200 resultados para Manejo florestal


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Inadequate vegetation and soil management leads to physical changes that affect aquifer recharge. The Araripe Plateau feeds an elevated number of springs on its northern slope; however, there are indications that their yield is decreasing. Through this research, it was studied the infiltration capacity of soils under different types of management. Soil samples from 21 sites were grouped into four groups. Group 1 represents areas of preserved vegetation, the others, anthropized ones. It was observed that soil moisture and infiltration capacity are linearly well correlated with organic matter; mean soil moisture during the dry season was significantly higher for Group 1 than for the other groups, even during the rainy season and anthropized areas show low organic matter contents, soil moisture, and infiltration capacity, indicating modifications in the soil's structure that reduce aquifer recharge.

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Population study of white-eared-opossum, Didelphis albiventris (Mammalia, Didelphidae), in a small forest fragment. The white-eared-opossums are habitat generalist animals and occur in high abundance in forest fragments. Therefore these animals are important to understand the dynamics of this landscape. The population of Didelphis albiventris in a 7 ha stational semidecidual forest fragment and its agricultural surroundings was studied during one year. The population abundance, age structure and sex ratio were estimated monthly. Two movements between the fragment and the surrounding area were detected. The population dynamics showed an annual pattern with a high peak during the dry season.

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A field trial was carried out in Santa Rita do Passa Quatro, SP, on sandy soil, between February 1993 to February 1995, aiming to study the effects of fertilizer doses and brachiaria grass control on the growth of E. grandis. In the field the plots (9×9 plants, spacing 2×3 m) were located following a randomized block experimental design with four repetitions. The treatments were arranged in a factorial design with four systems of brachiaria grass control in the space between the Eucalyptus rows: mowing, cultivation, chemical control with glyphosate (2,08 kg eq. ác./ha) and hand hoeing were developed when the population reached the early flowering stage and four doses of the fertilizer 20-05-20: 0, 115, 230 and 345 kg/ha, handled at 3, 6 and 12 monthes after the transplantation. The hand hoeing was the most effective method of brachiaria grass control. However the hand hoeing controlled plots showed a decrease on the E. grandis growth exhibiting slower growth rate, shorter plants, thinner stems, smaller leaf area results and reduction on dry matter accumulation than the plants from the other plots under different weed control management's. The glyphosate promoted an excellent brachiaria grass control while the E. grandis plants grow better. Both remainder weed control management systems were intermediary in terms of efficacy. The mowing management was the most similar method as compared to the hand hoeing one and the cultivation treatments to the chemical control method. The growth rate differences observed between the hand hoeing and chemical control treatments were not caused directly by late fertilizations. There were no significative interactions among the weed control systems and the fertilization doses. Considering the brachiaria grass that grew between the E. grandis rows there were detected benefits to the crop and these effects increased when the chemical control was used for weed management.

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A population survey was carried out in a forest fragment and in an area of vegetables, from November/1996 to February/1998, aiming to determine the predator insect species and the influence of abiotic factors. The samples were taken weekly by light traps. The results were evaluated using faunistic analysis and simple correlation with temperature, relative humidity and rainfall. In the forest fragment higher similarity in the abundance of species was observed comparing to the area of vegetables, but the largest number of captured individuals (95%) occurred in this last habitat. Metius sp., Polpochila impressifrons (Dej.), Eulissus sp. and Doru sp. were predominant species in both areas, evidencing they may play an important role as pest predators in areas of vegetables. Arthrostictus speciosus (Dej.) and Leptotrachelus sp. predominated in the forest fragment, and the same was observed with Paederus sp. in the vegetable area. This species is probably adapted for open and hot places, while A. speciosus and Leptotrachelus sp. can be adapted for dark and humid places of forests.

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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This study presents the results obtained in a field experiment carried out at Glicério, Northwest of São Paulo state, Brazil, whose objective was to analyze changes of selected soil physical properties and water infiltration rates on a Yellow-Red Latosol, under three different management conditions. The experimental design was arranged as completely randomized split-block with twelve treatments, which corresponded to four depths (0-0.05 m; 0.05-0.10 m; 0.10-0.20 m and 0.20-0.40 m) and three conditions of soil use and management with four replications. The soil surface conditions were: conventional tillage (one disking with moulboard plus two levelling passes with harrow), nine months before starting filed experiences; recent conventional tillage (also one disking with moulboard plus two levelling passes with harrow) and native forest. The conventional tillage areas were cropped for about fifteen years with annual cultures. The considered soil general physical properties were: macroporosity, microporosity, total porosity, bulk density, soil moisture and penetration resistance and, in addition; soil water infiltration rates were also recorded. According to our results, differences on general soil physical properties and infiltration rates appeared when both tilled sub-treatments and native forest were compared. Both, plots recently prepared by conventional tillage and those prepared by tillage but left nine months in rest, presented a statistically significant decrease of constant (final) water infiltration rates of 92.72% and 91.91% when compared with native forest plots.

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A field experiment was carried out in the Lageado Experimental Farm belonging to the São Paulo State University - UNESP, Campus of Botucatu, SP, in a distrophic Nitosoil in 1997/98. The objective was to compare the effects of magnesium termophosphate; termophosphate + lime; termophosphate + phosphogypsum + sugarcane vinnace application on the chemical characteristics of the soil and on the corn (Zea mays L.) yield cultivated in no-tillage and conventional tillage systems. The Crotalaria juncea was cultivated as mulch-producing to make possible the establishment of the tillage systems. The mean modifications in the soil fertility were due to aplication of the magnesium termophosphate. The differences between the two tillage systems, related to crop productivity, were associated to the smaller N content in the corn leaf in the no-tillage system.

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Soil management measures that increase the efficiency of organic matter cycling and maintain favorable soil structure are needed for improving soil quality. On the other hand, soil structure degradation due to inadequate soil management systems is widespread. Among the indicators of soil physical quality, saturated hydraulic conductivity and penetration resistance are thought to be sensitive to soil management system. The aim of this work was to study the influence of soil tillage system and organic fertilization on selected soil physical properties after the first year of treatment. The field work was conducted in Selviria, MS, Brazil on an Oxisol. The experimental design was randomized complete blocks with split-plots, with 12 treatments and 4 repetitions. Tillage treatments included conventional ploughing (CT) and direct drilling (DD). Fertilizer treatments were: 1) manure, 2) manure plus mineral, 3) traditional mineral 4) plant residues of Crotalaria juncea, 5) plant residues of Pennisetum americanum and 6) control plot. The plots were cropped to bean in winter and to cotton in summer, and both cultures were irrigated. After one year no significant differences between treatments in mechanical resistance and porosity were found. However, saturated hydraulic conductivity and infiltration were higher in the conventional tillage treatment at the 0.00-0.10 m depth. Moreover, an improvement in soil physical condition by organic fertilizers was shown.

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The conventional system for soil management and preparation has the intensive mechanization as its basic principle and that changes soil properties, especially physical ones, faster and significantly. This study aimed to obtain and compare physical properties such as distribution of particle sizes, density, distribution of pore sizes, curves of water retention and degradation index of a Red Latosol, under intensive cultivation and no-cultivation for six years. Soil samples were collected at depths of 0.1, 0.2, 0.3, 0.4, 0.6, 0.8 and 1.0 m. There was a clay increment as a result of cultivated soil increase. The no-till soil density decreased as depth increased; however, in the arable layer (0.3 m) of the cultivated soil, the opposite was verified. The largest volume of pores was verified in the cultivated soil, especially in the superficial layers. In the smallest applied tension (0.001 MPa), the cultivated soil retained more water; however, starting from 0.033 MPa, the highest humidity values occurred in the no-till soil. The highest degradation index was observed at a depth of 0.1 m in no-till soil. However, that value was superior (0.020) to what is physically considered very poor soil.

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This study objective was to evaluate the effective revegetation in a Mogi Guaçu River degraded floodplain area, located at Luiz Antonio municipality (21° 31' S e 47° 55' W), São Paulo State, Brazil. Two native riparian forest remnants (RIP1 and RIP2) and three 10-year-old reforested areas, planted of native species (R1, R2 and R3), were analyzed by using phytosociological describers of the arboreal stratum (trees with DBH ≥ 5 cm) as indicators. The arboreal stratum inventory was accomplished by 180 plots (10 × 10 m each), 60 representing every native forest and 20 for every reforested area. A total of 60 arboreal species was recorded, only six species (Cecropia hololeuca, Crotón urucurana, Genipa americana, Inga striata, Nectandra megapotamica e Peltophorum dubium) occurring in all the five studied areas. Seventeen species were common to both native forests, and nine species were recorded in all the reforested areas. Sebastlania commersonlana and Guarea macrophyllawere recorded in the native forests (RlP1 and RIP2), and Cecropia hololeuca, Croton urucurana and Inga striata occurring in all the reforested areas, were the species that best characterize the physiognomy of local diversity and were the most important among the studied species. The results showed that the rehabilitation of the areas made by the reforestation created conditions to implant forests with similar structures of the adjacent natural remainders. The reforestation with native species performed in the degraded floodplain of Mogi Guaçu River, initially with the predomination of invasive grasses, has been effective at the first stage of the ecological restoration process. The reforestation is making possible the natural regeneration of species from the adjacent remnants, what indicates that the similarity between planted forests and the native ones are rising through the time. The phytosociology, accomplished ten years after the planting date, is adequate to evaluate the effectiveness of the reforestation during the restoration process of degradated areas in the Mogi Guaçu floodplain.

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The purpose of the work is to evaluate the stability by dry and humid of theaggregate in different systems or the use and management in Argissolos: agricultural, pasture and torest utilization. This work was realized in agricultural property, in Anhumas city, SR Several analyses including percentage of the aggregate (by way of dry and humid); the weighted mean diameter of the aggregate calculation and statistic analysis. Conclusion: the organic matter content of the A horizon of the soil under forest is 64 % more than the soil under pasture and 79 % more than the soil under annual crop; the WMDA of the aggregate obtained by dry and humid ways of the horizon A and its mean value for the soil decrease in the following sequence: PVAd - forest > PVe -pasture > PVd - annual culture, respectively, with the following values: 1.33560 and 1.445496 (D), 2.81114 and 2.351380 (H); 0.66748 and 1.011830 (D); 2.79642 and 1.624250 (H); 0.32468 and 0.993775 (S), 1.25808 and 0.983135 mm (H); the two methods are equally sensitive to reveal the effect of the soil use and management; the organic matter provides additional stability to the aggregates submitted to humid sieving and clay to the dry sieving: the WMDA obtained by dry and humid ways are statistically different for the soil profiles.

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The tourist use of Santana cave provides a row of environmental damages, compromising partially the pristine conditions. Among the measures adopted to avoid this situation, this issue presents a contribution for the physical limits to tourist visitation and the indications for speleotouristic management. It was used the Cifuentes Carrying Capacity method and some basic principles of Visitors Impact Management Framework - VIM. The results show a Real Carrying Capacity (CCR) about 120 visits daily on the cave. The discussions raise a few hypotheses about the alteration in the method used and the temporal frequency between visitors groups, suggesting a provisional CCR of 117 and 135 visitors daily, respectively, during the week and in the weekends and holidays. The conclusions appoint the necessity of a conceptual revision in the Carrying Capacity methods, mainly about its adaptation for tourist management in caves. In the case studied, it is suggested the immediate beginning of environmental monitoring of the cave, to verify the plausibility from proposed visitation limits and the possible contributions for to mitigate the environmental impacts from speleotourism.

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This study has the objective of evaluate the influence of fluvial and road transport on the occurrence of bruising in carcass of slaughtered beef cattle. In this study was observed that from 209 evaluated carcass, 185 (88.5%) presented one or more lesions. In total of evaluated carcass occurred 523 lesions that resulted in 96.158 kg removal of bruises (0.519 kg per animal). In this study was possible the determination of age of bruises by color evaluation. We concluded that of way of transport influenced the occurrence of bruises. The most bruises occurred in the last 24 hours of transport. Educational measures will be necessary to reduce the problems of pre-slaughter management.

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This paper presents a new approach for solving constraint optimization problems (COP) based on the philosophy of lexicographical goal programming. A two-phase methodology for solving COP using a multi-objective strategy is used. In the first phase, the objective function is completely disregarded and the entire search effort is directed towards finding a single feasible solution. In the second phase, the problem is treated as a bi-objective optimization problem, turning the constraint optimization into a two-objective optimization. The two resulting objectives are the original objective function and the constraint violation degree. In the first phase a methodology based on progressive hardening of soft constraints is proposed in order to find feasible solutions. The performance of the proposed methodology was tested on 11 well-known benchmark functions.

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The intensive use of the land for agricultural propose causes a series of modifications in attributes, which can take to soil degradation. In this context, the main goal of this research was to evaluate the influence of the soil tillage systems and management on its physical and hydric characteristics. The evaluations were carried out in July of 1999, at experimental plots of a Latossolo vermelho, a clay oxisoil, in the Faculdade de Engenharia Agrícola of the UNICAMP, at the county of Campinas, state of São Paulo. These plots were managed with the following treatments, along a period of eight years: no-tillage, chisel ploughing, conventional system with disk ploughing and revolving hoe. The evaluated physical and hydric parameters of the soil were: soil bulk density, particle density, total porosity, macro-porosity, micro-porosity, soil-water retention curve, hydraulic conductivity and basic infiltration. Significant differences were observed between the treatments on soil bulk density, infiltration, total porosity, macro-porosity and the micro-porosity. The chisel ploughing and no-tillage systems presented the higher values of soil bulk density; nevertheless in these conservationist systems were observed the higher values of basic infiltration.