High frequency of Paracoccidioides brasiliensis infection in armadillos (Dasypus novemcinctus): an ecological study

The fungus Paracoccidioides brasiliensis has been isolated from nine-banded armadillos (Dasypus novemcinctus) in different regions where paracoccidiodomycosis (PCM) is endemic. The link between PCM and these animals has provided the first valuable clue in the effort to elucidate the ecological niche of P. brasiliensis. The present study was aimed at correlating P. brasiliensis infection in armadillos with local ecological features and, if possible, the presence of the fungus in the soil in the Botucatu hyperendemic area of PCM. In this region the mean temperature ranges from 14.8 to 25.8degreesC and the annual average precipitation is 1520 mm. The sites where 10 infected animals (positive group) were collected were studied and compared with the sites where five uninfected animals were found. The occurrence of the fungus in soil samples collected from the positive armadillos' burrows and foraging sites was investigated by the indirect method of animal inoculation. Environmental data from the sites of animal capture, such as temperature, rainfall, altitude, vegetation, soil composition, presence of water and proximity of urban areas, were recorded. All 37 soil samples collected from the sites had negative fungal cultures. Positive animals were found much more frequently in sites with disturbed vegetation, such as riparian forests and artificial Eucalyptus Or Pinus forests, in altitudes below 800 m, near water sources. The soil type of the sites of positive animals was mainly sandy, with medium to low concentrations of organic matter. The pH was mainly acidic at all the sites, although the concentrations of aluminum cations (H+Al) were lower at the sites where positive animals were found. Positive armadillos were also captured in sites very close to urban areas. Our data and previous studies indicate that P. brasiliensis occurs preferentially in humid and shady disturbed forests in a strong association with armadillos.

Short-term changes caused by fire and mowing in Brazilian Campos grasslands with different long-term fire histories

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Alternative paths for insertion of probes into high inclination lunar orbits

The dynamics of the restricted three-body Earth-Moon-particle problem predicts the existence of direct periodic orbits around the Lagrangian equilibrium point L1. From these orbits, we derive a set of trajectories that form links between the Earth and the Moon and are capable of performing transfers between terrestrial and lunar orbits, in addition to defining an escape route from the Earth-Moon system. When we consider a more complex and realistic dynamical system - the four-body Sun-Earth-Moon-particle (probe) problem - the trajectories have an expressive gain of inclination when they penetrate in the lunar influence sphere, thus allowing the insertion of probes into low-altitude lunar orbits with high inclinations, including polar orbits. In this study, we present these links and investigate some possibilities for performing an Earth-Moon transfer based on these trajectories. (C) 2007 COSPAR. Published by Elsevier Ltd. All rights reserved.

New Stylosanthes guianensis for tropical grasslands

Hybrid stylos (Stylosanthes guianensis var. vulgaris x var. pauciflora) with durable, quantitative resistance to anthracnose, mid-season harvest maturity date (early-July), high DM and seed yields have been selected at the Embrapa Beef Cattle Research Center, Campo Grande, Brazil. The hybrids displayed improved forage traits in Brazil, the native habitat and major center of diversity of the species and its pathogen, as well as in vastly different ecosystems. Dry forage yields and anthracnose resistance of superior selections and their composites were equal, in some instances, significantly better, than those of cv. Mineir (a) over tildeo in multilocational trials situated in the Cerrados from lat. 6degrees S to lat. 20degrees S. Selected hybrids performed well in comparison with the highly successful CIAT 184 (cv.Reyan II) on Hainan Island, China. Composites have also shown good promise in seed multiplication plots in Queensland, Australia. A positive attribute of composite hybrids is their great genetic diversity in contrast to pure-line cultivars with a relatively narrow genetic base. These truly tropical forms of stylo are best adapted to regions with >1500mm average annual rainfall.

Above- and below-ground biomass and carbon dynamics in Brazilian Cerrado wet grasslands

Questions: Grasslands are usually neglected as potential carbon stocks, partially due to the lack of studies on biomass and carbon dynamics in tropical grasslands. What is the importance of Brazilian tropical wet grasslands as carbon sinks? Does fire frequency and season affect biomass and carbon allocation in Brazilian wet grasslands? Location: Wet grasslands, tropical savanna, Jalapão, Tocantins, northern Brazil. Methods: We determined biomass above- and below-ground, estimated carbon stocks in biennially burned plots (B2) and plots excluded from fire for 4 yr (B4). Moreover, we determined biomass in both rainy and dry seasons. Samples were 0.25 m × 0.25 m × 0.2 m (eight samples per treatment, applying a nested design, total of 48 samples). The biomass was classified in above-ground graminoids, forbs and dead matter, and below-ground roots and other below-ground organs. We used ANOVA to compare variables between treatments and seasons. Results: More than 40% of the total biomass and carbon stocks were located below-ground, mostly in roots. A high proportion of dead biomass (B4) was found in the above-ground material, probably due to low decomposition rates and consequent accumulation over the years. Although these grasslands do not experience water stress, we found significant evidence of resource re-allocation from below-ground organs to the above-ground biomass in the rainy season. Conclusions: We found more dead biomass in the rainy season, probably due to low decomposition rates, which can increase fire risk in these grasslands during the following dry season. These tropical wet grasslands stored high amounts of carbon (621 to 716 g C.m-2), mostly in the roots. Thus, policymakers should consider tropical grasslands as potential carbon stocks, since they are one of the most threatened and unprotected ecosystems in Brazil. © 2012 International Association for Vegetation Science.

Fontes e doses de nitrogênio na adubação do capim-mombaça em cerrado de baixa altitude

Pós-graduação em Agronomia - FEIS

Live High-Train High increases hemoglobin mass in Olympic swimmers

This study tested whether 3-4 weeks of classical Live High-Train High (LHTH) altitude training increases swim-specific VO2max through increased hemoglobin mass (Hb(mass)).Ten swimmers lived and trained for more than 3 weeks between 2,130 and 3,094 m of altitude, and a control group of ten swimmers followed the same training at sea-level (SL). Body composition was examined using dual X-ray absorptiometry. Hb(mass) was determined by carbon monoxide rebreathing. Swimming VO2peak was determined and swimming trials of 4 x 50, 200 and 3,000 m were performed before and after the intervention.Hb(mass) (n = 10) was increased (P < 0.05)after altitude training by 6.2 +/- A 3.9 % in the LHTH group, whereas no changes were apparent in the SL group (n = 10). Swimming VO2peak was similar before and after training camps in both groups (LHTH: n = 7, SL: n = 6). Performance of 4 x 50 m at race pace was improved to a similar degree in both groups (LHTH: n = 10, SL: n = 10). Maximal speed reached in an incremental swimming step test (P = 0.051), and time to complete 3,000 m tended (P = 0.09) to be more improved after LHTH (n = 10) than SL training (n = 10).In conclusion, 3-4 weeks of classical LHTH is sufficient to increase Hb(mass) but exerts no effect on swimming-specific VO2peak. LHTH may improve performance more than SL training.

Does disturbance affect bud bank size and belowground structures diversity in Brazilian subtropical grasslands?

Brazilian Campos grasslands are ecosystems under high frequency of disturbance by grazing and fires. Absence of such disturbances may lead to shrub encroachment and loss of plant diversity. Vegetation regeneration after disturbance in these grasslands occurs mostly by resprouting from belowground structures. We analyzed the importance of bud bank and belowground bud bearing organs in Campos grasslands. We hypothesize that the longer the intervals between disturbances are, the smaller the size of the bud bank is. Additionally, diversity and frequency of belowground organs should also decrease in areas without disturbance for many years. We sampled 20 soil cores from areas under different types of disturbance: grazed, exclusion from disturbance for two, six, 15 and 30 years. Belowground biomass was sorted for different growth forms and types of bud bearing organs. We found a decrease in bud bank size with longer disturbance intervals. Forbs showed the most drastic decrease in bud bank size in the absence of disturbance, which indicates that they are very sensitive to changes in disturbance regimes. Xylopodia (woody gemmiferous belowground organs with hypocotyl-root origin) were typical for areas under influence of recurrent fires. The diversity of belowground bud bearing structures decreased in the absence of disturbance. Longer intervals between disturbance events, resulting in decrease of bud bank size and heterogeneity of belowground organs may lead to the decline and even disappearance of species that relay on resprouting from the bud bank upon disturbance. (C) 2014 Elsevier GmbH. All rights reserved.

Agroclimatic zoning of the state of Minas Gerais for the production of high quality soybean seeds

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Amphibians of grasslands in the state of Paraná, southern Brazil (Campos Sulinos)

Amphibian conservation depends on knowledge about species composition and distribution. This emphasizes the need for inventories, especially in poorly sampled areas. This is the case of Southern grasslands (Campos Sulinos) associated with Araucaria forest in the state of Paraná, southern Brazil. We sampled amphibians in 105 environments from 2004 to 2013 using transect sampling, active search and surveys at breeding sites. We found 61 anuran species and two caecilians. This is the first comprehensive list of amphibian species inhabiting grasslands in Paraná. This landscape deserves high conservation priority before these natural grasslands vanish.

Produção e qualidade de silagens de sorgo em sistema de integração lavoura-pecuária no cerrado de baixa altitude

Pós-graduação em Agronomia - FEIS

Relationships between plant diversity and environmental heterogeneity in rupicolous grasslands on gypsum. The case study of Alysso-Sedion albi (Habitat 6110).

Plant communities on weathered rock and outcrops are characterized by high values in species richness (Dengler 2006) and often persist on small and fragmented surfaces. Yet very few studies have examined the relationships between heterogeneity and plant diversity at small scales, in particular in poor-nutrient and low productive environment (Shmida and Wilson 1985, Lundholm 2003). In order to assess these relationships both in space and time in relationship, two different approaches were employed in the present study, in two gypsum outcrops of Northern Apennine. Diachronic and synchronic samplings from April 2012 to March 2013 were performed. A 50x50 cm plot was used in both samplings such as the sampling unit base. The diachronic survey aims to investigate seasonal patterning of plant diversity by the use of images analysis techniques integrated with field data and considering also seasonal climatic trend, the substrate quality and its variation in time. The purpose of the further, synchronic sampling was to describe plant diversity pattern as a function of the environmental heterogeneity meaning in substrate typologies, soil depth and topographic features. Results showed that responses of diversity pattern depend both on the resources availability, environmental heterogeneity and the manner in which the different taxonomic group access to them during the year. Species richness and Shannon diversity were positively affected by increasing in substrate heterogeneity. Furthermore a good turnover in seasonal species occurrence was detected. This vegetation may be described by the coexistence of three groups of species which created a gradient from early colonization stages, characterized by greater slope and predominance of bare rock, gradually to situation of more developed soil.

Impact of Land-Use Intensity and Productivity on Bryophyte Diversity in Agricultural Grasslands

While bryophytes greatly contribute to plant diversity of semi-natural grasslands, little is known about the relationships between land-use intensity, productivity, and bryophyte diversity in these habitats. We recorded vascular plant and bryophyte vegetation in 85 agricultural used grasslands in two regions in northern and central Germany and gathered information on land-use intensity. To assess grassland productivity, we harvested aboveground vascular plant biomass and analyzed nutrient concentrations of N, P, K, Ca and Mg. Further we calculated mean Ellenberg indicator values of vascular plant vegetation. We tested for effects of land-use intensity and productivity on total bryophyte species richness and on the species richness of acrocarpous (small & erect) and pleurocarpous (creeping, including liverworts) growth forms separately. Bryophyte species were found in almost all studied grasslands, but species richness differed considerably between study regions in northern Germany (2.8 species per 16 m2) and central Germany (6.4 species per 16 m2) due environmental differences as well as land-use history. Increased fertilizer application, coinciding with high mowing frequency, reduced bryophyte species richness significantly. Accordingly, productivity estimates such as plant biomass and nitrogen concentration were strongly negatively related to bryophyte species richness, although productivity decreased only pleurocarpous species. Ellenberg indicator values for nutrients proved to be useful indicators of species richness and productivity. In conclusion, bryophyte composition was strongly dependent on productivity, with smaller bryophytes that were likely negatively affected by greater competition for light. Intensive land-use, however, can also indirectly decrease bryophyte species richness by promoting grassland productivity. Thus, increasing productivity is likely to cause a loss of bryophyte species and a decrease in species diversity.

Response of temperate grasslands at different altitudes to simulated summer drought differed but scaled with annual precipitation

Water is an important resource for plant life. Since climate scenarios for Switzerland predict an average reduction of 20% in summer precipitation until 2070, understanding ecosystem responses to water shortage, e.g. in terms of plant productivity, is of major concern. Thus, we tested the effects of simulated summer drought on three managed grasslands along an altitudinal gradient in Switzerland from 2005 to 2007, representing typical management intensities at the respective altitude. We assessed the effects of experimental drought on above- and below-ground productivity, stand structure (LAI and vegetation height) and resource use (carbon and water). Responses of community above-ground productivity to reduced precipitation input differed among the three sites but scaled positively with total annual precipitation at the sites (R2=0.85). Annual community above-ground biomass productivity was significantly reduced by summer drought at the alpine site receiving the least amount of annual precipitation, while no significant decrease (rather an increase) was observed at the pre-alpine site receiving highest precipitation amounts in all three years. At the lowland site (intermediate precipitation sums), biomass productivity significantly decreased in response to drought only in the third year, after showing increased abundance of a drought tolerant weed species in the second year. No significant change in below-ground biomass productivity was observed at any of the sites in response to simulated summer drought. However, vegetation carbon isotope ratios increased under drought conditions, indicating an increase in water use efficiency. We conclude that there is no general drought response of Swiss grasslands, but that sites with lower annual precipitation seem to be more vulnerable to summer drought than sites with higher annual precipitation, and thus site-specific adaptation of management strategies will be needed, especially in regions with low annual precipitation.

Dry grasslands of NW Bulgarian mountains: first insights into diversity, ecology and syntaxonomy

We present the data of the 3rdresearch expedition of the European Dry Grasslands Group (EDGG), which was conducted in 2011 in two contrasting areas in NW Bulgarian mountains. The aim was to collect plot data for comparing Bulgarian dry grasslands with those of other parts of Europe in terms of syntaxonomy and biodiversity. We sampled 15 nested-plot series (0.0001–100 m²) and 68 normal plots(10 m²) covering the full variety of dry grassland types occurring in the Vratsa area (Balkan Mts.) and the Koprivshtitsa area (Sredna Gora Mt.). In the plots all vascular plants, terricolous non-vascular plants and a set of soil and other environmental parameters were determined. By applying modified TWIN-SPAN, we distinguished 10 floristically well characterised vegetation types at the association level. After comparison with the regional and European literature, we propose to place them within three classes and five orders: Festuco-Brometea with the orders Stipo pulcherrimae-Festucetalia pallentis (xerophilous dry grasslands of base-rich rocks; alliance Saturejion montanae), Brachypodietalia pinnate (meso-xeric, basiphilous grasslands; alliances Cirsio-Brachypodion pinnate and Chyrsopogono grylli-Danthonion calycinae),Calluno-Ulicetea with the order Nardetalia stricae (lowland to montane Nardus swards; alliance Violion caninae), and Koelerio-Corynephoretea with the orders Sedo-Scleranthetalia (open communities of skeleton-rich, acidic soils; alliance unclear) and Trifolioarvensis-Festucetalia ovinae(closed, meso-xeric, acidophilous grasslands; alliance Armerio rumelicae-Potentillion). The Violion caninae with the association Festuco rubrae-Genistelletum sagittalisis reported from Bulgaria for the first time, while the two occurring Koelerio-Corynephoretea communities are described as new associations (Cetrario aculeatae-Plantaginetum radicatae, Plantagini radicatae-Agrostietum capillaris). According to DCA the main floristic gradient was largely determined by soil conditions, differentiating the Festuco-Brometea communities on soils with high pH and high humus content from the Koelerio-Corynephoretea communities on acidic, humus-poor soils, while the Calluno-Ulicetea stands are the connecting link. At 10 m² Festuco-Brometea and Calluno-Ulicetea stands were richer in species across all investigated taxa and in vascular plants than Koelerio-Corynephoretea stands; the latter were richest in lichen species, while bryophyte richness did not differ significantly among syntaxa. Among the Bulgarian classes, the species-area relationships tended to be steepest in the Festuco-Brometea (i.e. highest beta diversity), but both alpha and beta diversity clearly fell behind the Festuco-Brometea communities in the Transylvanian Plateau, Romania, located less than 500 km north of the study region. Overall, our study contributes to a more adequate placement of the Bulgarian dry grasslands in the European syntaxonomic system and provides valuable data for large-scale analyses of biodiversity patterns