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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
91

No caminho dos antigos: agricultura de corte-e-queima e intensificação agrícola em populações quilombolas do Vale do Ribeira, SP / On the old ones\'track: shifting cultivation and agricultural intensification on quilombola populations at the Ribeira Valley, SP

Pedroso Junior, Nelson Novaes 05 September 2008 (has links)
A agricultura de corte-e-queima é praticada há milhares de anos nas áreas florestadas do planeta, principalmente nas regiões tropicais. Muitos estudos atestam a sustentabilidade desses sistemas quando praticados tradicionalmente e sob baixas densidades populacionais, mantendo, ou mesmo, promovendo a biodiversidade local e garantindo a subsistência de milhões de pessoas pobres rurais. No entanto, é crescente na literatura acadêmica e no debate político o papel que a agricultura de corte-e-queima vem desempenhando no desmatamento e demais impactos ambientais e sócio-econômicos. Esse processo é conseqüência das mudanças no uso do solo, intensificação agrícola e aumento demográfico que estão alterando as práticas e comprometendo a sustentabilidade desses sistemas agrícolas tradicionais. No Vale do Ribeira, sudeste do Estado de São Paulo, comunidades quilombolas têm sofrido um processo acelerado de mudanças nos seus padrões de subsistência. Dessa forma, esse estudo traz uma revisão da literatura sobre a agricultura de corte-equeima com o objetivo de traçar um panorama geral do que foi produzido até o momento, identificar as principais correntes teóricas envolvidas e apontar as alternativas propostas para sua manutenção. Em seguida, são caracterizados o perfil demográfico e sócio-econômico de nove comunidades quilombolas do Vale do Ribeira e identificados os principais fatores responsáveis pelas mudanças recentes nos seus padrões de subsistência. Por fim, é feita uma análise etnográfica, através de informações levantadas em três comunidades quilombolas pré-selecionadas, para a caracterização das atividades agrícolas praticadas atualmente e no passado recente, bem como o processo de mudanças ocorridas e os impactos causados no sistema agrícola de corte-equeima. Os resultados mostram que as restrições impostas pela legislação ambiental, os conflitos de terra, a construção de uma rodovia na região, a crescente inserção no mercado regional, e a atuação de órgãos governamentais e não-governamentais de desenvolvimento são os principais fatores responsáveis pelas mudanças observadas no sistema agrícola de corte-e-queima e, conseqüentemente, na organização socioeconômica destas populações. / Slash-and-burn agriculture has been practiced for thousands of years in the forests around the world, especially in the tropics, where it provides for the livelihood of countless poor rural populations. Many studies claim that slash-andburn agriculture is sustainable when performed under conditions of low human demographic density, maintaining or even increasing local biodiversity. However, it is growing in the academic literature, as well as in development debates, the concern regarding the role that this system has been playing in the deforestation of the planet´s tropical forests. This process appears to be closely linked to changes in land use patterns (agricultural intensification) and urban and rural demographic growth. In Ribeira Valley, State of São Paulo, Quilombola communities have had a significant increase of changes in their subsistence system. On the thread of these concerns, this study presents a critical review of the international and national academic literature on slash-and-burn agriculture. Thus, this review intends to draw a broad scenario of the current academic debate on this issue, as well as to identify the main alternatives strategies proposed to maintain or replace this cultivation system. Following this study aims to characterize the socioeconomic and demographic profile of nine Quilombola populations in the Ribeira Valley, and to identify the main factors responsible for the recent changes in their subsistence system. Por fim, an ethnographic analysis is done, through informations gathered in three pre-selected Quilombola communities, to characterize the agricultural activities practiced nowadays and in the recent past, besides the change process and impacts on the slash-and-burn agriculture. The results show that restrictions imposed by environmental laws, conflict over land, the construction of a major road in the region, the growing insertion into a market economy, and the intervention of governmental and nongovernmental development agencies are the main factors behind the changes observed in the subsistence system and, consequently, in the socioeconomic organization of these populations.
92

台灣同人誌裡的男男性戀情想像-以台灣霹靂布袋戲耽美迷為例 / Boy's love(BL) in Taiwan slash literature-pili hand puppet show

鄭青青, Cheng ,Ching Ching Unknown Date (has links)
台灣在文化與流行方面一向受鄰近國日本的影響,舉凡服飾流行、音樂、電影、動漫等,其中影響青少年最大的應該可以說是動漫畫,近幾十年來,動漫畫中的「耽美文學」,又可以說是一股在台灣出版界新興的文體類型。 「BL」漫畫即指「Boy's Love」,又稱耽美漫畫。原本是指女性漫畫家創作給女性讀者看的「少年愛」漫畫,內容以美貌男子之間的愛情為主。BL漫畫算是少女漫畫中比較另類的內容類型,內容唯美浪漫,而「耽美」的日文原意就是「唯美主義」。日本耽美漫畫在台灣從單純的閱讀,到現在發展出作家、網站、同人團體、甚至還有專門的商業出版社;而出版的物品,也從當初的日文翻譯漫畫、動畫到現在國人自行創作的漫畫、小說、周邊產品等。在台灣的耽美迷中,可以初分為兩種:一種只是純粹的耽美文本閱聽人,另一種除了閱聽文本外,還會主動衍生新的創作與文本,而在這些耽美迷的衍生文本中,居然有大半是台灣本土霹靂布袋戲迷所創作的耽美文本。 台灣的本土布袋戲為何會跟耽美牽上關係?日本式的耽美到了台灣又有什麼樣的變化?而這在台灣本土形成的新型耽美中佔最大比率的文本─「霹靂耽美文本」,竟也被日本耽美迷所承認,在日本有了台灣霹靂耽美文本的閱聽人。本研究將從日本的耽美文化在台灣的演化,以及文化逆流的現象,勾勒出一個屬於台灣在地耽美文化的輪廓。 關鍵字:漫畫、動漫、同人誌、Boy's Love(BL)、霹靂布袋戲 / The culture and fashion of Taiwan are historically influenced by Japan. Among many, the Slash Literature, or ‘Boy’s Love’ (BL), is one of rising style in recent decades. BL, which originally means ‘aestheticism’ in Japanese, features aesthetic and romantic in its content. While it is an alternative to mainstream style, BL allures remarkable amount of audience. The audience can be distinguished into two types: passive receiver on the one hand and active creator on the other. Surprisingly, most of the active creator of derivative BL context comes from enthusiasts of Pili Hand Puppet Show, a traditional Taiwanese culture. The locally shaped ‘Pili BL context’ not only is the most popular one in derivative BL context in Taiwan, but is recognized by Japanese BL enthusiasts. Thus, ‘Pili BL context’ is the countercurrent of BL culture back to Japan. This phenomenon prompts research questions of this study: how does Taiwanese Hand Puppet Show relate to BL? What are the transformations of Japanese BL adapted in Taiwan? To answer these questions, this study will investigate the evolution of Japanese BL culture in Taiwan and the countercurrent of ‘Pili BL context’ and will seek to contour the local BL culture of Taiwan. Keywords: Slash Literature, BL, Aestheticism, Subculture, Pili Hand Puppet Show.
93

Performance of slash pine (Pinus elliottii Engelm.) containerized rooted cuttings and bare-root seedlings established on five planting dates in the flatlands of western Louisiana

Akgul, Alper 29 August 2005 (has links)
The forest product industry is keenly interested in extending the normal planting season, as well as in the comparative field performance of standard nursery bare-root seedlings and containerized rooted cuttings. The effect of seasonal planting dates on survival, above and belowground biomass allocation, water relations, gas exchange attributes and foliar carbon isotope composition (δ13C) of two stock types of slash pine (Pinus elliottii Engelm.) were examined. Slash pine bare-root seedlings (BRS) and containerized rooted cuttings (CRC) were hand planted in September, November, January, March and April in three consecutive planting seasons (2000-2001, 2001-2002 and 2002-2003) on three sites with silt loam topsoils in southwestern Louisiana. First-year mean survival of CRC across all planting dates and sites was consistently high at 96 to 98%, whereas BRS survival was significantly (P < 0.0001) lower at 59 to 81% and highly variable among study sites and dates through three planting seasons. Generally, there was a negative relationship between soil moisture at the time of planting and first-year survival of BRS planted September through March in 2001-2002 and 2002-2003 planting seasons, whereas the opposite was observed only for BRS planted in April 2002 and 2003. Survival of CRC was affected very little by the variation in soil moisture. Containerized rooted cuttings had higher early above and belowground biomass, and height and diameter than did BRS. However, three years after planting the size differences between stock types disappeared or became negligible. Early size differences among trees planted September through March also decreased after three years, although September trees were tallest. Growth of the April-planted trees was poor compared to trees planted in other months. Late-planted April trees had higher δ13C values, and higher water-use efficiency in the first growing season compared to earlier planted trees. Differences in δ13C values among the planting dates disappeared in the second growing season. Net photosynthesis rates did not differ considerably between stock types or among planting dates in the second and third growing seasons. This study indicates that it is possible to extend the planting season to as early as September and as late as March by using CRC.
94

Performance of slash pine (Pinus elliottii Engelm.) containerized rooted cuttings and bare-root seedlings established on five planting dates in the flatlands of western Louisiana

Akgul, Alper 29 August 2005 (has links)
The forest product industry is keenly interested in extending the normal planting season, as well as in the comparative field performance of standard nursery bare-root seedlings and containerized rooted cuttings. The effect of seasonal planting dates on survival, above and belowground biomass allocation, water relations, gas exchange attributes and foliar carbon isotope composition (&#948;13C) of two stock types of slash pine (Pinus elliottii Engelm.) were examined. Slash pine bare-root seedlings (BRS) and containerized rooted cuttings (CRC) were hand planted in September, November, January, March and April in three consecutive planting seasons (2000-2001, 2001-2002 and 2002-2003) on three sites with silt loam topsoils in southwestern Louisiana. First-year mean survival of CRC across all planting dates and sites was consistently high at 96 to 98%, whereas BRS survival was significantly (P < 0.0001) lower at 59 to 81% and highly variable among study sites and dates through three planting seasons. Generally, there was a negative relationship between soil moisture at the time of planting and first-year survival of BRS planted September through March in 2001-2002 and 2002-2003 planting seasons, whereas the opposite was observed only for BRS planted in April 2002 and 2003. Survival of CRC was affected very little by the variation in soil moisture. Containerized rooted cuttings had higher early above and belowground biomass, and height and diameter than did BRS. However, three years after planting the size differences between stock types disappeared or became negligible. Early size differences among trees planted September through March also decreased after three years, although September trees were tallest. Growth of the April-planted trees was poor compared to trees planted in other months. Late-planted April trees had higher &#948;13C values, and higher water-use efficiency in the first growing season compared to earlier planted trees. Differences in &#948;13C values among the planting dates disappeared in the second growing season. Net photosynthesis rates did not differ considerably between stock types or among planting dates in the second and third growing seasons. This study indicates that it is possible to extend the planting season to as early as September and as late as March by using CRC.
95

Sistemas capacitivos aplicados na avaliação da umidade relativa de madeira de pinus / Capacitive systems applied in the evaluation of the relative moisture of pinus woods

Ferreira, Jéssimon 20 November 2017 (has links)
Este trabalho tem como propósito, caracterizar um sensor capaz de identificar o estado de umidade da madeira de Pinus da espécie Elliotti. O sensor projetado, foi implementado por duas placas metálicas de formato geométrico retangular formando um componente bipolar capacitivo. Para condicionar os sinais do sensor, foi implementado um circuito elétrico em ponte e integrado o sensor capacitivo nesse circuito elétrico que será alimentado por uma fonte de energia elétrica em corrente alternada (VCA) de alta frequência. O objetivo dessa integração, é obter nos ramos da ponte uma variação de sinal elétrico, em função da variação da reatância capacitiva entre as placas do sensor. A reatância capacitiva, é uma propriedade elétrica identificada na madeira quando essa atua como dielétrico entre as placas metálicas do sensor, e poderá sofrer variações em função da variação de umidade dos corpos de prova. Com a variação da reatância elétrica da madeira de pinus, foi possível registrar a variação da umidade dos corpos de prova tendo como parâmetro as variações dos sinais elétrico fornecidos pela ponte em função da reatância capacitiva. Para se obter os registros e realizar um método de comparação entre a umidade dos corpos de prova e sinal elétrico, os corpos de prova foram inicialmente saturados com água e durante um processo de secagem, foram coletados valores de leitura das grandezas elétrica envolvidas durante intervalos de tempos iguais até atingir o peso de massa seca. O diferencial desse trabalho em relação a outros do mesmo tema, é a sua capacidade de identificar em apenas uma ação, sem a utilização de processos destrutivos, pequenas áreas úmidas dentro de uma área de maior dimensão do material analisado. Os resultados obtidos, poderão ser visualizadas através de quadros, tabelas e gráficos. / This work proposes to characterize a sensor able to identify the Pinus wood moisture status of the Elliotti species. The designed sensor was implemented by two metal plates of rectangular geometric shape forming a bipolar capacitive component. To conditionate the sensor signals, a bridged electric circuit has been implemented and the capacitive sensor integrated into this electrical circuit to be fed by a high frequency alternating current power source (VCA). The purpose of this integration is to obtain in the bridge’s branches an electric signal variation, as a capacitive reactance variation function between the sensor plates. Capacitive reactance is an electrical property identified in the wood when it acts as a dielectric between the sensor metal plates, and may suffer variations depending on the sample humidity variation. With the Pinus wood electric reactance variation, it was possible to record the humidity variation of the samples having as a parameter the electric signals variations provided by the bridge as a capacitive reactance function. In order to obtain the records and perform a comparison method between the humidity of the samples tests and the electrical signal, the samples were initially saturated with water and during a drying process, and the values of the electrical quantities involved were collected during equal time periods, until reaching the dry mass weight. The differential of this work in relation to others of the same theme, is its ability to identify in only one action, without destructive processes usage, small humid spots within a larger area of the analyzed material. The obtained results can be visualized through tables, tables and graphs.
96

Romance versus slash - vývoj čtenářských strategií ženských čtenářek / Romance versus slash - evolution of reading strategies of female readers

Kalaninová, Soňa January 2018 (has links)
The aim of the theses is to describe meanings, which female readers of the slash subgenre derive from it, and interpretive strategies they use to create those meanings. Slash is a type of literature that conceives or develops the same-sex romantic and sexual relationships of male characters from original media art. The subject of work study is the public of this type of literature, which is composed primarily of women. The work is based on the perspective of interpretivism and uses the concept of interpretative communities. According to this concept, meanings are being negotiated within a group of readers sharing interpretative strategies. In this work, I view slashers as an interpretive community and therefore assume that the readers' strategies and meanings will show some similarities. The technique of semi-structured interviews is used to achieve the goals of the theses. The interviews took place with nine female slashers. Data collected in this way were analyzed by the method of grounded theory.
97

No caminho dos antigos: agricultura de corte-e-queima e intensificação agrícola em populações quilombolas do Vale do Ribeira, SP / On the old ones\'track: shifting cultivation and agricultural intensification on quilombola populations at the Ribeira Valley, SP

Nelson Novaes Pedroso Junior 05 September 2008 (has links)
A agricultura de corte-e-queima é praticada há milhares de anos nas áreas florestadas do planeta, principalmente nas regiões tropicais. Muitos estudos atestam a sustentabilidade desses sistemas quando praticados tradicionalmente e sob baixas densidades populacionais, mantendo, ou mesmo, promovendo a biodiversidade local e garantindo a subsistência de milhões de pessoas pobres rurais. No entanto, é crescente na literatura acadêmica e no debate político o papel que a agricultura de corte-e-queima vem desempenhando no desmatamento e demais impactos ambientais e sócio-econômicos. Esse processo é conseqüência das mudanças no uso do solo, intensificação agrícola e aumento demográfico que estão alterando as práticas e comprometendo a sustentabilidade desses sistemas agrícolas tradicionais. No Vale do Ribeira, sudeste do Estado de São Paulo, comunidades quilombolas têm sofrido um processo acelerado de mudanças nos seus padrões de subsistência. Dessa forma, esse estudo traz uma revisão da literatura sobre a agricultura de corte-equeima com o objetivo de traçar um panorama geral do que foi produzido até o momento, identificar as principais correntes teóricas envolvidas e apontar as alternativas propostas para sua manutenção. Em seguida, são caracterizados o perfil demográfico e sócio-econômico de nove comunidades quilombolas do Vale do Ribeira e identificados os principais fatores responsáveis pelas mudanças recentes nos seus padrões de subsistência. Por fim, é feita uma análise etnográfica, através de informações levantadas em três comunidades quilombolas pré-selecionadas, para a caracterização das atividades agrícolas praticadas atualmente e no passado recente, bem como o processo de mudanças ocorridas e os impactos causados no sistema agrícola de corte-equeima. Os resultados mostram que as restrições impostas pela legislação ambiental, os conflitos de terra, a construção de uma rodovia na região, a crescente inserção no mercado regional, e a atuação de órgãos governamentais e não-governamentais de desenvolvimento são os principais fatores responsáveis pelas mudanças observadas no sistema agrícola de corte-e-queima e, conseqüentemente, na organização socioeconômica destas populações. / Slash-and-burn agriculture has been practiced for thousands of years in the forests around the world, especially in the tropics, where it provides for the livelihood of countless poor rural populations. Many studies claim that slash-andburn agriculture is sustainable when performed under conditions of low human demographic density, maintaining or even increasing local biodiversity. However, it is growing in the academic literature, as well as in development debates, the concern regarding the role that this system has been playing in the deforestation of the planet´s tropical forests. This process appears to be closely linked to changes in land use patterns (agricultural intensification) and urban and rural demographic growth. In Ribeira Valley, State of São Paulo, Quilombola communities have had a significant increase of changes in their subsistence system. On the thread of these concerns, this study presents a critical review of the international and national academic literature on slash-and-burn agriculture. Thus, this review intends to draw a broad scenario of the current academic debate on this issue, as well as to identify the main alternatives strategies proposed to maintain or replace this cultivation system. Following this study aims to characterize the socioeconomic and demographic profile of nine Quilombola populations in the Ribeira Valley, and to identify the main factors responsible for the recent changes in their subsistence system. Por fim, an ethnographic analysis is done, through informations gathered in three pre-selected Quilombola communities, to characterize the agricultural activities practiced nowadays and in the recent past, besides the change process and impacts on the slash-and-burn agriculture. The results show that restrictions imposed by environmental laws, conflict over land, the construction of a major road in the region, the growing insertion into a market economy, and the intervention of governmental and nongovernmental development agencies are the main factors behind the changes observed in the subsistence system and, consequently, in the socioeconomic organization of these populations.
98

I Never Learned To Type With Ten Fingers

Strong, Laslo January 2022 (has links)
Luise Schröder founded a private business school in 1910 in Stettin, a city once part of Germany. With a focus on typewriting and stenography, she was a local educator of modern communication. Throughout four generations, her family was impacted by global technological developments and socio-political shifts.‘I Never Learned to Type with Ten Fingers’, edited by Schröder's great-great-grandson and graphic designer Laslo Strong, compiles stories from a family-run school. It delves into the past century of typography, through personal and corporate documents. Pictures, letterheads, graphic prints, signs, and newspaper articles provide insight into a particular corporate identity. In dialogue with this research, a series of typefaces was designed dedicated to the characters of the school. They give voice to anecdotes and speculative stories about family and typography.
99

Effects of clear felling and residue management on nutrient pools, productivity and sustainability in a clonal eucalypt stand in South Africa

Dovey, Steven Bryan 12 1900 (has links)
Thesis (PhD(For))--Stellenbosch University, 2012. / The subtropical ecosystem of the Zululand coastal plain is prized by the South African commercial plantation forestry industry for its rapid clonal Eucalyptus growth, short rotations (6 to 7 years) and high yields. This region is typified by sandy soils that are low in clay and organic matter, have small nutrient reserves and are poorly buffered against nutrient loss. The subtropical climate induces rapid decomposition of residues and tree litter resulting in small litter nutrient pools and rapid nutrient release into the soil, particularly after clearfelling. A combination of large nutrient demands through rapid growth, rapid nutrient turnover and small soil nutrient reserves implies that sites in this region are sensitive and may be at risk of nutrient decline under intensive management. The work in this study set out to determine the risk of nutrient depletion through harvesting and residue management on a site within the Zululand region, to assess nutritional sustainability and the risk of yield decline in successive rotations. Some bulk biogeochemical cycling processes of macro-nutrients nitrogen (N), phosphorus (P), potassium (K), calcium (Ca) and magnesium (Mg) were assessed, and assessments also included sodium (Na). An existing Eucalyptus stand was clearfelled and treatments were imposed on the residues after broadcasting to simulate various levels of nutrient loss through levels of harvesting intensity and residue management. These included residue burning (Burn), residue retention (No-Burn), fertilisation (stem wood nutrient replacement), whole tree harvesting and residue doubling. Outer blocks of the stand were not felled, but included as replicates of an undisturbed standing crop treatment. Biogeochemical nutrient cycling processes were assessed primarily in the standing crop, Burn and No-Burn treatments, in the assumption that these represented the furthest extremes of nutrient loss. Data collection commenced a year prior to clearfelling and continued to two years and six months after planting with key data collection over a 20.1 month period from clearfelling to canopy closure (one year after planting). Water related nutrient pools and fluxes were assessed as atmospheric deposition (bulk rainfall, throughfall and stemflow) and gravitational leaching to 1m soil depth. Drainage fluxes were predicted using the Hydrus model and real-time soil moisture data. Zero tension lysimeters collected soil solution for chemical analysis. Sequential coring in the 0 to 30cm soil layer was used to determine in situ soil N mineralisation. Soil chemical and physical properties were assessed over the first meter of soil at clearfelling and new crop canopy closure to determine soil nutrient pools sizes. Biomass nutrient fluxes were assessed from litterfall, residue and litter decomposition, and above ground accretion into the tree biomass. Leaching and N mineralisation were monitored in the No-Burn, Burn and standing crop treatments only. Atmospheric deposition, while variable, was shown to be responsible for large quantities of nutrients added to the Eucalyptus stand. Nitrogen and K additions were relatively high, but within ranges reported in previous studies. Rapid tree canopy expansion and subsequent soil water utilisation in the standing crop permitted little water to drain beyond 1m resulting in small leaching losses despite a sandy well drained soil. Further leaching beyond this depth was unlikely under the conditions during the study period. Mineralisation and immobilisation of N also remained low with net immobilisation occurring. The standing crop was shown to be a relatively stable system that, outside of extreme climatic events, had a relatively balanced or positive nutrient budget (i.e. nutrient inputs minus outputs). Large quantities of nutrients were removed with stem-wood-only harvesting in the No-Burn treatment leaving substantial amounts on the soil surface in the harvest residues. Whole tree removal increased losses of all nutrients resulting in the largest losses of P and base cations compared to all other treatments. This was mostly due to high nutrient concentrations in the removed bark. Loss of N in the Burn treatment exceeded whole tree N losses through combustion of N held in the harvest residues and litter layer. The majority of K leached from the residues prior to burning and a relatively small fraction of the base cations were lost from the partially decomposed residues during burning. Ash containing substantial amounts of Ca and relatively large amounts of N and Mg remained after burning. Surface soil Ca and Mg was significantly increased by the ash which moved into the soil with rainfall directly after burning. Rapid soil moisture recharge occurred within a few months after clearfelling, increasing leaching from the upper 50cm of soil. Clearfelling increased net N mineralisation rates, increasing mobile NO3-N ions in the soil surface layers. Nitrate concentration peaked and K concentration dipped in the upper soil layers of the Burn treatment directly after burning. Deep drainage and leaching (beyond 1m depth) over the 20.1 month period was, however, not significantly different between the Burn and No-Burn treatments. Rapid soil moisture depletion and nutrient uptake with new crop growth reduced leaching fluxes to levels similar to the standing crop by six months after planting. Taking the full rotation into account, clearfelling induced a short-lived spike in N and cation leaching compared with the low leaching losses in the undisturbed standing crop. Soil N mineralisation over the 20.1 month period in the burnt treatment was half that of the No-Burn treatment. Growth and nutrient accumulation was significantly higher in the fertilised treatment than in other treatments up to 2.5 years of age. Growth in the Burn treatment was greatest compared to other treatments during the first few months, but slowed thereafter. No significant growth differences were found between all other treatments from a year to 2.5 years after planting. Early growth was therefore apparently not limited by N supply despite large differences in N mineralisation between Burn and No-Burn. Foliar vector analysis indicated that fertilisation improved growth initially through increased foliar N and P at six months after planting followed by Mg and Ca at one year. The Burn treatment was not nutrient limited. These growth results contrasted with similar international research on sandy tropical sites where growth was reduced after residue removal and increased after residue doubling. The combined nutrients released from pools in the litter layer or ash and soil in addition to atmospheric inputs were sufficient to provide most nutrients required to maintain similar growth rates across all treatments. This demonstrated the importance of residue derived nutrients to early growth nutrient supply. Reduced N mineralisation through a lack of substrate may limit N supply later in the rotation where residue had been removed. Construction of a nutrient budget for the system revealed that high levels of atmospheric inputs have the potential to partially replenish a large proportion N, K, and Ca lost during clearfelling, provided losses are constrained to stemwood removal only. However, loss of Mg that occurred primarily through leaching may not be replaced under the low Mg inputs recorded in this study. Larger nutrient removals (i.e. stemwood plus other plant parts) placed a heavier reliance on the small soil nutrient pools at this site which can limit future productivity. More intense harvesting and residue management practices dramatically increased the risk of nutrient depletion. Losses of specific nutrients depended on a combination of clearfelling biomass removal, residue burning and subsequent leaching. Nitrogen losses due to harvesting and burning were more substantial than those due to leaching. Mg and K losses depended most strongly on the time after clearfelling before re-establishment of the new crop and rainfall patterns, while Ca and P losses depended directly on the amount of biomass removed. Depletion risk was the greatest for Mg and K through rapid leaching, even after stem wood only removal. Deep root uptake and deep drainage with associated cation loss needs to be investigated further to quantify ecosystem losses and recovery of cations displaced beyond 1m. Atmospheric deposition is one of major factors countering nutrient losses. However, atmospheric inputs may not be reliable as these may lessen in future through pollution control legislation and climate change. Changes in growth rate under poor nutrient management practices are small and difficult to detect relative to the large impacts of changing weather patterns (drought), wildfire and pest and disease. This makes it difficult to prove nutrient related growth decline. It may be possible that improvements in genetics, silvicultural technologies and atmospheric inputs may also be masking site decline (in general) and in part explain the lack of evidence of a growth reduction in the region. As the poorly buffered sandy soils on the Zululand Coast are at risk of nutrient depletion under the short rotation, high productivity stands, it may be necessary to stipulate more conservative harvesting and residue management practices. A more conservative stem-wood only harvesting regime is recommended, retaining all residues on site. Residue burning should be avoided if N losses become a concern. The length of the inter-rotation period must be kept short to reduce cation leaching losses. Site nutrient pools need to be monitored and cations may eventually need to be replenished through application of fertilisers or ash residues from pulp mills. Management practices therefore need to be chosen based on the specific high risk nutrients in order to maintain a sustainable nutrient supply to current and future plantation grown Eucalyptus.
100

Memória social e ecologia histórica: a agricultura de coivara das populações quilombolas do vale do Ribeira e sua relação com a formação da mata atlântica local / Social memory and historical ecology:slash and burn agriculture in the formation of an Atlantic rainforest area inhabited by quilombola communities, Ribeira Valley, Brazil

Munari, Lucia Chamlian 28 January 2010 (has links)
A Mata Atlântica é um dos biomas mais biodiverso e ameaçados do planeta. Grande parte de seus remanescentes está localizada no Vale do Ribeira (SP), onde se encontra a maioria das populações quilombolas do estado. Os quilombos do vale surgiram de povoados formados por escravos abandonados, fugidos e alforriados que vem ocupando o vale desde o início da colonização européia na região, no século XVI. A principal estratégia de subsistência destas populações ao longo dos séculos foi a coivara, sistema agrícola capaz de conferir grande heterogeneidade à paisagem florestal. Entretanto, nas últimas décadas, a coivara tem sofrido um processo de transformação, devido a fatores como: o aumento demográfico, o avanço da economia de mercado, a implantação de leis ambientais e políticas desenvolvimentistas. O objetivo deste estudo é compreender como a coivara contribuiu para a formação da paisagem florestal na comunidade de remanescente de quilombo de São Pedro, no vale do Ribeira. A construção de uma narrativa histórica dos processos que contribuíram para as transformações deste sistema auxilia na compreensão das mudanças nos padrões de subsistência locais e de que forma estas se refletem nessa paisagem. Para tanto, levantamos a memória social local, através de técnicas etnográficas e de história oral. Além disso, realizamos trilhas monitoradas para estudar a percepção ambiental das unidades paisagísticas, bem como a configuração espacial das roças e capoeiras. Com a aplicação de tais métodos, pudemos constatar que no passado, a abertura de clareiras para o cultivo dependia de uma série de fatores: a disponibilidade de capital social para o trabalho, a demanda familiar para a produção de alimento e as relações econômicas com o mercado regional. Ao mesmo tempo, a lógica de ocupação da paisagem era fruto da associação entre o conhecimento da dinâmica ecológica local e normas sociais estabelecidas. A unidade doméstica, composta pela casa de fora e pela capuova, foi a expressão material mais constante da agência humana na paisagem. Os processos de transformação da coivara se iniciaram na década de 1950, com a construção de rodovias e consequente diminuição do isolamento regional. A partir disso, a intensificação do corte de palmito e o estabelecimento da pecuária com a chegada dos grileiros, na década de 1970, levaram ao redirecionamento das atividades econômicas. Por consequência, ocorreu a diminuição da área das unidades agrícolas e do número de áreas sob cultivo. A partir da construção de uma escola no bairro, nos anos 70, ocorreu a concentração das residências em vila, que estimulou a concentração das unidades de cultivo ao redor. A intensificação da fiscalização ambiental na região, nos anos 80, passou a restringir as atividades locais de subsistência. Como resultado, observamos que duas tendências podem ser observadas atualmente: segmentação e homogeneização da paisagem em áreas destinadas ao manejo, por um lado, e o estabelecimento de uma formação de floresta madura, não mais passível de derrubada, por outro. Tal tendência pode resultar na diminuição da complexidade estrutural e da dinâmica ecológica da floresta local. Concluímos que, apesar da nova configuração espacial da coivara e da tendência à segmentação, a criação de pastagens e a extração de palmito parecem ser mais impactantes para a fragmentação da paisagem florestal. Por conta das mudanças levantadas, atualmente a população de São Pedro se depara com o desafio de combinar as restrições ambientais à necessidade de produzir itens com valor de mercado. Somado a isso, precisam reorganizar o trabalho coletivo e reformular a concepção local da paisagem e o seu uso para garantir, no futuro, sua permanência neste território. / The Atlantic Rainforest is one of the worlds most diverse and threatened biomes. The majority of its remnants are located at the Ribeira Valley (SP) where several of the States quilombola populations remain. The Valleys quilombos originated from a population of freed, abandoned or refugee slaves brought to the region in the beginning of the European colonization during the 16th century. The main subsistence strategy these populations have developed is the slash-and-burn agriculture (coivara), a system capable of proffering great heterogeneity to the forest landscape. However, the coivara system has been undergoing a transformation process in the last decades due to demographic increase, advance of the local economy and the implementation of environmental and political developmental legislation. The aim of this study is to understand how the coivara system has contributed to the forest landscape formation of the São Pedro quilombo community at the Ribeira Valley. A historic narrative of the processes that contributed to the systems transformation helps understand the changes in the local subsistence patterns and the way these changes reflect in the landscape. In order to do so, the local social memory was sought through ethnographic and oral history methods. Furthermore, monitored trails were carried out to study the environmental perception of landscape units and the spatial configuration of swidden and fallow plots. These methods allowed us to realize that, in the past, gap openings for crop cultures depended on a series of factors, such as: availability of social capital for labor, family demand on crop production, and economic ties with the regional market. Simultaneously, the landscape occupation was a product between the knowledge of the local ecological dynamics and the established social norms. The domestic unit, composed of the casa de fora and the capuova, was the most constant expression of human presence in the landscape. The coivara transformation processes began in the 1950s with road constructions decreasing the regions isolation. From then on, the intensification of palm-heart extraction and cattle ranching brought along with land grabbers in the 1970s, redirected the communities economic activities. As a consequence, both the number of cultivated areas and the area of each agricultural unit decreased. During the 70s, with the construction of a school in the region, the houses were displayed in a village form, which stimulated the concentration of cultivated units around it. Moreover, the intensification of environmental inspection in the region during the 80s restricted their local subsistence activities. As a result, two tendencies may be observed nowadays: segmentation and homogenization of the landscape into areas destined to management on one hand, and the establishment of a mature forest formation, unable to be cut down, on the other. This might result in a decrease of the structural complexity and ecological dynamics of the local forest. We conclude that, despite the new spatial configuration of the swidden plots and the tendency to segmentation, cattle grazing sites and palm-heart extraction seem to be most harmful, causing most of the forest landscape fragmentation. Due to these changes, the São Pedro community faces, nowadays, the challenge of combining their need to produce items with market value with the environmental restrictions brought upon them. Moreover, they must reorganize their collective labor activities and reformulate the local landscape conception and use to ensure, in the future, their permanence in that territory.

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