Thinning regimes and initial spacing for Eucalyptus plantations in Brazil

ABSTRACT This study focuses on the effects of different thinning regimes on clonal Eucalyptus plantations growth. Four different trials, planted in 1999 and located in Bahia and Espírito Santo States, were used. Aside from thinning, initial planting density, and post thinning fertilization application were also evaluated. Before canopy closure, and therefore before excessive competition between trees took place, it was found that stands planted under low densities (667 trees per hectare) presented a lower mortality proportion when compared to stand planted under higher densities (1111 trees per hectare). However, diameter growth prior to thinning operations was not statistically different between these two densities, presenting an overall mean of 4.9 cm/year. After canopy closure and the application of the thinning treatments, it was found that thinning regimes beginning early in the life of the stand and leaving a low number of residual trees presented the highest diameter and height growth. Unthinned treatments and thinning regimes late in the life of the stand (after 5.5 years), leaving a large number of residual trees presented the highest values of basal area production. The choice of the best thinning regime for Eucalyptus clonal material will vary according to the plantation objective.

Influence of climate variables in the initial growth of Corymbia citriodora and different species of eucalyptus / Influência das variáveis climáticas no crescimento inicial de Corymbia citriodora e diferentes espécies de eucalipto

This work aimed to analyze possible differences in growth patterns on Eucalyptus species and to identify the determinants climatic variables on the growth. We evaluated six Eucalyptus species (Eucalyptus camaldulensis, Eucalyptus grandis, Eucalyptus urophylla, Eucalyptus saligna, Corymbia citriodora and Eucalyptus globulus) and a Clone (GG100) implanted in an experimental arrangement of randomized blocks. We collected the collar diameter and height of all plants monthly in the course of a year, in addition to climate data (minimum temperature, maximum and rainfall). Sequentially, we obtained the correlations between the current monthly increments (collar diameter and height) and climatic variables (minimum temperature, maximum and rainfall). The Current Monthly Increment of the Collar diameter (CMI D) was not correlated to the climatic variables evaluated and the Current Monthly Increment of the Height (CMI H) was strongly correlated to the minimum temperature for the species E. camaldulensis, C. citriodora, E. saligna, E. urophylla, E. grandis and the GG100 Clone. The Rainfall showed positive correlations regarding the CMI H only for the Clone (GG100) and E. urophylla. Finally, the species E. camaldulensis, E. urophylla, E. grandis, E. saligna presented a mortality rate under 10% which is recommended according to the silvicultural criteria.

Objetivou neste trabalho analisar possíveis diferenças nos padrões de crescimento em espécies de eucalipto e identificar as variáveis climáticas determinantes no crescimento. Foram avaliadas seis espécies de eucalipto (Eucalyptus camaldulensis, Eucalyptus grandis, Eucalyptus urophylla, Eucalyptus saligna, Corymbia citriodora e Eucalyptus globulus) e um Clone (GG100) implantados em arranjo experimental de blocos casualizados. Foram coletados o diâmetro do colo e altura de todas as plantas mensalmente no decorrer de um ano, além dos dados climáticos (temperatura mínima, máxima e precipitação). Sequencialmente foram obtidas correlações entre os incrementos correntes mensais (diâmetro do colo e altura) e as variáveis climáticas (temperatura mínima, máxima e precipitações). O Incremento Corrente Mensal do Diâmetro do Colo não apresentou correlação com as variáveis climáticas avaliadas e o Incremento Corrente Mensal em Altura (ICM H) é fortemente correlacionado com a temperatura mínima para as espécies E. camaldulensis, C. citriodora, E. saligna, E. urophylla, E. grandis e o Clone GG100. A precipitação apresentou correlações positiva com o ICM H somente para o Clone (GG100) e para E. urophylla. Por fim, as espécies E. camaldulensis, E. urophylla, E. grandis, E. saligna apresentaram taxa de mortalidade inferior a 10%, valor este recomendável de acordo com critérios silviculturais.

Rhizobacterial characterization for quality control of eucalyptus biogrowth promoter products

Abstract Plant growth-promoting rhizobacteria strains from special formulations have been used to optimize eucalyptus cutting production. To undertake quality control for the formulated products, the rhizobacterial strains should be characterized to assess their purity and authentication. In the present study, we characterized nine strains of rhizobacteria, including three Bacillus subtilis (S1, S2 and 3918), two Pseudomonas sp. (MF4 and FL2), P. putida (MF2), P. fulva (Ca), Frateuria aurantia (R1), and Stenotrophomonas maltophilia (CIIb). The strains were differentiated by colony morphology after 24 h of incubation in three different solid state culture media (glucose-nutritive agar, 523 medium and yeast extract-mannitol agar), sensitivity to a panel of 28 antibiotics (expressed according to the formation of inhibition halos of bacterial growth in the presence of antibiotics), and PCR-RFLP profiles of the 16S rDNA gene produced using nine restriction enzymes. It was possible to differentiate all nine strains of rhizobacteria using their morphological characteristics and sensitivity to antibiotics. The molecular analysis allowed us to separate the strains CIIb, FL2 and R1 from the strains belonging to the genera Bacillus and Pseudomonas. By using these three methods concomitantly, we were able to determine strain purity and perform the authentication.

Pollen analysis of honey and pollen collected by Apis mellifera linnaeus, 1758 (Hymenoptera, Apidae), in a mixed environment of Eucalyptus plantation and native cerrado in Southeastern Brazil / Espectro polínico do alimento coletado por Apis mellifera linnaeus, 1758 (hymenoptera, apidae), em ambiente contendo plantações de Eucalyptus e cerrado nativo no sudeste brasileiro

Abstract Eucalyptus plantations are frequently used for the establishment of bee yards. This study was carried on at Fazenda Brejão, northwestern region of the State of Minas Gerais, Brazil. This farm is covered both with native Cerrado vegetation (Brazilian savanna) and eucalyptus plantations. This paper reports on the botanic origin of pollen pellets and honey collected from honeybee (Apis mellifera) hives along a thirteen-month period (January 2004 to January 2005). The most frequent pollen types found in the pollen pellets during the rainy season were Trema micrantha (Ulmaceae), Copaifera langsdorffii (Fabaceae), an unidentified Poaceae, unidentified Asteraceae-2, Cecropia sp. 1 (Cecropiaceae) and Eucalyptus spp. (Myrtaceae); during the dry season the most frequent pollen types were Acosmium dasycarpum (Fabaceae), Cecropia sp. 1 (Cecropiaceae) and Eucalyptus spp. (Myrtaceae). Pollen grains of Baccharis sp. (Asteraceae), Cecropia sp. 1 (Cecropiaceae), Copaifera langsdorffii (Fabaceae), Mimosa nuda (Fabaceae), Eucalyptus spp. (Myrtaceae) and Trema micrantha (Ulmaceae) were present in the honey samples throughout the study period.

Resumo Plantações de Eucalyptus são, frequentemente, utilizadas como locais de instalação para colmeias. Este estudo foi realizado na Fazenda Brejão, localizada no noroeste de Minas Gerais, Brasil. Esta fazenda é coberta por Cerrado nativo (savana brasileira) e por plantações de eucaliptos. Este trabalho indica a origem botânica de bolotas e mel coletados em colmeias de Apis mellifera por um período de 13 meses (Janeiro/2004 a janeiro/2005). Os tipos polínicos mais frequentes nas amostras de pólen durante a estação chuvosa foram Trema micrantha (Ulmaceae), Copaifera langsdorffii (Fabaceae), Poaceae, Asteraceae não identificada 2, Cecropia sp. 1 (Cecropiaceae) e Eucalyptus spp. (Myrtaceae); na estação seca, os tipos polínicos mais frequentes foram Acosmium dasycarpum (Fabaceae), Cecropia sp. 1 (Cecropiaceae) e Eucalyptus spp. (Myrtaceae). As espécies Baccharis sp. (Asteraceae), Cecropia sp. 1 (Cecropiaceae), Copaifera langsdorffii (Fabaceae), Mimosa nuda (Fabaceae), Eucalyptus spp. (Myrtaceae) e Trema micrantha (Ulmaceae) estiveram presentes durante todo o período amostrado.

Eucalyptus grandis Hill ex Maiden inoculated with Pisolithus microcarpus (UFSC-Pt116) in land subject to the sandy process in southern Brazil

Eucalypts is one of the main species used for commercial reforestation in the state of Rio Grande do Sul, Brazil. This study aimed to evaluate the survival and early growth of eucalyptus trees in an area subject to sandy process after three years of growth. The Eucalyptus grandis seedlings were grown in a greenhouse, innoculated or not with the isolated ectomycorrhizal Pisolithus microcarpus (UFSC-Pt116), produced in peat or Entisol. After 120 days, the seedlings were transplanted to an area subject to the sandy process, in the city of São Francisco de Assis, RS. The plants have been evaluated regarding survival, height, stem diameter, nitrogen, phosphorus and potassium levels and total phosphorus, inorganic phosphorus, organic phosphorus and wood production on different days after planting. The seedlings grown on the Entisol which was inoculated with the isolated UFSC-Pt116 presented higher survival rates, height, stem diameter, nitrogen concentration and wood production compared to the non-inoculated seedlings. Inoculation with ectomycorrhizal fungi enhanced the production of E. grandis seedlings in survival rates, height, stem diameter.

Bacillus subtilis: enraizamento e crescimento de miniestacas de eucalipto em Sinop, norte de Mato Grosso / Bacillus subtilis: rooting and growth of eucalyptus mini-cuttings in Sinop, northern Mato Grosso

A crescente demanda pela implantação de florestas plantadas tem exigido diversos estudos para inovações no processo de produção e melhor aproveitamento econômico da floresta. O uso de rizobactérias promotoras de crescimento em plantas vem despontando como uma alternativa viável para otimizar o desenvolvimento e produção dessas florestas. Este trabalho teve como objetivo avaliar o enraizamento e crescimento de miniestacas em cinco clones de eucalipto, H13, 1004, GG100, 1277 e I144, mediado por rizobactérias, através de um inoculante biológico que possui em sua formulação como princípio ativo a rizobactéria Bacillus subtilis. A inoculação foi realizada de três maneiras distintas: diretamente no substrato, por imersão das miniestacas em suspensão de inóculo e pela combinação dos referidos métodos, sendo comparado com o tratamento testemunha que seguiu o padrão do viveiro. Foram avaliados, número de raízes emitidas abaixo do tubete, comprimento de raízes (cm), massa fresca e seca do sistema radicular e da parte aérea (g) e altura (cm) das mudas. Os resultados variaram de acordo com o clone, parâmetros avaliados e método de inoculação. Com base nos resultados houve ganho significativo em todos os parâmetros analisados, com aumento na emissão de raízes de até 53,2%. Na biomassa do sistema radicular e da parte aérea, houve incrementos que variaram entre 45,9 e 45,1%, respectivamente. Para o crescimento das mudas observou-se aumento, variando entre 20,3 a 37,2%. Estes resultados indicam o potencial de uso da rizobactéria Bacillus subtilis para incrementar a produção de mudas de eucalipto em viveiro.

The increasing demand for planted forests has required several studies about innovations in the production process and better economic use of the forest. The use of growth promoting rhizobacteria in plants is emerging as a viable alternative, to optimize the development and production of these forests. This study evaluated rooting and growth of mini-cuttings in five clones of eucalyptus, H13, 1004, GG100, 1277 and I144, mediated by rhizobacteria of the biological inoculant that has in its formulation as the active ingredient Bacillus subtilis rhizobacterium. Inoculation was done in three ways: directly on the substrate, by immersion of mini-cuttings in inoculum suspension and the combination of these methods, in comparison with standard nursery treatment. The parameters evaluated were number of roots below the container, root length (cm), fresh and dry weight of the root system and aboveground part (g) and height (cm) of the seedlings. The results varied according to the clone, the evaluated parameters and method of inoculation. Based on the results, there was significant gain in all parameters analyzed, with an increase in the emission of roots up to 53.2%. Biomass in the root system and aboveground part increased ranging between 45.9 and 45.1%. Seedling height showed an increase ranging from 20.3 to 37.2%. These results indicate the great potential of using Bacillus subtilis to increase the production of eucalyptus seedlings in nurseries.

Comparação entre parâmetros abióticos e a estrutura florestal de um fragmento de floresta e um reflorestamento abandonado de eucalipto (Eucalyptus saligna Smith) no parque ecológico da Klabin, Telêmaco Borba/PR / Comparison between abiotic parameters and the forest structure of a forest fragment and an eucalyptus (Eucalyptus saligna Smith) abandoned reforestation in the ecological park of Klabin, Telemaco Borba/PR

A estrutura florestal tem impacto direto sobre o microclima, e é importante para a continuidade dos processos sucessionais e para o restabelecimento dos processos do ecossistema. Estudos acerca da estrutura florestal são importantes para auxiliar as ações de restauração ecológica, melhorando a sua aplicação. Visando comparar duas formações florestais, sendo uma delas um fragmento florestal secundário e a outra uma área abandonada de reflorestamento com eucalipto, neste trabalho foram avaliados alguns parâmetros abióticos, bem como a estrutura florestal das áreas. Dentre os fatores abióticos estudados estão: temperatura e umidade relativa do ar, compactação, umidade e pH do solo e espessura da serapilheira. Para analisar a estrutura florestal, foram avaliados: cobertura de herbáceas sobre o solo, índice de cobertura do dossel, diâmetro a altura do peito (DAP), área basal (AB) e altura das árvores de todas as espécies. Entre os parâmetros analisados, comparando-se as áreas, foram observadas que: a compactação do solo é maior na floresta secundária (0,57 MPa) do que no reflorestamento de eucalipto (0,43 MPa); a presença de herbáceas sobre o solo é menor no reflorestamento de eucalipto (17,96%) do que na floresta secundária (59,4%); o índice de cobertura do dossel foi de 45,99% para o reflorestamento de eucalipto, enquanto na floresta secundária este valor foi de 61,02%. No entanto, de acordo com o teste de Kolmogorov-Smirnov, a estrutura florestal não é diferente entre as áreas, já que os valores de DAP e altura não diferiram entre o calculado e o observado. .

The forest structure causes a direct impact on the microclimate, being important for the continuity of the successional processes as well as for the restoration of ecosystem processes. Studies on forest structure are important to help determine ecological restoration actions, improving its implementation. In order to compare two forest formations, being one of them a secondary forest fragment and the other one an abandoned area of eucalyptus reforestation, some abiotic parameters were evaluated in this study, as well as the forest structure of the areas. Amongst the abiotic factors studied, there are: temperature and relative air humidity, soil compaction, moisture and soil pH and thickness of the litter. In order to analyze the forest structure, the following items were evaluated: herbaceous cover on the soil, rate of canopy cover, the diameter at breast height (DBH), basal area (BA) and height of trees of all species. Among the parameters analyzed, comparing the areas, it was observed that: soil compaction was higher in the secondary forest (0.57 MPa) than in the eucalyptus reforestation (0.43 MPa); the presence of herbaceous plants on the soil occurred less in the eucalyptus reforestation (17.96%) than in the secondary forest (59.4%); the canopy cover index was of 45.99% for the eucalyptus reforestation, while in the secondary forest it was of 61.02%, being therefore higher for the latter. Nevertheless, according to Kolmogorov Smirnov test, the forest structure is not different between the areas, since the DBH and height values were not different between what was calculated and what was observed. .

Rhizobacterial promotion of eucalypt rooting and growth

A total of 107 rhizobacterial isolates, obtained from the rhizosphere of eucalypt clones were tested as rooting inducers of cuttings and mini-cuttings planted in substrate composed of carbonized rice husk and vermiculite (1:1). Cuttings and mini-cuttings were planted in conical plastic tubes containing treated and untreated (control) substrate and kept under intermittent mist irrigation at 26-28°C. After 35 days, rooting percentage and dry root matter of cuttings were evaluated. Ten isolates capable of providing gains of up to 110 percent in root formation and up to 250 percent in root biomass over non-inoculated control cuttings were selected. Gains in rooting varied according to clone and isolate tested. The greatest gains were obtained for the mini-cuttings exhibiting the lowest rooting efficiency. Among the ten isolates tested, only 3918 (code R98) and MF4 (code R87), produced 3-indole-acetic acid in vitro, at concentrations of 0.7 and 0.67 µg ml-1, respectively. Significant increases in rooting and root dry matter of cuttings grown on rhizobacteria-inoculated substrate were found when compared to untreated or indole-butyric acid (IBA) treated mini-cuttings.

Neste trabalho, testaram-se 107 rizobactérias, isoladas da rizosfera de mudas de clones de eucalipto, quanto ao seu potencial como promotoras de enraizamento de estacas e miniestacas de eucalipto, em substrato à base de casca de arroz carbonizada e vermiculita (1:1). Estacas e miniestacas foram plantadas em tubetes cônicos contendo substrato tratado e não tratado (testemunha) e foram mantidas sob nebulização intermitente de água a 26-28°C. Aos 35 dias, avaliou-se a porcentagem média de estacas enraizadas e a massa seca do sistema radicular. Dez isolados destacaram-se como indutores de enraizamento e crescimento, propiciando ganhos de até 110 por cento e de 250 por cento, respectivamente. Esses isolados também foram eficientes no enraizamento de miniestacas, cujos ganhos variaram de acordo com o clone e isolado testado. Os maiores incrementos obtidos no enraizamento de estacas foram superiores aos observados para miniestacas. Em geral, quanto menor o índice de enraizamento do clone, maior foi o ganho médio obtido com a inoculação. Apenas os isolados 3918 (código R98) e MF4 (código R87) foram capazes de produzir ácido indol-acético (AIA) in vitro, em quantidades equivalentes a 0,7 e 0,67 µg/ml de suspensão, respectivamente. Quando comparados ao tratamento de miniestacas em ácido indol butírico (AIB), estes isolados promoveram incrementos significativos na porcentagem de enraizamento e na massa seca do sistema radicular de miniestacas.