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Search Results: 1 - 10 of 44959 matches for " RODRIGUES RICARDO RIBEIRO "
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Impacto da remo??o de plantulas sobre a estrutura da comunidade regenerante de Floresta Estacional Semidecidual
Viani, Ricardo Augusto Gorne;Rodrigues, Ricardo Ribeiro;
Acta Botanica Brasilica , 2008, DOI: 10.1590/S0102-33062008000400012
Abstract: transplanting seedlings and saplings from natural forests has been considered an alternative to producing saplings of native species for forest restoration purposes, but the possible impact of this procedure on plant community regeneration has not been investigated. this work evaluates the impact of different treatments of shrub and tree-seedling (up to 30 cm) removal from a seasonal semideciduous forest fragment located in southeastern brazil on the natural regeneration process. eighty 2×2 m plots were installed in two habitats (forest edge and interior) and submitted to four seedling-removal treatments (i, ii - 100% removal with or without soil mixing; iii - 50% removal without soil mixing; and iv - control treatment without seedling removal). regeneration density and richness were evaluated before treatment as well as 6, 12 and 18 months later. the results were compared among treatments for each evaluation period and among periods within treatments. there were similarities between edge and interior. the natural regeneration process did not improve with soil mixing. plots submitted to seedling removal partially recovered plant density; however, these plots had lower species richness when compared to the control and to the initial values before treatment. seedling removal has a negative impact on the regeneration process of low-density species, thus the use of natural regeneration as a sapling source for forest restoration purposes should focus only on high-density species with well-known regeneration strategies and not on the community as a whole.
Sobrevivência em viveiro de mudas de espécies nativas retiradas da regenera??o natural de remanescente florestal
Viani, Ricardo Augusto Gorne;Rodrigues, Ricardo Ribeiro;
Pesquisa Agropecuária Brasileira , 2007, DOI: 10.1590/S0100-204X2007000800002
Abstract: seedling survival was evaluated regarding transplanted saplings obtained from natural regeneration of a semideciduous seasonal forest fragment, located at bofete, s?o paulo state, brazil. shrub and trees species seedlings up to 30 cm height were collected from samples sited on a forest remnant, transplanted to a nursery under 50% shade tissue, and evaluated periodically during nine months. a total of 2,424 seedlings, belonging to 110 species were transferred to the nursery. average survival reached 69%, although this survival rate was quite variable according to the species, families and height classes of the evaluated individuals. in spite of the fact that pioneer species presented higher survival rate, several non-pioneer species also obtained high values of survival. besides, many of the survivor species are usually not available in forest nurseries of the s?o paulo state. the transference of seedlings from natural regeneration of forest fragments to forest nurseries seems to be a complementary and a viable method in order to produce saplings of native species, increasing diversity within nurseries with forest restoration purposes.
Potential of the seedling community of a forest fragment for tropical forest restoration
Viani, Ricardo Augusto Gorne;Rodrigues, Ricardo Ribeiro;
Scientia Agricola , 2009, DOI: 10.1590/S0103-90162009000600008
Abstract: forest restoration projects are usually planted with a reduced number of species as compared to standing forests, largely due to the low availability of native species in seedling nurseries. in the present study, the potential of the native seedling community as a source of seedlings for forest restoration is analyzed. to do so, the seedling community from a forest fragment located in the southeast of brazil was evaluated. individuals (tree and shrub species) up to 30 cm height were measured and identified in 20 4 × 4 m plots. altogether, 6,136 individuals (17 individuals m-2) belonging to 119 species were sampled. the seedling community showed a spatial heterogeneity with respect to the density of individuals and composition of species, and also a spatial aggregation for the 10 most abundant species. several species that occurred in high densities in the seedling community are not presently available in regional forest nurseries and are therefore not used in restoration projects. this result and the high number of individuals and species found in the fragment suggest a great potential of this type of forest remnants as a source of highly diverse seedling banks for use in restoration projects.
Implica??es do cumprimento do Código Florestal vigente na redu??o de áreas agrícolas: um estudo de caso da produ??o canavieira no Estado de S?o Paulo
Brancalion, Pedro Henrique Santin;Rodrigues, Ricardo Ribeiro;
Biota Neotropica , 2010, DOI: 10.1590/S1676-06032010000400009
Abstract: one of the major reasons of the proposed changes of the brazilian forest code is that its compliance would supposedly harm several agricultural sectors, although this reason has been weakly supported by data. the goal of this work was to evaluate the implication of the compliance with the forest code for reducing areas of sugarcane production in the state of s?o paulo, aiming to estimate the upper limit of potential losses that the application of the forest code could bring to the economic viability of important sectors of brazilian agricultural production. we analyzed 23 projects of environmental planning carried out in 1,961 landholdings of sugarcane mills from s?o paulo state, which totalized 533,097 ha (9.7% of the cultivated area with sugarcane in the state). in these projects, we carried out an environmental zoning of permanent protected areas (ppa), lands of agricultural production, and potential lands to constitute legal reserves. the results indicated that, on average, 10.4% of the total area of each farm was classified as ppa, and that only 21.2% of ppa area (2.2% of the total area) were occupied by some kind of agricultural production. sugarcane occupied, in average, 12.1% of the areas classified as ppa (1.2% of the total area). overall, 76.5% of the total area of projects was occupied by sugarcane fields and the sum of potential areas for compliance with the legal reserve, which were constituted by forest remnants (5.0% of total area), abandoned lands (2.3% of total area), and lands with other uses (6.3% of total area), would result in 13.6% of the total area and consequently generate a deficit of 6.4% of lands for the full compliance with the legal reserve (20%). this deficit could even be compensated, by law, outside the landholding register in landscapes with lower agriculture suitability. therefore, the diagnostics presented in this work for the sugarcane sector in the state of s?o paulo indicates that compliance with the current forest code would no
Florística e fitossociologia de remanescentes de floresta estacional decidual em Piracicaba, S?o Paulo, Brasil
Brazilian Journal of Botany , 2000, DOI: 10.1590/S0100-84042000000300005
Abstract: this study was conducted in two remnants of deciduous seasonal forest with 4 and 10 ha, in piracicaba, s?o paulo state, brazil. this forest has peculiar abiotic characteristics, growing on inceptisol, with hydric deficit in the dry season and water excess in the wet season determining a peculiar flora and a physiognomy similar to the dry forests. a floristic survey was carried out in both remnants while a phytosociological was carried out in the10 ha remnant, where the individuals with pbh 3 15 cm, present in 43 plots of 10 x 10 m, were recorded. one hundred and ten species, 86 genera and 42 families were registered. we found 20.7% of the species bearing spines, 31.0% of the 894 individuals registered had ramification at the soil level, and in the dominant stratum there were species that lose leaf turgescence (24.7% of individuals), and deciduous (59.4%), leafless (13.3%), perenial (1.6%) and semi-deciduous species (1.0%). the families with the highest number of species were leguminosae, myrtaceae and rutaceae. the most important species were cereus hildmanianus, eugenia florida, eugenia uniflora, pseudobombax grandiflorum and sebastiania serrata. the shannon?s diversity index (h?) was 3.0 nats/individuals and the eqüability (j) was 0.7 nats/indivíduos.
Análise do mosaico silvático em um fragmento de floresta tropical estacional no sudeste do Brasil
Leite, Eliana Cardoso;Rodrigues, Ricardo Ribeiro;
Revista árvore , 2008, DOI: 10.1590/S0100-67622008000300007
Abstract: this study was carried out in "mata da camara", a fragment of a seasonal semideciduous forest, in s?o roque - sp, brazil. the objective of the present work was to identify and analyze the silvatic mosaic, by discussing its current architectural aspects and inferring about its construction dynamics. the line-intercept inventory method was used in three 50 x 105 m areas. the results showed that percentages of the area occupied by 2a steady-state eco-units, were 46.8%, 48.6%, and 75.7% for areas a, b and c respectively. it can be concluded that there is a young forest in area a; a pre-mature forest with signs of both recent and old disturbances in area b, and in area c a mature forest with signs of old disturbances. compared with the results of other phytosociological researches carried out in the same area, this analysis showed to be an important tool for the discussion of forest dynamics, though in some cases the mosaic silvatic analysis tended to overestimate the level of forest maturity. it can be stated that among the remaining seasonal forests in the state of s?o paulo, "mata da camara" represents a patch of a relatively well-preserved forest.
Fitossociologia e caracteriza??o sucessional de um fragmento de floresta estacional no sudeste do Brasil
Leite, Eliana Cardoso;Rodrigues, Ricardo Ribeiro;
Revista árvore , 2008, DOI: 10.1590/S0100-67622008000300019
Abstract: in brazil, the seasonal tropical forest is located between the humid forests in the east and savannas in the west and it has been historically fragmented, leaving few remnants today. this study was carried out at the "s?o roque municipal park" also known as "mata da camara", in s?o roque, sp, brazil. the objective of the present work was to carry out a phytosociological survey of the tree stratum in three different altitudinal situations within a forest fragment, as well as the successional characterization of this fragment by identifying the ecological groups of species. the plot method was used with a total of 42 plots arranged in 3 blocks of 14 plots each, totaling 0.945 ha of sampled area. all individuals with pbh (perimeter at breast height) of 15 cm or more were sampled. a total of 1413 individuals belonging to117 species and 47 families were sampled. the shannon diversity index was 4.011. the three areas showed respectively 22, 32 and 13% of individuals of pioneer species, 42, 28 and 46% of individuals of early secondary species, and 32, 38 and 39% of individuals of late secondary species. it is concluded that the area is in initial stage of succession in its peripheral portion, and in intermediate tending to terminal stage in its inner portion, but taking the seasonal forest fragments of the state of s?o paulo as reference, one can say that mata da camara represents a portion of preserved forest.
Florística e fitossociologia de remanescentes de floresta estacional decidual em Piracicaba, S o Paulo, Brasil
Brazilian Journal of Botany , 2000,
Abstract: O estudo foi realizado em dois remanescentes de floresta estacional decidual de 4 e 10 ha, em Piracicaba, S o Paulo, Brasil. Esta floresta tem características abióticas próprias, como solo litólico, estresse hídrico no período seco e excesso de água no período úmido, definindo uma flora particular e fisionomia semelhante a de florestas secas. O levantamento florístico foi realizado nos dois remanescentes e o fitossociológico naquele de 10 ha, onde foram amostrados os indivíduos com perímetro à altura do peito (PAP) > ou = 15 cm existentes em 43 parcelas de 10 x 10 m. Foram registradas 110 espécies, 86 gêneros e 42 famílias. Do total de espécies, 20,7% continham espinhos, 31,0% dos 894 indivíduos amostrados apresentaram-se perfilhados e, no estrato dominante, ocorreram espécies com perda de turgescência foliar (24,7% dos indivíduos), decíduas (59,4%), áfilas (13,3%) perenes (1,6%) e semidecíduas (1,0%). As famílias de maior riqueza na fitossociologia foram Leguminosae, Myrtaceae e Rutaceae. As espécies de maior valor de importancia foram Cereus hildmanianus, Eugenia florida, Eugenia uniflora, Pseudobombax grandiflorum e Sebastiania serrata. O índice de diversidade de Shannon (H?) foi de 3,0 nats/indivíduos e a equabilidade (J) de 0,7 nats/indivíduos.
Classifica??o fitogeográfica das florestas do Alto Rio Xingu
Ivanauskas, Natália Macedo;Monteiro, Reinaldo;Rodrigues, Ricardo Ribeiro;
Acta Amazonica , 2008, DOI: 10.1590/S0044-59672008000300003
Abstract: this paper proposes the inclusion of the "evergreen seasonal forest" category in the official system used to classify brazilian forests. this proposal is based upon the floristic and physiognomic particularities of the southern amazonian forest, which reach a greater magnitude around the upper xingu river. in order to justify the inclusion, the paper reports environmental characteristics (climate, soil and hydrology) as well as floristic and physiognomic differences between the upper xingu river forest and both the ombrophilous forest from the amazon basin and the seasonal forest of the central plateau.
Estrutura de um trecho de floresta Amaz?nica na bacia do alto rio Xingu
Ivanauskas, Natália Macedo;Monteiro, Reinaldo;Rodrigues, Ricardo Ribeiro;
Acta Amazonica , 2004, DOI: 10.1590/S0044-59672004000200015
Abstract: this paper shows the structure of patch of forest at gaúcha do norte-mt (13° 10's e 53° 15' o) in southern amazonia. for the phytosociological survey, the 3 sample areas of 1 ha were subdivided into 50 sections of 10 x 20 m. all the individuals with circumference at breast height (cbh) > 15 cm were sampled. to characterise the structural similarity between the areas, correspondence analysis (ca) was used. the indicator species of the interfluvial environments and of the areas subject to flooding were obtained using twinspan (two way indicator species analysis) and a system of weights. it was observed that the forests present in the pacuneiro river basin belong to the same phytogeographical unit, but may present floristic and structural subtypes according to the relief position, the proximity to rivers and streams and the stratum analysed, demonstrating the predominance of some species, or even possible endemic species, in certain areas or stratums. the formation demonstrated a comparatively low alpha (2.91 - 3.50) and beta beta diversity (3.62 a 3.86) which is not common in amazonian forests. various hypothesis may explain this diversity, such as the low rainfall and high seasonallity, the apparently homogenous regional physical environment favourable to competing species, or historic events such as possible exploration by indigenous tribes or the recent expansion of these forests over savannic areas.
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