Artigos - Ciência Florestal - FCA

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Soil Structure under Forest and Pasture Land-Uses Affecting Compressive Behavior and Air Permeability in a Subtropical Soil
(2022-12-01) Suzuki, Luis Eduardo Akiyoshi Sanches; Reinert, Dalvan José; Secco, Deonir; Fenner, Paulo Torres [UNESP]; Reichert, José Miguel; Federal University of Pelotas; Federal University of Santa Maria; Universidade Estadual do Oeste do Paraná-UNIOESTE; Universidade Estadual Paulista (UNESP)
Machinery traffic and animal trampling can deform the soil and, consequently, impair soil pore functioning. This study aimed to evaluate how soil structure affects the compressibility, physical properties and air permeability of a Typic Paleudalf under forest, pasture and eucalyptus. Soil samples with preserved structure were used to determine soil physical (bulk density, porosity, degree of water saturation at 33 kPa-tension, air permeability) and mechanical properties (soil deformation, precompression stress, compressibility index). After these evaluations, each soil sample was fragmented, sieved, and the metal rings filled with structureless soil, and underwent the same determinations as the samples with preserved structure. For loads greater than the precompression stress (load greater than 200 kPa), soil with non-preserved structure had the largest deformation. An increase in bulk density decreased macropores linearly (R2 = 0.77 and 0.87, respectively, to preserved and non-preserved soil structure) and air flow exponentially. The soil with preserved structure was less susceptible to further compaction. Air flow was greatest in soils with lower bulk density, microporosity and water saturation degree, and a high volume of macropores. Soil structure (preserved and non-preserved) had more significative differences in microporosity, compressibility index, soil deformation, and bulk density at the end of the compression test.
Seasonal Cambial Activity and Formation of Secondary Phloem and Xylem in White Oaks (Quercus alba L.)
(2023-05-01) Pace, Marcelo R. [UNESP]; Dutra, Rafaella [UNESP]; Marcati, Carmen R. [UNESP]; Angyalossy, Veronica; Evert, Ray F.; Universidad Nacional Autónoma de México; Universidade Estadual Paulista (UNESP); Université du Québec à Chicoutimi; Universidade de São Paulo (USP); University of Wisconsin in Madison
(1) Background: the cambium has seasonal activity, forming earlywood and early phloem with relatively wide conducting cells, which will function during the most favorable season, and latewood and late phloem with narrower conducting cells, which typically function during the less favorable season. However, few studies have focused on when these two contrasting tissue types are formed in relation to climatic conditions. (2) Methods: the senior author of this paper made weekly collections for an entire year of four specimens per collection back in the 1960s, using traditional anatomical methods to study in detail what the cambium was producing progressively. (3) Results: annual growth rings are evident in both secondary xylem and secondary phloem. The cambium resumes activity in early April, with simultaneous formation of wood and secondary phloem. Both latewood and late phloem production are initiated in early June, the peak of the favorable season. The cambium ends its activity in early August. Phloem growth rings are marked by radially narrow sieve elements interspersed among a band of axial parenchyma with dark contents. Most specimens produce only one fiber band per season. This feature may be used as an indirect phloem growth ring marker. Wood growth rings are marked by very wide vessels and thick-walled, radially narrow fibers. (4) Conclusions: growth rings are evident in both secondary xylem and secondary phloem. The trees produce their latewood and late phloem long before the beginning of autumn, indicating that they prepare ahead of the selective regime, a phenomenon most likely dependent on the photoperiod. Living sieve elements are present yearlong.
Water availability influences both wood anatomy and laticifer density in rubber tree saplings
(2023-07-01) Nery, Ícaro Renã Alves Moureira [UNESP]; Vergilio, Paula Cristina Benetton [UNESP]; Viégas, Lucas Bertacini [UNESP]; da Silva, Magali Ribeiro [UNESP]; Resende, Rafael Tassinari; Chagas, Matheus Peres; Pace, Marcelo Rodrigo [UNESP]; Marcati, Carmen Regina [UNESP]; Universidade Estadual Paulista (UNESP); Universidade Federal de Goiás (UFG); Universidade de Brasília (UnB); Ciudad Universitaria
Given the predicted intensification of droughts and floods in the context of climate change, it is critical to understand the effect of water availability on secondary xylem and laticifers in rubber trees (Hevea brasiliensis (Willd. ex A.Juss.) Müll.Arg, Euphorbiaceae). Thus, we investigated the effects of different substrate water availability treatments on anatomical features of the secondary xylem, and the diameter, density, and proportion of laticifers in saplings of rubber trees. Lower substrate water availability resulted in shorter fibers and higher fiber fraction, lower gelatinous fiber fraction, higher vessel density, and lower laticifer density. Under lower water availability, changes in the secondary xylem favor safety in water transport. In the case of laticifers, which are present in the secondary phloem, their structural characteristics may represent a significant decrease in the latex production capacity, which in large forest plantations may reflect economic losses.
DYNAMICS OF WATER QUALITY PARAMETERS IN HYDROGRAPHIC CATCHMENTS WITH NATIVE FOREST AND PINE-PLANTED FORESTS
(2023-01-01) Cardoso, Kaíque Mesquita; Zakia, Maria José Brito [UNESP]; Rodrigues, Carolina Bozetti; de Souza Santos, Vanessa; Instituto Federal do Norte de Minas Gerais; Universidade Estadual Paulista (UNESP); Prática socioambiental; Instituto Federal da Bahia
The search for productive forests in line with an environmental balance is one of the tasks of good sustainable forest management, in which studies on water quality in production areas support the improvement of environmental conservation programs. Thus, this study aimed to determine the water quality in watersheds covered with native forest and pine-planted forests and to evaluate the effects of forest operations and precipitation on the dynamics of physical and chemical parameters of water. Data were collected for 10 years (2005 - 2015) in a fortnightly sampling frequency. The concentrations of nitrate, phosphorus, potassium, calcium, and magnesium were determined, as well as the physical parameters of total suspended solids, pH, turbidity, apparent color, and electrical conductivity in the water. Data were analyzed using the Mann-Whitney test at 5% probability and through multivariate analysis (principal component analysis and hierarchical cluster analysis). The water quality of both watersheds is similar and there is no significant difference between the physical parameters. While the watershed composed of native forest has a higher concentration of NO3-, K, and Mg in the water, the watershed with planted forests of Pinus has a higher concentration of Ca. There was a chemical and physical difference in the dynamics of the water concerning its precipitation. Mosaic forest management can influence the stability of quality parameters.
Richness and composition of terrestrial mammals vary in eucalyptus plantations due to stand age
(2023-06-01) de Abreu Pestana, Luís Fernando [UNESP]; Martello, Felipe; Fonseca, Renata Cristina Batista; Universidade Estadual Paulista (UNESP); Vale Technological Institute – Sustainable Development
Plantation forests substitute natural habitats and have rotation cycles of 7 years due to their high growth rates. This variation reflects on local and landscape changes, influencing habitat availability and affecting mammal communities. In this study, our general hypothesis was that the richness and composition of mammals varied in eucalyptus plantations in relation to native forest patches and in relation to the age of eucalyptus plantations. We predicted that (1) there would be lower mammalian richness and compositional differences in eucalyptus plantations compared to native vegetation due to monocultures having simplified environmental characteristics and (2) predicted that the richness and composition would vary according to eucalyptus age and that the highest values of richness would be found in plantations of up to middle age, considering that in these phases there are environmental characteristics that positively qualify these structures for a greater presence of fauna, such as the shrubby aspect of the plantations and the presence of undergrowth. We performed model selection to observe the effect of environmental variables on mammalian richness. We also performed a multivariate permutational analysis of variance, a non-metric multidimensional scaling and partitioned the beta diversity to observe how the composition was influenced by environmental variables. We found greater richness in the native vegetation compared to eucalyptus plantations. The richness of the plantations varied according to the age, with higher values up to middle age. The composition varied according to the land user/cover, with the eucalyptus age and with the management unit due to the nestedness of species. We suggest that eucalyptus plantations at early ages are more used by mammals due to the shrubby aspect of the stand, generating a positive visual effect for the search of resources and shelter, in addition to the possibility of the occurrence of grasses, some understory and lower anthropogenic disturbance.
The Role of Organ and Leaf Habit on the Secondary Xylem Anatomy Variation across 15 Species from Brazilian Cerrado
(2023-02-01) Dutra, Rafaella [UNESP]; Nogueira, Anselmo; Rossi, Sergio; Chacon Dória, Larissa; Buttò, Valentina; Marcati, Carmen Regina [UNESP]; Université du Québec à Chicoutimi; Universidade Estadual Paulista (UNESP); Universidade Federal do ABC (UFABC); Universidade Estadual de Campinas (UNICAMP); Université du Québec en Abitibi-Témiscamingue
Xylem is a complex tissue connecting the organs of plants and it performs multiple functions, including water transport, mechanical support, and storage. Because of the interaction between structure and function, xylem anatomy can provide useful information about its role in plant strategies. However, knowledge of how xylem anatomical traits change across organs and species functional groups is still limited. Here, we tested the role of different plant organs (stem and roots) and leaf habits (deciduous, semi-deciduous, and evergreen) on xylem anatomy variation across 15 woody species from the Brazilian Cerrado. Vessels, fibers, and parenchyma traits were measured on 45 individuals sampled in 2014 in Botucatu, São Paulo, Brazil. Our results revealed a higher parenchyma fraction and less fiber fraction in roots than in stems across species. Differences in wood anatomical traits between organs were mainly species-specific in parenchyma traits rather than vessel and fiber traits. Across leaf habits, only the root ray fraction was higher in evergreen species compared to deciduous species. These findings highlight a potential role of organs and leaf habits in xylem storage across Cerrado woody species.
Prevention of additional compaction in eucalyptus and pasture land uses, considering soil moisture and bulk density
(2022-12-01) Suzuki, Luis Eduardo Akiyoshi Sanches; Reinert, Dalvan José; Fenner, Paulo Torres [UNESP]; Secco, Deonir; Reichert, José Miguel; Universidade Federal de Pelotas; Universidade Federal de Santa Maria; Universidade Estadual Paulista (UNESP); Centro de Ciências Exatas e Tecnológicas
Soil compaction is harmful to agricultural and forestry areas, and strategies to avoid soil deformation are of great interest. The objective of this study was to evaluate the compressibility of a soil submitted to different land uses in an area located in southern Brazil. The land uses assessed were a) Anthropized Forest: constituted by tree and shrub species; b) Pasture: five years old; c) Eucalyptus 20: twenty years old; and d) Eucalyptus 4.5: conducted in 2nd rotation, and 4.5 years old, with Eucalyptus harvesting in the first cut made manually with a chainsaw and wood extraction with a Forwarder. Undisturbed soil samples were taken in 2006, and they were submitted to the uniaxial compression test. Bulk density and volumetric moisture were calculated before the test, as well as soil deformation, compression index and precompression stress at the end of the test. Anthropized Forest and Pasture soils presented the highest volumetric soil moisture, a mean of, respectively, 0.301 and 0.304 m3 m−3. Eucalyptus 20 had the lowest bulk density (mean of 1.15 Mg m−3), and Eucalyptus 4.5 the highest bulk density (mean of 1.47 Mg m−3). Precompression stress is low for all soil land uses, ranging from 31.24 to 50.92 kPa, and care should be taken to avoid further compaction. Load-bearing capacity of the soil presented positive and negative relationship with, respectively, bulk density and volumetric moisture, but the low coefficient of correlation (r) and determination (r2) shows the need of further studies for a better adjustment of the data. From the knowledge of volumetric soil moisture, it is possible to monitor and define the most suitable soil condition for traffic of machinery and animals trampling into the areas to avoid additional compaction, while the load-bearing capacity of the soil can be estimated by bulk density, being useful to monitor the occurrence or not of additional compaction.
Psysiological maturing and dormancy in seeds of Parkia platycephala Benth. (Fabaceae)
(2022-08-01) dos Santos, Graziele Nunes Lopes; de Farias, Séfora Gil Gomes; de Oliveira Silva, Dandara Yasmim Bonfim [UNESP]; Silva, Romario Bezerra E.; Ribeiro, Andressa; de Matos, Daniele Cristina Pereira; Universidade Federal Rural de Pernambuco (UFRPE); Universidade Federal do Piauí (UFPI); Universidade Estadual Paulista (UNESP); Universidade Federal do Paraná (UFPR)
The germination capacity of freshly harvested legume seeds is controlled by two antagonistic processes, the maturation process and the establishment of tegument dormancy. Current analysis, foregrounded on the change of color of the fruits, determines, throughout the maturation process of Parkia platycephala seeds, when: i) the seeds reach the germination capacity and ii) the dormancy of the integument is imposed. It also evaluates the efficacy of methods to overcome the dormancy of the species. Two experiments were carried out: (I) assay with a completely randomized design, 2 x 6 (with and without breaking dormancy x six maturation stages); (II) completely randomized design, with 23 treatments to overcome dormancy. Both assays comprised four replications of 25 seeds each. In experiments I and II, the following variables were evaluated: moisture content, germination percentage, germination speed index, shoot length and primary root, shoot dry mass and seedling root system. Results showed a gradual increase in germination capacity, vigor and establishment of the dormancy mechanism with the reduction of water content and occurrence of physiological maturation. Seed germination capacity occurred prior to dormancy; however, seeds have low physiological quality and high water-contents. Mechanical scarification with sandpaper and immersion in sulfuric acid for 20 minutes are the most efficient methods for breaking dormancy.
Previous Preservation of Veneers Promotes Higher Preservative Retention and More Effective Protection in CCA-Preserved Plywood
(2022-01-01) Athanázio-Heliodoro, Julia Carolina [UNESP]; da Silva, Gisleine Aparecida; Palma, Hernando Alfonso Lara [UNESP]; D’Elaqua-Santos, Gabriel Francisco [UNESP]; Ballarin, Adriano Wagner [UNESP]; Universidade Estadual Paulista (UNESP); Instituto de Pesquisas Tecnológicas
Plywood panel has a promising market in Wood Frame Construction System. Like any wood-based product, it can suffer deterioration, and preservative treatment is imperative. The preservative treatment can be done directly on a pressed panel - a conventional method that supposedly causes a decrease in physical-mechanical performance - or incorporated into the production process, by the previous treatment of veneers to develop panels with durability and quality. We compared the performance of these two processes. Panels were produced with Pinus taeda L., using 360 g m-2 of phenolic adhesive in a double line, a pre-pressing and hot pressing for 20 minutes under 1.2 MPa pressure and 130°C and treatement on veneers and panels with CCA-C. Tests followed Brazilian standards. Panels with previous treatment had lower water absorption and swelling. Preservation of the veneers also promoted higher retention levels and better penetration of preservatives. Both treatments did not affect the mechanical performance.
Modelo matemático logístico para aquecimento de toras de Eucalyptus grandis w. hill com vapor e água quente
(2017-01-01) Coneglian, Ademilson; Severo, Elias Taylor Durgante [UNESP]; Batista, Wagner Roberto; Pereira, Ismael Martins; Gomes, Ivana da Silva; Universidade Estadual de Goiás; Universidade Estadual Paulista (UNESP); Universidade Federal do Triângulo Mineiro
The aims of this study was to obtain a mathematical logistics model that represents the best heating of logs of Eucalyptus grandis in function of the diameter and the length of the logs in the thermal treatments with steam and hot water. To this end, were collected 6 logs 30 trees to 32 years of age, from the Horto Florestal de Mandurí-SP, Brazil. Diameter classes of logs were 25 ⊣ 30 cm, 30 ⊣ 35 cm, 35 ⊣ 40 cm. In each of the logs were inserted three thermocouples with depths of 1/3, of the radius, 2/3 of the third beam, near the center thereof. Were used 15 heat-treated logs with steam at 85°C and 100% relative humidity, and 15 logs heated with hot water to the thermocouple reach 85° C of temperature at position 50 mm radius. It is concluded that the mathematical model set obtained a logistic behavior in the treatments steam and hot water, presents an optimal consumption of energy e technical feasibility in heating process of logs.
Anatomical and tree rings differences in two provenances of Cordia trichotoma (Vell.) Arráb. ex Steud. (Boraginaceae)
(2022-01-01) Longui, Eduardo Luiz; Caum, Caroline [UNESP]; Tomazello-Filho, Mario; Lisi, Claudio Sergio; Roig, Fidel Alejandro; Marcati, Carmen Regina [UNESP]; Instituto de Pesquisas Ambientais; Universidade Estadual Paulista (UNESP); Universidade de São Paulo (USP); Universidade Federal de Sergipe (UFS); IANIGLA (CONICET-Universidad Nacional de Cuyo); Universidad Mayor
The parental effect on wood anatomy and growth rings of Cordia trichotoma trees was studied. Tree seeds of two provenances (Cerrado and Atlantic Forest biomes) were collected in 1986. Seedlings were planted, and after 25 years, twelve wood disks were collected from six trees from each provenance. Anatomical features and growth rings were analyzed according to standard techniques. Qualitative anatomy of wood indicated similarities between the two provenances, except for the presence of geniculate vessels found in woods from the Cerrado. However, the greatest differences in wood anatomy were quantitative. Provenances from Cerrado had wood with shorter vessel and fibers elements, less fiber lumen, less parenchyma per mm2, and more vessels per group than did provenances from the Atlantic Forest. Cross dating among the radial growth ring series was performed through visual and statistical procedures. The relationships between tree rings and meteorological records were performed through Pearson's correlation, and through dendro-climatic analysis that identified the end summer precipitation as the major factor affecting tree growth at inter annual timescale. The standard chronologies of tree-ring width series showed similarity between Cerrado and Atlantic Forest provenances, but with small differences in the juvenile period of live of trees. The rains that decreased between April and June associated with the gradual decrease in temperature may have reduced the cambial activity and caused the formation of tree rings with small differences between the two provenances. The results of this study are relevant for climate adaptive forestry: they emphasize the importance of heritability in the plasticity of certain features of wood anatomy related to the environmental conditions in which they grow, while the growth rate and its year-by-year variability show small differences.
Low-intensity cattle grazing is better than cattle exclusion to drive secondary savannas toward the features of native Cerrado vegetation
(2022-05-01) Durigan, Giselda; Pilon, Natashi A.L.; Souza, Flaviana M.; Melo, Antônio C.G.; Scorzoni, R. Danilo [UNESP]; Souza, Silvana C.P.M.; Instituto de Pesquisas Ambientais; Universidade Estadual de Campinas (UNICAMP); Grupo de Atuação Especial de Defesa do Meio Ambiente; Fundação para Conservação e Produção Florestal do Estado de São Paulo; Universidade Estadual Paulista (UNESP)
Although livestock have been historically associated with land conversion and biodiversity loss, well-managed cattle grazing has been reported to contribute to conservation of open ecosystems. Knowing the balance between positive and negative effects of livestock (presence or exclusion) on different ecosystems is, therefore, crucial to support management decisions. We conducted an experiment in a secondary savanna with exotic grasses, used as pasture, to assess the effect of cattle presence in low density and cattle exclusion (in paired plots) on the trajectory of these ecosystems. Richness, composition and structure of the woody community, and exotic grass cover and biomass were compared between treatments in the beginning of the experiment and after 7 years. At the end of the experiment, we also compared composition, richness, and density of the native ground layer. We verified that (a) cattle exclusion accelerates the undesirable woody encroachment, changes the species composition and leads to huge grass fuel accumulation, while (b) cattle grazing/browsing hinders changes in savanna structure and composition and reduces the exotic grass cover and biomass, thus favoring native herbaceous plants. By decreasing the grass biomass, cattle grazing also reduces the system flammability and, therefore, the risk and intensity of wildfires. Together, the positive effects of cattle presence and the negative effects of cattle exclusion lead to the conclusion that cattle should be maintained in these systems. Low-intensity cattle grazing limits woody and exotic grass invasion, improves native forb biodiversity, and help to maintain composition and structural features of secondary savannas of the Cerrado. Abstract in Portuguese is available with online material.
Functional trade-offs in volume allocation to xylem cell types in 75 species from the Brazilian savanna Cerrado
(Oxford Univ Press, 2022-07-22) Doria, Larissa Chacon [UNESP]; Sonsin-Oliveira, Julia; Rossi, Sergio; Marcati, Carmen Regina [UNESP]; Universidade Estadual Paulista (UNESP); Universidade Estadual de Campinas (UNICAMP); Univ Brasilia (UnB); Univ Quebec Chicoutimi
Background and Aims Xylem is a crucial tissue for plant survival, performing the functions of water transport, mechanical support and storage. Functional trade-offs are a result of the different assemblages of xylem cell types within a certain wood volume. We assessed how the volume allocated to different xylem cell types can be associated with wood functional trade-offs (hydraulics, mechanical and storage) in species from the Cerrado, the Brazilian savanna. We also assessed the xylem anatomical characters linked to wood density across species. Methods We analysed cross-sections of branches collected from 75 woody species belonging to 42 angiosperm families from the Cerrado. We estimated the wood volume fraction allocated to different cell types and performed measurements of vessel diameter and wood density. Key Results The largest volume of wood is allocated to fibres (0.47), followed by parenchyma (0.33) and vessels (0.20). Wood density is positively correlated to cell wall (fibre and vessel wall), and negatively to the fractions of fibre lumen and gelatinous fibres. We observed a trade-off between hydraulics (vessel diameter) and mechanics (cell wall fraction), and between mechanics and storage (parenchyma fraction). The expected positive functional relationships between hydraulics (vessel diameter) and water and carbohydrate storage (parenchyma and fibre lumen fractions) were not detected, though larger vessels are linked to a larger wood volume allocated to gelatinous fibres. Conclusions Woody species from the Cerrado show evidence of functional trade-offs between water transport, mechanical support and storage. Gelatinous fibres might be potentially linked to water storage and release by their positive relationship to increased vessel diameter, thus replacing the functional role of parenchyma and fibre lumen cells. Species can profit from the increased mechanical strength under tension provided by the presence of gelatinous fibres, avoiding expensive investments in high wood density.
Quantitative analysis of uncertainty in financial risk assessment of road transportation of wood in uruguay
(2016-10-01) Simões, Danilo [UNESP]; Mosquera, Gustavo Andrés Daniluk; Batistela, Gislaine Cristina [UNESP]; Passos, José Raimundo de Souza [UNESP]; Fenner, Paulo Torres [UNESP]; Universidade Estadual Paulista (UNESP); Universidad de la República
The uncertainty in road transportation of wood is inherent to its operational costs, to the amount of transported wood, to the traveled distance, to its revenue, and more. Although it is not possible to measure this uncertainty fully, it can be quantified by the investment risk, which is the probability and degree of financial loss. The objective of this study is to quantify the financial risk of the investment in wood transportation through Monte Carlo simulation, which uses realistic situations to estimate the operational cost of vehicles used for road transportation of wood. We quantify these uncertainties by assessing financial risk and building pseudorandom scenarios with the Monte Carlo simulation method, in addition to the Net Present Value techniques, the Modified Internal Rate of Return, and the Profitability Index, all commonly used in financial investment projects. The results show that the estimated operational costs are equivalent to the actual ones, along with the evidence that the cost of fuel, the driver’s manpower, and tires are components that mainly increase the degree of financial risk for an investment project in road transportation of wood. In contrast, optimizing the amount of transported wood and maximizing wood transportation cost have a significant and positive correlation with the volume of transported wood and the average price of wood transportation, leading to a reduction in the degree of financial risk.
Rendimento e classificação das lâminas de Eucalyptus grandis W. Hill utilizando dois tratamentos térmicos
(2017-01-01) Coneglian, Ademilson; Severo, Elias Taylor Durgante [UNESP]; Batista, Wagner Roberto; Pereira, Ismael Martins; da Silvas Gomes, Ivana; Dr. Universidade Estadual de Goiás; Universidade Estadual Paulista (UNESP); Dr. Universidade Federal do Triângulo Mineiro
This study aims to verify the influence of thermal treatments (water and steam of à 85°C ) in the yield and final classification of Eucalyptus grandis sheets. Six trees, obtaining a total of thirty logs adequate for lamination, with diameters of 25-40 cm. The average yield of Eucalyptus grandis lamination process was of 38.43% for steam heated logs, and 24.31% for water heated logs, with a significant difference at 5% probability. Wood sheets from Eucalyptus grandis have shown viability for plywood manufacturing in both treatments, therefore, it is recommended to use indirect heating with steam for a lower incidence of top cracks, and consequently higher lamination yield.
Productivity and costs of Feller-Buncher and forest processor in stands of Eucalyptus in first cut
(2014-07-01) Simões, Danilo [UNESP]; Fenner, Paulo Torres [UNESP]; Esperancini, Maura Seiko Tsutsui [UNESP]; Universidade Estadual Paulista (UNESP)
The rationalization of forest harvesting and minimization costs is a constant search by the managers involved in this process, making them decide practices which are economically viable to optimize that operation. This study aimed to evaluate technically and economically the performance of feller-buncher and the forest processor in stands of Eucalyptus in first cut. The technique analysis included time and movements, productivity, efficiency operational and mechanical availability. The economic analysis included the parameters operational cost, harvesting cost and energy consumption. Aiming the optimization the cost of forest harvesting, the system composed by feller-buncher and processor forest presented itself as a technically and economically viable alternative to harvesting eucalypt in first cut or stands that do not have bifurcated trees.
Seasonal presence of acicular calcium oxalate crystals in the cambial zone of Citharexylum myrianthum (Verbenaceae)
(2005-01-01) Marcati, Carmen Regina [UNESP]; Angyalossy, Veronica; Universidade Estadual Paulista (UNESP); Universidade de São Paulo (USP)
This study focuses on the seasonal presence of acicular crystals in the cambial zone of Citharexylum myrianthum Cham. (Verbenaceae). Specimens collected in different months from 1996 to 2000 were examined for the abundance of acicular crystals in the cambium. This information was correlated with the phenology of the species and the climate of the region. Acicular calcium oxalate crystals were found in cambial fusiform and ray cell initials, as well as in their daughter cells. An abundance of crystals was observed during periods of water deficit and leaf fall (July). Fewer crystals were found in the beginning of the wet season and bud swelling (September). When trees were flowering and the soil was wet (November and December), acicular crystals were rarely observed. During this period, acicular crystals were found in differentiating phloem and xylem parenchyma cells, in fully differentiated phloem cells, but not in fully differentiated xylem cells.
Superação de dormência em ormosia arborea (Fabaceae: Papilionoideae) pela utilização de dois métodos de escarificação mecânica em diferentes pontos do tegumento
(2011-09-01) Basqueira, Reginaldo Augusto; Pessa, Henderson; De Souza-Leal, Thiago; Pedroso-De-Moraes, Cristiano; Meio Ambiente No Centro Universitário Hermínio Ometto -UNIARARAS; Ciências Ambientais No Centro Universitário Hermínio Ometto -UNIARARAS-NUCIA
The dormancy state in Ormosia arborea seeds is caused by tegument impermeability. Two scarification mechanisms at different sites in the tegument are analyzed to determine the best methodology in the overcoming of dormancy and germination of the specie. Seeds were distributed in batches on four petri plates with 25 seeds each. They were previously covered with two sheets of filter paper moistured with 10 mL distilled water and taken to B.O.D climate chamber at 25°C ± 2, under a white light from 32.85 ?mol.m-2.s-1 fluorescent lamps, until their germination. Germination test results underwent ANOVA variance analysis and Turkey's test at 5% probability. Statistical analysis showed that scarification treatment with sandpaper on the medial portion of the orange-reddish lateral surface provides the best method in overcoming dormancy in Ormosia arborea seeds. The highest germinability rates and germination velocity are thus reached.
Wood quality for kraft pulping of Eucalyptus globulus origins planted in Uruguay
(2006-12-01) Resquin, Fernando; Barrichelo, Luiz Ernesto George; Da Silva Jr., Francides Gomes; Brito, José Otávio; Sansigolo, Cláudio Angeli; INIA - Instituto Nacional de Investigación Agropecuaria; Universidade de São Paulo (USP)
Eucalyptus globulus is an important raw-material for kraft pulping and has a wide geographical distribution. The objective of this paper was to evaluate E. globulus origins in terms of their wood and pulp properties. The results showed that wood density values for the origins are within the values considered advisable for kraft pulp production; origins with the highest wood density were from the south of Victoria state; fiber dimensions indexes obtained in this study allow us to infer that all origins are suitable for paper production; holocellulose content varied from 69 to 72%; the highest screened yield values correspond to the origins from south Victoria.
Forest restoration by direct seeding: a global bibliometric analysis
(2022-01-01) de Souza, Diego C. [UNESP]; Universidade Estadual Paulista (UNESP)
Direct seeding has been suggested to be a highly cost-efficient system for forest restoration but is still not applied on a large scale worldwide. Thus, to improve the knowledge surrounding the application of this system, I conducted a global bibliometric analysis about forest restoration by direct seeding. Based on a literature search of three online databases (Web of Science, Scopus, and Google Scholar), I found 81 peer-reviewed articles related to field experiments testing direct seeding for forest restoration. Each article was analyzed according to the following aspects: publication years, countries, continents, forest types, stages of restoration, journals, and authors. The results showed an increase in the number of articles published in recent years but a still low number of studies conducted to test the application of the system. These included field studies from a number of tropical and temperate countries worldwide, with a concentration of studies in Brazil and United States. Monitoring forests established by direct seeding is rare. A few researchers have paid special attention to the development of the field, and a few journals have published three or more articles on this topic. Overall, this study concludes that the application of direct seeding for forest restoration is a promising area for research, as the field is still little studied and has great potential to help achieve restoration goals. Furthermore, the results show trends and gaps that should be considered in future research to improve the application of direct seeding around the world.

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