Pasture Dynamics after Sodseeding Cool Season Species with or without Glyphosate in Subtropical Natural Grasslands

This trial was conducted to evaluate vegetation dynamics of natural grasslands fertilized and sodseeded with the cool season species Italian ryegrass (Lolium multiflorum), white clover (Trifolium repens) and birdsfoot trefoil (Lotus corniculatus) with or without glyphosate. Treatments that included herbicide spraying on natural vegetation caused a substitution of perennial grasses by undesirable species, and did not show a significant contribution of introduced species. Andropogon lateralis, Paspalum notatum, Paspalum dilatatum and Paspalum plicatulum almost disappeared, and were replaced by Chaptalia nutans and Apium spp, among others

Monitoramento da restauração de butiazais em campo nativo sob manejo pecuário.

A Embrapa Clima Temperado tem conduzido vários projetos de pesquisa e desenvolvimento com o objetivo de promover a conservação e o uso sustentável dos ecossistemas de butiazais, com apoio financeiro de várias instituições, além de recursos de passivos ambientais de empresas. Este Documento apresenta diretrizes técnicas para restauração de ecossistemas campestres com butiazais e decorre da lacuna existente para esse tipo de produto técnico, relacionado à disponibilidade de orientações para restaurar campos nativos com butiazais. Considerando-se o estado de vulnerabilidade em que se encontram as populações remanescentes dos butiazais, esta publicação contribui para atingir as metas 15.1 e 15.5 dos Objetivos de Desenvolvimento Sustentável (ODS), uma vez que traz avanços no conhecimento relacionado aos ecossistemas de butiazais, com sua biodiversidade associada. O conhecimento ora disponibilizado é importante para subsidiar ações de conservação desses ecossistemas e apoiar a formulação de políticas públicas para a proteção do meio ambiente.ODS 15

Morphogenesis and Defoliation Frequency of Italian Ryegrass (\u3ci\u3eLolium multiflorum\u3c/i\u3e) and \u3ci\u3ePaspalum urvillei\u3c/i\u3e in Lowland under Three Levels of P and K

This trial was conducted to evaluate growth dynamics and defoliation frequency of Italian ryegrass (Lolium multiflorum) and Paspalum urvillei in a lowland area under three levels of P and K. Using randomization tests we observed that, in a general way, fertilizer treatments were not the determinant factors of leaf appearance and elongation rates for both species. Only the leaf appearance rate of Paspalum urvillei at 100 % of recommendation level and the elongation rate for Italian ryegrass, in the same treatment, was different. Probably other factors, like drainage, are contributing to these results. I. ryegrass phyllochron ranged from 57.3 to 72.6 degree-days. Paspalum urvillei presented higher grazing frequency in almost all evaluated periods, revealing a high preference by the grazing animals

Análise fractal do padrão espacial de plantas em pastagem.

ABSTRACTThe use of fractal analysis was evaluated as a tool in the determination of grazing patterns in natural grasslands submitted to different managements. The treatments tested in Santa Maria were grazing with burning, grazing without burning, exclusion with burning and exclusion without burning. In Bagé, the evaluated treatments were natural pasture and introduction of ryegrass, white clover and birdsfoot trefoil in a natural grassland. The characterization of the floristic composition of the pasture was performed by the BOTANAL method. The pasture diversity was calculated by Shannon (H') and Evenness (J) indexes. The fractal dimension information was calculated by regression between H'(ε) and ε natural algorithm, with the line?s slope being the fractal dimension information. Shannon and Evenness indexes showed dependence on the sample area, where the highest floristic diversity and homogeneity of the distribution frequency of plants between species were observed in the sample range of 0.87 to 1.03m2. The fractal dimension can be a tool in determining patterns in the plant community on the reduced grazing scale. The limitation of the use of this technique for reduced scales is the need for a greater number of repetitions.Keywords: burn, diversity, evenness, grazing, shanno

Os butiazais e as transformações das paisagens na região do Parque Estadual do Podocarpus, Encruzilhada do Sul, RS.

Esta publicação é um produto do projeto Rota dos Butiazais: fortalecimento da cadeia produtiva do butiá associado à recuperação da vegetação nativa na região do Parque Estadual do Podocarpus (Encruzilhada do Sul, RS), e discute o estado de conservação dos butiazais e região do entorno do Parque Estadual do Podocarpus, no município de Encruzilhada do Sul, RS. Foram realizadas atividades com o objetivo de identificar remanescentes de vegetação nativa (campos, butiazais, florestas) na região do Parque Estadual do Podocarpus e arredores e identificar áreas degradadas de campos e butiazais com potencial para restauração ecológica. Este trabalho descreve o uso e cobertura do solo atual (2020) e evidencia as transformações ocorridas nessa cobertura ao longo dos últimos 30 anos (1990 - 2020) na região do Parque Estadual do Podocarpus e arredores, considerando sua zona de amortecimento e os remanescentes de butiazais no município de Encruzilhada do Sul. Elucidar essas transformações e, principalmente, localizá-las espacialmente possibilita definir áreas potenciais para ações de restauração e identificar áreas que seguem sendo cobertas por formações campestres, ou seja, locais potenciais para coleta de sementes de espécies nativas que possam vir a ser utilizadas na recuperação de áreas de campo degradadas no Bioma Pampa.ODS 15

Tricritical behaviour in deterministic aperiodic Ising systems

We use a mixed-spin model, with aperiodic ferromagnetic exchange interactions and crystalline fields, to investigate the effects of deterministic geometric fluctuations on first-order transitions and tricritical phenomena. The interactions and the crystal field parameters are distributed according to some two-letter substitution rules. From a Migdal-Kadanoff real-space renormalization-group calculation, which turns out to be exact on a suitable hierarchical lattice, we show that the effects of aperiodicity are qualitatively similar for tricritical and simple critical behaviour. In particular, the fixed point associated with tricritical behaviour becomes fully unstable beyond a certain threshold dimension (which depends on the aperiodicity), and is replaced by a two-cycle that controls a weakened and temperature-depressed tricritical singularity.Comment: Formatting improved. 7 pages, 2 figures (included). Journal reference adde

Design and Development of a Magnus Hydrokinetic Rotor

The energy matrix diversification has become noticed in the latest years. Energy conversion of the free flow in rivers and canals into electrical energy has been a good complementation for the conventional generation. The first application of hydrokinetic turbines, commercially, were in Mississippi's river (Minnesota, USA), in 2008. The USAge of Magnus effect in hydrokinetic turbines occurred in an innovative manner. In this project, rotational cylinders actuate as blades of an axial hydrokinetic rotor, converting kinetic energy of the flow into potency in the rotor axle. This effect was initially observed in 1853 by Henrich Magnus and, since then, few researches were carried out to its application in hydraulic generation of energy. Therefore, tests in reduced-scale prototype and numerical simulations were made for the development and executive design of a hydrokinetic rotor. At the end of this study, a hydro generator with 62% hydraulic efficiency, considering the Betz Limit, was constructed