Andropogon lateralis is a tall and highly plastic tussock-forming grass native from southern South America. It is a frequent component of Campos and Subtropical highland grasslands that often becomes dominant under lax grazing regimes. The aim of this work was to analyze the response of species diversity and forage production of a natural grassland dominated by A. lateralis to a wide range of grazing intensity. We hypothesized that species diversity and forage production would both peak at the intermediate canopy heights determined by grazing regimes of moderate intensity. A grazing experiment was conducted in a highland grassland with mesothermal humid climate at 922 masl (Atlantic Forest biome, Santa Catarina state, Brazil) that comprised 87 species from 20 families but had 50% of its standing biomass accounted by A. lateralis. Four pre-/post-grazing canopy heights—12/7, 20/12, 28/17, and 36/22 cm (measured on A. lateralis)—were arranged in a complete randomized block design with four replications, and intermittently stocked with beef heifers from October 2015 to October 2017. Andropogon lateralis cover decreased (from 75 to 50%), and species richness increased (15–25 species m−2) as canopy height decreased. Grazing intensity did not affect annual forage production (4.2 Mg DM ha−1). This natural grassland dominated by A. lateralis had a high capacity to adjust to grazing regimes of contrasting intensity, maintaining forage production stable over a wide range of canopy heights. However, to prevent losses in floristic diversity, such grassland should not be grazed at canopy heights higher than 28 cm.

Find shade-tolerant species is essential to the success of silvopastoral systems, increasingly frequent in recent years. In legumes, which have potential of biological nitrogen fixation, there is a great lack of knowledge when in shaded environments.The cultivation of four tropical forage (Neonotonia wightii, Pueraria phaseoloides, Macrotyloma axilare and Arachis pintoi) was evaluated when submitted to artificial shade levels (30, 50 and 70% shade) and in full sun during water and drought seasons. The design used was in randomized complete blocks in a sub-divided plot scheme with four replications. In the Water-season the Forage Peanuts had higher forage production in full sun (11 ton ha-1 DM), and under shade did not differ from Perennial Soybean, higher than the others in all levels of shade. In Drought-season the forage production was 61% lower than in Water-season. The highest crude protein levels were reported in Forage Peanuts, Tropical Kudzu and Perennial Soybean, 19.0; 18.3 and 18.2% respectively in the Water-season. Forage Peanuts is a good option for use in silvopastoral systems although there is a small reduction in forage production (average of 23.7%). In general, species of fabaceae showed a greater reduction in forage production in the period of water deficit; however, shading at levels of 30% to 50% contribute to mitigation of water shortage. Although, there is a small reduction in forage production, withexception of perennial soybeans in dry season, it is advisable to use tropical forage legumes in silvopastoral systems, since forage quality is not affected by shade.

Objetivou-se com esse estudo avaliar o potencial produtivo do pasto de Urochloa decumbens sob três arranjos silvipastoris mais o tratamento controle (monocultivo) além das características dendrométricas de Eucaliptus urophylla nos espaçamentos 3x2, 6x4 e 10x4 m dos 48 meses aos 66 meses pós-plantio do eucalipto. O delineamento experimental utilizado foi em blocos completos casualizados, com quatro blocos e duas repetições por bloco. Para avaliar a forrageira e o eucalipto, foram utilizados os arranjos em parcelas subdivididas. Para avaliar as distâncias da linha de plantio do eucalipto de cada espaçamento, foi utilizado o arranjo em parcela subsubdividida. O acúmulo de forragem, taxa de acúmulo de forragem, altura e teor de matéria seca da forrageira foram maiores no monocultivo. O teor de proteína bruta foi maior no espaçamento 6x4 m. Os menores teores de fibra em detergente neutro foram encontrados nos tratamentos sombreados. A altura do eucalipto teve influência somente de idade. O diâmetro a altura do peito, diâmetro de copa foram maiores nos espaçamentos 6x4 e 10x4 m. A relação altura: diâmetro a altura do peito foi maior no espaçamento 3x2 m. O volume/planta foi maior no espaçamento 6x4 e 10x4 m, respectivamente. O volume/ha e incremento médio anual foram maiores no espaçamento 3x2 m. O espaçamento 6x4 m até os 5,5 anos de avaliação é o mais indicado para produção e qualidade de pasto e produção de madeira.

This study aimed to evaluate the effect of tree shading levels on tillers’ morphogenetic and structural traits, besides the herbage accumulation of Tanganyika grass ( Megathyrsus maximus Jacq. cv. Tanganyika). For that, an experiment was carried out from December 2010 to March 2012, under a completely randomized design, with four treatments (shading levels) and five repetitions. Phyllochron (PHY), leaf and stem elongation rates (LER and SER, respectively), number of leaves per tiller (NLT), leaf blade length (LBL), stem length (ST), tiller population density (TPD), leaf (LGR) and stem growth rates (SGR), senescence rate (SR) and herbage accumulation rate (HAR) were assessed. Excepted by the LER and NLT, the shading levels influenced the other morphogenetic variables (P<0.05), positively or negatively. Except in the spring, the TPD linearly increased because of the shading levels (P<0.05). At tiller level, except in the spring, the LBL linearly increased with the shading levels (P<0.05). In general, the SL linearly decreased with the shading levels. Regarding the growth rates, summer II and spring provided greater values, and the lowest one occurred in autumn (P<0.05). The adjustments of both morphogenetic and structural traits ensured the Tanganyika grass a great adaptation to the shaded environment.

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