871 resultados para broadleaved plantation


Relevância:

10.00% 10.00%

Publicador:

Resumo:

Dissertação de Mestrado, Energias Renováveis e Gestão de Energia, Faculdade de Ciências e Tecnologia, Universidade do Algarve, 2016

Relevância:

10.00% 10.00%

Publicador:

Resumo:

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.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Tese (doutorado)—Universidade de Brasília, Centro de Desenvolvimento Sustentável, Programa de Pós-Graduação em Desenvolvimento Sustentável, 2016.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Dissertação (mestrado)—Universidade de Brasília, Faculdade de Tecnologia, Departamento de Engenharia Mecânica, 2016.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

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.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

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

Relevância:

10.00% 10.00%

Publicador:

Resumo:

An increase in plantation forestry has been linked to a reduction in streamflows in some catchments. Quantifying the relative contribution of this land-use change on streamflows can be complex when those changes occur during weather extremes such as drought. In this study, the Soil and Water Assessment Tool (SWAT) model was applied to two sub-catchments in south-eastern Australia which have seen the introduction and establishment of plantation land use in the past 15 years, coinciding with severe drought (1997–2009). The models were both manually and auto-calibrated and produced very good fits to observed streamflow data during both calibration (1980–1991) and validation (1992–2009) periods. Sensitivity analyses indicated that the models were most sensitive to soil and groundwater parameterisation. Analysis of drought conditions on streamflows showed significant declines from long-term average streamflows, while assessment of baseflow contributions by the models indicated a mix of over- and underestimation depending on catchment and season. The modelled introduction of plantation forestry did not significantly change streamflows for a scenario which did not include the land-use change, suggesting that the modelled land-use change in the catchments was not sufficiently extensive to have an impact on streamflows despite simulating actual rates of change. The SWAT models developed by this study will be invaluable as a basis for future use in regional climate-change studies and for the assessment of land management and land-use change impact on streamflows.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Reforestation is an important tool for reducing or reversing biodiversity loss and mitigating climate change. However, there are many potential compromises between the structural (biodiversity) and functional (carbon sequestration and water yield) effects of reforestation, which can be affected by decisions on spatial design and establishment of plantings. We review the environmental responses to reforestation and show that manipulating the configuration of plantings (location, size, species mix and tree density) increases a range of environmental benefits. More extensive tree plantings (>10. ha) provide more habitat, and greater improvements to carbon and water cycling. Planting a mixture of native trees and shrubs is best for biodiversity, while traditional plantation species, generally non-native species, sequester C faster. Tree density can be manipulated at planting or during early development to accelerate structural maturity and to manage water yields. A diversity of habitats will be created by planting in a variety of landscape positions and by emulating the patchy distribution of forest types, which characterized many regions prior to extensive landscape transformation. Areas with shallow aquifers can be planted to reduce water pollution or avoided to maintain water yields. Reforestation should be used to build forest networks that are surrounded by low-intensity land use and that provide links within regions and between biomes. While there are adequate models for C sequestration and changes in water yields after reforestation, the quantitative understanding of changes in habitat resources and species composition is more limited. Development of spatial and temporal modelling platforms based on empirical models of structural and functional outcomes of reforestation is essential for deciding how to reconfigure agricultural regions. To build such platforms, we must quantify: (a) the influence of previous land uses, establishment methods, species mixes and interactions with adjacent land uses on environmental (particularly biodiversity) outcomes of reforestation and (b) the ways in which responses measured at the level of individual plantings scale up to watersheds and regions. Models based on this information will help widespread reforestation for carbon sequestration to improve native biodiversity, nutrient cycling and water balance at regional scales.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Rubber tree is a very important crop in Thailand, representing an essential source of income for farmers. In the past two decades, rubber tree plantations have been greatly expanding in unfavorable areas, where climate conditions are difficult and soil fertility is very poor. To optimize latex yields, mineral fertilizers have been widely used. A better understanding of the roles of the biological compartment in soil fertility is essential to determine alternative management practices to sustain soil fertility and optimize latex yields. Arbuscular mycorrhizal fungi (AMF) are widely recognized as beneficial for plants, mainly through their role in improving plant nutrient uptake. The objective of this study was to assess the AMF populations in rubber tree plantations and the impact of both soil characteristics and plantation age on these communities. Our results showed that all rubber trees were highly colonized, regardless of the soil structure and nutrient contents. AMF colonization was not affected by the age of the trees, suggesting that maintaining the symbiosis is likely to be beneficial at all stages. A better understanding and management of the microbial communities would contribute to maintaining or restoring soil fertility, leading to a better tree growth and optimized latex yield.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

A growing human population, shifting human dietary habits, and climate change are negatively affecting global ecosystems on a massive scale. Expanding agricultural areas to feed a growing population drives extensive habitat loss, and climate change compounds stresses on both food security and ecosystems. Understanding the negative effects of human diet and climate change on agricultural and natural ecosystems provides a context within which potential technological and behavioral solutions can be proposed to help maximize conservation. The purpose of this research was to (1) examine the potential effects of climate change on the suitability of areas for commercial banana plantations in Latin America in the 2050s and how shifts in growing areas could affect protected areas; (2) test the ability of small unmanned aerial vehicles (UAVs) to map productivity of banana plantations as a potential tool for increasing yields and decreasing future plantation expansions; (3) project the effects on biodiversity of increasing rates of animal product consumption in developing megadiverse countries; and (4) estimate the capacity of global pasture biomass production and Fischer-Tropsch hydrocarbon synthesis (IGCC-FT) processing to meet electricity, gasoline and diesel needs. The results indicate that (1) the overall extent of areas suitable for conventional banana cultivation is predicted to decrease by 19% by 2050 because of a hotter and drier climate, but all current banana exporting countries are predicted to maintain some suitable areas with no effects on protected areas; (2) Spatial patterns of NDVI and ENDVI were significantly positively correlated with several metrics of fruit yield and quality, indicating that UAV systems can be used in banana plantations to map spatial patterns of fruit yield; (3) Livestock production is the single largest driver of habitat loss, and both livestock and feedstock production are increasing in developing biodiverse tropical countries. Reducing global animal product consumption should therefore be at the forefront of strategies aimed at reducing biodiversity loss; (4) Removing livestock from global pasture lands and instead utilizing the biomass production could produce enough energy to meet 100% of the electricity, gasoline, and diesel needs of over 40 countries with extensive grassland ecosystems, primarily in tropical developing countries.^

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Changes in soil sulfur (S) fractions were assessed in oil palm and food garden land use systems developed on forest vegetation in humid tropical areas of Popondetta in northern Province. The study tested a hypothesis that S in food gardens are limiting nutrient factor and are significantly lower than in plantations and forests. Subsistence food gardens are under long-term slash and burn practice of cropping and such practice is expected to accelerate loss of biomass S from the ecosystem. From each land use, surface soil (0–15 cm) samples were characterised and further pseudocomplete fractionated for S. Conversion of forest to oil palm production decreased (p<0.001) soil pH and electrical conductivity values. The reserve S fraction in soil increased significantly (p<0.05) due to oil palm production ( 28 %) and food gardening activity (∼ 54 %). However, plant available SO42--S was below 15 mg kg^(−1) in the food garden soils and foliar samples of sweet potato crop indicating deficiency of plant available S. Soil organic carbon content (OC) was positively and significantly correlated to total S content (r=0.533; p<0.001) among the land use systems. Thus, crop management practices that affect OC status of the soils would potentially affect the S availability in soils. The possible changes in the chemical nature of mineralisable organic S compounds leading to enhanced mineralisation and leaching losses could be the reasons for the deficiency of S in the food garden soils. The results of this study conclude that long-term subsistence food gardening activity enriched top soils with reserve S or total S content at the expense of soluble S fraction. The subsistence cropping practices such as biomass burning in food gardens and reduced fallow periods are apparently threatening food security of oil palm households. Improved soil OC management strategies such as avoiding burning of fallow vegetation, improved fallows, mulching with fallow biomass, use of manures and S containing fertilisers must be promoted to sustain food security in smallholder oil palm system.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

The Marine Park Prof. Luiz Saldanha, in the coast of Arrabida, is the first marine park in continental Portugal. This area is a Nature 2000 site and is considered to be a hotspot for European marine biodiversity. In 2005, the management plan of the park was implemented, ending several habitat menaces, thereby allowing an application to the LIFE-NATURE Programme. The LIFE-BIOMARES project aimed at the restoration and management of the biodiversity of the marine park through several actions. The restoration of the seagrass prairies that were completely destroyed by fishing activities and recreational boating, was one of the most challenging. It included the transplanting of seagrasses from donor populations and the germination of seagrass seeds for posterior plantation to maintain genetic diversity in the transplanted area. One of the most popular actions was the implementation of environmental friendly moorings to integrate recreational use of the area with environmental protection. Several dissemination and environmental education actions concerning the marine park and the project took place and contributed to the public increase of the park acceptance. The seabed habitats were mapped along the park and a surrounding area to 100 m depth in order to create a habitat cartography of the park and to help locate alternative fishing zones. Biodiversity assessments for macrofauna revealed seasonal variations and an effect of the protection status. Preliminary results are presented and show that the marine park regulations are having a positive effect on biodiversity conservation and sustainable fisheries, thereby showing that these kind of conservation projects are important to disseminate coastal conservation best practices. The Biomares project is a model project that can be followed in the implementation of marine reserves and the establishment of the Natura 2000 marine network.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Resumen Este trabajo estudia la historia de las implicaciones ecológico-ambientales del azúcar en Cuba durante la etapa del auge de la plantación esclavista entre 1800 y 1870 aproximadamente. En primer lugar, analiza las dos problemáticas que más llamaron la atención de los contemporáneos por sus implicaciones para el mantenimiento de la propia economía plantacionista, a saber: la creciente escasez de combustible y la pérdida de la fertilidad de los suelos. En segundo lugar, se exploran algunas manifestaciones del impacto sobre la biodiversidad a partir de la llegada de las plantaciones esclavistas a distintos territorios. Por último, se ofrece una primera aproximación a las implicaciones de este proceso para los regímenes hidrológicos locales y la contaminación de los acuíferos por la industria azucarera, un tema que cuenta con escasas referencias en la bibliografía existente. Abstract This paper studies the history of ecological-environmental consequences of cane sugar plantation in Cuba between 1800 and 1870. First, it analyzes two major problems for the existence of cane sugar plantation: the increasing lack of fuel and fertility loss. Second, it explores some impacts on biodiversity produced by the slavery plantation extension to different lands. Finally, it offers a first look at the implications of this extension on hydrologic local regimes and aquifer contamination by sugar cane industry.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

The sugarcane in Brazil is passing through a management transition that is leading to the abolition of pre-harvest burning. Without burning, large amounts of sugarcane trash is generated, and there is a discussion regarding the utilization of this biomass in the industry versus keeping it in the field to improve soil quality. To study the effects of the trash removal on soil quality, we established an experimental sugarcane plantation with different levels of trash over the soil (0%, 50% and 100% of the original trash deposition) and analyzed the structure of the bacterial and fungal community as the bioindicators of impacts. The soil DNA was extracted, and the microbial community was screened by denaturing gradient gel electrophoresis in two different seasons. Our results suggest that there are no effects from the different levels of trash on the soil chemistry and soil bacterial community. However, the fungal community was significantly impacted, and after twelve months, the community presented different structures among the treatments.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

A produção agrícola da Malásia é caracterizada por um sistema em que convivem a produção especializada, normalmente chamada de plantation, e a não-especializada, baseada em pequenos produtores. Na especializada predomina as culturas voltadas ao mercado externo, os pequenos produtores se dedicam às lavouras para o mercado de alimentos sendo os terraços de arroz, o principal cultivo alimentício malaio. A palma foi introduzida na Malásia no começo do século XX como uma planta ornamental e depois plantada comercialmente, dando origem à indústria de óleo de palma. A crescente produção de óleo de palma tem recebido muita atenção pelo mundo afora. É considerado o ‘petróleo agrícola’ da região, por ser um óleo de uso alimentício, medicinal, oleoquímico e industrial, sua demanda tem aumentado de forma significativa nos últimos anos. Sendo sua expansão motivo de grande preocupação de ONG’s internacionais que condenam o avanço do plantio sobre as florestas tropicais. A área de plantação é um pouco mais de 4 milhões de hectares, utilizando mais de 60% da terra usada para agricultura. O uso da terra, é objeto de controle do Estado, o governo define estratégias e objetivos de política agrícola, mas não impõe restrições quanto a produção.