Primary succession is a fundamental process in macroecosystems; however, if and how soil development influences microbial community structure is poorly understood. Thus, we investigated changes in the bacterial community along a chronosequence of three unvegetated, early successional soils ( approximately 20-year age gradient) from a receding glacier in southeastern Peru using molecular phylogenetic techniques. We found that evenness, phylogenetic diversity, and the number of phylotypes were lowest in the youngest soils, increased in the intermediate aged soils, and plateaued in the oldest soils. This increase in diversity was commensurate with an increase in the number of sequences related to common soil bacteria in the older soils, including members of the divisions Acidobacteria, Bacteroidetes, and Verrucomicrobia. Sequences related to the Comamonadaceae clade of the Betaproteobacteria were dominant in the youngest soil, decreased in abundance in the intermediate age soil, and were not detected in the oldest soil. These sequences are closely related to culturable heterotrophs from rock and ice environments, suggesting that they originated from organisms living within or below the glacier. Sequences related to a variety of nitrogen (N)-fixing clades within the Cyanobacteria were abundant along the chronosequence, comprising 6-40% of phylotypes along the age gradient. Although there was no obvious change in the overall abundance of cyanobacterial sequences along the chronosequence, there was a dramatic shift in the abundance of specific cyanobacterial phylotypes, with the intermediate aged soils containing the greatest diversity of these sequences. Most soil biogeochemical characteristics showed little change along this approximately 20-year soil age gradient; however, soil N pools significantly increased with soil age, perhaps as a result of the activity of the N-fixing Cyanobacteria. Our results suggest that, like macrobial communities, soil microbial communities are structured by substrate age, and that they, too, undergo predictable changes through time.

The microbiome is essential for extraction of energy and nutrition from plant-based diets and may have facilitated primate adaptation to new dietary niches in response to rapid environmental shifts. Here we use 16S rRNA sequencing to characterize the microbiota of wild western lowland gorillas and sympatric central chimpanzees and demonstrate compositional divergence between the microbiotas of gorillas, chimpanzees, Old World monkeys, and modern humans. We show that gorilla and chimpanzee microbiomes fluctuate with seasonal rainfall patterns and frugivory. Metagenomic sequencing of gorilla microbiomes demonstrates distinctions in functional metabolic pathways, archaea, and dietary plants among enterotypes, suggesting that dietary seasonality dictates shifts in the microbiome and its capacity for microbial plant fiber digestion versus growth on mucus glycans. These data indicate that great ape microbiomes are malleable in response to dietary shifts, suggesting a role for microbiome plasticity in driving dietary flexibility, which may provide fundamental insights into the mechanisms by which diet has driven the evolution of human gut microbiomes.

High-alpine life forms and ecosystems exist at the limits of habitable environments, and thus, are especially sensitive to environmental change. Here we report a recent increase in the elevational limit of anurans following glacial retreat in the tropical Peruvian Andes. Three species have colonized ponds in recently deglaciated terrain at new record elevations for amphibians worldwide (5244-5400 m). Two of these species were also found to be infected with Batrachochytrium dendrobatidis (Bd), an emerging fungal pathogen causally associated with global amphibian declines, including the disappearance of several Latin American species. The presence of this pathogen was associated with elevated mortality rates of at least one species. These results represent the first evidence of upward expansion of anurans to newly available habitat brought about by recent deglaciation. Furthermore, the large increase in the upper limit of known Bd infections, previously reported as 4112 m in Ecuador, to 5348 m in this study, also expands the spatial domain of potential Bd pathogenicity to encompass virtually all high elevation anuran habitats in the tropical Andes.

Capsule We installed the world’s highest weather stations on Mount Everest, offering new insights into water resources under climate change, and potentially improving climber safety.

ABSTRACT:The Cordillera Vilcanota in the southern Peruvian Andes has been the site of significant research focused on paleoclimatic reconstructions from ice cores (Quelccaya), past glaciations, climate-glacier interactions, and ecological and human responses to climate change. In this article, we analyse precipitation patterns in the region from 2004 to 2010 using twice daily precipitation observations from six regional climate stations and hourly observations of precipitation intensity from nearby Cusco International Airport. We also analyse atmospheric fields of temperature, wind, and moisture at 700 and 200 hPa from the National Centers for Environmental Prediction/National Center for Atmospheric Research (NCEP/NCAR) reanalysis dataset and create 72-h antecedent upstream air trajectories for the heaviest precipitation events using the National Oceanic and Atmospheric Administration (NOAA) Hybrid Single Particle Lagrangian Integrated Trajectory (HYSPLIT) model. Results indicate that the majority of annual precipitation across the cordilleras and inter-montane valleys alike occurs from nocturnal, regionally coherent rainfall events, inferred to be stratiform in structure, that occur in association with deep moist convection over adjacent Amazon lowlands. Low-level moisture (as inferred from the antecedent upstream air trajectories) for precipitation events can be supplied from a number of different regions, including from the northwest and west. The trajectory analysis reveals a strong dominance (83%) of precipitation events occur under weak flow regimes from nearby Amazon basin source regions, with 50% associated with trajectories from the northwest. In addition, the El Niño-Southern Oscillation (ENSO) signal reported in previous work in the central Andes is not necessarily representative of the Cordillera Vilcanota, where La Niña years (including 2007-2008) typically experience slightly below normal precipitation and El Niño years (including 2009-2010) are considerably wetter. These results are of particular value in understanding atmospheric signals registered in Andean low latitude ice cores, and point the way towards obtaining greater climatological inference from parameters preserved in annual snow and ice stratigraphy.

An F5 tornado that devastated Plainfield, Illinois, and environs on 28 August 1990, killing 29 people, is shown to be produced by a thunderstorm characterized by highly anomalous cloud-to-ground (CG) lightning activity. Unlike typical summertime convection in which the majority of CG flashes lower negative charge to ground, the Plainfield storm produced predominantly positive-polarity CG flashes during development. Changes in storm structure revealed by radar imagery appear tied to distinct patterns in the CG flash parameters of polarity, flash frequency, first stroke peak current, flash multiplicity, and flash location relative to the parent cumulonimbus. The primary findings are 1) the anomalous predominance (91%) of positive-polarity CG flashes during development; 2) positive CG flashes anomalously occurring mainly within the region of the storm's radar reflectivity core; 3) the onset of a major downburst coinciding with a sudden increase in CG flash rate, from 4 to 17 flashes min -1 , and positive percentage, from 91% to 100%; 4) a reduction in flash rate from 17 to 3 flashes min -1 in 3 min, coinciding with the rapid development of a front-flank mesocyclone; 5) a 20-min span of reduced CG activity (1-2 flashes min -1 ) coinciding with tornado formation and intensification; 6) the reversal in dominant CG flash polarity from positive to negative over the entire thunderstorm domain at the time of tornado touchdown, an occurrence previously undocumented in any other tornadic thunderstorm; 7) steadily weakening mean peak current values (from +100 to +38 kA) leading to the reversal, and steadily strengthening values (from -20 to -40 kA) following the reversal; and 8) the temporary clustering of all CG flashes within 10 km of the tornadic mesocyclone at maximum (F5) tornadic intensity. These findings suggest the possibility of a relationship between this tornadic thunderstorm's dynamics and electrical activity.

High-elevation periglacial soils are among the most extreme soil systems on Earth and may be good analogs for the polar regions of Mars where oligotrophic mineral soils abut with polar ice caps. Here we report on preliminary studies carried out during an expedition to an area where recent glacial retreat has exposed porous mineral soils to extreme, daily freeze-thaw cycles and high UV fluxes. We used in situ methods to show that inorganic nitrogen (NO(3) (-) and NH(4) (+)) was being actively cycled even during a period when diurnal soil temperatures (5 cm depth) ranged from -12 to 27 degrees C and when sub-zero, soil cooling rates reached 1.8 degrees C h(-1) (the most rapid soil cooling rates recorded to date). Furthermore, phylogenetic analyses of microbial phylotypes present at our highest sites (5410 m above sea level) showed the presence of nitrifying bacteria of the genus Nitrospira and newly discovered nitrite-oxidizing Betaproteobacteria. These soils were overwhelmingly dominated (>70% of phylotypes) by photosynthetic bacteria that were related to novel cyanobacteria previously found almost exclusively in other plant-free, high-elevation soils. We also demonstrated that soils from our highest sites had higher potential for mineralizing glutamate and higher microbial biomass than lower elevation soils that had been more recently covered by ice. Overall, our findings indicate that a diverse and robustly functioning microbial ecosystem is present in these previously unstudied high-elevation soils.

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