268 resultados para SUB-POPULATIONS
Resumo:
O objetivo deste trabalho foi mapear e quantificar as áreas de preservação permanente (APPs) de acordo com a Resolução nº 303/02 do CONAMA para, então, com base no mapa de uso da terra e cobertura vegetal, identificar e quantificar os eventuais conflitos de uso da terra, com vistas a nortear o cumprimento da lei e promover o uso adequado dos recursos da sub-bacia hidrográfica do rio Camapuã/Brumado, MG. Utilizaram-se uma imagem digital do sensor ETM+/LANDSAT 7, bases cartográficas planialtimétricas do IBGE para a área de estudo, e os softwares Anudem 5.2, Erdas Imagine 9.2 e ArcGIS 9.3. As APPs ocuparam 63.095 ha, representando 57,0% da área total da sub-bacia (110.711,9 ha). Com relação às categorias de APPs, o terço superior da bacia, ao longo das linhas de cumeada, correspondeu a 52,6% dos 63.095 ha; as zonas de proteção às margens dos cursos d'água, a 31,4%; a proteção das nascentes, a 15,6%; e as encostas com declividade superior a 45° e o terço superior de morros totalizaram 0,4%. As áreas de terço superior da bacia, ao longo das linhas de cumeada, foram as mais desrespeitadas (55,9%), seguidas das margens de curso d'água (23,12%), proteção de nascentes (20,83%), encostas com declividade superior a 45° (0,3%) e terço superior de morros (0,1%). Foram identificados 21.939,3 ha de APPs sendo explorados por atividades agropecuárias, o que representa 34,8% do total de APPs. Entretanto, constatou-se que 30.734,3 ha dos 47.616,9 ha situados fora das áreas de APP, i.e., 64,5% das áreas legalmente passíveis de conversão de uso da terra, estavam cobertos por vegetação nativa. Encontraram-se sólidas evidências de que a falta de conhecimento a respeito da espacialização das APPs dentro da propriedade é a principal causa do descumprimento da lei. A delimitação e espacialização das APPs pelo geoprocessamento viabilizam a aplicação da legislação florestal, contribuindo notoriamente para minimizar os conflitos de uso da terra e evitar a degradação dos remanescentes florestais pela formação de corredores ecológicos naturais que mitiguem os efeitos deletérios da fragmentação de habitats.
Resumo:
As espécies distílicas Psychotria conjugens, P. hastisepala e P. sessilis (Rubiaceae) são típicas de sub-bosques sombreados. Ocorrem no maior fragmento de Floresta Estacional Semidecidual de Viçosa, Minas Gerais, Sudeste brasileiro - a Mata do Paraíso, com 194 ha. A distilia caracteriza-se pela presença dos morfos florais longistilos (L) e brevistilos (B) em indivíduos distintos e pela dependência de polinizações intermorfos (L x B ou B x L) para a produção de frutos; é esperada a proporção equilibrada (isopletia) dos indivíduos na população. Foram objetivos deste trabalho verificar, nas espécies citadas, a proporção dos morfos florais em uma área de 7 ha e a dependência por polinizadores, testando a incompatibilidade intramorfos (L x L e B x B) por meio de polinizações manuais in vivo, a viabilidade dos grãos de pólen e dimorfismo dos grãos entre os morfos florais; e quantificar as produções de frutos e de sementes por morfo. Os morfos florais das espécies se encontram em proporções equilibradas. Houve incompatibilidade e a viabilidade dos grãos de pólen foi alta (> 64%). Verificou-se dimorfismo dos grãos, e os maiores diâmetros foram os de B. As produções de frutos e de sementes (uma ou duas) dos morfos de P. sessilis e de P. conjugens foram semelhantes e, em P. hastisepala, foram maiores em B. Na Mata do Paraíso, as condições adequadas, como o hábitat, a isopletia e a atuação de polinizadores, são fatores que parecem favorecer o sucesso reprodutivo e, consequentemente, a manutenção local das espécies estudadas.
Resumo:
ABSTRACT This study estimates the repeatability coefficients of two production traits in two native populations of Brazil nut trees. It determines the number of years of suitable evaluations for an efficient selection process, determines the permanent phenotypic correlation between production traits and also the selection of promising trees in these populations. Populations, located in the Itã region (ITA) and in the in the Cujubim region (CUJ), are both belonging to the municipality of Caracaraí, state of Roraima - Brazil, and consist of 85 and 51 adult trees, respectively. Each tree was evaluated regarding the number of fruits per plant (NFP) and fresh seed weight per plant (SWP), for eight (ITA) and five consecutive years (CUJ). Statistical analyses were performed according to the mixed model methodology, using Software Selegen-REML/BLUP (RESENDE, 2007). The repeatability coefficients were low for NFP (0.3145 and 0.3269 for ITA and CUJ, respectively) and also for SWP (0.2957 and 0.3436 for ITA and CUJ, respectively). It on average takes nine evaluation years to reach coefficients of determination higher than 80%. Permanent phenotypic correlation values higher than 0.95 were obtained for NFP and SWP in both populations. Although trees with a high number of fruits and seed weight were identified, more evaluation years are needed to perform the selection process more efficiently.
Resumo:
The net radiation (Rn) represents the main source of energy for physical and chemical processes that occur in the surface-atmosphere interface, and it is used for air and soil heating, water transfer, in the form of vapor from the surface to the atmosphere, and for the metabolism of plants, especially photosynthesis. If there is no record of net radiation in certain areas, the use of information is important to help determine it. Among them we can highlight those provided by remote sensing. In this context, this work aims to estimate the net radiation, with the use of products of MODIS sensor, in the sub-basins of Entre Ribeiros creek and Preto River, located between the Brazilian states of Goiás and Minas Gerais. The SEBAL (Surface Energy Balance Algorithm for Land) was used to obtain the Rn in four different days in the period of July to October, 2007. The Rn results obtained were consistent with others cited in the literature and are important because the orbital information can help determine the Rn in areas where there are not automatic weather stations to record the net radiation.
Resumo:
The Bartlett-Lewis Rectangular Pulse Modified (BLPRM) model simulates the precipitous slide in the hourly and sub-hourly and has six parameters for each of the twelve months of the year. This study aimed to evaluate the behavior of precipitation series in the duration of 15 min, obtained by simulation using the model BLPRM in situations: (a) where the parameters are estimated from a combination of statistics, creating five different sets; (b) suitability of the model to generate rain. To adjust the parameters were used rain gauge records of Pelotas/RS/Brazil, which statistics were estimated - mean, variance, covariance, autocorrelation coefficient of lag 1, the proportion of dry days in the period considered. The results showed that the parameters related to the time of onset of precipitation (λ) and intensities (μx) were the most stable and the most unstable were ν parameter, related to rain duration. The BLPRM model adequately represented the mean, variance, and proportion of the dry period of the series of precipitation lasting 15 min and, the time dependence of the heights of rain, represented autocorrelation coefficient of the first retardation was statistically less simulated series suitability for the duration of 15 min.
Resumo:
This study aimed to apply mathematical models to the growth of Nile tilapia (Oreochromis niloticus) reared in net cages in the lower São Francisco basin and choose the model(s) that best represents the conditions of rearing for the region. Nonlinear models of Brody, Bertalanffy, Logistic, Gompertz, and Richards were tested. The models were adjusted to the series of weight for age according to the methods of Gauss, Newton, Gradiente and Marquardt. It was used the procedure "NLIN" of the System SAS® (2003) to obtain estimates of the parameters from the available data. The best adjustment of the data were performed by the Bertalanffy, Gompertz and Logistic models which are equivalent to explain the growth of the animals up to 270 days of rearing. From the commercial point of view, it is recommended that commercialization of tilapia from at least 600 g, which is estimated in the Bertalanffy, Gompertz and Logistic models for creating over 183, 181 and 184 days, and up to 1 Kg of mass , it is suggested the suspension of the rearing up to 244, 244 and 243 days, respectively.
Resumo:
ABSTRACTThe current study aimed to evaluate the influence of three colors and two types of roofing materials under the internal temperature of bee colonies Apis mellifera. The experiment was conducted at the Agricultural Sciences Campus at the Federal University of Sao Francisco Valley located in Petrolina-PE, in November and December 2013, using 24 colonies housed in Langstroth hives. The experiment was a completely randomized factorial design (3x2) with three colors of box (blue, white, and traditional) and two types of cover (with and without the use of plaster) with six treatments and four replications. The internal temperature dates of the colonies were hourly recorded, during 24 hours, and surface temperatures were hourly recorded between 08h00 and 17h00. The highest values for surface and internal temperature were registered in the blue painted boxes without the use of plasterboard, and the blue painted boxes covered with plasterboard respectively. However, the lowest values were found in the white painted hives and hives that have not received the plasterboard. It is recommended to paint boxes with bright colors, and the use of plasterboard had no effect in reducing the internal temperature.
Resumo:
Field experiments were carried out in 1999 and 2000 to investigate the effects of conventional (CT) and no-tillage (NT) systems, interacting with three herbicide dose levels and three nitrogen (N) levels on weed growth and wheat production of two varieties. There was a higher grain yield for NT system compared with CT in one year. CT weed biomass was lower than from NT weed biomass, in both varieties. No differences on wheat biomass and grain yield were observed between full and reduced herbicide rates. N fertilizer increased wheat biomass and grain yield significantly. Only N medium level had an effect upon weed biomass with respect to non-fertilized plots, while the highest fertilization rate lowered weed biomass. Conventional tillage, reduced herbicide rates and nitrogen fertilization were effective ways of limiting weed production in wheat.
Resumo:
This study aimed to control different populations of Digitaria insularisby glyphosate herbicide, isolated and mixed, besides the combination of methods (chemical and mechanical) to manage resistant adult plants. Three experiments were conducted, one in pots which were maintained under non-controlled conditions and two under field conditions. In the experiment in pots, twelve populations of D. insularis were sprayed with isolated glyphosate (1.44 and 2.16 kg a.e. ha-1) and mixed (1.44 and 2.16 kg a.e. ha-1) with quizalofop-p tefuryl (0.12 kg i.a. ha-1). The treatment of 1.44 kg a.e. ha-1 of glyphosate plus 0.12 kg a.i. ha-1 of quizalofop was sufficient for adequate control (>95%) of all populations. Population 11 (area of grain production in Itumbiara, GO) was considered sensitive to glyphosate. Others populations were moderately sensitive or tolerant to the herbicide. In the field, the plants of D. insularis of one of the experiments were mowed and, in the other, there were not. Eight treatments with herbicides [isolated glyphosate (1.44 and 2.16 kg a.e. ha-1) and mixed (1.44 and 2.16 kg a.e. ha-1) with quizalofop-p-tefuryl at 0.12 kg a.i. ha-1), clethodim at 0.108 kg a.i. ha-1) or nicosulfuron at 0.06 kg a.i. ha-1)] were assessed, in combination with or without sequential application of the standard treatment, sprayed 15 days after the first application. The combination of the mechanic control with the application of glyphosate (2.16 and 1.44 kg a.e. ha-1) plus quizalofop-p-tefuryl (0.12 kg a.i. ha-1) or clethodim (0.108 kg a.i. ha-1), associated to the sequential application, was the most effective strategy for the management of adult plants of resistant D. insularis.
Resumo:
Weeds in pastures can intoxicate animals, and Arrabidaea bilabiata is the most important species for herbivores in floodplain areas in the Amazon Basin. Genetic diversity studies in natural populations may contribute to the better understanding of the range of toxicity and the genetic variability organization in this species. The objective of this study was to assess the variability and genetic structure in six populations of A. bilabiata sampled in floodplain areas in three municipalities of the Amazonas State, from the AFLP markers analysis. AFLP markers were efficient to characterize the genetic variability of the 65 individuals analyzed. From four combinations of oligonucleotides, a total of 309 AFLP fragments was obtained, where 304 (98.38%) were polymorphic. By the dendrogram and Bayesian cluster analysis, there was a formation of two isolated groups, the first one comprising individuals from Autazes municipality and the second one comprising individuals from Itacoatiara and Parintins. However, depending on the method to define the most probable cluster number, there was a separation of the six populations, according to their geographical origin. Mantel test confirmed that geographically closer populations are more akin, although low gene flow (0.538) is observed among the sampled populations. The molecular analysis of variance found that 49.29% of the genetic variability are among individuals inside populations and 50.71% among the populations analyzed. The results indicate the possibility that isolated A. bilabiata populations contain plants with different toxicity levels and suggest a strong adaptability of the species.
Resumo:
A spatial autocorrelation study of enzyme loci detected by starch gel electrophoresis was performed to verify the occurrence of spatial genetic structure within two natural populations of Machaerium villosum Vog. The sampled populations were termed "Antropic Model (MA)" and "Natural Model (MN)" and they are situated in Campininha Farm areas, at Moji-Guaçu municipality, 22°10'43''-22°18'19'' S and 47°8'5"-47°11'34" W, in the state of São Paulo. Ten polymorphic loci in the MA population and nine polymorphic loci in the MN population were assessed by Moran's I autocorrelation statistic. No spatial autocorrelation was detected among individuals within sampled populations. Results are in line with other studies in woody species from tropical rain forest.
Resumo:
A comparação da fenologia de diferentes espécies de uma família, ocorrendo no mesmo hábitat, pode auxiliar na compreensão dos fatores reguladores das fenofases. Os padrões fenológicos vegetativos e reprodutivos de dez espécies de Rubiaceae foram estudados durante 14 meses no sub-bosque de floresta Atlântica, Núcleo Picinguaba, Ubatuba, SP. A produção e queda de folhas ocorreram simultaneamente nas espécies estudadas e ao longo de todo o período de estudo, proporcionando ao sub-bosque uma aparência sempre verde. A floração foi pouco sazonal, com aumento no número de espécies durante o período de maior precipitação e temperatura, porém não apresentando correlações significativas com os fatores climáticos. Este resultado contrasta com o padrão de floração sazonal, correlacionado ao fotoperíodo e temperatura, observado nas espécies de Rubiaceae de dossel na mesma área. A produção de frutos ocorreu ao longo de todo período de estudo, com aumento no número de espécies com frutos maduros no final da estação chuvosa, resultando em disponibilidade constante desses frutos para frugívoros. Os padrões fenológicos reprodutivos diferiram entre as espécies, sugerindo que fatores distintos devem estar regulando a ocorrência das fenofases nestas espécies de Rubiaceae.
Resumo:
The aim of this study was to investigate the photosynthetic performance in populations of two legume tree species, Stryphnodendron adstringens (Mimosoideae), typical from Cerrado, and Cassia ferruginea (Caesalpinoideae) from the Atlantic Rain Forest. The photosynthetic traits were assessed by measures of chlorophyll fluorescence in progenies of naturally pollinated plants from three populations of S. adstringens and a population of C. ferruginea. Plants of S. adstringens growing under similar conditions of C. ferruginea plants demanded higher light values for photosynthesis saturation, 600 µmol.m-2.s-1 and 350 µmol.m-2.s-1 respectively, and showed higher intrinsic photosynthetic efficiency of photosystem II, Fv/Fm of 0.814 versus 0.783 in C. ferruginea. The highest values of Fv/Fm observed in S. adstringens can explain the highest electron transport rates (ETR) obtained for this species. No significant differences were found among progenies from different C. ferruginea trees nor among populations of S. adstringens, and only in few cases, variation among progenies within populations were found for S. adstringens plants. The fact that fluorescence parameters distinguished species but not populations or most of progenies may be related to low intraspecific genetic variation of these chlorophyll fluorescence traits or due to lack of expression on genetic differences in plants under no stressful conditions.
Resumo:
Devido à ampla distribuição geográfica, a Floresta Atlântica e os ecossistemas associados estão sujeitos a condicionantes ambientais que variam de acordo com a latitude e que devem influenciar nos processos dinâmicos das comunidades. Para avaliar se a fenologia de florestas da região atlântica pode ser determinada por tais variações, plantas do dossel e do subbosque (total 55 espécies) de duas Florestas de Restinga (Floresta não inundável e Floresta inundável) foram acompanhadas por dois anos na Ilha do Mel, localizada em região meridional da distribuição da Floresta Atlântica e com pouca diferença climática entre o período superúmido (setembro a maio) e úmido (junho a agosto). Apesar das diferenças florísticas e estruturais, as duas florestas apresentaram padrões semelhantes, com pico de queda de folhas (outubro a dezembro), brotação (dezembro a janeiro), floração (dezembro a janeiro) e frutificação (março a abril) ocorrendo sucessivamente ao longo da estação superúmida, o que esteve correlacionado principalmente com as variações do comprimento do dia e da temperatura. Dossel e sub-bosque apresentaram padrões fenológicos distintos, sendo que no primeiro houve maior sincronia interespecífica. Os resultados mostraram que mesmo localizadas na situação marginal de distribuição do clima tropical, as Florestas de Restinga da Ilha do Mel apresentam semelhanças fenológicas com outros ecossistemas da região atlântica, o que deve refletir a similaridade florística entre estas áreas.
Resumo:
Psychotria ipecacuanha is a perennial, medicinal herb that grows in clusters in the understory of humid, shady areas of the Atlantic Rain Forest of southeastern Brazil. The present study characterized the variation in floral traits among 35 clusters from three natural populations of this plant species. Field observations showed that the clusters are isomorphic, that is, a given cluster will either set long-styled or short-styled flowers. Stigmas and anthers are reciprocally placed in each morph, a dimorphism characteristic of distyly. The populations are isoplethic, that is, a given population exhibits an equilibrium 1:1 ratio of floral morphs. Morphometric analyses revealed that anther length, stigma length, corolla diameter, and pollen grain diameter were consistently greater in short-styled flowers, regardless of the population investigated. Significant differences for floral traits in the short-styled morph were found among populations. Floral traits in the long-styled morph also showed some significant differences among populations, but not for stigma height and corolla length. Controlled pollinations carried out in natural populations showed that fruit production was higher after inter-morph pollination. Nevertheless, observations of pollen tube growth in style, and also fruit production after spontaneous self-pollination and intra-morph pollination, indicated partial intramorph compatibility in this plant species.