Reproductive phenology of Brazilian savannas and riparian forests: environmental and phylogenetic issues

Introduction   

The reproductive phenology of plants is expected to be influenced by climatic factors and by the phylogenetic history of the species. In savannas, the peaks of flowering and fruiting are associated with climate seasonality. However, there is still a controversy about the reproductive phenology of plants in riparian forests, a vegetation type that does not experience a severe water shortage.     

What a few hairs can tell us about the resource use of giant armadillos

Understanding of resource requirements of vulnerable species is key for conservation planning. Here, we used stable carbon (δ¹³C) and nitrogen isotopes (δ¹⁵N) of hair from giant armadillos (Priodontes maximus) to understand individual resource use. We collected hair from 19 giant armadillos analyzing 34 samples from the Brazilian Pantanal and compared the resource use between sexes and age classes. We also assessed the relationship of isotopic values with individuals’ body mass and the habitat type used. We observed a wide variation in resource use by giant armadillos, showing that individuals consume prey that feeds on distinct resources and occupies different habitat types, indicating that there is individual variation in foraging behavior. Most giant armadillos presented a mixed diet (C₃/C₄ resources, forests/open areas), but a quarter of individuals had strictly C₄ diets (open areas). Males are more prone to forage on C₄ resources, presenting an isotopic niche 2.6-times larger than that of females. Subadults presented diets more associated with habitats with high arboreal cover (C₃ resources, forests), while adults foraged more in open areas (C₄ resources). This result is mirrored by the positive relationship between δ¹³C values and body mass, suggesting that larger giant armadillos tend to feed more in open areas. We observed that δ¹³C values decreased as individuals increased the use of habitats with high arboreal cover. We stress the importance of conserving the natural mosaic in the Pantanal landscape for the species persistence, given that giant armadillos require all habitat types to fulfill their dietary, spatial, and developmental needs.     

Phosphorus availability and grass growth in biochar-modified acid soil: A study excluding the effects of soil pH

The low efficiency of phosphorus fertilization in weathered soils can limit plant development. The application of biochars in these areas has been seen as an important way to increase the efficiency of phosphorus fertilization and to promote better plant growth. However, biochars are alkaline materials that can increase soil pH and thus change the nutrient dynamics, which has been often ignored in studies of this nature. Here, all treatments had their pH standardized at 6.1 to eliminate the influence of pH on biochar application responses. The main goal of this study was to evaluate the real potential of coffee straw and eucalyptus bark biochars, produced under different pyrolysis temperatures, in the optimization of phosphorus fertilization and the development of Brachiaria brizantha. A greenhouse experiment was set up in a 2 × 2 × 5 factorial scheme, conducted for 120 days. The biochars, prepared from coffee straw and eucalyptus bark at 350 and 600°C, were applied at five rates in a Red-Yellow Oxisol. The application of biochars may reduce the demand for nutrients and correctives, optimize phosphorus fertilization and improve the development of Brachiaria brizantha, but this ability depends on the raw material and the pyrolysis temperature used in its production. All analysed biochars can contribute to higher tillering and dry matter production, but only coffee straw biochars and eucalyptus bark biochar produced at 350°C were efficient in the optimization of phosphorus fertilization until 120 days of cultivation of Brachiaria brizantha.     

Histological Biomarkers and Protein Expression in Hyphessobrycon eques Fish Exposed to Atrazine

Water, Air, & Soil Pollution - Decentralized tap water systems are an important drinking water source worldwide. A good quality, high-pressure continuous water supply (CWS) is always the target...     

Fractionation of soil phosphorus in organic amended farms located on savanna sandy soils of Venezuelan Amazonian

In Venezuelan Amazonian, some producers have established small agroforestry systems of production on sandy savanna soils by a long-term addition (more than 25 years) of animal manures at a low dressing (2 Mg ha⁻¹) as fertilizer input. As a result of the organic fertilizers regime, the original savanna soil has been changed in terms of soil quality parameters. The main objective of the study was to investigate using sequential fractionation of soil P the impact of organic manures on the amount and partitioning of bioavailable P in soils of the Amazonas. Fractionation was carried out on Typic Ustipsamments amended with three different organic manure sources for extended periods. In general, after fertilization, all Pi and Po fractions increased significantly. The increase was striking in the resin-Pi and HCl-Pi, and among the organic P fractions, the changes were highest for the NaOH-Po sonicated and non-sonicated fractions. The total P increment was more relevant when soils were amended with chicken manure (1,194 mg Pt kg⁻¹) and less relevant for the farm soil treated with compost (500 mg Pt kg⁻¹), where the soil amended with cattle waste presented an intermediate value in total soil P (851 mg Pt kg⁻¹). The importance of this field study was to assess the sustainability of long-term established organic management characterized by the low inputs, and this information is poor in the Amazonas.     

A new resistance gene to PepYMV (Pepper yellow mosaic virus) in Capsicum annuum L.

Pvr4 locus, commonly associated with a co-dominant CAPS marker, confers monogenic dominant resistance to potyvirus complex in Capsicum spp. Aiming to investigate whether the resistance found in resistant genotypes not bearing Pvr4 marker is due to allelism in the Pvr4 locus, or due to a new locus of the pvr series, segregation analyses of an F₂ population obtained from a cross between two pepper lines “Myr-29-10” (P₁) (resistant to PepYMV, showing a single band of 444 bp, Pvr4/Pvr4) and “PIM-025” (P₂) (resistant to PepYMV, showing a single band of 458 bp, Pvr4⁺/Pvr4⁺) were performed. According to the results, there is strong evidence that the locus controlling PepYMV resistance in PIM-025 (P₂) is not Pvr4. These results provide evidence that those resistant genotypes, bearing a susceptible band pattern in the Pvr4 locus (458 bp, Pvr4⁺/Pvr4⁺), carry a different gene from those described in the literature up to the present time.     

Semen characteristics of Colossoma macropomum from three successive sample collections in the same reproductive cycle

The objective of this work was to evaluate the semen characteristics of C. macropomum fish from three successive semen sample collections taken during the same reproductive cycle. Six breeders (6.4 ± 1.5 kg) induced with crude carp pituitary extract (2.5 mg kg^?1) were used. Samples of semen were collected in graduated syringes after a period of 260 degree‐hours. The semen was collected from the same males in September 2014 (sample 1), December 2014 (64 days after the first collection – sample 2) and February 2015 (86 days after the second collection – sample 3). The semen volume was higher (P < 0.05) in the sample 1 (6.7 mL) and sample 2 (3.4 mL) than in the sample 3 (1.0 mL). Sperm concentration and normal sperm did not significantly differ between samples. Likewise, sperm motility, curvilinear velocity, displacement velocity, oscillation and beat cross frequency did not vary, whereas straight‐line velocity, straightness and progression were higher (P < 0.05) in sample 2 (December). In general, despite lower amounts, the semen appeared to be of good quality for all three samples collected during the same reproductive period.     

Differences and similarities among experts' opinions on Salmonella enterica dynamics in swine pre-harvest

A workshop was conducted to elicit expert opinion on infection status and transmission of salmonella in pigs at the farm of origin, during transport and during lairage. A second objective was to compare opinions regarding risk factors for salmonella introduction and control at the farm level between experts from different countries. Thirty-six experts from 11 countries filled in a paper-and-pencil questionnaire during an international conference. Experts from all countries agreed on the risk of salmonella introduction related to live animals and the importance of general hygiene and all-in/all-out management for salmonella control. However, workshop participants from Denmark put more weight on factors related to feed while experts from USA rated factors related to rodents and people contact higher. The experts believed that 21-33% of pigs coming from a chronically infected farm would be infected with salmonella, but only one-third of the infected pigs would be shedders. Regarding transport and lairage, the US participants believed that contamination was occurring in the majority of pigs regardless of initial infection status and particularly during lairage; in contrast, the Danish experts were more optimistic with respect to the contamination and infection risk. US experts believed that the incidence of salmonella shedding would be high among pigs infected during transport and lairage and that an important proportion of 'carrier' pigs would start shedding.Our results reflect the differences in the level of salmonella infection and implemented control strategies between countries as well as the different philosophies that professionals have. The differences in opinion regarding salmonella dynamics could be due either to true differences in risk as a consequence of distinct management and transport practices in Denmark and USA or to a difference in perception.     

Roost selection by barbastelle bats (Barbastella barbastellus, Chiroptera: Vespertilionidae) in beech woodlands of central Italy: consequences for conservation

We investigated roost selection by Barbastella barbastellus in a mountainous area of central Italy. Twenty-five bats, mostly lactating females, were radio-tracked to 33 roost trees. Trees in unmanaged woodland were favoured as roost trees; woodland subject to limited logging was used in proportion to availability, and areas where open woodland and pasture occurred were avoided. Selection depended on tree condition (dead beech trees were preferred) and height (roost trees were taller than random ones). Cavity selection was based on cavity type, height and entrance direction: roost cavities were mainly beneath loose bark, at a greater height above ground and facing south more frequently than random cavities. Untouched areas of mature woodland should be preserved to provide roosting conditions for B. barbastellus. In logged areas, harvesting protocols should save dead and mature trees; frequent roost switching and small colony size imply that large numbers of roost trees are needed.