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Studies of the pyrolysis of wood at low temperaturesZaror Zaror, Claudio Alfredo January 1982 (has links)
No description available.
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Impact of charcoal production on populations of selected Savanna tree species on clay soils in Catuane, southern MozambiqueManjate, Nelson Belecuane 21 February 2007 (has links)
Student Number : 0215337D -
MSc research report -
School of Animal, Plant and Environmental Science -
Faculty of Science / The impact of charcoal production on populations of selected savanna tree species was investigated on clay soils in Catuane, southern Mozambique. The study focused on answering questions related to the contribution of charcoal production to the local economy, the way populations of selected species were changed by the activity and the way in which they recover. Acacia nigrescens, Acacia nilotica and Ziziphus mucronata were identified as being amongst the most utilised species for charcoal production due to their hard wood quality. The charcoal production is being done by individuals from outside the local community. They are able to generate relatively high revenues from their product, which they sell to external markets, notably Maputo. The local community do not share in the benefits of the production. Interviews with members of the local community, indicated that they would prefer the activity to be stopped or more rigourously controlled. A comparison was made between adjacent harvested and un-harvested areas to assess the effects of charcoal production on the tree populations. Population structure by stem circumference classes were broadly similar in all three study species being characterised by a high frequency in the smallest circumference class. All other classes had considerably lower frequencies. With regards density, Acacia nigrescens and Acacia nilotica showed significantly lower densities in the harvested area. Ziziphus mucronata showed no significant difference. The frequency of stump circumference classes of Acacia nigrescens and Acacia nilotica were normally distributed with the class 81-90 cm being the most common. Ziziphus mucronata data were skewed to the left, with most stumps in the class 52-60 cm. Stump heights were mostly in the region of 20 cm. Circumferences of stumps were similar across the study species, being in the region of 90 cm. Coppicing in stumps was relatively poorly developed, with the majority of stumps having no successful coppice shoots. Kilns had an average density of two kilns per hectare. There was an inverse relationship between species abundance and mean harvesting radius. The results of the study indicate that harvesting has had an effect on species abundance and population structures. With decreases in density and a shift in age distribution towards a predominance of juvenile trees. However, the results are not unequivocal, since the area is not pristine and may have been subjected to other activities before harvesting for charcoal. The charcoal producers appear to harvest all sizes of tree. Their production data, approximately 1300 kg of charcoal produced per hectare, indicate the potential for over utilisation of the woodland resource. Futhermore their practice of cutting at low height subjects the stumps to growth retarding elements such as herbivory and fire, possibly contributing towards relatively unsuccessful coppicing and exacerbating the sustainability issue. To address these issues, along with the socio-economics issues, appropriate structures need to be implemented by government, in consultation with communities.
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Redução das emissões de gases efeito estufa no processo de fabricação do sinterAbreu, Guilherme Corrêa [UNESP] 15 December 2011 (has links) (PDF)
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abreu_gc_dr_guara.pdf: 4181088 bytes, checksum: eb2a9fc2114d10d93d945c3ea5bf9361 (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / O uso de biomassa renovável para a produção de carvão vegetal é uma das alternativas atuais de obtenção de agente redutor na siderurgia e possui características de neutralidade nas emissões de gases efeito estufa, uma vez que absorve o CO2 emitido durante o crescimento das florestas. O uso do carvão vegetal no processo de fabricação do sinter (sinterização) não é empregado atualmente na prática observada. Além disto, a sinterização consiste, dentro da siderurgia, em uma das etapas com maior potencial de impacto ambiental. Testes em escala piloto para produção de sinter foram conduzidos buscando avaliar diferentes participações de carvão vegetal na mistura de combustíveis com o intuito de quantificar o desempenho operacional e de qualidade de produto, bem como as variáveis ambientais decorrentes das emissões atmosféricas do processo. Foram avaliados os principais parâmetros ambientais, dentre eles, as emissões de dioxinas e furanos. Como resultados, obteve-se que é possível uma participação de até 50% de carvão vegetal na mistura de combustíveis com qualidade aceitável do sinter produto obtido, implicando em uma redução de até 50% nas emissões de gases efeito estufa, mesmo com maior emissão relativa de CH4. Uma redução de até 50% nas emissões de dioxinas e furanos também foi observada / Renewable biomass use for charcoal production is one of the current alternatives aiming the reduction agent supply at steel making process. This alternative has the greenhouse gases emission neutrality characteristics once it uses the emitted CO2 during the trees growing period. The use of charcoal at sinter making process is not commonly applied at current practices. In addition, sinter making process consists, among the other steel making steps, as one of the most potential environmental impact. Laboratory tests for sinter making were conducted aiming the evaluation of different participations of charcoal in fuel mix in order to quantify the operational performance and product quality as well as environmental variables resulting from process atmospheric emissions. The main environmental parameters were evaluated, among them, dioxins and furans. As a result, it was found that a participation of 50% of charcoal in the fuel mix is possible with acceptable quality of the final sinter product, and a reduction of greenhouse gases up to 50% even though a higher CH4 relative emission. Reductions of 50% at dioxins and furans emissions were also observed
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Redução das emissões de gases efeito estufa no processo de fabricação do sinter /Abreu, Guilherme Corrêa. January 2011 (has links)
Orientador: João Andrade de Carvalho Junior / Coorientador: José Adilson de Castro / Banca: Luiz Roberto Carrocci / Banca: José Antonio Perrella Balestieri / Banca: Alexandre José da Silva / Banca: Antonio Rosa do Nascimento / Resumo: O uso de biomassa renovável para a produção de carvão vegetal é uma das alternativas atuais de obtenção de agente redutor na siderurgia e possui características de neutralidade nas emissões de gases efeito estufa, uma vez que absorve o CO2 emitido durante o crescimento das florestas. O uso do carvão vegetal no processo de fabricação do sinter (sinterização) não é empregado atualmente na prática observada. Além disto, a sinterização consiste, dentro da siderurgia, em uma das etapas com maior potencial de impacto ambiental. Testes em escala piloto para produção de sinter foram conduzidos buscando avaliar diferentes participações de carvão vegetal na mistura de combustíveis com o intuito de quantificar o desempenho operacional e de qualidade de produto, bem como as variáveis ambientais decorrentes das emissões atmosféricas do processo. Foram avaliados os principais parâmetros ambientais, dentre eles, as emissões de dioxinas e furanos. Como resultados, obteve-se que é possível uma participação de até 50% de carvão vegetal na mistura de combustíveis com qualidade aceitável do sinter produto obtido, implicando em uma redução de até 50% nas emissões de gases efeito estufa, mesmo com maior emissão relativa de CH4. Uma redução de até 50% nas emissões de dioxinas e furanos também foi observada / Abstract: Renewable biomass use for charcoal production is one of the current alternatives aiming the reduction agent supply at steel making process. This alternative has the greenhouse gases emission neutrality characteristics once it uses the emitted CO2 during the trees growing period. The use of charcoal at sinter making process is not commonly applied at current practices. In addition, sinter making process consists, among the other steel making steps, as one of the most potential environmental impact. Laboratory tests for sinter making were conducted aiming the evaluation of different participations of charcoal in fuel mix in order to quantify the operational performance and product quality as well as environmental variables resulting from process atmospheric emissions. The main environmental parameters were evaluated, among them, dioxins and furans. As a result, it was found that a participation of 50% of charcoal in the fuel mix is possible with acceptable quality of the final sinter product, and a reduction of greenhouse gases up to 50% even though a higher CH4 relative emission. Reductions of 50% at dioxins and furans emissions were also observed / Doutor
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Monopolização do território e carvoejamento na Amazônia: a produção do carvão vegetal nos assentamentos e acampamentos de reforma agrária e nas carvoeiras tradicionais de Rondon do Pará / Monopolization of the territory and charcoal production in Amazon: the charcoal production in settlements and camps of agrarian reform and in the traditional charcoal production areas in Rondon do Pará-PAAmaral, Mayka Danielle Brito 01 December 2011 (has links)
O presente trabalho versa sobre o processo de monopolização do território pelo capital, materializado nas indústrias siderúrgicas, a partir da atividade de carvoejamento realizada no município de Rondon do Pará, localizado no sudeste do estado do Pará, na Amazônia brasileira. As indústrias siderúrgicas constituem a materialização do capital, caracterizado como desigual, combinado e contraditório, que ao se implantarem na Amazônia promoveram uma relação de subordinação de diversos sujeitos sociais em diferentes municípios, para produzirem o carvão vegetal. Dentre esses municípios, este trabalho destaca a realidade de Rondon do Pará, que produz o carvão vegetal desde o início da produção da siderurgia na Amazônia. Dessa maneira, buscou-se caracterizar e analisar o processo de monopolização do território a partir da atividade de carvoejamento nesse município, onde se verificou que a produção do carvão vegetal tem sido realizada através de relações de produção capitalistas assalariadas, e de relações não-capitalistas camponesas de produção. Além de se produzir carvão da forma tradicional, por meio do reaproveitamento do resíduo de serraria e da pecuária, do desmatamento primário e secundário, essa atividade foi introduzida nos assentamentos e acampamentos rurais de reforma agrária, e tem substituído a produção de alimentos. Dessa forma, notou-se que a monopolização do território pelas indústrias siderúrgicas, a partir da atividade de carvoejamento, é realizada através da apropriação da renda camponesa da terra e da extração da mais-valia, tanto nas carvoeiras tradicionais quanto nas carvoeiras localizadas no interior dos assentamentos e acampamentos rurais de reforma agrária no município de Rondon do Pará. / The paper concerns the territory monopolization process by the capital, present in steel industries, starting from the charcoal production that takes place in the city of Rondon do Pará, located southeastern of the state of Pará, in the Brazilian Amazon. The steel industries constitute the capital materialization, considered uneven, combined and contradictory, that when implemented in the Amazon promoted a subordination relationship of several social actors in different cities, for the production of charcoal. Among these cities, this paper emphasizes the reality of Rondon do Pará, which produces charcoal since the beginning of the steel production in the Amazon. Thus, it was sought to characterize and analyze the territory monopolization due to the charcoal production activity in this city, where it was verified that such production has taken place though employment capitalist production relations and rural non-capitalist production relations. In addition to the traditional charcoal production, through reuse of sawmills and livestock waste, and primary and secondary deforestation, this activity has been introduced in the land reform rural settlements and camps and has substituted food production. Thus, the territory monopolization by the steel industries, starting from the charcoal production, takes place through the appropriation of land peasantry income and surplus value extraction, in traditional charcoal production areas as well as in charcoal production areas located in the interior of land reform rural settlements and camps in the city of Rondon do Pará.
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Na labuta do carvoejar: trabalho e modernização no setor carvoeiro no norte de Minas Gerais / In carvoejar labor: work and modernization in the carvoeiro sector in the north of Minas GeraisMendes, Joelena de Jesus 25 May 2018 (has links)
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Previous issue date: 2018-05-25 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / The production of charcoal is a prominent activity in the brazilian economy, mainly in the State of
Minas Gerais, where its production has as main destination the steel industry. In Brazil, the activity
of charcoal was marked by processes of hard and intense work and in many cases "analog to slave
labor". In the last decade of the XX Century and the beginning of the XXI Century, the production
of charcoal in Minas Gerais underwent a process of restructuring, this process changed so how to
produce as the lives of those involved in the production. This research has as analyze the charcoal
production process in the north of the State of Minas Gerais, considering the work process, the
socioeconomic profile of the workers and the current context. The new production context
contrasts with the traditional forms of charcoal production in a scenario of great social, economic
and environmental impacts. This contrast takes place in the form of production and organization of
work in charcoal and coal-mining companies, where, at the same time as they have real industries
in this field, there are visible archaic productions, small manufactures that go back to forms of
production considered as exceeded by this sector.The labor allows understand the capitalist society
and its way of organize, because it has significant importance in social life, besides impacting
individual workers. / A produção de carvão vegetal é uma atividade de destaque na economia brasileira, principalmente
no Estado de Minas Gerais, onde sua produção tem por principal destino a indústria siderúrgica.No Brasil, a atividade de carvoejamento foi marcada por processos de trabalho árduo e intenso e
em inúmeros casos “análogo ao trabalho escravo”. Na ultima década do século XX e início do
século XXI, a produção de carvão vegetal em Minas Gerais vivencia um processo de
reestruturação, tal processo alterou tanto a forma de produzir quanto a vida daqueles/as
envolvidos/as na produção. Este trabalho tem por objetivo analisar o processo de produção do
carvão vegetal no município de Grão Mogol, localizado no norte do Estado de Minas Gerais, onde
essa análise se estende, considerando o processo de trabalho, perfil socioeconômico dos/as
trabalhadores/as e o contexto atual. O novo cenário de produção contrasta com as formas
tradicionais de produção do carvão vegetal, em um campo de grandes impactos sociais,
econômicos e ambientais. Esse contraste se dá na forma de produção e organização do trabalho em
carvoarias e empresas voltadas para o carvoejamento, onde ao mesmo tempo em que se têm
verdadeiras indústrias nesse ramo, se mostram visíveis produções arcaicas, pequenas fabriquetas
que remontam a formas de produção e gestão do trabalho, consideradas como ultrapassadas por
esse setor. Ater ao trabalho como centro de debate, possibilita compreender aspectos da sociedade
capitalista e sua forma de organização, tal qual a importância na vida social, além de impactar
individualmente trabalhadores/as.
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Monopolização do território e carvoejamento na Amazônia: a produção do carvão vegetal nos assentamentos e acampamentos de reforma agrária e nas carvoeiras tradicionais de Rondon do Pará / Monopolization of the territory and charcoal production in Amazon: the charcoal production in settlements and camps of agrarian reform and in the traditional charcoal production areas in Rondon do Pará-PAMayka Danielle Brito Amaral 01 December 2011 (has links)
O presente trabalho versa sobre o processo de monopolização do território pelo capital, materializado nas indústrias siderúrgicas, a partir da atividade de carvoejamento realizada no município de Rondon do Pará, localizado no sudeste do estado do Pará, na Amazônia brasileira. As indústrias siderúrgicas constituem a materialização do capital, caracterizado como desigual, combinado e contraditório, que ao se implantarem na Amazônia promoveram uma relação de subordinação de diversos sujeitos sociais em diferentes municípios, para produzirem o carvão vegetal. Dentre esses municípios, este trabalho destaca a realidade de Rondon do Pará, que produz o carvão vegetal desde o início da produção da siderurgia na Amazônia. Dessa maneira, buscou-se caracterizar e analisar o processo de monopolização do território a partir da atividade de carvoejamento nesse município, onde se verificou que a produção do carvão vegetal tem sido realizada através de relações de produção capitalistas assalariadas, e de relações não-capitalistas camponesas de produção. Além de se produzir carvão da forma tradicional, por meio do reaproveitamento do resíduo de serraria e da pecuária, do desmatamento primário e secundário, essa atividade foi introduzida nos assentamentos e acampamentos rurais de reforma agrária, e tem substituído a produção de alimentos. Dessa forma, notou-se que a monopolização do território pelas indústrias siderúrgicas, a partir da atividade de carvoejamento, é realizada através da apropriação da renda camponesa da terra e da extração da mais-valia, tanto nas carvoeiras tradicionais quanto nas carvoeiras localizadas no interior dos assentamentos e acampamentos rurais de reforma agrária no município de Rondon do Pará. / The paper concerns the territory monopolization process by the capital, present in steel industries, starting from the charcoal production that takes place in the city of Rondon do Pará, located southeastern of the state of Pará, in the Brazilian Amazon. The steel industries constitute the capital materialization, considered uneven, combined and contradictory, that when implemented in the Amazon promoted a subordination relationship of several social actors in different cities, for the production of charcoal. Among these cities, this paper emphasizes the reality of Rondon do Pará, which produces charcoal since the beginning of the steel production in the Amazon. Thus, it was sought to characterize and analyze the territory monopolization due to the charcoal production activity in this city, where it was verified that such production has taken place though employment capitalist production relations and rural non-capitalist production relations. In addition to the traditional charcoal production, through reuse of sawmills and livestock waste, and primary and secondary deforestation, this activity has been introduced in the land reform rural settlements and camps and has substituted food production. Thus, the territory monopolization by the steel industries, starting from the charcoal production, takes place through the appropriation of land peasantry income and surplus value extraction, in traditional charcoal production areas as well as in charcoal production areas located in the interior of land reform rural settlements and camps in the city of Rondon do Pará.
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Compostos carbonílicos no ar em ambientes de trabalho de carvoarias na BahiaCarvalho, Albertinho Barreto de 16 September 2016 (has links)
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Tese Albertinho.pdf: 2368551 bytes, checksum: 417090fff955b8696ce1e600d35af5e0 (MD5) / CNPq, à CAPES e à FINE / Este trabalho foi realizado com os seguintes objetivos: apresentar uma metodologia analítica
aplicável à determinação de compostos carbonílicos (CC) em fase vapor, em amostras
estacionárias e pessoais coletadas em ambientes de trabalho de carvoarias; determinar o perfil
dos CC presentes no ar inalado pelos trabalhadores e; quantificar os CC no ar, na fase vapor,
em locais de trabalho e na zona respiratória de trabalhadores carvoeiros. Os trabalhos de
campo foram realizados em quatro carvoarias que produziam o carvão a partir da queima de
pinho e de eucalipto, todas localizadas a cerca de 150 km, a nordeste de Salvador. Cartuchos
Sep-Pak® C18 impregnados com solução ácida a 0,2% de 2,4 dinitrofenilhidrazina coletaram
eficientemente os CC atmosféricos, em vazões em torno de 0,1 L/min e quando a duração da
coleta foi de, no máximo, 240 minutos, para as amostras pessoais e 120 minutos, para as
estacionárias. Foram desenvolvidos dois protocolos analíticos (Método “1” e Método “2”),
ambos por cromatografia líquida de alta eficiência utilizando bomba com gradiente de eluição
de solventes e sistema de detecção por UV/Visível (365 nm), para a separação e quantificação
das 2,4-dinitrofenilhidrazonas de vários CC. O Método “1” permitiu separar e quantificar, em
menos de 16 minutos, acetaldeído, acroleína, benzaldeído, ciclohexanona, ciclopentanona, 2-
etil hexanal, formaldeído, furfural, hexanal, 2-hexenal, octanal, 2-pentenal, propanal, e
propanona, com destaque para a separação dos pares acroleína-furfural e propanona-propanal.
Além disso, permitiu estimar a soma das concentrações dos isômeros C4, butanal-isobutanal-
butanona. O Método “2” permitiu separar e quantificar, em menos de 30 minutos, 13 dos 17
CC citados para o Método “1”. Por este método foi possível separar a butanona da mistura de
butanal e isobutanal. O mesmo não ocorreu com a acroleína e o furfural, que co-eluíram. Os
limites de detecção e de quantificação para o formaldeído, o acetaldeído e a propanona foram
bastante afetados pelos níveis desses compostos encontrados nos brancos de amostra.
Acetaldeído, formaldeído, furfural, isômeros C4 e propanona foram os CC confirmados em
todas as amostras coletadas, nas quatro carvoarias. Vários outros CC desconhecidos foram
detectados nas amostras. Ciclopentanona, 2-pentenal e CC acima de C8 não foram detectados
nas amostras pelos dois métodos cromatográficos. Em amostras válidas foram determinadas
concentrações de formaldeído entre 15,0 e 139,1 µg m-3, de acetaldeído entre 37,9 e 164,8 µg
m-3, de propanona entre 9,6 e 483,0 µg m-3, de furfural entre 38,9 e 113,7 µg m-3 e de
isômeros C4 (butanal+isobutanal+butanona) entre 9,8 e 132,4 µg m-3, em amostras pessoais.
Em amostras estacionárias, as faixas de concentrações desses mesmos compostos foram
respectivamente, 20,4 a 160,2 µg m-3, 118,6 a 283,6 µg m-3, 327,5 a 643,6 µg m-3, 69,9 a
162,9 µg m-3 e 100,0 a 176,1 µg m-3. Os resultados indicam que os trabalhadores das
carvoarias se expõem a concentrações de formaldeído, acetaldeído e furfural acima dos
limites estabelecidos por alguns organismos internacionais, como o National Institute for
Occupational Safety and Health - NIOSH e o Health Based Exposure Levels Committee -
HBELC, ambos dos Estados Unidos. Estes são os primeiros resultados de concentrações de
CC no ar obtidos em ambientes de trabalho e na zona respiratória de trabalhadores de
carvoarias, que se tem conhecimento até o momento. / The goals of the present work were to present an analytical methodology applicable to the
determination of carbonyl compounds (CC) in vapor phase, in area and personal samples
collected in charcoal company workplaces; to determine the CC profile in air inhaled by
charcoal workers; and to quantify the CC in vapor phase in air of workplaces and breathing
zone of workers in charcoal companies. The measurements were obtained in air samples
collected in four companies located about 150 km north of Salvador, Bahia, Brazil, which
burn eucalyptus and pinus to produce charcoal. The results showed that CC were efficiently
collected on Sep-Pak® C18 cartridges coated with 0.2% acidic solution of 2,4-
dinitrophenylhydrazine when the sampling flow rates were around 100 mL/min and the
sampling time was 240 minutes for the personal samples and 120 minutes for area samples.
Two chromatographic methods (Method 1 and Method 2) for separation and quantification of
several 2,4-dinitrophenylhydrazones (2,4-DNPHO) were developed using a high performance
liquid chromatography system with a gradient pump for the solvent elution and a UV detector
(365 nm). Method 1 was able to separate and quantify, in less than 16 minutes, the 2,4-
DNPHO of acetaldehyde, acrolein, benzaldehyde, cyclohexanone, cyclopentanone, 2-ethyl
hexanal, formaldehyde, furfural, hexanal, 2-hexenal, octanal, 2-pentenal, propanal, and
propanone, and estimated the sum of C4 isomers, butanal-isobutanal-butanone. This method
separated well acrolein from furfural and propanal from propanone hydrazones. Method “2”
allowed separation and quantification, in less than 30 minutes, of 13 of the 17 CC listed for
Method 1. This method separated butanone from other components of the C4 mixture and
enables the separation of acrolein from furfural. In both methods, the detection and the
quantification limits of acetaldehyde, formaldehyde, and propanone were affected by the
amount of these compounds found in the blank samples. Acetaldehyde, formaldehyde,
furfural, C4 isomers, and propanone were the CC confirmed in all samples collected in all
charcoal companies. Several unknown CC were also found. Cyclopentanone, 2-pentenal, and
carbonyl compounds with more than 8 carbon atoms were not detected in any of the samples
by these methods. Concentrations of formaldehyde, acetaldehyde, propanone, furfural, and C4
isomers (butanal+isobutanal+butanone) found in personal samples ranged between 15.0 and
139.1 µg m-3, 37.9 and 164.8 µg m-3, 9.6 and 483.0 µg m-3, 38.9 and 113.7 µg m-3, and 9.8
and 132.4 µg m-3, respectively. In area samples, the concentrations of the same CC were
between 20.4 and 160.2 µg m-3, 118.6 and 283.6 µg m-3, 327.5 and 643.6 µg m-3, 69.9 and
162.9 µg m-3, and 100.0 and 176.1 µg m-3. These results indicated that charcoal workers were
exposed to formaldehyde, acetaldehyde, and furfural concentrations that exceed the limit
values suggested by the National Institute for Occupational Safety and Health - NIOSH and
the Health Based Exposure Levels Committee - HBELC. These were the first results of CC
concentrations in workplace air and in breathing zone of charcoal workers reported in the
scientific literature up to this mome
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Biodiversity of the African savanna woodlands : how does it change with land use?Tripathi, Hemant Gangaprasad January 2018 (has links)
The savanna woodlands of Southern Africa, colloquially termed the miombo, are poorly described in terms of biodiversity compared to other biomes. They have therefore been underrepresented in the wider understanding of how land use intensification is shaping global biodiversity. Land use change is known to reduce biodiversity and disrupt intactness of ecological communities with consequences for ecosystem functioning, resilience, and services. Miombo woodlands are described as biodiversity hotspots due to a high endemism of species and the presence of megafauna. At the same time, they are also considered dynamic socio-ecological systems shaped by disturbances and the land use activities of people. The patterns of biodiversity change in these tropical ecosystems may, therefore, have their own unique contexts, understanding of which will be essential for biodiversity and land use management in these ecosystems. In this thesis, I identified the patterns of biodiversity change in response to the two major land use practices in the two dominant woodland types in southern African woodlands: the selective logging due to charcoal production in the mopane woodlands, and agricultural expansion in the miombo. I also examined the impact of two main disturbance agents, humans and elephants, on habitat structure and biodiversity in mopane woodlands. Across all chapters in this thesis, I investigated the effects of land use change and habitat modification on biodiversity empirically using chronosequences. To understand biodiversity change, I employed a hierarchical multilevel modelling approach making inferences at the three levels of ecological communities: species, community, and meta-community (set of ecological communities at different sites). I selected six villages in the charcoal production hotspot of southern Mozambique and carried out field surveys for three taxonomic groups: trees, mammals and ground beetles. I modelled the counts of trees and beetles and incidence of mammals using meta-community occurrence models in a Bayesian framework with the intensity class of the villages, above-ground biomass and land cover type as predictors. The results suggested that the species richness of trees and mammals declined by 12 and 8.5 % respectively while that of beetles increased by 3.5%, albeit non-significantly. In addition, the beta diversity of trees decreased while that of mammals increased. The results show that while both trees and mammals reduced in richness, they responded differently to charcoal production in terms of community organisation. The trees underwent subtractive homogenisation (decrease in alpha and beta diversities) primarily because of deterministic processes induced by selective harvesting of tree stems for charcoal. Mammal communities, on the other hand, showed subtractive heterogenization (decrease in alpha, but increase in beta diversity) mainly due to random extinctions. In the agriculture frontier of miombo-dominated northern Mozambique, I investigated the effects of fragmentation and habitat loss caused by agricultural expansion on diversity and composition of trees and mammals. I modelled the occurrences of trees and mammals using occupancy models with the fragmentation and quantity of woodland cover as predictors. The model showed that most tree species (n=10), mainly the timber and firewood species, linearly declined in population size as fragmentation increased. Mammals, on the other hand, showed a nonlinear response. Seven mammal species increased at the lower levels of fragmentation. However, at the higher levels, none of the mammal species increased while two declined. Similarly, the species richness of trees linearly declined, while that of mammals increased up to a fragmentation level of 55-65% and declined above this limit. The beta diversity of trees increased with fragmentation while that of mammals decreased. The results suggest that, although fragmentation reduces species richness of both trees and mammals, it affects their species compositions in different ways. Trees undergo subtractive heterogenization due to random species losses while mammals experience subtractive homogenisation mainly due to the combined effects of fragmentation-led habitat loss and intensified hunting. Finally, this study concludes that, above 75% fragmentation or below 26% habitat quantity, both taxonomic groups endure biodiversity loss. The threshold results here corroborate similar habitat quantity thresholds (20-30%) observed elsewhere in different ecosystems. However, they differ with the widespread notion that above 30% habitat quantity, the effect of fragmentation is non-existent. The results here emphasize that taxonomic groups respond differently, the diversity and population size of mammals reduced only after the habitat threshold, whereas, those of trees showed linear decrease with fragmentation most likely due to fragmentation-led habitat loss. Lastly, I examined the effects of disturbance by humans and elephants on habitat structure and bird diversity by conducting a space for time substitution comparison in the mopane woodlands of Zambia. To examine the woodland structure, I modelled the structural attributes of habitat (stem diameter, stand density, and basal area) using mixed models with the proportion of affected stems by humans and elephants as explanatory variables. I found that elephant disturbance was associated with higher stem diameters, low stand densities, but no change in basal area. Human disturbance, on the other hand, was related to reductions in stand density and basal area, but no change in the stem diameter. Further, I tested species and functional diversity of birds against the covariates of habitat structure and disturbance. I found that bird communities reduced in species richness in both, human as well as elephant disturbed areas. However, the functional diversity did not change with elephant disturbance. I concluded that human disturbance reduces woody biomass (basal area is correlated with woody biomass) of mopane woodlands and functional diversity of birds whilst elephants do not. In this thesis, I conclude that human driven land use change in the miombo woodlands erodes alpha diversity of all taxonomic groups. However, increases in beta diversity of mammals with charcoal land use and trees in agricultural land use may maintain their diversities at the meta-community level.
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