Durability of eucalyptus citriodora wood (Corymbia citriodora (Hook.) K.D. Hill & L.A.S. Johnson) treated with CCA in the Amazon environment [Durabilidade de madeira de eucalipto citriodora (corymbia citriodora (Hook.) K.D. Hill & L.A.S. Johnson) tratada com CCA em ambiente amazônico]
de Araujo H.J.B.,Pesquisador da Embrapa Acre |
Magalhaes W.L.E.,Pesquisador da Embrapa Florestas
Acta Amazonica | Year: 2012
The intense economic exploration has caused a decrease of the original stock of Amazon woody species, including those of high natural durability used in soil contact. The lack of those species results in increased price that makes economically unfeasible of the use, an alternative is the replacement by planted species of fast-growing treated with preservatives. Another advantage of to use species planted to replace the traditional species is environmental, because this will reduce the exploratory pressure on these species. The objective of this study is to evaluate the degree of biological degradation of eucalyptus citriodora wood (Corymbia citriodora (Hook.) K.D. Hill & L.A.S. Johnson) treated with chromated copper arsenate (CCA) under vacuum and pressure process and exposed in field experiment in Rio Branco-AC. The experiment was implemented in May 2005 with cuttings treated with CCA and not treated. The variables evaluated were: 1) degradation by fungi, 2) degradation by termites, and 3) region or part of the piece affected. After the 3rd evaluation (47 months of test), 100% of the specimens without treated were classified with the maximum degree of degradation and, in contrast, 100% of the specimens treated with CCA, after 60 months of test, were classified with the minimum degree of degradation. The parties of the pieces without treatment with the higher and the lesser degrees of degradation were, respectively, the inferior head and the aerial part above 10 cm of soil. The degradation caused by fungi was slightly lower than that of termites. The field experiment has shown that is technically feasible the use of eucalyptus wood to replace the traditional species of the Amazon.
Structural variation of seasonal deciduous forest in Santa Catarina state and its relationship with altitude and climate [VariaÇÃO da estrutura da floresta estacional decidual no estado de Santa Catarina e sua RelaÇÃO com a altitude e clima]
De Gasper A.L.,Regional University of Blumenau |
Uhlmann A.,Pesquisador da Embrapa Florestas |
Vibrans A.C.,Regional University of Blumenau |
Sevegnani L.,Regional University of Blumenau
Ciencia Florestal | Year: 2015
This study aims to identify structural similarities between the remnants of seasonal deciduous forest (SDF) in Santa Catarina state and check the influence of environmental factors that leads the formation of these groups. Associated with this primary objective, it was also sought to identify the areas of contact between this forest type and Araucaria forest (mixed ombrophilous forest – MOF). We analyzed data from 78 sample units (AU) installed in the remnants of SDF between 2008 and 2009 by professional team of Floristic and Forest Inventory of Santa Catarina project (IFFSC). The data were processed through the Detrended Correspondence Analysis (DCA) and Canonical Correspondence Analysis (CCA), using a matrix of species density associated with a environmental variables matrix, that consisted of altitude and climate parameters. The proportion of variance explained by the first three axes of DCA was low, accounting for approximately 21% of the information contained in the original data set. This result provides low power of interpretation of the results. However, when DCA was applied to the data of mean density of species in each river basin, the results pointed to better explanatory eigenvectors (three first eigenvectors explain 58.1% of total variance). The first ordination axis of DCA grouped the eastern watersheds SUs at one end, and the western watersheds SUs at the other end of this axis. At the right end of the first axis are arranged the watersheds of the river Canoas, Pelotas and Peixe, which are characterized by the presence of species such as Ocotea pulchella, Zanthoxylum fagara, Lithrea brasiliensis, Matayba laeagnoides, Cinnamodendron dinisii commonly associated with Mixed Ombrophilous Forest (Araucaria forest). At the left end, the grouped SUs are mainly those of western watersheds, a group that includes the basins of he Jacutinga, Irani, Chapecó, Antas and Peperi-guaçu rivers. Among the species that most strongly influence the results in the analysis, we highlight Apuleia leiocarpa, Rauvolfia sellowii, Bastardiopsis ensiflora, Chrysophyllum gonocarpum, Cordia trichotoma, Holocalyx balansae, Myrocarpus frondosus and Pisonia zapallo, which are common in seasonal forests of the hinterlands of southern Brazil. The analysis through the ACC pointed to similar results and joint interpretation of environmental data indicated that the basins located in the east are associated with colder climates where frosts are more frequent as a result of igher altitudes. As the altitudes tend to decline from east to west and portions, the authors propose the existence of a transition zone between the two phytoecological regions (MOF and SDF) in the range of 600 m asl, where occurs the interdigitation of elements from seasonal flora and those of Araucaria forest, resulting in the delineation of a core area of the SDF below this altitudinal level. © 2015, Universidade Federal de Santa Maria. All rights reserved.
Kratz D.,Federal University of Parana |
Wendling I.,Pesquisador da Embrapa Florestas |
Nogueira A.C.,Federal University of Parana |
De Souza P.V.D.,Federal University of Rio Grande do Sul
Ciencia Florestal | Year: 2013
The pressing need to increase the number of seedlings planted annually, as well as the reduced availability of traditional raw materials for the composition of substrates have led to a need of developing studies aimed to evaluate and to provide new materials for the composition of substrates, technically and economically efficient. On this basis, the present study aimed to evaluate the technical feasibility of using components based on renewable coconut fiber (FC), rice hulls (CAC) in different grain sizes, biosolids (BIO) and semi-decomposed pine bark in the composition substrates for the production of seedlings of Eucalyptus benthamii, as well as to assess the correlation between physical and chemical properties of substrates formulated with the quality of seedlings produced. For this, we formulated 41 treatments, which had their physical and chemical properties evaluated, and sowing in tubes made from 55 cm 3. We evaluated the height of the shoot and the stem diameter every 30 days, as well as the dry biomass of shoots and radicial areas, the ease of removal of the cartridge and the aggregation of the roots to the substrate at 90 days. It was found that all renewable materials examined were suitable for the production of seedlings. However, the screening of CAC is not justified when compared with the CAC in its entirety. Measurements of height and diameter prior to final evaluation are unreliable for predicting the outcome. BIO different particle size and CAC had low root aggregation to the substrate. The high levels of salinity, conductivity and pH did not harm the growth of seedlings. Concerning to the physical properties, it was observed that substrates with higher densities and smaller micro-porosity root aggregation provided to the substrate and provided with greater macro-porosity increased growth of shoots and radicial.
Correa P.R.R.,Federal University of Parana |
Auer C.G.,Pesquisador da Embrapa Florestas |
dos Santos A.F.,Pesquisador da Embrapa Florestas |
Higa A.R.,Federal University of Parana
Ciencia Florestal | Year: 2012
Sphaeropsis sapinea is an important pathogen for some Pinus radiata causing tip blight and death of trees, in commercial plantings. This study was developed to select Pinus radiata progenies resistant to the pathogen, for new plantings in Brazil. Seedlings tips of 16 Pinus radiata progenies were inoculated with three pathogen monosporic isolates of Sphaeropsis sapinea, under greenhouse conditions. Lesions length and tip blight degree were evaluated. Responses of progenies to the pathogen varied according to tested isolate. The results indicated that early selection methodology was adequate to select Pinus radiata progenies resistant against Sphaeropsis sapinea. Average heritability of the progenies varied according to tested isolate and the selection criterion used.