6 research outputs found

    Cama-de-frango em mono e policultivo de fáfia com cravo-de-defunto e manjericão Poultry manure in mono and intercrop of Brazilian ginseng with marigold and basil

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    O experimento foi conduzido em campo da Universidade Federal da Grande Dourados (UFGD), em Dourados-MS, de março de 2005 a setembro de 2006, em Latossolo Vermelho distroférrico. O objetivo foi avaliar a produção da Pfaffia glomerata (Spreng) Pedersen (fáfia) em monocultivo e os policultivos com Tagetes erecta L. (cravo-de-defunto) e Ocimum basilicum L. (manjericão), sem e com incorporação de cama-de-frango semidecomposta. Os fatores em estudo foram a fáfia (F), o cravo-de-defunto (C) e o manjericão (M) em monocultivos e os policultivos com duas fileiras de fáfia e três de cravo (F2C3) e duas fileiras de fáfia e três de manjericão (F2M3), todos sem e com incorporação ao solo de cama-de-frango de corte semidecomposta. Os dez tratamentos foram arranjados no delineamento blocos casualizados, com quatro repetições. A produção de massa fresca e seca da parte aérea da fáfia foi maior (13,22 t ha-1 e 4,39 t ha-1, respectivamente) em monocultivo, independente do uso da cama-de-frango. Por outro lado, nenhum dos tratamentos influenciou a massa fresca e seca e o número de raízes da fáfia, que foram, em média, de 10,02 e 2,07 t ha-1 e 417.916 raízes ha-1, respectivamente. O diâmetro das raízes foi maior (23,5 mm) no policultivo com o manjericão. As produções de massas frescas e secas dos capítulos florais do cravo-de-defunto foram maiores (14,28 t ha-1e 1,278 t ha-1, respectivamente) no policultivo com a fáfia, mas apenas a produção de massa fresca dos capítulos foi maior (14,17 t ha-1) com o uso da cama-de-frango. A produção de parte aérea do manjericão foram maiores (52,91 t ha-1) no policultivo, independente com qual espécie; porém, não foi influenciada pelo uso da cama-de-frango. A razão de área equivalente (RAE) para o policultivo da fáfia com o cravo-de-defunto foi de 2,15 com cama-de-frango e de 1,99 sem cama e com o manjericão, foi 2,44 com cama e de 3,08 sem cama. Como os valores foram maiores que 1,0, indicam que os policultivos foram efetivos.<br>This study was carried out in field of the Universidade Federal da Grande Dourados, in Dourados, Brazil, during the period from March 2005 to September 2006. The aim of the experiment was to evaluate Pfaffia glomerata (Spreng) Pedersen yield under monocropping system or intercropped with Tagetes erecta L. and Ocimum basilicum L, in a Distroferric Red Latosol (sand loam Rhodic Oxisol), using semi-decomposed poultry manure (PM). The study objects were Brazilian ginseng (BG), marigold (M) and basil (B) under monocropping and the intercropping of two Brazilian ginseng, three marigold (BG2M3) and three basil (BG2B3) lines, all of them with or without semi-decomposed poultry manure (PM) as fertilizer. Ten treatments were arranged in randomized blocks design, with four replications. Fresh and dry weight production from shoot of Brazilian ginseng were higher (13.22 t ha-1 and 4.39 t ha-1, respectively) under monocropping, independently of the use of poultry manure. Nevertheless, none of experimental designs influenced the dry and fresh weight production or root number of Brazilian ginseng which produced average values of 10.02 and 2.07 t ha-1 and 417,916 roots ha-1, respectively. Root diameter was higher (23.5 mm) under intercropping system with basil. Dry and fresh weight of marigold flowers were higher (14.28 t ha-1and 1.278 t ha-1, respectively) when intercropped with Brazilian ginseng, but only fresh weight of the flowers was increased (14.17 t ha-1) by poultry manure application. Basil shoot production was higher (52.91 t ha-1) when intercropped, independently of the used species; however, they were not influenced by the use of poultry manure. Land equivalent ration (LER) for the Brazilian ginseng intercropped with marigold was 2.15 under poultry manure application and 1.99 without it, and for the basil 2.44 under poultry manure application and 3.08 without it. Values higher than 1.0 indicate that the intercropping systems were effective

    High conservation value forests for burn-associated saproxylic beetles: an approach for developing sustainable post-fire salvage logging in boreal forest

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    1. Fire-killed timber is considered as a loss of potential revenues andis thus increasingly salvaged, though not without concerns for biodiversity con-servation. Indeed, a large diversity of burn-associated saproxylic beetles userecently burned trees. 2. This study intends to reduce potential impacts of salvage logging on biodi-versity by identifying high conservation value forests (HCVFs) for burn-associated beetles, which are considered the most at risk. 3. In five burns ignited naturally in 2010 in the eastern Canadian boreal for-est, we selected 31 and 29 stands of black spruce and jack pine respectively.Three 50-cm bole segments were retrieved from each stand and placed inemergence cages to measure tree utilisation by saproxylic beetles. This yielded7235 beetles from 103 taxa, of which 67 were considered rare (5% occurrence in logs). 4. Among the common taxa, we identified six groups of ecologically relatedspecies using co-occurrence-based hierarchical clustering, among which threewere mainly formed by opportunistic species that are currently of little concernin a post-fire logging context. The three other groups were formed by burn-associated species that could be affected by salvage logging. 5. HCVFs include jack pine stands and large trees of either tree species oflow- to mid-range burn severity. We also recommend retaining the periphery ofburned stands, as ecotones are rich habitats used by several burn-associatedspecies that are found in low numbers in green forests but they benefit fromburned habitats by increasing their populations significantly

    Potential impacts of climate change on biogeochemical functioning of Cerrado ecosystems

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    The Cerrado Domain comprises one of the most diverse savannas in the world and is undergoing a rapid loss of habitats due to changes in fire regimes and intense conversion of native areas to agriculture. We reviewed data on the biogeochemical functioning of Cerrado ecosystems and evaluated the potential impacts of regional climate changes. Variation in temperature extremes and in total amount of rainfall and altitude throughout the Cerrado determines marked differences in the composition of species. Cerrado ecosystems are controlled by interactions between water and nutrient availability. In general, nutrient cycles (N, P and base cations) are very conservative, while litter, microbial and plant biomass are important stocks. In terms of C cycling, root systems and especially the soil organic matter are the most important stocks. Typical cerrado ecosystems function as C sinks on an annual basis, although they work as source of C to the atmosphere close to the end of the dry season. Fire is an important factor altering stocks and fluxes of C and nutrients. Predicted changes in temperature, amount and distribution of precipitation vary according to Cerrado sub-regions with more marked changes in the northeastern part of the domain. Higher temperatures, decreases in rainfall with increase in length of the dry season could shift net ecosystem exchanges from C sink to source of C and might intensify burning, reducing nutrient stocks. Interactions between the heterogeneity in the composition and abundance of biological communities throughout the Cerrado Domain and current and future changes in land use make it difficult to project the impacts of future climate scenarios at different temporal and spatial scales and new modeling approaches are needed
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