Grupos funcionales y variación en rasgos foliares y de tallo de 113 especies leñosas en un bosque seco tropical

In seasonally dry tropical forest (SDTF) plant trait variation has been associated with adaptation to light and water availability and a coordinated tolerance of plants to shortage of both resources has been proposed. We tested this hypothesis in a set of 113 species by analyzing the relationships amongst eleven leaf and stem traits that have been related to shade and drought tolerance. In addition, the usefulness of different types of functional classifications describing community plant trait variation was evaluated. Strong relationships were observed between leaf and stem traits, potentially conferring coordinated tolerance to shade and drought, and three axes of variation were identified by means of a principal component analysis. The first axis described leaf and stem economy, the second was related to leaf thickness and organization and the third was related to the trade-offs between leaf size, stem density and bark thickness. Stem density was correlated strongly with several plant traits, emphasizing its key role in explaining variation in life history strategies of SDTF species. Significant differences were found between functional groups categorized by phylogeny and leaf phenology, whereas for life forms differences were only observed for palms and bamboos. En los bosques secos tropicales (BST) la variación en rasgos vegetales se ha relacionado con adaptaciones a cambios en la disponibilidad de luz y agua y se ha propuesto una tolerancia coordinada a la escasez de ambos recursos. En este estudio probamos dicha hipótesis en un conjunto de 113 especies mediante el análisis de la relación entre once rasgos funcionales de hojas y tallos, que se han asociado con la tolerancia a la sombra y la sequía. Adicionalmente, evaluamos la utilidad de diferentes clasificaciones funcionales para describir la variación de los rasgos en la comunidad de plantas estudiada. Se observaron relaciones fuertes entre rasgos de las hojas y el tallo, otorgando potencialmente tolerancia a la sombra y la sequía, además se identificaron tres ejes de variación a través de un análisis de componentes principales. El primer eje se relacionó con la economía de hojas y tallo, el segundo con el grosor y la organización de las hojas y el tercero con compromisos entre el tamaño de hoja, la densidad del tallo y el grosor de la corteza. La densidad del tallo se relacionó fuertemente con varios rasgos, enfatizando su papel clave explicando la variación en las estrategias de historia de vida de las especies de BST. Se observaron diferencias significativas entre grupos funcionales categorizados por filogenia y fenología, mientras que entre formas de vida solo se observaron diferencias para las palmas y guaduas

Preliminary investigations in Brealito and Luracatao area: firsts results (dpt. Molinos, Salta)

Las quebradas altas del sector medio del valle Calchaquí en la provincia de Salta como Luracatao, Gualfín y Tacuil, son vías de comunicación naturales entre la puna y las tierras bajas y han sido visitadas y estudiadas por varios investigadores desde principios del siglo XIX (von Tschudi 1966; Bertrand 1885; Baldini y De Feo 2000; Baldini et al. 2004; Williams 2010; Martel 2012). En esta oportunidad presentamos los primeros resultados de las investigaciones iniciadas en el año 2011 por un equipo argentino-italiano en el valle de Brealito y en la quebrada de Luracatao en el marco del proyecto Arqueología y paleoambiente en el valle Calchaquí medio: Brealito y Luracatao. Las tareas de prospección en sectores aledaños a la localidad de Brealito y a la laguna homónima, así como en el área cercana a La Puerta, en la quebrada de Luracatao, permitieron conocer y registrar una diversidad de sitios como aleros con arte y asentamientos habitacionales en distintos emplazamientos y con materialidad asociada.Sociedad Argentina de Antropologí

Preliminary investigations in Brealito and Luracatao area: firsts results (dpt. Molinos, Salta)

Las quebradas altas del sector medio del valle Calchaquí en la provincia de Salta como Luracatao, Gualfín y Tacuil, son vías de comunicación naturales entre la puna y las tierras bajas y han sido visitadas y estudiadas por varios investigadores desde principios del siglo XIX (von Tschudi 1966; Bertrand 1885; Baldini y De Feo 2000; Baldini et al. 2004; Williams 2010; Martel 2012). En esta oportunidad presentamos los primeros resultados de las investigaciones iniciadas en el año 2011 por un equipo argentino-italiano en el valle de Brealito y en la quebrada de Luracatao en el marco del proyecto Arqueología y paleoambiente en el valle Calchaquí medio: Brealito y Luracatao. Las tareas de prospección en sectores aledaños a la localidad de Brealito y a la laguna homónima, así como en el área cercana a La Puerta, en la quebrada de Luracatao, permitieron conocer y registrar una diversidad de sitios como aleros con arte y asentamientos habitacionales en distintos emplazamientos y con materialidad asociada.Sociedad Argentina de Antropologí

Preliminary investigations in Brealito and Luracatao area: firsts results (dpt. Molinos, Salta)

Las quebradas altas del sector medio del valle Calchaquí en la provincia de Salta como Luracatao, Gualfín y Tacuil, son vías de comunicación naturales entre la puna y las tierras bajas y han sido visitadas y estudiadas por varios investigadores desde principios del siglo XIX (von Tschudi 1966; Bertrand 1885; Baldini y De Feo 2000; Baldini et al. 2004; Williams 2010; Martel 2012). En esta oportunidad presentamos los primeros resultados de las investigaciones iniciadas en el año 2011 por un equipo argentino-italiano en el valle de Brealito y en la quebrada de Luracatao en el marco del proyecto Arqueología y paleoambiente en el valle Calchaquí medio: Brealito y Luracatao. Las tareas de prospección en sectores aledaños a la localidad de Brealito y a la laguna homónima, así como en el área cercana a La Puerta, en la quebrada de Luracatao, permitieron conocer y registrar una diversidad de sitios como aleros con arte y asentamientos habitacionales en distintos emplazamientos y con materialidad asociada.Sociedad Argentina de Antropologí

Free-living competitive racewalkers and runners with energy availability estimates of <35 kcal·kg fat-free mass−1·day−1 exhibit peak serum progesterone concentrations indicative of ovulatory disturbances: a pilot study

Introduction: The release of luteinising hormone (LH) before ovulation is disrupted during a state of low energy availability (EA). However, it remains unknown whether a threshold EA exists in athletic populations to trigger ovulatory disturbances (anovulation and luteal phase deficiency) as indicated by peak/mid-luteal serum progesterone concentration (Pk-PRG) during the menstrual cycle. Methods: We assessed EA and Pk-PRG in 15 menstrual cycles to investigate the relationship between EA and Pk-PRG in free-living, competitive (trained-elite) Guatemalan racewalkers (n = 8) and runners (n = 7) [aged: 20 (14–41) years; post-menarche: 5 (2–26) years; height: 1.53 ± 0.09 m; mass: 49 ± 6 kg (41 ± 5 kg fat-free mass “FFM”)]. EA was estimated over 7 consecutive days within the follicular phase using food, training, and physical activity diaries. A fasted blood sample was collected during the Pk-PRG period, 6–8 days after the LH peak, but before the final 2 days of each cycle. Serum progesterone concentration was quantified using electrochemiluminescence immunoassay. Results: Participants that reported an EA of 9.40 ng·mL−1), except for a single racewalker with the lowest reported protein intake (1.1 g·kg body mass−1·day−1). EA was positively associated with Pk-PRG [r(9) = 0.79, 95% confidence interval (CI): 0.37–0.94; p = 0.003; 1 − β = 0.99] after excluding participants (n = 4) that likely under-reported/reduced their dietary intake. Conclusions: The result from the linear regression analysis suggests that an EA ≥ 36 kcal·kg FFM−1·day−1 is required to achieve “normal ovulation.” The threshold EA associated with ovulatory disturbances in athletes and non-invasive means of monitoring the ovulatory status warrant further researc

There's an App for That:Development of an Application to Operationalize the Global Diet Quality Score

BACKGROUND: The global diet quality score (GDQS) is a simple, standardized metric appropriate for population-based measurement of diet quality globally.OBJECTIVES: We aimed to operationalize data collection by modifying the quantity of consumption cutoffs originally developed for the GDQS food groups and to statistically evaluate the performance of the operationalized GDQS relative to the original GDQS against nutrient adequacy and noncommunicable disease (NCD)-related outcomes.METHODS: The GDQS application uses a 24-h open-recall to collect a full list of all foods consumed during the previous day or night, and automatically classifies them into corresponding GDQS food group. Respondents use a set of 10 cubes in a range of predetermined sizes to determine if the quantity consumed per GDQS food group was below, or equal to or above food group-specific cutoffs established in grams. Because there is only a total of 10 cubes but as many as 54 cutoffs for the GDQS food groups, the operationalized cutoffs differ slightly from the original GDQS cutoffs.RESULTS: A secondary analysis using 5 cross-sectional datasets comparing the GDQS with the original and operationalized cutoffs showed that the operationalized GDQS remained strongly correlated with nutrient adequacy and was equally sensitive to anthropometric and other clinical measures of NCD risk. In a secondary analysis of a longitudinal cohort study of Mexican teachers, there were no differences between the 2 modalities with the beta coefficients per 1 SD change in the original and operationalized GDQS scores being nearly identical for weight gain (-0.37 and -0.36, respectively, P &lt; 0.001 for linear trend for both models) and of the same clinical order of magnitude for waist circumference (-0.52 and -0.44, respectively, P &lt; 0.001 for linear trend for both models).CONCLUSION: The operationalized GDQS cutoffs did not change the performance of the GDQS and therefore are recommended for use to collect GDQS data in the future.</p

Rarity of monodominance in hyperdiverse Amazonian forests.

Tropical forests are known for their high diversity. Yet, forest patches do occur in the tropics where a single tree species is dominant. Such "monodominant" forests are known from all of the main tropical regions. For Amazonia, we sampled the occurrence of monodominance in a massive, basin-wide database of forest-inventory plots from the Amazon Tree Diversity Network (ATDN). Utilizing a simple defining metric of at least half of the trees ≥ 10 cm diameter belonging to one species, we found only a few occurrences of monodominance in Amazonia, and the phenomenon was not significantly linked to previously hypothesized life history traits such wood density, seed mass, ectomycorrhizal associations, or Rhizobium nodulation. In our analysis, coppicing (the formation of sprouts at the base of the tree or on roots) was the only trait significantly linked to monodominance. While at specific locales coppicing or ectomycorrhizal associations may confer a considerable advantage to a tree species and lead to its monodominance, very few species have these traits. Mining of the ATDN dataset suggests that monodominance is quite rare in Amazonia, and may be linked primarily to edaphic factors

Documento en extenso que incluye los resultados de la revisión de información secundaria y la obtenida en el taller con actores regionales, con la identificación de vacíos de información y prioridades de investigación y monitoreo en la cuenca del rió claro

En el marco del convenio de cooperación técnica y científica No. 19-100, celebrado entre la Fundación Grupo Argos y el Instituto de Investigación de Recursos Biológicos Alexander von Humboldt, con el objeto de aunar esfuerzos administrativos, técnicos, financieros y de gestión para la generación de conocimiento útil en escenarios de evaluación y manejo integral de impactos sobre la biodiversidad, desde una mirada ecosistémica integral del territorio de la cuenca del río Claro (Antioquia) en los múltiples contextos socioecológicos, se ha comprometido la construcción de la línea base de información secundaria disponible sobre biodiversidad para la cuenca del río Claro, Antioquia, que incluya, entre otros, datos sobre ecología, genética, uso, conservación, distribución, uso de hábitat, impactos e información espacial, procesos ecológicos.BogotáCiencias Básicas de la Biodiversida

Geographic patterns of tree dispersal modes in Amazonia and their ecological correlates

Unidad de excelencia María de Maeztu CEX2019-000940-MAim: To investigate the geographic patterns and ecological correlates in the geographic distribution of the most common tree dispersal modes in Amazonia (endozoochory, synzoochory, anemochory and hydrochory). We examined if the proportional abundance of these dispersal modes could be explained by the availability of dispersal agents (disperser-availability hypothesis) and/or the availability of resources for constructing zoochorous fruits (resource-availability hypothesis). Time period: Tree-inventory plots established between 1934 and 2019. Major taxa studied: Trees with a diameter at breast height (DBH) ≥ 9.55 cm. Location: Amazonia, here defined as the lowland rain forests of the Amazon River basin and the Guiana Shield. Methods: We assigned dispersal modes to a total of 5433 species and morphospecies within 1877 tree-inventory plots across terra-firme, seasonally flooded, and permanently flooded forests. We investigated geographic patterns in the proportional abundance of dispersal modes. We performed an abundance-weighted mean pairwise distance (MPD) test and fit generalized linear models (GLMs) to explain the geographic distribution of dispersal modes. Results: Anemochory was significantly, positively associated with mean annual wind speed, and hydrochory was significantly higher in flooded forests. Dispersal modes did not consistently show significant associations with the availability of resources for constructing zoochorous fruits. A lower dissimilarity in dispersal modes, resulting from a higher dominance of endozoochory, occurred in terra-firme forests (excluding podzols) compared to flooded forests. Main conclusions: The disperser-availability hypothesis was well supported for abiotic dispersal modes (anemochory and hydrochory). The availability of resources for constructing zoochorous fruits seems an unlikely explanation for the distribution of dispersal modes in Amazonia. The association between frugivores and the proportional abundance of zoochory requires further research, as tree recruitment not only depends on dispersal vectors but also on conditions that favour or limit seedling recruitment across forest types

Estimating the global conservation status of more than 15,000 Amazonian tree species

Estimates of extinction risk for Amazonian plant and animal species are rare and not often incorporated into land-use policy and conservation planning. We overlay spatial distribution models with historical and projected deforestation to show that at least 36% and up to 57% of all Amazonian tree species are likely to qualify as globally threatened under International Union for Conservation of Nature (IUCN) Red List criteria. If confirmed, these results would increase the number of threatened plant species on Earth by 22%. We show that the trends observed in Amazonia apply to trees throughout the tropics, and we predict thatmost of the world’s >40,000 tropical tree species now qualify as globally threatened. A gap analysis suggests that existing Amazonian protected areas and indigenous territories will protect viable populations of most threatened species if these areas suffer no further degradation, highlighting the key roles that protected areas, indigenous peoples, and improved governance can play in preventing large-scale extinctions in the tropics in this century