperate postglacial ecosystems
(2025) Lucie Bivaud; Anaïs Zimmer; Guillaume Papuga; Tristan Charles‐Dominique; Álex Aguilar; Rosa Isela Meneses; Antoine Rabatel; Jean Salcedo Aliaga; Sophie Vallée; Álvaro Soruco
Global glacier retreat is rapidly exposing vast terrains of bare ground, leading to the emergence of postglacial ecosystems. The success of this emergence will determine the future of a substantial fraction of alpine biodiversity and associated ecosys
Fine nurse variations explain discrepancies in the stress‐interaction relationship in alpine regions
(Wiley, 2017) Fabien Anthelme; Rosa Isela Meneses; Nerida Nadia H. Valero; Paola Pozo; Olivier Dangles
Despite a large consensus on increasing facilitation among plants with increasing stress in alpine regions, a number of different outcomes of interaction have been observed, which impedes the generalisation of the ‘stress‐gradient hypothesis’ (SGH). With the aim to reconcile the different viewpoints on the stress‐interaction relationship in alpine environments we hypothesized that fine nurse variations within a single life form (cushion) may explain this pattern variability. To test this hypothesis, we compared the magnitude of the stress‐interaction relationship in a single study area with that observed in existing studies involving cushions, worldwide. We characterized the nurse effects of cushions on the whole plant community at inter‐specific, intra‐specific and intra‐individual levels along a stress gradient in the dry, alpine tropics of Bolivia (4400 m, 4700 m and 4900 m a.s.l). Using a relative index of interaction (RII) we included our data in a meta‐analysis on the nurse effects of cushions along alpine gradients, worldwide. At inter‐specific level, the loose cushion Pycnophyllum was a better nurse than the compact Azorella compacta . However, at intra‐individual level facilitation was higher at the periphery than at the centre of cushions, exceeding in magnitude the variation observed at inter‐specific level. This pattern was associated with higher minimum temperature and lower mortality at the periphery of cushions. The net effects of cushions on plant communities became more positive at higher elevation, corroborating the SGH. Within our single site in Bolivia, fine morphological nurse variations captured a similar variability in the stress‐interaction relationship as that observed in a subset of studies on cushions on a worldwide scale. This suggests that fine variations in nurse traits, in general those not considered in protocols dealing with facilitation or in restoration/conservation management plans, explain in part the current discrepancies among SGH studies in alpine regions.
Flora of Bolivia - where do we stand?
(Rio de Janeiro Botanical Garden Research Institute, 2015) Rosa Isela Meneses; Stephan Beck; E. García; M. Mercado; A. Araujo; Monica G. Serrano
Abstract 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.
Glacier influence on bird assemblages in habitat islands of the high Bolivian Andes
(Wiley, 2021) Tatiana Cárdenas; Kazuya Naoki; Carlos Miguel Landivar; Quentin Struelens; María Isabel Gómez; Rosa Isela Meneses; Sophie Cauvy‐Fraunié; Fabien Anthelme; Olivier Dangles
Abstract Aim Climate projections for the upcoming decades predict a significant loss of ice mass particularly critical for glaciers in tropical mountains. In the dry landscapes of the southern Andes (from Southern Peru to Chile), this global trend has strong ecological impacts on high‐altitude wetlands that support a unique avifauna for feeding, roosting and nesting. As glacier runoffs are expected to affect the area and the quality of wetland habitats, these changes may potentially affect bird communities. To address this issue, we studied the structural and functional diversity of bird assemblages in glacier‐fed high‐altitude wetlands (>4500 m). Location Five valleys of the Cordillera Real, Bolivia. Methods We surveyed bird communities during dry, wet and intermediate seasons in 40 wetlands (total of 27,720 observations of birds and habitats from 540 transects) showing different degrees of dependence on glacial meltwater. We examined the potential effect of glacier retreat on bird communities through changes in wetland area and environmental quality and heterogeneity. Results We found strong relationship between wetland area and taxonomic and functional diversity, but not on phylogenetic diversity. Generalized additive models revealed that avian diversity was influenced by wetland's productivity and elevation and maximized at intermediate levels of glacier influence. Multivariate analysis further showed that habitat productivity and humidity, both potentially influenced by future glacial retreat trends, are the main drivers of bird community composition, with the wettest habitats being crucial for aquatic birds and uncommon species. Main conclusions Glacier retreat may significantly affect bird community diversity and composition through changes in both area and quality of high‐altitude wetlands, with a particular concern for aquatic birds.
Latitudinal and altitudinal patterns of plant community diversity on mountain summits across the tropical Andes
(Wiley, 2016) Francisco Cuesta; Priscilla Muriel; Luis D. Llambí; Stephan Halloy; Nikolay Aguirre; Stephan Beck; Julieta Carilla; Rosa Isela Meneses; Soledad Cuello; Alfredo Grau
The high tropical Andes host one of the richest alpine floras of the world, with exceptionally high levels of endemism and turnover rates. Yet, little is known about the patterns and processes that structure altitudinal and latitudinal variation in plant community diversity. Herein we present the first continental‐scale comparative study of plant community diversity on summits of the tropical Andes. Data were obtained from 792 permanent vegetation plots (1 m 2 ) within 50 summits, distributed along a 4200 km transect; summit elevations ranged between 3220 and 5498 m a.s.l. We analyzed the plant community data to assess: 1) differences in species abundance patterns in summits across the region, 2) the role of geographic distance in explaining floristic similarity and 3) the importance of altitudinal and latitudinal environmental gradients in explaining plant community composition and richness. On the basis of species abundance patterns, our summit communities were separated into two major groups: Puna and Páramo. Floristic similarity declined with increasing geographic distance between study‐sites, the correlation being stronger in the more insular Páramo than in the Puna (corresponding to higher species turnover rates within the Páramo). Ordination analysis (CCA) showed that precipitation, maximum temperature and rock cover were the strongest predictors of community similarity across all summits. Generalized linear model (GLM) quasi‐Poisson regression indicated that across all summits species richness increased with maximum air temperature and above‐ground necromass and decreased on summits where scree was the dominant substrate. Our results point to different environmental variables as key factors for explaining vertical and latitudinal species turnover and species richness patterns on high Andean summits, offering a powerful tool to detect contrasting latitudinal and altitudinal effects of climate change across the tropical Andes.
Methods to evaluate the effects of domestic herbivores on the vegetation communities of bofedales
(2014) Mary Carolina García; Rosa Isela Meneses; Kazuya Naoki; Fabien Anthelme
Métodos para cuantificar diversidad y productividad vegetal de los bofedales frente al cambio climático
(2014) Rosa Isela Meneses; Susi Loza Herrera; Ariel Lliully; Arely Palabral; Fabien Anthelme
Se espera que el rapido retroceso glaciar, resultado del cambio climatico iniciado hace muchas decadas pueda tener efectos negativos sobre la diversidad y productividad de plantas de los bofedales, a traves de cambios de su extension o area y de su distribucion altitudinal. Esto manifiesta la importancia y necesidad de entender la estructura y funcionamiento de estos ecosistemas ante el calentamiento del clima. Proponemos un protocolo metodologico para examinar las respuestas de las comunidades vegetales de bofedales alto-andinos frente al cambio climatico, tomando en cuenta en primer lugar variaciones de area y de altitud entre bofedales. Con 200 cuadrantes de 1 m² distribuidos a escala regional, proponemos hacer mediciones bioticas de riqueza especifica (numero de especies) y de cobertura relativa de cada especie de planta. Tambien proponemos medir el contenido de materia foliar seca como indice de productividad (LDMC, por sus siglas en ingles, leaf dry matter content). Describimos medidas abioticas como parametros fisicoquimicos (pH, conductividad electrica, y nutrientes) en el agua y sustrato sobre los que se desarrollan estas plantas. Dado que las comunidades estan dominadas por plantas en forma de cojin, tambien describimos metodos para caracterizar variaciones intra e interespecificas entre cojines. Se sugieren metodos practicos que optimizan el trabajo en campo y son aptos segun los objetivos de investigacion que se tengan. Se discute la pertinencia de los metodos sugeridos en este trabajo con otros metodos disponibles en la literatura, y de acuerdo con los resultados preliminares obtenidos, se comparan sus beneficios e inconveniencias.
Métodos para evaluar el efecto del pastoreo sobre las comunidades vegetales de bofedales
(2014) Mary Carolina García; Rosa Isela Meneses; Kazuya Naoki; Fabien Anthelme
Modelando patrones geográficos de distribución de gramíneas (Poaceae) en Bolivia: Implicaciones para su conservación
(2014) Rosa Isela Meneses; Daniel M. Larrea‐Alcázar; Stephan Beck; Sara Espinoza
Nurse species and indirect facilitation through grazing drive plant community functional traits in tropical alpine peatlands
(Wiley, 2017) Alain Danet; Sonia Kéfi; Rosa Isela Meneses; Fabien Anthelme
Facilitation among plants mediated by grazers occurs when an unpalatable plant extends its protection against grazing to another plant. This type of indirect facilitation impacts species coexistence and ecosystem functioning in a large array of ecosystems worldwide. It has nonetheless generally been understudied so far in comparison with the role played by direct facilitation among plants. We aimed at providing original data on indirect facilitation at the community scale to determine the extent to which indirect facilitation mediated by grazers can shape plant communities. Such experimental data are expected to contribute to refining the conceptual framework on plant-plant-herbivore interactions in stressful environments. We set up a 2-year grazing exclusion experiment in tropical alpine peatlands in Bolivia. Those ecosystems depend entirely on a few, structuring cushion-forming plants (hereafter referred to as "nurse" species), in which associated plant communities develop. Fences have been set over two nurse species with different strategies to cope with grazing (direct vs. indirect defenses), which are expected to lead to different intensities of indirect facilitation for the associated communities. We collected functional traits which are known to vary according to grazing pressure (LDMC, leaf thickness, and maximum height), on both the nurse and their associated plant communities in grazed (and therefore indirect facilitation as well) and ungrazed conditions. We found that the effect of indirectly facilitated on the associated plant communities depended on the functional trait considered. Indirect facilitation decreased the effects of grazing on species relative abundance, mean LDMC, and the convergence of the maximum height distribution of the associated communities, but did not affect mean height or cover. The identity of the nurse species and grazing jointly affected the structure of the associated plant community through indirect facilitation. Our results together with the existing literature suggest that the "grazer-nurse-beneficiary" interaction module can be more complex than expected when evaluated in the field.
Plant communities of high-Andean wetlands of the Cordillera Real (Bolivia) in the face of global warming
(Centre National de la Recherche Scientifique, 2015) Rosa Isela Loza Herrera; Rosa Isela Meneses; Fabien Anthelme