Assessment of the diversity of epigeous Basidiomycota under different soil-management systems in a montado ecosystem: a case study conducted in Alentejo

Several management practices that are employed in Montados are known to affect the establishment and maintenance of Basidiomycota communities immediately after disturbances have occurred, contributing to their development or, conversely, decreasing their diversity. In this study we aim to evaluate the effects of the most common understory and soil-management practices on the diversity of the epigeous Basidiomycota a long time after disturbances have taken place. The study was conducted in a Montado (cork and holm-oak ecosystem) area in Southern Portugal (Alentejo). In 1998, four experimental treatments—control (C), mulching (Mu), mowing (Mo) and ploughing (P)—with three replicates each were carried out: C—untreated/untouched; Mu—cutting of shrubs followed by deposition of plant residues on soil surfaces; Mo—cutting of shrubs followed by biomass removal and soil tilling; P—cutting of shrubs followed by the incorporation of plant biomass into the soil through tillage. Macrofungal surveys were conducted fortnightly in the experimental plots between Autumn 2007 and Spring 2012. Significant differences in total and mycorrhizal richness were found between plots, with higher values being found for non-tilled plots and lower values for tilled plots. No significant differences were found in saprotrophic richness between treatments. Regarding the composition of taxa, Boletus and Russula were the main taxonomic groups affected by experimental treatments. Our results showed that soil tillage can result in a decrease in mycorrhizal taxa even a long time after disturbances have taken place.     

Canopy cover influence on macrofungal richness and sporocarp production in montado ecosystems

In this study we aimed to find out how macrofungi richness and sporocarp production varies in relation to both canopy cover and proximity of crown projection area, in order to discuss strategies and point out management actions that ensure macrofungal communities sustainability in montado ecosystems. The sporocarp survey was conducted once every two weeks, from October to February, between 2007 and 2009 in two representative sites of the most common (cork and holm oak) open montado ecosystems in southern Portugal. Results showed that canopy cover strongly shaped macrofungal communities composition and yield. Denser canopy cover enhanced mycorrhizal richness and reduced saprotrophic yield. Furthermore, mycorrhizal richness and yield increased with tree proximity. Finally some forest management strategies are suggested in order to enhance macrofungal richness and productivity, in montado ecosystems.     

Typing of Tomato Yellow Leaf Curl Viruses in Europe

Tomato yellow leaf curl disease is spreading in southern Europe, where it has quickly become a serious problem. In recent years, several virus isolates have been characterised. Although with some genetic variability, all isolates found in Europe belong to one of two species Tomato yellow leaf curl-Sardinia (TYLCV-Sar) or Tomato yellow leaf curl-Israel (TYLCV-Is). Several methods were tested to identify and type TYLCV isolates from field samples: (1) RFLP of a DNA fragment amplified from the coat protein gene; (2) PAGE of a fragment amplified from the C2 gene; (3) dot-blot hybridisation. All methods enabled the detection of the TYLCVs and provided good indications for attributing them to one species or the other. However, for typing purposes, the RFLP method was the most reliable, due to the easily recognisable pattern produced by the two virus species present in Europe. Dot-blot hybridisation is less expensive for identifying TYLCVs in large numbers of samples, particularly when a mixture of two probes is used. PAGE of the C2 fragment is the fastest of the methods tested.     

Utilization of deoiled castor cake for crop production

A screen house experiment was undertaken to study effect of time of application of deoiled castor cake on the yield, N and P uptake by wheat crop. The results indicate that the wheat growth decreased significantly with increasing dose of castor cake, when castor cake was applied just before sowing of wheat. When castor cake was applied 10 days before wheat sowing, the dry matter yield (DMY) of wheat increased up to 0.125% dose of castor cake and reduced thereafter. But when the castor cake was applied 20 days before wheat sowing, the DMY was at par under all the doses of castor cake and better than control indicating the degradation of the toxicants produced by the castor cake. Application of castor cake can also be helpful in reducing the cost of phosphatic fertilizer. Thus it can be concluded that castor cake should be applied at least 3 weeks before sowing of the crop and keeping the field moist for degradation of the toxicants.     

Spectral Properties of Near-Earth Asteroids: Evidence for Sources of Ordinary Chondrite Meteorites

Although ordinary chondrite (OC) meteorites dominate observed falls, the identification of near-Earth and main-belt asteroid sources has remained elusive. Telescopic measurements of 35 near-Earth asteroids ( approximately3 kilometers in diameter) revealed six that have visible wavelength spectra similar to laboratory spectra of OC meteorites. Near-Earth asteroids were found to have spectral properties that span the range between the previously separated domains of OC meteorites and the most common (S class) asteroids, suggesting a link. This range of spectral properties could arise through a diversity of mineralogies and regolith particle sizes, as well as through a time-dependent surface weathering process.     

Direct demonstration of milk as an element of archaeological economies

The stable carbon isotope (delta13C) compositions of individual fatty acid components of remnant fats preserved in archaeological pottery vessels show that dairying was a component of archaeological economies. Characteristic delta13C values arise from biases in the biosynthetic origins of the C18:0 fatty acids in milk and adipose fat. Milk and adipose fat from animals raised on similar pastures and fodders have distinct isotopic signatures.     

The Solar Acoustic Spectrum and Eigenmode Parameters

The Global Oscillation Network Group (GONG) project estimates the frequencies, amplitudes, and linewidths of more than 250,000 acoustic resonances of the sun from data sets lasting 36 days. The frequency resolution of a single data set is 0.321 microhertz. For frequencies averaged over the azimuthal order m, the median formal error is 0.044 microhertz, and the associated median fractional error is 1.6 x 10(-5). For a 3-year data set, the fractional error is expected to be 3 x 10(-6). The GONG m-averaged frequency measurements differ from other helioseismic data sets by 0.03 to 0.08 microhertz. The differences arise from a combination of systematic errors, random errors, and possible changes in solar structure.