697 resultados para Plantation
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Eucalyptus pellita demonstrated good growth and wood quality traits in this study, with young plantation grown timber being suitable for both solid and pulp wood products. All traits examined were under moderate levels of genetic control with little genotype by environment interaction when grown on two contrasting sites in Vietnam. Eucalyptus pellita currently has a significant role in reforestation in the tropics. Research to support expanded of use of this species is needed: particularly, research to better understand the genetic control of key traits will facilitate the development of genetically improved planting stock. This study aimed to provide estimates of the heritability of diameter at breast height over bark, wood basic density, Kraft pulp yield, modulus of elasticity and microfibril angle, and the genetic correlations among these traits, and understand the importance of genotype by environment interactions in Vietnam. Data for diameter and wood properties were collected from two 10-year-old, open-pollinated progeny trials of E. pellita in Vietnam that evaluated 104 families from six native range and three orchard sources. Wood properties were estimated from wood samples using near-infrared (NIR) spectroscopy. Data were analysed using mixed linear models to estimate genetic parameters (heritability, proportion of variance between seed sources and genetic correlations). Variation among the nine sources was small compared to additive variance. Narrow-sense heritability and genetic correlation estimates indicated that simultaneous improvements in most traits could be achieved from selection among and within families as the genetic correlations among traits were either favourable or close to zero. Type B genetic correlations approached one for all traits suggesting that genotype by environment interactions were of little importance. These results support a breeding strategy utilizing a single breeding population advanced by selecting the best individuals across all seed sources. Both growth and wood properties have been evaluated. Multi-trait selection for growth and wood property traits will lead to more productive populations of E. pellita both with improved productivity and improved timber and pulp properties.
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The replacement of native vegetation by other land uses is one of the main degrading ecosystem agents, being the most important component of terrestrial environments, natural or with different levels of human disturbance, besides being the main substrate used by plants to obtain conditions soil for its development. In this context, there is the need to adopt the use and sustainable management of land systems. The study aimed to evaluate what is forest restoration system more efficient degraded areas, based on the potential recovery of physical, chemical, carbon and biological activity in the soil. The work was conducted in a forest restoration area UTFPR- Campus two neighbors, whose experiment was established in October 2010. The experimental design is completely randomized, with four replications and experimental plot of 40 m wide by 54 m long ( 2160 m2) were collected and six sampling points per plot. The soil is classified as a Typic. The models evaluated are: 1 - natural or passive regeneration; 2 - Nucleation; 3 - Planting trees in the total area under lines fill and diversity (total planting); 4 - Reference area (forest). The collection of soil samples in layers of 0.0-0.05, 0.05-0.10, 0.10-0.20 and 0.20-0.40 m was carried out in October 2013 and evaluated physical attributes of texture, bulk density, total porosity, microporosity and soil macroporosity and stability of water in households, chemical properties, and total organic carbon (TOC) and physical particle size fractionation and soil biological activity. To find the best forest restoration model, we designed a Restoration Quality Weighted Index for each variable analyzed. Natural regeneration and total plantation showed generally better soil aggregation over 0.10 m and nucleation volume of similar porosity the forest for these layers. There were no differences between the models below 0.10 m for the variables aggregation and soil porosity. The nucleation template had the lowest bulk density, but being greater than the density in the layer forest 0.05-0.10 m, however, was similar to below 0.10 m above the ground. The models had chemical properties similar to or greater than the forest. The forest had the highest stock of COT and carbon associated with minerals (CAM), but natural regeneration was similar to the particulate organic carbon (POC) in the superficial layers of the soil (0-0.10 m), below 0, 10 m, the forest showed higher stock of COT and COP on the ground. The highest peak of C-CO2 emissions occurred in the 28-35 day range where the total plantation was similar to forest. After four years of experiments, it was found that the effect of restoration methods on physical attributes and soil carbon restricted to 0.10 m deep.
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Land-use change can have a major influence on soil organic carbon (SOC) and above-ground C pools. We assessed a change from native vegetation to introduced Pinus species plantations on C pools using eight paired sites. At each site we determined the impacts on 0–50 cm below-ground (SOC, charcoal C, organic matter C, particulate organic C, humic organic C, resistant organic C) and above-ground (litter, coarse woody debris, standing trees and woody understorey plants) C pools. In an analysis across the different study sites there was no significant difference (P > 0.05) in SOC or above-ground tree C stocks between paired native vegetation and pine plantations, although significant differences did exist at specific sites. SOC (calculated based on an equivalent soil mass basis) was higher in the pine plantations at two sites, higher in the native vegetation at two sites and did not differ for the other four sites. The site to site variation in SOC across the landscape was far greater than the variation observed with a change from native vegetation to introduced Pinus plantation. Differences between sites were not explained by soil type, although tree basal area was positively correlated with 0–50 cm SOC. In fact, in the native vegetation there was a significant linear relationship between above-ground biomass and SOC that explained 88.8% of the variation in the data. Fine litter C (0–25 mm diameter) tended to be higher in the pine forest than in the adjacent native vegetation and was significantly higher in the pine forest at five of the eight paired sites. Total litter C (0–100 mm diameter) increased significantly with plantation age (R2 = 0.64). Carbon stored in understorey woody plants (2.5–10 cm DBH) was higher in the native vegetation than in the adjacent pine forest. Total site C varied greatly across the study area from 58.8 Mg ha−1 at a native heathland site to 497.8 Mg ha−1 at a native eucalypt forest site. Our findings suggest that the effects of change from native vegetation to introduced Pinus sp. forest are highly site-specific and may be positive, negative, or have no influence on various C pools, depending on local site characteristics (e.g. plantation age and type of native vegetation).
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This thesis examines three key moments in the intersecting histories of Scotland, Ireland and England, and their impact on literature. Chapter one Robert Bruce and the Last King of Ireland: Writing the Irish Invasion, 1315- 1826‘, is split into two parts. Part one, Barbour‘s (other) Bruce‘ focuses on John Barbour‘s The Bruce (1375) and its depiction of the Bruce‘s Irish campaign (1315-1318). It first examines the invasion material from the perspective of the existing Irish and Scottish relationship and their opposition to English authority. It highlights possible political and ideological motivations behind Barbour‘s negative portrait of Edward Bruce - whom Barbour presents as the catalyst for the invasion and the source of its carnage and ultimate failure - and his partisan comparison between Edward and his brother Robert I. It also probes the socio-polticial and ideological background to the Bruce and its depiction of the Irish campaign, in addition to Edward and Robert. It peers behind some of the Bruce‘s most lauded themes such as chivalry, heroism, loyalty, and patriotism, and exposes its militaristic feudal ideology, its propaganda rich rhetoric, and its illusions of freedom‘. Part one concludes with an examination of two of the Irish section‘s most marginalised figures, the Irish and a laundry woman. Part two, Cultural Memories of the Bruce Invasion of Ireland, 1375-1826‘, examines the cultural memory of the Bruce invasion in three literary works from the Medieval, Early Modern and Romantic periods. The first, and by far the most significant memorialisation of the invasion is Barbour‘s Bruce, which is positioned for the first time within the tradition of ars memoriae (art of memory) and present-day cultural memory theories. The Bruce is evaluated as a site of memory and Barbour‘s methods are compared with Icelandic literature of the same period. The recall of the invasion in late sixteenth century Anglo-Irish literature is then considered, specifically Edmund Spenser‘s A View of the State of Ireland, which is viewed in the context of contemporary Ulster politics. The final text to be considered is William Hamilton Drummond‘s Bruce’s Invasion of Ireland (1826). It is argued that Drummond‘s poem offers an alternative Irish version of the invasion; a counter-memory that responds to nineteenth-century British politics, in addition to the controversy surrounding the publication of the Ossian fragments. Chapter two, The Scots in Ulster: Policies, Proposals and Projects, 1551-1575‘, examines the struggle between Irish and Scottish Gaels and the English for dominance in north Ulster, and its impact on England‘s wider colonial ideology, strategy, literature and life writing. Part one entitled Noisy neighbours, 1551-1567‘ covers the deputyships of Sir James Croft, Sir Thomas Radcliffe, and Sir Henry Sidney, and examines English colonial writing during a crucial period when the Scots provoked an increase in militarisation in the region. Part two Devices, Advices, and Descriptions, 1567-1575‘, deals with the relationship between the Scots and Turlough O‘Neill, the influence of the 5th Earl of Argyll, and the rise of Sorley Boy MacDonnell. It proposes that a renewed Gaelic alliance hindered England‘s conquest of Ireland and generated numerous plantation proposals and projects for Ulster. Many of which exhibit a blurring‘ between the documentary and the literary; while all attest to the considerable impact of the Gaelic Scots in both motivating and frustrating various projects for that province, the most prominent of which were undertaken by Sir Thomas Smith in 1571 and Walter Devereux, 1st Earl of Essex in 1573.
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O nitrogênio e um dos nutrientes mais demandados pelas espécies vegetais, sua presença no solo, sob formas orgânicas ou minerais disponíveis para as plantas, está vinculada à qualidade e quantidade dos resíduos vegetais aportados ao solo. O estudo teve o objetivo de avaliar a influência do cultivo do eucalipto e da acácia na composição das formas orgânicas e inorgânicas de N e, na abundância natural de 15N em um Argissolo Amarelo. Para isso, foram coletadas amostras de solo e serapilheira em monocultivos do Eucalyptus urograndis (clone do Eucalyptus urophylla S. T. Blake x Eucalyptus grandis W. Hill ex Spreng) de ciclo curto (sete anos), sistemas de cultivo de rotação com acácia ( Acacia mangium Willd.) após monocultivo de eucalipto, monocultivo de eucalipto de ciclo longo (24 anos) e mata nativa (Mata Atlântica) como condição original de solo do litoral Norte do Espírito do Santo. Foram avaliados os teores de C orgânico total, N total, N-NH4+, N-NO3-, relação C/N, fracionamento do N orgânico e abundância natural de 15N no solo e serapilheira. Das formas de N-orgânico hidrolisado, o N-amino foi a fração que apresentou maior contribuição (39%), seguida pela fração de N-não identificado (27%), da fração N-amida (18%) e N-hexosamina (15%). O povoamento de acácia promoveu menor abundância natural de 15N e maiores teores de N total e C orgânico no solo e aumentou as formas orgânicas de N-hidrolisado, quando comparado àqueles de eucalipto de ciclo curto. Isso indica o aumento de formas lábeis de N orgânico no solo para as plantas e redução da humificação da matéria orgânica do solo (MOS) de acácia. Nesse sentido, a rotação de cultivos florestais com acácia após eucalipto de ciclo curto contribuiu para o aumento de formas orgânicas no solo, importantes para a nutrição de plantas, por serem potenciais fontes de nutrientes às plantas em curto período de tempo.
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Management of coconut ( Cocos nucifera ) lethal yellowing disease (CLYD), which has killed about eight million coconut trees in Mozambique, has proved challenging. The objective of this study was to investigate the impact of farming practices and related history, on the CLYD incidence in Mozambique. The methodology included a socioeconomic questionnaire to the households and direct observations on the palm farms. The collected data were analysed using logistic regression. Five out of 11 explanatory variables tested, namely farm age, availability of other palm species on the coconut farm, type of coconut varieties grown, root cut practices, and intercropping had a significant (P< 0.05) effect on CLYD incidence. Coconut farms <10 years had higher odds of higher disease incidence compared to the farms between 10 to 40 years old. The presence of other palm species in the coconut farms had two times higher odds of having higher disease incidence levels compared to farms without other palm species. Tall coconut varieties were likely to be more tolerant to CLYD compared to dwarf varieties. Coconut farms with some kind of intercropping had two times higher odds of having higher disease incidence levels compared to pure stands. The practice of cutting coconut roots had three times higher odds of having high disease incidence levels compared to non-practicing farms. Farm age, availability of other palm species on the coconut farm, type of coconut varieties grown, root cut practices and intercropping need to be considered for integrated CLYD management.
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The rehabilitation of the old cocoa ( Theobroma cacao L. ) farms is one of the major challenges for a sustainable cocoa production. A study was carried out to set up a guide which could be used as a decision making tool for a quick and efficient diagnosis of the old cocoa orchards and to choose the appropriate regeneration option (rehabilitation or replanting). A sample of 90 rehabilitated cocoa farms and of 75 replanted cocoa farms was surveyed in 12 regions representing the three main cocoa producing sectors in the country. Data were collected on the key agronomic characteristics of these cacao farms. These were cocoa variety, farm size, age, yield, planting density, number of shade trees and the level of damages caused by insects and diseases. The results showed that age, planting density and yield were the discriminating criteria of these farms. The average values of these criteria were 25 to 30 years for the age, 800 to 1 000 trees ha-1 for the planting density and 250 to 400 kg ha-1 an-1 for the yield. Based on these criteria and their average values, a decision making guide was designed for the diagnosis of cocoa farms and the choice of regeneration option. According to this guide, old cocoa farms (more than 25 years), degraded and unproductive should be replanted. However, younger farms having planting density and yield higher than the average values above should be rehabilitated.
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Black sigatoka (Mycosphaerella fijiensis) control consists in the continuous use of fungicide sprays and cultural practices. Cultural control reduces inoculum sources of the pathogen and favorable environmental conditions for its development, as well as it increases the vigor of the plants. In order to manage the disease it is necessary to know its behavior through the time, its relationship with the weather and the crop management. The most important cultural practice to reduce the inoculum source is the removal of the whole affected leaves or only the diseased portions of the leaves. The removed tissue is placed over the ground and the use of urea is feasible to accelerate its decomposition. An alternative practice is the "mini-composting" that consists in forming small heaps with the dead leaves and harvested plants for its quick degradation, which allows to reduce the pathogen inoculum and to incorporate nutrients and organic matters into the soil. The early pruning of the tips of the Young leaves before they show symptoms of the disease and the quick elimination of harvested plants reduce the inoculum. Also, the agronomic management of the crop helps to reduce the favorable conditions and to increase the vigor of the plants: this management considers plantation density, drainage systems, irrigation methods, control of weeds, chemical-biological fertilization, and nematode control.
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Dissertação (mestrado)—Universidade de Brasília, Instituto de Ciências Humanas, Departamento de Geografia, 2015.
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Dissertação de Mestrado, Energias Renováveis e Gestão de Energia, Faculdade de Ciências e Tecnologia, Universidade do Algarve, 2016
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Resumen Los medios de vida de las familias productoras de café de altura están ligados a la finca. Esta relación tan marcada (familia – finca) los hace vulnerables a presiones externas que alteran el funcionamiento cotidiano interno de la unidad productiva. Dentro de estas presiones externas se encuentran los bajos precios, efectos climáticos y plagas en el cafetal. El artículo busca identificar los impactos que ejercen dichas presiones sobre los medios de vida de las familias cafetaleras del cantón de León Cortés, además se intenta mostrar las estrategias que han seguido estas unidades familiares para poder soportar y reponerse a los impactos generados por el clima, las plagas y la inestabilidad de precios del café. Las familias han generado diversas “estrategias de adaptación” en relación con los precios bajos, las organizaciones de productores han buscado nuevas alternativas de comercialización del café, tales como mercado justo y denominación de origen; además, han buscado la generación de un mayor valor agregado mediante la diversificación del producto final enfocado al café de calidad y a la presentación de café molido. Por su parte, las unidades familiares han buscado alternativas de diversificación como la siembra de aguacate. Para combatir las plagas los productores se han enfocado en la introducción de prácticas de conservación de suelos, mejorar sistemas de recolección e introducir sombra en los cultivos; el combate químico también ha sido una estrategia. Por último, la presión del clima no había sido muy tomada en cuenta por los caficultores de la zona, sin embargo, la Tormenta Alma sufrida en el año 2008 hizo que los caficultores comenzaran a pensar en un manejo adecuado y sostenible de la finca que minimice el riesgo climático. Abstract Livelihoods of family coffee growers are strongly determined by their farm. This makes families vulnerable to external shocks that affect the operations in the plot. Within these external shocks are included low prices, pests, and climate effects on the plantation. This paper aims to identify the impact of the aforementioned shocks on family coffee grower livelihoods in the canton of León Cortés. For this purpose, the article shows the strategies followed by families in order to support and recover themselves from the impact which come from climate, pests, and coffee price instability. Families have pursued various “adapting strategies”. Regarding low prices, producers' organizations have sought coffee marketing alternatives, such as fair trade and appellation of origin. Likewise, they work on increasing added value through diversification, improving coffee quality, and by a better packaging of ground coffee. Also, households have sought diversification options, such as avocado production. In order to combat pests, producers have focused on the introduction of soil conservation practices, improvement of collection systems, growing trees on coffee plantations, and chemical control. Finally, climate shocks had not been considered as a real problem by the farmers until the storm Alma affected the region. Nowadays, they think more about sound and sustainable management for their farm.
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Tese (doutorado)—Universidade de Brasília, Centro de Desenvolvimento Sustentável, Programa de Pós-Graduação em Desenvolvimento Sustentável, 2016.
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Dissertação (mestrado)—Universidade de Brasília, Faculdade de Tecnologia, Departamento de Engenharia Mecânica, 2016.
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Leaf-cutting ants are well-known insects due to their remarkable activity as herbivores and the considerable economic damage they cause to many crops. The identification of season and time of day when leaf-cutting ants are most active is an important tool, not just to understand the foraging ecology of these ants, but also to optimize their control in plantation areas where they are pests. Thus, the aims of this study are to evaluate the daily foraging activity of leafcutting ant species of the genus Acromyrmex, which occur in forest plantations in Southern Brazil. Foraging activity of Acromyrmex crassispinus (Forel) and Acromyrmex subterraneus subterraneus (Forel) were correlated with weather conditions, and it was more intense during spring and summer. Workers that forage at night are significantly heavier than workers that forage during the day. This study showed that A. crassispinus and A. subterraneus subterraneus did not forage at temperatures below 10-11°C. Then, the use of granulated baits to control these leaf-cutting ants species where they are pests should be done just under favorable conditions of temperature for Acromyrmex foraging activity (over 12°C), to ensure maximum collection of baits by ants and the least left-over baits.
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The extent of the Brazilian Atlantic rainforest, a global biodiversity hotspot, has been reduced to less than 7% of its original range. Yet, it contains one of the richest butterfly fauna in the world. Butterflies are commonly used as environmental indicators, mostly because of their strict association with host plants, microclimate and resource availability. This research describes diversity, composition and species richness of frugivorous butterflies in a forest fragment in the Brazilian Northeast. It compares communities in different physiognomies and seasons. The climate in the study area is classified as tropical rainy, with two well defined seasons. Butterfly captures were made with 60 Van Someren-Rydon traps, randomly located within six different habitat units (10 traps per unit) that varied from very open (e.g. coconut plantation) to forest interior. Sampling was made between January and December 2008, for five days each month. I captured 12090 individuals from 32 species. The most abundant species were Taygetis laches, Opsiphanes invirae and Hamadryas februa, which accounted for 70% of all captures. Similarity analysis identified two main groups, one of species associated with open or disturbed areas and a second by species associated with shaded areas. There was a strong seasonal component in species composition, with less species and lower abundance in the dry season and more species and higher abundance in the rainy season. K-means analysis indicates that choice of habitat units overestimated faunal perceptions, suggesting less distinct units. The species Taygetis virgilia, Hamadryas chloe, Callicore pygas e Morpho achilles were associated with less disturbed habitats, while Yphthimoides sp, Historis odius, H. acheronta, Hamadryas feronia e Siderone marthesia likey indicate open or disturbed habitats. This research brings important information for conservation of frugivorous butterflies, and will serve as baseline for future projects in environmental monitoring