Universidade Federal de Viçosa

About: Universidade Federal de Viçosa is a education organization based out in Viçosa, Brazil. It is known for research contribution in the topics: Population & Biology. The organization has 16012 authors who have published 26711 publications receiving 353416 citations.

Fungal Planet description sheets: 214–280

Abstract: Novel species of microfungi described in the present study include the following from South Africa: Cercosporella dolichandrae from Dolichandra unguiscati, Seiridium podocarpi from Podocarpus latifolius, Pseudocercospora parapseudarthriae from Pseudarthria hookeri, Neodevriesia coryneliae from Corynelia uberata on leaves of Afrocarpus falcatus, Ramichloridium eucleae from Euclea undulata and Stachybotrys aloeticola from Aloe sp. (South Africa), as novel member of the Stachybotriaceae fam. nov. Several species were also described from Zambia, and these include Chaetomella zambiensis on unknown Fabaceae, Schizoparme pseudogranati from Terminalia stuhlmannii, Diaporthe isoberliniae from Isoberlinia angolensis, Peyronellaea combreti from Combretum mossambiciensis, Zasmidium rothmanniae and Phaeococcomyces rothmanniae from Rothmannia engleriana, Diaporthe vangueriae from Vangueria infausta and Diaporthe parapterocarpi from Pterocarpus brenanii. Novel species from the Netherlands include: Stagonospora trichophoricola, Keissleriella trichophoricola and Dinemasporium trichophoricola from Trichophorum cespitosum, Phaeosphaeria poae, Keissleriella poagena, Phaeosphaeria poagena, Parastagonospora poagena and Pyrenochaetopsis poae from Poa sp., Septoriella oudemansii from Phragmites australis and Dendryphion europaeum from Hedera helix (Germany) and Heracleum sphondylium (the Netherlands). Novel species from Australia include: Anungitea eucalyptorum from Eucalyptus leaf litter, Beltraniopsis neolitseae and Acrodontium neolitseae from Neolitsea australiensis, Beltraniella endiandrae from Endiandra introrsa, Phaeophleospora parsoniae from Parsonia straminea, Penicillifer martinii from Cynodon dactylon, Ochroconis macrozamiae from Macrozamia leaf litter, Triposporium cycadicola, Circinotrichum cycadis, Cladosporium cycadicola and Acrocalymma cycadis from Cycas spp. Furthermore, Vermiculariopsiella dichapetali is described from Dichapetalum rhodesicum (Botswana), Marasmius vladimirii from leaf litter (India), Ophiognomonia acadiensis from Picea rubens (Canada), Setophoma vernoniae from Vernonia polyanthes and Penicillium restingae from soil (Brazil), Pseudolachnella guaviyunis from Myrcianthes pungens (Uruguay) and Pseudocercospora neriicola from Nerium oleander (Italy). Novelties from Spain include: Dendryphiella eucalyptorum from Eucalyptus globulus, Conioscypha minutispora from dead wood, Diplogelasinospora moalensis and Pseudoneurospora canariensis from soil and Inocybe lanatopurpurea from reforested woodland of Pinus spp. Novelties from France include: Kellermania triseptata from Agave angustifolia, Zetiasplozna acaciae from Acacia melanoxylon, Pyrenochaeta pinicola from Pinus sp. and Pseudonectria rusci from Ruscus aculeatus. New species from China include: Dematiocladium celtidicola from Celtis bungeana, Beltrania pseudorhombica, Chaetopsina beijingensis and Toxicocladosporium pini from Pinus spp. and Setophaeosphaeria badalingensis from Hemerocallis fulva. Novel genera of Ascomycetes include Alfaria from Cyperus esculentus (Spain), Rinaldiella from a contaminated human lesion (Georgia), Hyalocladosporiella from Tectona grandis (Brazil), Pseudoacremonium from Saccharum spontaneum and Melnikomyces from leaf litter (Vietnam), Annellosympodiella from Juniperus procera (Ethiopia), Neoceratosperma from Eucalyptus leaves (Thailand), Ramopenidiella from Cycas calcicola (Australia), Cephalotrichiella from air in the Netherlands, Neocamarosporium from Mesembryanthemum sp. and Acervuloseptoria from Ziziphus mucronata (South Africa) and Setophaeosphaeria from Hemerocallis fulva (China). Several novel combinations are also introduced, namely for Phaeosphaeria setosa as Setophaeosphaeria setosa, Phoma heteroderae as Peyronellaea heteroderae and Phyllosticta maydis as Peyronellaea maydis. Morphological and culture characteristics along with ITS DNA barcodes are provided for all taxa.

Biodiversity recovery of Neotropical secondary forests

Abstract: Old-growth tropical forests harbor an immense diversity of tree species but are rapidly being cleared, while secondary forests that regrow on abandoned agricultural lands increase in extent. We assess how tree species richness and composition recover during secondary succession across gradients in environmental conditions and anthropogenic disturbance in an unprecedented multisite analysis for the Neotropics. Secondary forests recover remarkably fast in species richness but slowly in species composition. Secondary forests take a median time of five decades to recover the species richness of old-growth forest (80% recovery after 20 years) based on rarefaction analysis. Full recovery of species composition takes centuries (only 34% recovery after 20 years). A dual strategy that maintains both old-growth forests and species-rich secondary forests is therefore crucial for biodiversity conservation in human-modified tropical landscapes.

Surface water dynamics in the Amazon Basin: Application of satellite radar altimetry

Abstract: [1] Satellite radar altimetry has the ability to monitor variations in surface water height (stage) for large wetlands, rivers, and associated floodplains. A clear advantage is the provision of data where traditional gauges are absent. As part of an international program, a complete altimetric analysis of the Amazon Basin is being undertaken. Here, an updated and more rigorous evaluation of the TOPEX/POSEIDON (T/P) data set is presented for the first ∼7.5 years of the mission. With an initial study group of 230 targets, height variability at many ungauged locations can be observed for 30–50%, the range reflecting the clarity of the variations in lieu of instrument limitations. An assessment of the instrument performance confirms that the minimum river width attainable is ∼1 km in the presence of some inundated floodplain. This constraint does allow observation of the main stem (Solimoes/Amazon) and the larger tributaries, but rugged terrain in the vicinity of the target additionally places severe limitations on data retrieval. First-order validation exercises with the deduced 1992–1999 time series of stage fluctuations reveal accuracies ranging from tens of centimeters to several meters (mean ∼1.1 m rms). Altimetric water levels in the Solimoes and Amazon are particularly well defined with amplitudes <13 m and variations in peak-level timing from May to July. The water-surface gradient of the main stem is found to vary both spatially and temporally, with values ranging from 1.5 cm/km downstream to 4.0 cm/km for more upstream reaches. In agreement with ground-based estimates, the seasonal variability of the gradients reveals that the hysteresis characteristic of the flood wave varies along the main stem and the derived altimetric velocity of this flood wave is estimated to be ∼0.35 m/s. Overall, the altimetric results demonstrate that the T/P mission is successfully monitoring the transient flood waves of this continental-scale river basin.

Above- and below-ground net primary productivity across ten Amazonian forests on contrasting soils

Abstract: The net primary productivity (NPP) of tropi- cal forests is one of the most important and least quan- tified components of the global carbon cycle. Most rel- evant studies have focused particularly on the quantifica- tion of the above-ground coarse wood productivity, and lit- tle is known about the carbon fluxes involved in other el- ements of the NPP, the partitioning of total NPP between its above- and below-ground components and the main en- vironmental drivers of these patterns. In this study we quantify the above- and below-ground NPP of ten Amazo- nian forests to address two questions: (1) How do Ama- zonian forests allocate productivity among its above- and below-ground components? (2) How do soil and leaf nu- trient status and soil texture affect the productivity of Ama- zonian forests? Using a standardized methodology to mea- sure the major elements of productivity, we show that NPP varies between 9.3±1.3 Mg C ha 1 yr 1 (mean±standard er- ror), at a white sand plot, and 17.0±1.4 Mg C ha 1 yr 1 at a very fertile Terra Preta site, with an overall average of 12.8±0.9 Mg C ha 1 yr 1 . The studied forests allocate on average 64±3% and 36±3% of the total NPP to the above- and below-ground components, respectively. The ratio of above-ground and below-ground NPP is almost invariant with total NPP. Litterfall and fine root production both in- crease with total NPP, while stem production shows no over- all trend. Total NPP tends to increase with soil phospho- rus and leaf nitrogen status. However, allocation of NPP to below-ground shows no relationship to soil fertility, but ap- pears to decrease with the increase of soil clay content.

Insecticide‐induced hormesis and arthropod pest management

Abstract: Ecological backlashes such as insecticide resistance, resurgence and secondary pest outbreaks are frequent problems associated with insecticide use against arthropod pest species. The last two have been particularly important in sparking interest in the phenomenon of insecticide-induced hormesis within entomology and acarology. Hormesis describes a biphasic dose-response relationship that is characterized by a reversal of response between low and high doses of a stressor (e.g. insecticides). Although the concept of insecticide-induced hormesis often does not receive sufficient attention, or has been subject to semantic confusion, it has been reported in many arthropod pest species and natural enemies, and has been linked to pest outbreaks and potential problems with insecticide resistance. The study of hormesis remains largely neglected in entomology and acarology. Here, we examined the concept of insecticide-induced hormesis in arthropods, its functional basis and potential fitness consequences, and its importance in arthropod pest management and other areas.