Neotropical mustelids: fecal metabolome diversity and its potential for taxonomic discrimination

Chemical profiles of non-invasive biological material, such as feces, have great potential to study elusive animals or those with low population densities. Here, we use a metabolomic approach to evaluate Neotropical mustelids as a biological model to describe the diversity of the metabolites present in fecal samples, as well as to evaluate the potential of chemical profiles for taxonomic discrimination. We collected fecal samples from captive individuals of 5 species of mustelids occurring in Brazil and analyzed them by liquid chromatography coupled to high-resolution mass spectrometry. Over 200 compounds have been annotated; “bile acids, alcohols and derivatives” was the most expressive class in the metabolome of all the species. We successfully discriminated 3 taxonomic groups: 1—tayra (Eira barbara); 2—otters (Lontra longicaudis and Pteronura brasiliensis; 1); and 3—grisons (Galictis vittata and Galictis cuja). Several compounds seemed to be associated with food intake and the digestive process, while others were found for the first time in Neotropical mustelids. We concluded that mustelids show high metabolome diversity and that species-specific identification through metabolomic profiles is possible, thus contributing to the development and implementation of additional non-invasive approaches in the study of mustelids.     

An economic and ecological multi-criteria evaluation of reforestation methods to recover burned Pinus nigra forests in NE Spain

Recurrence of recent large wildfires is threatening the permanence of Pinus nigra Arnold (Black pine) forests in central Catalonia (NE Spain), due to the almost nil post-fire regeneration of this non-serotinous pine. Potential practices to carry out extensive reforestation programs with P. nigra may differ widely in terms of their final success, economic cost and undesired ecological impact. In this framework, we have analysed different types of vegetation clearing (mechanical, controlled burning or grazing), soil preparation (ripping or planting holes) and reforestation methods (broadcast seeding, spot seeding and planting) to restore P. nigra forests. We have compared these practices in terms of seedling establishment, but also in the light of their economic costs and ecological impact, through a new multi-criteria analysis. Seedling establishment after sowing was very poor and not influenced by vegetation clearing. In plantations, seedling survival was higher in the ripper treatment than in planting holes for all vegetation clearing treatments except the control one. Nevertheless, the higher economic cost of the planting holes treatment and the negative impact of mechanical clearing and burning on the small mammals community made the stated differences in seedling survival irrelevant. Thus, the multi-criteria analysis revealed that the two most preferred options were planting in uncleared or lightly grazed areas with soil preparation through ripping. This study gives some valuable insights about the use of new decision-support tools in restoration programs and provides practical guidelines concerning the restoration of extensive burned P. nigra forests.     

Interactions between<Emphasis Type="Italic"> Orthotomicus erosus</Emphasis> (Woll.) (Col., Scolytidae) and the Argentine ant<Emphasis Type="Italic"> Linepithema humile</Emphasis> (Mayr) (Hym., Formicidae)

Interactions occurring between Orthotomicus erosus, an economically important pine bark beetle in Portugal, and the aggressive Argentine ant Linepithema humile were investigated. Tri-trophic experimental enclosures consisting of Pinus pinaster logs, O. erosus adults and L. humile workers were set up in the field and in the laboratory. Interactions between ants and scolytids were observed and quantified in terms of the bark beetles success in colonizing the logs. The presence of L. humile did not influence the ability of O. erosus to colonize the logs, apparently due to the difficulties met by the ants in handling the bark beetles and to their inability to injure them. Thus, although abundant in many pine stands in Portugal and in spite of its aggressiveness, L. humile does not seem to affect populations of O. erosus.     

Predispersal seed predation in Acacia macrostachya,its impact on seed viability,and germination responses to scarification and dry heat treatments

Predispersal seed predation among individual Acacia macrostachya trees over two sites in Burkina Faso was assessed. In addition, the effects of seed predation on seed viability; germination responses to scarification (mechanical, hot water at 60, 70 and 80°C, and sulphuric acid for 10, 20 and 30 min) and dry heat (at 60, 70 and 80°C for 15, 30 and 60 min each) treatments were investigated under laboratory conditions. The results indicated a large difference in predation intensity among individual trees, as well as between sites. Predispersal predation significantly decreased seed germination, particularly when the number of insect larvae per seed increased. Scarified and unscarified seeds germinated equally well, except for hot water treatments of high temperature. This indicates lack of physical dormancy and dispersed seeds can readily germinate provided that conditions for germination are conducive. Seeds exposed to dry heat treatments also germinated close to 97% under low intensity and short exposure times. This suggests that fire, under natural condition, plays a key role in triggering germination of A. macrostachya seeds.     

Seedling growth and ectomycorrhizal colonization of Pinus patula and P. radiata inoculated with spores of Helvella lacunosa,Russula brevipes or Lycoperdon perlatum

Seedling growth and ectomycorrhizal colonization of Pinus radiata and P. patula seedlings growing in nursery containers with two application rates of spores of 3 different ectomycorrhizal fungi, Helvella lacunosa, Russula brevipes and Lycoperdon perlatum, was evaluated at 5 and 12 months. At 5 months of growth P. patula was less susceptible than P. radiata to colonization by fungi and percentage of ectomycorrhizal feeder roots was lower in all treatments. Growth response (either volume or top dry weight) to treatments was different among pines species. A significant seedling growth response was observed after 5 months in both pine species with the double rate of spores of either H. lacunosa or L. perlatum; this response was sustained in P. patula at 12 months with Helvella only. P. radiata seedlings inoculated with the double rate of spores of R. brevipes showed a significant growth response at 12 months.

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Resumen Se estudió en dos intervalos del crecimiento de Pinus patula y P. radiata, en envases de vivero, la inoculación con dos dosis de esporas de los hongos ectomicorrícicos Helvella lacunosa, Russula brevipes y Lycoperdon perlatum. P. patula se mostró, en la temprana edad (5 meses) menos susceptible a la colonización radicular por bongos; la proporción de sus raicillas micorrizadas es, en todos los tratamientos, mas baja que la del otro pino. La respuesta a la inoculación (volumen o peso seco) es diferente en las dos especies de pinos; a los 5 meses se observa en ambos un respuesta significativa a la doble dosis de esporas tanto de Helvella como de Lycoperdon. Esta respuesta es consistente a los 12 meses solo en P.patula inoculado con esporas de Helvella; en esta misma etapa, las plantulas de P.radiata inoculadas con la doble dosis de esporas de Russula mostraron una respuesta significativa en su crecimiento.

     

Roraimine: a bisbenzylisoquinoline alkaloid from Cissampelos sympodialis roots

The roots of Cissampelos sympodialis yielded Roraimine (1), a novel bisbenzylisoquinoline alkaloid and liriodenine (2), a known oxoaporphine alkaloid.     

Long lasting effects of O3 and SO2 on the sensitivity to drought in two clones of Picea abies (L.) Karst.

Rooted cuttings of two Picea abies-clones were fumigated with O₃ and O₃+ SO₂ for 12 weeks. After 4 and 16 months without fumigation the treated plants showed much higher sensitivity to drought (expressed in osmotic potential of cell sap and in percent survival) than the untreated ones.     

Seasonal variations in location and population structure of endophytes in buds of Scots pine

We studied the location and distribution of a bacterial isolate, a Mycobacterium sp., in buds of Scots pine (Pinus sylvestris L.). Using a probe specific for the 16S rRNA of the Mycobacterium sp., the bacterium was found by in situ hybridization in the meristematic tissues of 40% of all bud samples examined. Because we had previously found other bacterial and fungal endophytes in the meristematic tissues of Scots pine buds, we studied their occurrence in buds during shoot development and dormancy. Using probes targeted to the 16S or 18S rRNA of the endophytes Mycobacterium sp., Methylobacterium spp., Pseudomonas spp. and Rhodotorula minuta, endophytes were found in association with growing tissues, with Methylobacterium spp. being the dominant species. Endophytes were detected in abundance before elongation or differentiation of a bud, but once a tissue was fully developed, endophytes were no longer detected. Metabolic activity of the endophytes was suppressed at the onset of, and during, dormancy of Scots pine, but recovered before the following growing season.