Dissimilarity between Andropogon lateralis ecotypes under different defoliation frequencies and heights

ABSTRACT: Andropogon lateralis Nees is a native grass of southern Brazil and is one of the most frequent specie found in native grasslands. The species is widely distributed and has a high degree of phenotypic plasticity, which makes it highly adaptable to different edaphoclimatic conditions and management. This study aimed to evaluate the behavior of twelve ecotypes of A. lateralis, collected in different regions of the state of Rio Grande do Sul and cut to three different heights and subjected to two different defoliation frequencies. From September to February, the ecotypes were evaluated for total dry matter, leaf and stem yields. In addition, total, vegetative and reproductive tillers and plant height were measured. These characteristics are important for the selection of superior genotypes in terms of genetic variability and forage production. Total dry matter and leaf dry matter are characteristics with agronomic importance and they showed the highest correlation (r = 0.77), enabling an indirect selection for one of these characteristics. The natural selection of plants resulted in distinct structural, morphological and productive characteristics with heterogeneity that allows the selection and grouping according to the characteristics, ecotypes with superior agronomic characteristics can be included in breeding programs.

Caracterização do conhecimento de pecuaristas gaúchos da serra do sudeste sobre o carrapato Rhipicephalus microplus

The purpose of this research project was to determine knowledge of the Rhipicephalus microplus tick among seventy cattle ranchers in the Caçapava do Sul and Lavras do Sul municipalities in Rio Grande do Sul State, through completing a structured questionnaire. The replies to the questions on the land areas covered by the properties show that 27%, 26%, 21.5%, 20% and 5.5% cover more than 500 hectares, between 150 and 300 hectares, between 300 and 500 hectares, between 50 and 150 hectares, and under 50 hectares, respectively; 75% of the ranchers are raising more than 100 head of cattle; 84.3% have cultivated grazing pastures and 15.7% have only native grasslands; 87.14% of the ranchers rated bovine babesiosis as the main tick-borne disease, and 76% checked out tick control products recommended by veterinarians. They mentioned 13 formulations and/or associations of tick control products. The tick control biogram test is a new tool for 58.6% of these cattle ranchers. Producers use late control, based on tick control chemicals.

Northern bobwhite select for shrubby thickets interspersed in grasslands during fall and winter

Resource selection is a key component in understanding the ecological processes underlying population dynamics, particularly for species such as northern bobwhite (Colinus virginianus), which are declining across their range in North America. There is a growing body of literature quantifying breeding season resource selection in bobwhite; however, winter information is particularly sparse despite it being a season of substantial mortality. Information regarding winter resource selection is necessary to quantify the extent to which resource requirements are driving population change. We modeled bobwhite fall and winter resource selection as a function of vegetation structure, composition, and management from traditionally (intensively) managed sites and remnant (extensively managed) grassland sites in southwest Missouri using multinomial logit discrete choice models in a Bayesian framework. We captured 158 bobwhite from 67 unique coveys and attached transmitters to 119 individuals. We created 671 choice sets comprised of 1 used location and 3 available locations. Bobwhite selected for locations which were closer to trees during the winter; the relative probability of selection decreased from 0.45 (85% Credible Interval [CRI]: 0.17–0.74) to 0.00 (85% CRI: 0.00–0.002) as distance to trees ranged from 0–313 m. The relative probability of selection increased from near 0 (85% CRI: 0.00–0.01) to 0.33 (85% CRI: 0.09–0.56) and from near 0 (85% CRI: 0.00–0.00) to 0.51 (85% CRI: 0.36–0.71) as visual obstruction increased from 0 to 100% during fall and winter, respectively. Bobwhite also selected locations with more woody stems; the relative probability of selection increased from near 0.00 (85% CRI: 0.00–0.002) to 0.30 (85% CRI: 0.17–0.46) and near 0.00 (85% CRI: 0.00–0.001) to 0.35 (85% CRI: 0.22–0.55) as stem count ranged from 0 to 1000 stems in fall and winter, respectively. The relative probability of selection also decreased from 0.35 (85% CRI: 0.20–0.54) to nearly 0 (85% CRI: 0.00–0.001) as percent grass varied from 0 to 100% in fall. We suggest that dense shrub cover in close proximity to native grasslands is an important component of fall and winter cover given bobwhite selection of shrub cover and previously reported survival benefits in fall and winter.

Eryngium (Apiaceae, Saniculoideae) in the state of Paraná, southern Brazil

Eryngium has about 220 species, mostly distributed in subtropical and temperate regions of all continents. With about 60 species, the genus is widely distributed in Brazil, being present in all states of the country. Its species are perennial or biennial plants that preferentially colonize terrestrial, aquatic and rocky substrates. They usually have an erect or creeping habit, with rosulate leaves and white, blue or purple flowers. Within Apiaceae, the genus can be easily distinguished from the other genera by its capitulate inflorescences and by having a single bract per flower. We present the first taxonomic treatment for the genus in the state of Paraná, which is based on herbarium collections and fieldwork across the state. In total, 25 species were recorded. Of these, seven are endemic to Brazil. Eryngium aloifolium and E. regnelli are new records for Paraná. Fifteen species grow in native grasslands at high elevations, whereas one species is restricted to remnants of savannas in the northern portion of the state (E. rochei). Identification key, descriptions, illustrations, distributions maps, and taxonomic comments are provided.

Cytisus scoparius (scotch broom).

C. scoparius is a perennial shrub that has been widely commercialized as an ornamental in temperate and subtropical regions of the world. It is a prolific seeder that escaped from cultivation and has become an invasive species and a serious weed in temperate areas of the United States, Canada, Hawaii, Chile and Argentina, the eastern halves of both islands of New Zealand, Australia (including Tasmania), India, Iran, Japan and South Africa (Holm et al., 1979; Parsons and Cuthbertson, 1992; Hosking et al., 1998; Peterson and Prasad, 1998; Isaacson, 2000). C. scoparius is an aggressive fast-growing invader with the capability to grow forming dense impenetrable monospecific stands that degrade native grasslands, forests, rangelands, and agricultural lands; prevent the regeneration of natural forests and prairies; and create fire hazards (Syrett et al., 1999; USDA-NRCS, 2016). Because of its association with nitrogen fixing bacteria, it is very competitive in areas with poor soils and can alter the nutrient cycling of invaded areas (Peterson and Prasad, 1998).

Seasonal Effect on Feed Intake and Methane Emissions of Cow–Calf Systems on Native Grassland with Variable Herbage Allowance

The aim of this study was to measure methane emissions (CH4) and herbage intake, and, on the basis of these results, obtain the methane yield (MY, methane yield as g CH4/kg dry matter intake (DMI) and Ym, methane yield as a percentage of Gross Energy intake), from beef cows grazing on native grasslands. We used forty pregnant heifers, with two treatments of herbage allowance (HA) adjusted seasonally (8 and 5 kg dry matter (DM)/kg cattle live weight (LW), on average), during autumn, winter and spring. Methane emissions (207 g CH4/d), organic matter intake (OMI, 7.7 kg organic matter (OM)/d), MY (23.6 g CH4/kg DMI) and Ym (7.4%), were similar between treatments. On the other hand, all variables had a marked increase in spring (10.8 kg OM/d and 312 g CH4/d), except for Ym. The methane emission factor from Intergovernmental Panel on Climate Change (IPCC) Tier 2 estimated with these results was 78 kg CH4/head/year. The results show that methane emissions and intake were influenced by the season, but not by the HA analyzed in this study. This information for cow–calf systems in native grasslands in Uruguay can be used in National greenhouse gases (GHG) inventories, representing a relevant contribution to global GHG inventories.

COMPARISON OF DIURNAL BIRDS OF PREY COMMUNITY BETWEEN NATURAL AND ANTHROPIZED ENVIRONMENTS IN HIGHLAND GRASSLANDS OF RIO GRANDE DO SUL, BRAZIL

The highland grasslands, characteristic of the mountain region of the state of Rio Grande do Sul, have been used historically for several commercial purposes, including extensive livestock, forestry, and agriculture. The biodiversity has a high endemism, but there is a lack of studies on various animal and plant groups. Birds of prey are a great group to assess environmental quality, as they are top predators. This study aimed to test if the diurnal birds of prey community is changing due to the replacement of native grasslands by other human economic activities. We surveyed birds of prey at 12 sampling points from August 2018 to June 2019, including protected grasslands and livestock grasslands, agricultural, and forestry areas. We obtained 1,582 records of birds of prey of 17 species, and the highest richness and number of records, were obtained in the protected grasslands (17 spp.; 393 records) and livestock grasslands (15 spp.; 434 records), followed by agriculture (13 spp.; 418 records) and forestry areas (9 spp.; 337 records). There was a significant difference in the richness of birds of prey in the protected grasslands, livestock grasslands and agriculture areas over the forestry areas. In the number of records, there was a significant difference between livestock grasslands and agriculture areas over forestry areas. This study showed that the conversion of native grassland areas, mainly by forestry, affects the composition of the diurnal birds of prey community, especially the rarest and most endangered species.