Thesis (Ph. D.) -- Lincoln University, 2005. / Also available via the World Wide Web.

Includes bibliographical references.

Thesis (Ph. D. (soil science))--Washington State University, May 2007. / Includes bibliographical references.

Two BSC based indicators for rangeland condition assessment are species composition and cover. While there is strong agreement that BSC composition is a good indicator, there is less agreement that BSC cover alone is a good indicator. Although BSC have been included in previous remotely- sensed studies, their spectral characteristics, and hence their contributions to remotely-sensed spectral signatures, are not well known. / Data collection methods were refined for suitable method selection, stratification and site characterization, and morphological/functional group classification. Cover data of BSC were collected using a 100m line-intercept method on the stratified land units and statistical analyses were based on the cover variance analyses. Spectra of BSC groups were collected and characterized for different remote sensing indices. Five grazing gradient models based on collected spectra were developed for the evaluation of BSC effect on remotely-sensed data. Both existing and newly developed remote sensing indices were examined for BSC detection. / Sampling for cover of BSC in the field showed that there is indeed a detectable change with distance from water, suggesting that BSC cover can be used as an indicator of rangeland condition, provided that appropriate stratification of the study sites is carried out prior to sampling, and spectral differences in morphological and functional groups are taken into account. / Spectral analysis of BSC components showed that different classes of organisms in the crusts have different spectral characteristics, an din particular, that the (commonly-used) perpendicular vegetation index (PD54) is not suitable for detecting BSC. On the other hand, ground-level spectral modelling showed that the Normalized Difference Vegetation Index (NDVI) and Soil Stability Index (SSI) did show a distinguishable contribution from BSC. / A procedure for detecting cover of BSC was developed for image taken during the period after an effective rain, in contrast to the normal practice of selecting images of dry surfaces for interpretation. / The most suitable interval appears to be 2-4 days after rain in late autumn, winter and early spring. Of the existing indices, the SSI is the best for estimating cover of BSC from Landsat images. However, eight new indices, specifically designed for detection of BSC were developed during the course of this work. The best results were obtained for indices using the middle-infrared bands. / These results are promising for application to rangeland monitoring and suggest that BSC cover is an important indicator of rangeland condition if appropriate stratification, classification and data-collection methods are used. The effects of BSC cover on a remotely-sensed method are considerable, and thus they can not be neglected during image interpretation. There are different phenological patterns for BSC, annual and perennial elements, thus there is the possibility for the selection of imagery based on each phenological stage to detect these elements. Application of certain indices such as the PD54 may create mis-estimation of land covers. Although some of the existing and newly developed indices had significant results for BSC cover estimation, there is a requirement for a standalone remotely-sensed method to conclude the best index. / This thesis considers various aspects of the use of ground-based methods and remote sensing of Biological Soil Crusts (BSC). They are mostly distributed in winter rainfall dominated areas such as those at Middleback Field Centre (MFC) in South Australia. They can be used potentially as an indicator of rangeland condition by estimating grazing pressure (trampling). / Thesis (PhDEnvironmentalManagement)--University of South Australia, 2007.

Two BSC based indicators for rangeland condition assessment are species composition and cover. While there is strong agreement that BSC composition is a good indicator, there is less agreement that BSC cover alone is a good indicator. Although BSC have been included in previous remotely- sensed studies, their spectral characteristics, and hence their contributions to remotely-sensed spectral signatures, are not well known. / Data collection methods were refined for suitable method selection, stratification and site characterization, and morphological/functional group classification. Cover data of BSC were collected using a 100m line-intercept method on the stratified land units and statistical analyses were based on the cover variance analyses. Spectra of BSC groups were collected and characterized for different remote sensing indices. Five grazing gradient models based on collected spectra were developed for the evaluation of BSC effect on remotely-sensed data. Both existing and newly developed remote sensing indices were examined for BSC detection. / Sampling for cover of BSC in the field showed that there is indeed a detectable change with distance from water, suggesting that BSC cover can be used as an indicator of rangeland condition, provided that appropriate stratification of the study sites is carried out prior to sampling, and spectral differences in morphological and functional groups are taken into account. / Spectral analysis of BSC components showed that different classes of organisms in the crusts have different spectral characteristics, an din particular, that the (commonly-used) perpendicular vegetation index (PD54) is not suitable for detecting BSC. On the other hand, ground-level spectral modelling showed that the Normalized Difference Vegetation Index (NDVI) and Soil Stability Index (SSI) did show a distinguishable contribution from BSC. / A procedure for detecting cover of BSC was developed for image taken during the period after an effective rain, in contrast to the normal practice of selecting images of dry surfaces for interpretation. / The most suitable interval appears to be 2-4 days after rain in late autumn, winter and early spring. Of the existing indices, the SSI is the best for estimating cover of BSC from Landsat images. However, eight new indices, specifically designed for detection of BSC were developed during the course of this work. The best results were obtained for indices using the middle-infrared bands. / These results are promising for application to rangeland monitoring and suggest that BSC cover is an important indicator of rangeland condition if appropriate stratification, classification and data-collection methods are used. The effects of BSC cover on a remotely-sensed method are considerable, and thus they can not be neglected during image interpretation. There are different phenological patterns for BSC, annual and perennial elements, thus there is the possibility for the selection of imagery based on each phenological stage to detect these elements. Application of certain indices such as the PD54 may create mis-estimation of land covers. Although some of the existing and newly developed indices had significant results for BSC cover estimation, there is a requirement for a standalone remotely-sensed method to conclude the best index. / This thesis considers various aspects of the use of ground-based methods and remote sensing of Biological Soil Crusts (BSC). They are mostly distributed in winter rainfall dominated areas such as those at Middleback Field Centre (MFC) in South Australia. They can be used potentially as an indicator of rangeland condition by estimating grazing pressure (trampling). / Thesis (PhDEnvironmentalManagement)--University of South Australia, 2007.

Diss. (sammanfattning) Uppsala : Sveriges lantbruksuniversitet, 2005. / Härtill 4 uppsatser.

ARAÚJO, Jackson de Lima. Artrópodes e atributos microbiológicos do solo em cultivo de fruteiras no Vale do Curu - CE. 2014. 79 f. Dissertação (Mestrado em agronomia)- Universidade Federal do Ceará, Fortaleza-CE, 2014. / Submitted by Elineudson Ribeiro (elineudsonr@gmail.com) on 2016-08-30T20:44:45Z No. of bitstreams: 1 2014_dis_jlaraújo.pdf: 1782360 bytes, checksum: bd8086576c989888ae34f3e1963337d2 (MD5) / Approved for entry into archive by Jairo Viana (jairo@ufc.br) on 2016-08-31T23:29:51Z (GMT) No. of bitstreams: 1 2014_dis_jlaraújo.pdf: 1782360 bytes, checksum: bd8086576c989888ae34f3e1963337d2 (MD5) / Made available in DSpace on 2016-08-31T23:29:51Z (GMT). No. of bitstreams: 1 2014_dis_jlaraújo.pdf: 1782360 bytes, checksum: bd8086576c989888ae34f3e1963337d2 (MD5) Previous issue date: 2014 / A major concern related to agricultural management systems used by the man lies on the effects on biological processes in the soil, whose action within ecosystems aiming at the farm, modifies the intensity of these processes under use of techniques that exclusively aim to maximize crop yield. One of the challenges of research in soil biology is precisely understand the impacts on the complex interactions of all soil organisms at the community level by the management that are critical in maintaining soil quality. The objective of this work was to evaluate the influence of management practices on fruit trees (mango, guava and coconut trees) in the composition and distribution of soil arthropods (edaphic macrofauna, mesofauna) and on microbial biomass, the activity and interaction with the chemical, physical and environmental attributes. The study of soil arthropods began in July 2013 and followed until May 2014, with measurements at four periods. Microbiological soil activities were evaluated by the determination of microbial soil properties (RBS, CBM, NBM, NBM / N, qCO2 and qMIC). It was found that the soil arthropods were sensitive to changes arising from different soil tillage systems, allowing it to be used as an important tool to apply as bio-indicators of the quality of edaphic system. The system with guava cultivation proved to be unstable over time in relation to the structure of the community of soil arthropods. The system with coconut tree cultivation allows for better soil quality, increase in abundance and species richness of invertebrate macrofauna. The microbial biomass carbon (MBC), microbial biomass nitrogen (NBM) and the metabolic quotient (qCO2) were the main microbiological soil properties responsible for identifying dissimilarities between areas. Correlations between microbiological and faunal characteristics of the soil were low with significant correlations only between Collembola, NBM and NBM / N. / Uma das grandes preocupações relacionadas aos sistemas de manejo agrícola adotado pelo homem reside nos efeitos sobre os processos biológicos que ocorrem no solo, cuja ação dentro dos ecossistemas visando à exploração agrícola, modifica a intensidade desses processos em virtude do emprego de práticas que objetivam exclusivamente a maximização da produção vegetal. Um dos desafios da pesquisa em biologia do solo é justamente entender os impactos do manejo sobre as complexas interações de todos os organismos edáficos ao nível de comunidade que são fundamentais na manutenção da qualidade do solo. Objetivou-se avaliar a influência dos manejos em cultivos de fruteiras (mangueira, goiabeira e coqueiro) na composição e distribuição dos artrópodes de solo (mesofauna e macrofauna edáfica) e sobre a biomassa microbiana, sua atividade e interação com os atributos químicos, físicos e ambientais. O estudo dos artrópodes edáficos teve início em julho de 2013 e seguiu até maio de 2014, com coletas realizadas em quatro períodos. As atividades microbiológicas do solo foram avaliadas mediante as determinações dos atributos microbianos do solo (RBS, CBM, NBM, NBM/N, qCO2 e qMIC). Constatou-se que os artrópodes de solo mostraram-se sensíveis as alterações ocasionadas pelos sistemas de manejos do solo, possibilitando a sua indicação como importante ferramenta para aplicar-se como bioindicadores da qualidade do sistema edáfico. O sistema com cultivo de goiabeiras mostrou-se instável ao longo do tempo em relação à estrutura da comunidade dos artrópodes de solo. O sistema com cultivo de coqueiros propicia melhores características do solo e aumento na abundância e riqueza de espécies da macrofauna invertebrada. O carbono da biomassa microbiana (CBM), nitrogênio da biomassa microbiana (NBM) e o quociente metabólico (qCO2), foram os principais atributos microbiológicos do solo responsáveis por identificar dissimilaridades entre as áreas. Correlações entre as variáveis microbiológicas e faunísticas do solo foram baixas, com correlações significativas somente entre Collembola, NBM e NBM/N.

Made available in DSpace on 2015-06-17T19:34:47Z (GMT). No. of bitstreams: 0 Previous issue date: 2014-02-28. Added 1 bitstream(s) on 2015-06-18T12:47:05Z : No. of bitstreams: 1 000830788.pdf: 822528 bytes, checksum: a180e8a4717cf27205b84b2017a24f10 (MD5) / De maneira geral, resíduos industriais como vinhaça e torta de filtro, causam preocupação devido ao risco de impactos ambientais que podem ser causados quando utilizados na reposição de nutrientes em solos com cultivo de cana-de-açúcar (Saccharum spp.). Devido à falta de estudos que busquem desvendar os impactos destes resíduos na estrutura e composição de comunidades bacterianas, este trabalho teve como proposta utilizar o gene 16S rRNA para avaliar a diversidade bacteriana presente em 5 biomas com diferentes manejo de cana-de-açúcar e os resíduos vinhaça e torta de filtro. Foram analisados um total de 1.090 sequencias do 16S rRNA de bactérias, recuperadas de: i) solo com fertirrigação de vinhaça e plantio de cana-de-açúcar (SV), ii) solo depositado sobre o canal mestre da vinhaça (MC), iii) solo de mata nativa localizada próxima a áreas de plantio de cana-de-açúcar (MT), iv) solo com plantio de cana-de-açúcar sem a aplicação de vinhaça (CH) e v) semicomposto de torta de torta de filtro (CP). Com base na curva de rarefação e índice Richness, SV foi considerado o ambiente mais diverso, MT foi considerado como portador de diversidade intermediária e, com base nos outros índices, MC foi considerado o ambiente menos diverso. O filo Actinobacteria, relacionado com a degradação da biomassa vegetal e produção de antimicrobianos, dominou a população do ambiente CP, fato possivelmente relacionado a elevada quantidade de material lignocelulósico disponível na torta de filtro. CP também apresentou os filos Firmicutes e Proteobacteria, ambos presentes em diferentes estágios do processo de compostagem. Os ambientes de solos foram considerados como portadores de poucos táxons relacionados a gêneros bacterianos cultivados, além de apresentarem elevado número de clones afiliados a bactérias não classificadas. Os testes de variância molecular Unifrac e Libshuff demonstram que os cinco biomas ... / Generally, industrial wastes as vinasse and filter cake cause public apprehension due to the risk of environmental impacts caused by their use as nutrients replenishment in soils with cultivation of sugarcane (Saccharum spp.). Due to lack of studies that seek to unravel the impacts of these residues in the structure and composition of bacterial communities, this work aimed to apply the 16S rRNA gene to assess the bacterial diversity present in five biomes with different sugarcane crop management besides waste vinasse and filter cake. A total of 1,090 sequences of bacterial 16S rRNA were recovered and analyzed: i) soil under sugarcane crop fertilized by vinasse (SV); ii) soil from the master channel for vinasse distribution (MC), iii) soil under native forest located next to areas of sugarcane planting (MT), iv) soil under sugarcane crop without vinasse irrigation (CH), and v) filter cake semi-composting compound (CP). Based on Richness index and rarefaction curve, the SV is considered the most diverse, followed by MT as the intermediary, and MC as the least diverse environment. The Actinobacteria phylum related to the degradation of plant biomass and production of antimicrobials has dominated the population of the CP environment, that was possibly related to high amount of lignocellulosic material available on the filter cake. CP also presented the Firmicutes and Proteobacteria phyla, both present at different stages of the composting process. Soil environments showed few taxa related to cultured bacterial genera unlike the high number of clones affiliated to bacteria not classified. Unifrac and Libshuff tests for molecular variance show that the five biomass present variation in the structure of bacterial communities. In addition, SV and MC does not share species each other. These results demonstrate that the environments containing vinasse and filter cake are different from other biomes with management of sugarcane. These ...

Orientador: Jackson Antônio Marcondes de Souza / Coorientador: Eliana Gertrudes de Macedo Lemos / Banca: Janete Apparecida Desidério / Banca: Luciano Takeshi Kishi / Resumo: De maneira geral, resíduos industriais como vinhaça e torta de filtro, causam preocupação devido ao risco de impactos ambientais que podem ser causados quando utilizados na reposição de nutrientes em solos com cultivo de cana-de-açúcar (Saccharum spp.). Devido à falta de estudos que busquem desvendar os impactos destes resíduos na estrutura e composição de comunidades bacterianas, este trabalho teve como proposta utilizar o gene 16S rRNA para avaliar a diversidade bacteriana presente em 5 biomas com diferentes manejo de cana-de-açúcar e os resíduos vinhaça e torta de filtro. Foram analisados um total de 1.090 sequencias do 16S rRNA de bactérias, recuperadas de: i) solo com fertirrigação de vinhaça e plantio de cana-de-açúcar (SV), ii) solo depositado sobre o canal mestre da vinhaça (MC), iii) solo de mata nativa localizada próxima a áreas de plantio de cana-de-açúcar (MT), iv) solo com plantio de cana-de-açúcar sem a aplicação de vinhaça (CH) e v) semicomposto de torta de torta de filtro (CP). Com base na curva de rarefação e índice Richness, SV foi considerado o ambiente mais diverso, MT foi considerado como portador de diversidade intermediária e, com base nos outros índices, MC foi considerado o ambiente menos diverso. O filo Actinobacteria, relacionado com a degradação da biomassa vegetal e produção de antimicrobianos, dominou a população do ambiente CP, fato possivelmente relacionado a elevada quantidade de material lignocelulósico disponível na torta de filtro. CP também apresentou os filos Firmicutes e Proteobacteria, ambos presentes em diferentes estágios do processo de compostagem. Os ambientes de solos foram considerados como portadores de poucos táxons relacionados a gêneros bacterianos cultivados, além de apresentarem elevado número de clones afiliados a bactérias não classificadas. Os testes de variância molecular Unifrac e Libshuff demonstram que os cinco biomas ... / Abstract: Generally, industrial wastes as vinasse and filter cake cause public apprehension due to the risk of environmental impacts caused by their use as nutrients replenishment in soils with cultivation of sugarcane (Saccharum spp.). Due to lack of studies that seek to unravel the impacts of these residues in the structure and composition of bacterial communities, this work aimed to apply the 16S rRNA gene to assess the bacterial diversity present in five biomes with different sugarcane crop management besides waste vinasse and filter cake. A total of 1,090 sequences of bacterial 16S rRNA were recovered and analyzed: i) soil under sugarcane crop fertilized by vinasse (SV); ii) soil from the master channel for vinasse distribution (MC), iii) soil under native forest located next to areas of sugarcane planting (MT), iv) soil under sugarcane crop without vinasse irrigation (CH), and v) filter cake semi-composting compound (CP). Based on Richness index and rarefaction curve, the SV is considered the most diverse, followed by MT as the intermediary, and MC as the least diverse environment. The Actinobacteria phylum related to the degradation of plant biomass and production of antimicrobials has dominated the population of the CP environment, that was possibly related to high amount of lignocellulosic material available on the filter cake. CP also presented the Firmicutes and Proteobacteria phyla, both present at different stages of the composting process. Soil environments showed few taxa related to cultured bacterial genera unlike the high number of clones affiliated to bacteria not classified. Unifrac and Libshuff tests for molecular variance show that the five biomass present variation in the structure of bacterial communities. In addition, SV and MC does not share species each other. These results demonstrate that the environments containing vinasse and filter cake are different from other biomes with management of sugarcane. These ... / Mestre

Quartz fields contribute significantly to plant diversity in the Succulent Karoo biome. They are distinctly different from surrounding habitats and have high levels of plant endemism. Biological soil crusts are features of quartz field soils and fulfill a vital function in that they stabilize soils. It is important for managers of nature reserves and agricultural rangelands to know what factors influence quartz field soils and vegetation. Both stakeholders could benefit from new information that would allow for informed decision-making regarding land-use on quartz fields. The present study took place in the Namaqua National Park that contains a significant proportion of the Riethuis-Wallekraal quartz fields phytochorion. The first part of the study aimed to understand whether certain land-use activities potentially destabilize quartz field soils, which might have possible ramifications for associated biological soil crusts and vegetation. It was followed by relating variation in soil stability with species richness, cover and species composition of quartz field vegetation. Overall, positions assumed to be impacted by land-use activities had less stable soils compared to positions assumed not be impacted. Soil stability had a significant influence on species richness and cover but to a lesser degree on species composition. Quartz field vegetation was significantly influenced by soil physical and chemical properties as well as location in the quartz fields landscape. The second part of the study aimed at understanding how species richness of isolated quartz outcrops is related to their size compared to that of a mainland body of quartz outcrops. No clear species-area relationships emerged from the study. There were significant differences between isolated outcrops and mainland outcrops in substrate and vegetation composition. Findings are discussed in relation to Island Biogeography Theory.