28 resultados para 770807 Rehabilitation of degraded farmland
Resumo:
ABSTRACT An alternative for recovery of areas degraded by coal mining is revegetation with rapidly growing leguminous trees, which often do not establish in low fertility soils. The objective of this study was to evaluate the efficiency of native rhizobia isolated from coal mining areas in the nodulation and growth of leguminous trees. We isolated 19 strains of rhizobia from a degraded soil near Criciúma, SC, Brazil, and evaluated the nodulation and growth-promoting capacity of the inoculated isolates for bracatinga (Mimosa scabrella), maricá (M. bimucronata) and angico-vermelho (Parapiptadenia rigida). Isolates UFSC-B2, B6, B8, B9, B11 and B16 were able to nodulate bracatinga, providing average increases of 165 % in shoot dry matter, with a significant contribution to N accumulation. Isolates UFSC-B5, B12, and M8 favored nodulation and growth of maricá, especially isolate UFSC-B12, which promoted increases of 370 % in N accumulation compared to treatment with N fertilizer. All strains were inefficient in promoting growth and N uptake by angico-vermelho. In conclusion, isolation and use of selected rhizobia for bracatinga and maricá plant inoculation can contribute to the growth and accumulation of N, with prospects for use in programs for revegetation of degraded soils in coal mining areas.
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Tapirira guianensis (Anacardiaceae) is used in traditional medicine and is important for the recovery of degraded areas and riparian forests because the T. guianensis fruits are highly consumed by wildlife. Volatile components from dried leaves and branches of five individual plants of T. guianensis were collected in two sandbank forests of the State of Pará (Extractive Reserve Maracanã and Area of Environmental Protection Algodoal/Maiandeua), extracted by hydrodistillation using a Clevenger-type apparatus, and analyzed by GC/MS. The ten oils obtained are comprised mostly of sesquiterpene hydrocarbons (58.49 to 100%), with (E)-caryophyllene, β-selinene, α-selinene, β-sesquiphellandrene, and α-zingiberene being the most prominent. The results of the oil compositions were processed by Hierarchical Component Analysis (HCA) allowing the establishment of three groups of essential oils for T. guianensis differentiated by the content of β-selinene/α-selinene (Type I), (E)-caryophyllene (Type II), and β-sesquiphellandrene/α-zingiberene (Type III).
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Four levels of shading (full sunlight (0%), 30, 50, 70% of solar radiation interception on growth, chlorophyll concentration and photosynthetic rate were studied in Croton urucurana Baill., a pioneer plant species. This species seedlings are of potential interest for reforestation projects and recovery of degraded areas. The seedlings were grown in pots containing soil and sand (2:1) and later transferred to plastic bags of 3 dm³ and submitted to different levels of shading (30, 50, 70%) of solar radiation and full sunlight, as control. The experimental design was completely randomized with five replicates and each experimental unit was composed of five plants. The results suggest that plants submitted to 70% shading showed higher dry weight accumulation in leaf and root, and higher plant height and leaf area. However, the seedlings root system showed higher dry biomass under full sunlight. It was observed a tendency to increase chlorophyll concentration and to decrease photosynthetic rate with the increase of the shading level.
Resumo:
The objective of this study was to test the hypothesis that the distribution of tree species in a fragment of submontane seasonal semideciduous forest, a buffer zone in the Parque Estadual do Rio Doce, Minas Gerais, is influenced by geomorphological and weather and soil variables, therefore it can represent a source of information for the restoration of degraded areas where environmental conditions are similar to those of the study area. A detailed soil survey was conducted in the area by sampling three soil profiles per slope segment, totaling 12 profiles. To sample the topsoil, four composite samples were collected from the 10-20 cm layers in each topographic range totaling 16 composite samples. In the low ramp and the lower and upper concave slopes, the texture ranged from clay to sandy-clay. The soil and topographic gradient was characterized by changes in the soil physical-chemical properties. The soil in the 10-20 cm sampled layer was sandier, slightly more fertile and less acid in the low ramp than the clayer soil, nutrient-poor and highly acid soil at the top. The soil conditions in the lower and upper slope of the sampled layers, in turn, were intermediate. The P levels were limiting in all soils. The species distribution along the topographic gradient was associated with variations in chemical fertility, acidity and soil texture. The distribution of Pera leandri, Astronium fraxinifolium, Pouteria torta, Machaerium brasiliense and Myrcia rufipes was correlated with high aluminum levels and to low soil fertility and these species may be indicated for restoration of degraded areas on hillsides and hilltops in regions where environmental conditions are similar. The distribution of Pouteria venosa, Apuleia leiocarpa and Acacia polyphylla was correlated with the less acid and more fertile soil in the environment of the low ramps, indicating the potential for the restoration of similar areas.
Resumo:
Planting trees is an important way to promote the recovery of degraded areas in the Caatinga region. Experiments (E1, E2, and E3) were conducted in a randomized blocks design, with three, three, and five replicates, respectively. The objectives were to evaluate biomass of the shoots of: a) gliricidia (G) and sabiá (S), as a response to planting density; b) G, S, and neem (N) in competition; c) G, and S in agroforestry. E1 was conducted in split-plots, and planting densities (400, 600, 800, 1000, and 1200 plants ha-1) as subplots. E2 consisted of a factorial comprising the following plots: GGG, NGN, SGS, NNN, GNG, SNS, SSS, GSG, NSN (each letter represents a row of plants). E3 was conducted with G and S in agroforestry experiment. The trees were harvested after 54, 42, and 27 months old, in E1, E2 and E3, respectively. In E1, G presented higher green biomass of the stems and leaf at smaller densities than S, but lower green biomass of branches at most densities. The species did not differ for mean stem dry biomass and leaf dry biomass, but G showed higher branch dry biomass at most densities. Higher planting densities increased green and dry biomass of stems, branches, and leaves in S, but decreased those characteristics in G, with the exception of leaf dry mass, which was not influenced by density. In E2, the behavior of each species was identical in plots containing the same or different species. Griricidia showed the highest green biomass of stems and branches, and the highest values for geren biomass of the leaf were observed for gliricidia and neem. The highest stem, branch, and leaf dry biomass values were obtained for G, S, and N, respectively. In E3, G was superior for stem and leaf green biomass, and for stem and branch dry biomass. There were no differences between species for the other biomass values.
Resumo:
ABSTRACT The ecological restoration of degraded areas using seeds collected in forest remnants has shown significant results. This study was developed to verify the potential of seed rain to regenerate forest fragments of a Permanent Preservation Area (PPA) in the Apa River Basin which is located in the southwestern portion of the Mato Grosso do Sul state, Brazil. To develop the study, we installed 25 collectors measuring 1 m2 each, which were systematically distributed on an area of 1.5ha. Seed gathering was conducted in a monthly basis throughout the year of 2013. A total of 26.411 propagules were identified and distributed among 50 species, 45 genera and 32 families. In terms of the propagules distribution, 70.51% were identified as trees, 22.8% as lianas, 6.5% as shrubs, 0.1 as herbaceous, 0.05% as palm and 0.05% could not be classified. The value for the Shannon Diversity Index was (H') = 1.67 and the Pielou Evenness index was (J) = 0.42. These results indicate that the seeds rain has low species diversity with the abundance of a few species. The overall results suggest that seed rain can be a potential technique for restoration of the PPAs and other forested areas. However, it is necessary to enhance the diversity of tree species.
Resumo:
Lutzomyia longipalpis, 15 other species of the genus Lutzomyia, and one species of Brumptomyia were collected in an endemic focus of cutaneous leishmaniasis in a river canyon 450 m above sea-level, in Rio Claro, Antioquia, Colombia. The presence of Lu. longipalpis is associated with the destruction of the primary forest and the development of new farmland and rural settlement in this region. The composition of species identified a different habitat for Lu. longipalpis in Colombia. Lu. yuilli and Lu. longipalpis were predominant (68.26%) followed by Lu. trapidoi, Lu. hartmani, Lu. triramula, Lu. panamensis, Lu. gomezi.
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The discovery of two atypical specimens of Rhodnius pictipes Stål, 1872 in French Guiana and the examination of the female holotype of R. amazonicus Almeida, Santos & Sposina, 1973, the only specimen of this species so far known, lead us to propose the rehabilitation of R. amazonicus synonymized with R. pictipes. The male is described for the first time and the female redescribed. Both external characters and genitalia distinguish R. amazonicus from R. pictipes. R. amazonicus shows affinities not only with pictipes but also with R. stali Lent, Jurberg & Galvão, 1993 and R. paraensis Sherlock, Guitton & Miles, 1977. A key is provided for these four species forming, in all likelihood, a natural group, i.e. the "pictipes group".
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Water resource quality is a concern of today's society and, as a consequence, low pollutant wastewaters and sludges are being increasingly treated, resulting in continuous production of sewage sludge. Sewage sludge (SS) can be used as soil physical conditioner of agricultural or degraded lands, due to its organic C component. The objective of this research was to evaluate the long-term SS effects on soil physical quality of properties such as bulk density, porosity, permeability and water retention of degraded soils treated with annual SS applications. The SS rates were calculated according to the crop N demand. The field experiment consisted of three treatments: mineral fertilization, 10 and 20 Mg ha-1 of SS (once and twice the SS quantity to meet the maize N demand, respectively), in annual applications to the surface layer of a eutroferric Red Latosol. SS reduced bulk density, increased macroporosity and decreased microporosity after the third application, but did not significantly alter the soil permeability and physical quality as measured by the S index in the surface layer.
Resumo:
The symbiosis of plants with mycorrhizal fungi represents an alternative to be considered during the processes of revegetation and rehabilitation of arsenic-contaminated soil. The aim of this study was to evaluate under greenhouse conditions the effect of arsenic on the mycorrhizal association of two species of tropical fern (Thelypteris salzmannii and Dicranopteris flexuosa). T. salzmannii had higher rates of colonization and higher density of spores while D. flexuosa showed greater sensitivity to smaller concentrations of arsenic and association with mycorrhizal fungi. Our results indicate that screening and selection of mycorrhizal fungal isolates/species is possible and effective for phytoremediation of arsenic-contaminated soils.
Resumo:
After listing the five key elements of ecological restoration, ecology, economics, social values, cultural values, and politics, I celebrate the fact that in Brazil there is legislation on how to perform ecological restoration of degraded tropical forests, as well as an ongoing dialogue among legislators and scientists about this legislation, and also a lively debate among scientists as the best way forward, referring to articles by Brancalion et al. (2010) and Durigan et al. (2010) in this issue of Revista Árvore. Legislators elsewhere, especially megadiversity countries, should take note. I do not take sides in the debate; I think both groups of authors make very good points. Instead I call on the scientists and legislators concerned with restoration to ponder five strategic tools: A. Start with clear concepts. B. Decide where you want to go and why. C. Negotiate who should benefit & how, and who should pay, how, & why. D. Work out how an honest cost-benefit analysis of restoration would look, regardless of the biome in which you are working. Finally, figure out how to make the restoration immediately attractive for private landowners. Otherwise, they will not cooperate as fully as they could or should, and restoration efforts will not achieve its full potential.
Resumo:
In some cases of esophageal reconstruction, it is not possible to use the gastric tube. In those cases, the second option is the reconstruction with a colonic segment. In the present paper, the authors present the use of microsurgical technique to improve vascular supply in esophageal reconstructions using the colon. Therefore, the transposed segment becomes perfused by two vascular pedicles: a proximal one and a distal one. The authors describe a case of 52 years-old patient, suffering of middle third esophagus carcinoma, who underwent a primarily esophageal resection with an unsuccessful reconstruction using gastric transposition. A new reconstruction was proposed using a bipedicle microcirurgical colonic tube, four months later. The post operative was uneventful with rehabilitation of swallowing and satisfactory recovery of nutritional state.
Resumo:
Occupational therapy (OT) is a profession concerned with promoting health and well-being through occupation, by enabling handicapped people to participate in the activities of everyday life. OT is part of the clinical rehabilitation of progressive genetic neurodegenerative diseases such as spinocerebellar ataxias; however, its effects have never been determined in these diseases. Our aim was to investigate the effect of OT on both physical disabilities and depressive symptoms of spinocerebellar ataxia type 3 (SCA3) patients. Genomically diagnosed SCA3 patients older than 18 years were invited to participate in the study. Disability, as evaluated by functional independence measurement and Barthel incapacitation score, Hamilton Rating Scale for Depression, and World Health Organization Quality of Life questionnaire (WHOQOL-BREF), was determined at baseline and after 3 and 6 months of treatment. Twenty-six patients agreed to participate in the study. All were treated because OT prevents blinding of a control group. Fifteen sessions of rehabilitative OT were applied over a period of 6 months. Difficult access to food, clothing, personal hygiene, and leisure were some of the main disabilities focused by these patients. After this treatment, disability scores and quality of life were stable, and the Hamilton scores for depression improved. Since no medication was started up to 6 months before or during OT, this improvement was related to our intervention. No association was found between these endpoints and a CAG tract of the MJD1 gene (CAGn), age, age of onset, or neurological scores at baseline (Spearman test). Although the possibly temporary stabilization of the downhill disabilities as an effect of OT remains to be established, its clear effect on depressive symptoms confirms the recommendation of OT to any patient with SCA3 or spinocerebellar ataxia.