Thesis (M.S.)--Florida State University, 2003. / Title from PDF t.p. (viewed Feb. 19, 2006). Advisor: Dr. Walter R. Tschinkel, Florida State University, College of Arts and Sciences, Dept. of Biological Science. Includes bibliographical references (p. 53-58).

Doctorat en Sciences / info:eu-repo/semantics/nonPublished

Made available in DSpace on 2016-12-23T14:37:26Z (GMT). No. of bitstreams: 1 Victor Mauricio da Silva.pdf: 2335495 bytes, checksum: 3d045f5906117f1acc05e0efbd6cdfc1 (MD5) Previous issue date: 2012-02-28 / O cafeeiro conilon (Coffea canephora Pierre ex Froehner) apresenta alta exigência em nutrientes e a reposição no solo é feita geralmente por meio de adubos minerais. Para reduzi-los, o uso de resíduos orgânicos disponíveis na propriedade agrícola pode ser uma alternativa. Os objetivos do estudo foram: (i) avaliar parâmetros agronômicos (produtividade, estado nutricional, atributos químicos de solo e densidade do solo) de uma lavoura conduzida a partir da substituição parcial e total da adubação mineral pela orgânica; e (ii) monitorar e comparar a biodiversidade da meso e macrofauna edáfica do cafeeiro conilon conduzido em diferentes sistemas de adubação. Em lavoura localizada no município de Linhares, Estado do Espírito Santo Brasil, foi montado, no ano agrícola 2009/2010, um experimento em blocos casualizados com distribuição fatorial de 2 x 2 x 5, com três repetições, sendo os fatores: dois tipos de composto orgânico; presença e ausência de leguminosa; e cinco proporções de cada composto (0; 25; 50; 75; e 100%) em substituição da adubação mineral recomendada para o cafeeiro conilon. Cada repetição foi formada por parcela de 30 plantas do cafeeiro conilon, sendo 12 plantas úteis centrais. Os compostos utilizados foram: composto 1 (C1), preparado com a mistura de capim elefante (Pennisetum purpureum) e palha-de-café na proporção 1:1(v:v); e composto 2 (C2), preparado pela mistura de capim elefante, palha-de-café e cama-de-frango na proporção 2:1:1 (v:v:v). A leguminosa utilizada foi o feijão-de-porco (Canavalia ensiformis), semeada nas entrelinhas dos cafeeiros. O capítulo 1 apresenta a introdução geral, enfatizando a área de investigação e as justificativas para a realização do estudo. Atributos químicos do solo e a densidade do solo foram avaliados no capítulo 2. Aos 30 dias após a adubação do 2º ano agrícola, verifica-se aumento do estoque de C orgânico e N total com o incremento das proporções do C1 e do C2 na profundidade de 0-5 cm. No capítulo 3, avaliaram-se o estado nutricional e a produtividade dos cafeeiros. O aumento das proporções do C1 e C2 decresce os teores foliares de Mn possivelmente em resposta ao acréscimo do pH do solo. Valores máximos de 61,13 e 66,42 sacas beneficiadas por hectare são obtidos com proporções de substituição (da fonte mineral por orgânica) de 40,42 e 37,32% para o C1 e C2, respectivamente. A caracterização da meso e macrofauna edáfica foi feita no capítulo 4. Independente do tratamento e do período de avaliação, Formicidae (formigas) pertencente ao gênero Pheidole sp. (associada com a cochonilha da roseta dos cafeeiros) é predominante. Por fim, o capítulo 5 apresenta as considerações finais, ponderando sobre aspectos importantes de pesquisas futuras para ratificar o uso de resíduos orgânicos no cafeeiro conilon / The conilon coffee plant (Coffea canephora Pierre ex Froehner) has high nutrient requirement and the soil recovery is usually done thru mineral fertilizers. To reduce them, the use of organic waste available on the farm can be an alternative. The objectives of this study were: (i) evaluate agronomic parameters (yield, nutritional status, soil chemical properties and bulk density) of a crop conducted from the partial and total substitution of mineral fertilizer by organic fertilizer, and (ii) monitor and compare the biodiversity of the soil meso and macrofauna of conilon coffee plant conducted in different systems of fertilization. In a crop located in Linhares in the state of Espirito Santo, Brazil, in the agricultural year 2009/2010, was carried out in a random block design (RBD) experiment with a factorial distribution 2 x 2 x 5, with three replications, the following factors: two type of organic compost; presence and absence of legumes; and five proportion of each compost (0; 25; 50; 75 and 100%) as a substitute for mineral fertilizer as recommended for conilon coffee. Each replicate was formed of 30 conilon coffee plants per plot being 12 central plants. The composts used were: compost 1 (C1), prepared with a mixture of elephant grass and coffee straw in a ratio 1:1 (v;v); and compost 2 (C2) prepared by mixing elephant grass, coffee straw and poultry litter in a ratio 2:1:1 (v;v;v). A legume a jack bean was used sown between the rows of coffee plantations. Chapter 1 presents a general introduction, emphasizing the research area and the justifications for the study. Soil chemical properties and bulk density were evaluated in chapter 2. At 30 days after fertilization of the 2nd growing season, there is to increase of stocks of organic C and total N with increased proportions of C1 and C2 at a depth of 0-5 cm. In chapter 3, were evaluated the nutritional status and yield of coffee plant. Increasing proportions of C1 and C2 decreases leaf contents of Mn possibly response to increase soil pH. Maximum values of 61.13 and 66.42 sacks ha-1 are obtained with proportions of substitution of 40.42 and 37.32% for C1 and C2, respectively. The characterization of soil meso and macrofauna was performed in chapter 4. Independently of treatment and evaluation period, Formicidae (ants) of the genus Pheidole sp. is predominant.Finally, chapter 5 presents the final remarks, pondering the important aspects of future research to ratify the use of organic wastes in conilon coffee plant

Submitted by Edisangela Bastos (edisangela@ufpa.br) on 2013-08-02T20:54:02Z No. of bitstreams: 2 Dissertacao_ImpactosExploracaoMadeireira.pdf: 6089993 bytes, checksum: dd72cbb7ec768aa3a72938a9748f65a5 (MD5) license_rdf: 23898 bytes, checksum: e363e809996cf46ada20da1accfcd9c7 (MD5) / Approved for entry into archive by Ana Rosa Silva(arosa@ufpa.br) on 2013-08-21T12:55:13Z (GMT) No. of bitstreams: 2 Dissertacao_ImpactosExploracaoMadeireira.pdf: 6089993 bytes, checksum: dd72cbb7ec768aa3a72938a9748f65a5 (MD5) license_rdf: 23898 bytes, checksum: e363e809996cf46ada20da1accfcd9c7 (MD5) / Made available in DSpace on 2013-08-21T12:55:13Z (GMT). No. of bitstreams: 2 Dissertacao_ImpactosExploracaoMadeireira.pdf: 6089993 bytes, checksum: dd72cbb7ec768aa3a72938a9748f65a5 (MD5) license_rdf: 23898 bytes, checksum: e363e809996cf46ada20da1accfcd9c7 (MD5) Previous issue date: 2001 / A exploração madeireira na Amazônia atinge anualmente cerca de 1,5 milhões de hectares de floresta. Esta atividade promove mudanças estruturais e microclimáticas na floresta, que potencialmente afetam a diversidade e a composição das espécies animais. Como grande parte das sementes florestais são dispersas por animais, a regeneração dos ambientes explorados pode ser comprometida. Por outro lado, é possível que a fauna de florestas exploradas através de técnicas de extração madeireira com impactos reduzidos, mantenha sua integridade original, não afetando os mecanismos de dispersão de sementes. Tomando as formigas como um grupo animal ecologicamente representativo e integrado aos processos de regeneração, via dispersão e predação de sementes, foi avaliado neste trabalho se (1) a exploração madeireira afeta a fauna (diversidade e composição de espécies) destes insetos, se (2) planos de exploração de baixo impacto são capazes de preservá-la e se (3) a exploração afeta a eficiência ecológica das formigas na remoção (dispersão ou predação) de sementes. Os efeitos da exploração madeireira sobre a diversidade e a composição de espécies de formigas, bem como sobre a remoção de sementes florestais realizada por estes insetos, foram investigados em três ambientes de floresta, no município de Paragominas, estado do Pará: uma floresta que sofreu exploração madeireira convencional (FC), outra floresta explorada por técnicas de extração de baixo impacto (FB) e uma floresta primária, como controle (FP). A fauna de formigas foi amostrada em quatro ocasiões de coleta durante o ano de 1998. Em cada ocasião, as formigas foram coletadas através do método de Winkler, em quatro transecções por área. O experimento de remoção de sementes foi realizado colocando-se sementes de seis espécies madeireiras, distribuídas em 12 pontos por ambiente. Durante o experimento, foi quantificado diariamente o número de formigas e outros artrópodes visitando as sementes. O número total de sementes removidas por ambiente foi contado ao final do experimento. A diversidade e a abundância de espécies de formigas não foram afetadas pela exploração madeireira. Contudo, a composição de espécies foi alterada em 36% na FB e 37% na FC. O gênero Pheidok teve sua riqueza e abundância reduzidas exclusivamente na FC. A remoção de sementes também foi significativamente menor (ca. 33%) na FC se comparada àquela registrada na FB e FP. As formigas representaram 92% dos artrópodes que visitaram as sementes, nos três ambientes. As sementes maiores foram as mais removidas, independente de sua adaptação ao dispersor e do ambiente estudado. Os resultados obtidos sugerem que a exploração madeireira pode promover modificações na composição de espécies de formigas, sem, contudo, alterar sua diversidade (exceto de Pheidok). O sistema de exploração com baixo impacto é capaz de preservar a diversidade de espécies de Pheidole, garantindo quantitativamente, uma mobilização de sementes semelhante à de uma floresta primária. Por outro lado, a exploração convencional pode diminuir a diversidade deste gênero, resultando em um menor número de sementes removidas. Tal redução, possivelmente compromete a regeneração da floresta após a retirada da madeira. / Logging in the Amazon Forest affects approximately 1.5 million hectares of forestlands each year. These activities result in forest structural and microclimatic changes that could potentially affect diversity and animal species composition. Regeneration of these areas could be jeopardized since animals disperse most seeds. On the other hand, it is possible not to affect seed dispersal mechanisms by maintaining forest fauna integrity through the implementation of reduced impact logging techniques. By using ants as an ecologically representative animal group and integrated into the regeneration processes through dispersion and predation, this work evaluated; (1) if logging affects fauna (diversity and species composition), (2) if reduced impact logging techniques are capable of preserving it, and (3) if logging affects ants ecological efficiency in seed removal (dispersion and predation). Logging effects on ants' diversity and species composition, as well as seed removal done by these insects, were studied in three different forest areas in the municipality of Paragominas in the state of Pará. The first area was a forest that went through high impact logging (FC), the second a forest affected by reduced impact logging techniques (FB), and the third one a primary forest used as the control group (FP). Ants’ were sampled four times during 1998 using the Winkler method at four transects per area. The seed removal experiment was conducted by distributing seeds of six wood species through twelve points in each area. During the experiment the daily number of ants and other arthropods that visited the seed points was quantified. The amount of seeds removed was counted at the end of the experiment. Diversity and abundance of ant species were not affected by logging activities. However, species composition changed by 36% in FB and by 37% in FC. The Pheidole genus experienced richness and abundance reduction only in FC. Seed removal was also significantly lower (-33%) in FC compared to the ones registered in FB and FP. Ants represented 92% of all arthropods that visited the seed points in the three forest areas. The bigger seeds were the most removed ones, independently of its seed disperser adaptations and of the studied forest area. The results obtained suggest that forest logging can affect ant species composition, without affecting its diversity (except that of Pheidole). Reduced impact logging techniques have the capacity of preserving Pheidole species diversity, which guarantees seed movements similar to those of a primary forest. Nevertheless, conventional logging can reduce, both the number of species and occurrences of this genus, thus resulting in a reduced number of removed seeds. Such reduction probably jeopardizes forest regeneration after wood extraction.

The main objective of this study was to examine the abundance and diversity of ants in suburban sites following vegetation removal or modification for development. This research examines the capacity of suburban sites to support ant diversity, which is dependent on the site characteristics and their surrounding environment. The study focused on 29 suburban garden and 3 suburban reserve sites on the Gold Coast, Queensland, Australia. This region, through continuing land development, undergoes ongoing habitat disturbance and modification. Ground-dwelling ants were collected by pitfall trapping in study sites over three summers between 1997 and 1999. In total, 28,512 ants from 60 species in 31 genera were collected. Garden sites that maintain vegetation structural diversity were found to be most similar to reserve sites in terms of ant community composition. These sites were highest in ant richness and diversity and contained particularly high proportions of specialized ant species. Sites in close proximity to remnants of native vegetation contained higher species diversity and a greater proportion of specialized ant species. The introduced tramp ant, Pheidole megacephala was found in 28 of the 32 sites and was found to significantly reduce ant species richness and diversity and displace the dominant ant Iridomyrmex sp. 1 in suburban environments. This ant poses a serious threat to the recovery of a diverse ant fauna to suburban environments. Ant community composition was shown to vary significantly among suburban sites. The ant functional groups commonly found in disturbed sites were abundant in open sites with little canopy cover in this study. Sites that provided vegetation structural diversity and areas of closed canopy supported similar functional groups to natural vegetation remnants. These results indicate that ant communities in suburban environments respond to disturbance in a similar manner to ant communities in tropical forests and rainforests. The dominance by functional groups and presence of specialized species may therefore be used as an indicator of disturbance and the restoration of suitable habitat in suburban sites. The presence of specialized species of ants in suburban garden sites and their clear preference for particular site characteristics indicate that these species utilize resources available in the suburban matrix. These results indicate that residential suburban sites are of value in the enhancement of ant diversity in fragmented landscapes and that they may provide supportive habitat to, and act as corridors between, vegetation fragments. In order to preserve biodiversity within suburban environments, landowners should be advised to retain as much existing vegetation within a site as possible. Clearing should be limited to that necessary to allow construction of dwellings and for safety. In addition, landowners should be encouraged to establish or maintain structurally diverse vegetation layers within sites in order to provide diverse microenvironments for fauna habitat.

Thesis (PhD)--Stellenbosch University, 2013. / ENGLISH ABSTRACT: Invasive species are among the most important global conservation threats. Their management is one of the key conservation challenges that will have to be addressed in the next few decades. The study of real invasions and their management in natural ecosystems provides an opportunity to gain important information on theoretical and applied aspects of biological invasions. This project focuses on the broader ecological context of invasive ant management in an ecologically sensitive island habitat. The thesis has three main components: 1) assessing the role of the invasive ant Pheidole megacephala in the ecosystem and evaluating its threat to the system, 2) evaluating a low-impact management program for the ant, and 3) using a community-level approach to assess ecosystem response to ant removal. The ant occupied almost 30% of the island‘s total land area and reached extremely high densities in some areas. The ant was associated with exotic hemipteran scale insects through trophobiotic mutualisms that facilitated high ant and hemipteran abundances. The highly destructive scale insect Pulvinaria urbicola was among the hemipterans that benefited from ant attendance. High levels of hemipteran feeding resulted in dieback of functionally important and threatened native Pisonia trees, which represented a significant threat to the forest ecosystem. A management program was initiated in response to this threat, consisting of baiting with selective hydramethylnon-based bait delivered in bait stations, accompanied by detailed pre-and post-baiting monitoring. The method was highly effective at suppressing the ants, whilst preventing bait uptake by non-target organisms. It was also cost-effective and adaptable to ant density in the field, but was only effective over short distances. The method may be applicable to other sensitive environments with similar challenges. After ant control, the ant-scale mutualism was decoupled and the Pu. urbicola population collapsed. There were variable responses in different taxa to the removal of these highly abundant exotic species, the most important of which was the recovery in Pisonia trees. Shoot condition and foliage density improved and there was a decrease in sooty mold. Herbivory on Pisonia increased due to recovery of native canopy herbivores, but the overall impact was far less than that of the exotic hemipterans. Soil surface arthropods, a group that may have been vulnerable to the treatment method, were unaffected by baiting. Instead, they increased significantly after ant removal, confirming the ant‘s impact on other arthropods. Other ant diversity and non-ant arthropod abundance increased post-baiting, including the endemic ant Pheidole flavens farquharensis and some functionally important insects such as the Indian cockroach. Natural enemies that interacted predictably with the mutualists were influenced by management. Predators of hemipterans increased significantly after ant removal and were instrumental in the scale population collapse, whereas parasitoids of hemipterans that benefited from the mutualism declined. Additionally, groups that were unrelated to the mutualism were indirectly influenced by management. The natural enemy assemblage as a whole showed recovery to pre-invasion conditions. The study shows how widely interconnected and influential the ant was in the ecosystem. It highlights the threat of the species in natural systems as well as the complex responses following invasive ant removal. Yet, it also demonstrates the potential to safely and effectively manage the species, thereby raising the opportunity for ecosystem recovery. / AFRIKAANSE OPSOMMING: Indringerspesies is van die belangrikste globale bedreigings vir natuurbewaring. Hulle bestuur is van die grootste bewaringsuitdagings wat in die volgende paar dekades aangespreek moet word. Die studie van werklike invalle en hul bestuur in natuurlike ekosisteme bied 'n geleentheid om belangrike inligting te verkry oor teoretiese en toegepaste aspekte van biologiese indringing. Hierdie projek fokus op die breër ekologiese konteks van uitheemse mier bestuur in 'n ekologies sensitiewe eiland habitat. Die tesis het drie hoofkomponente: 1) die beoordeling van die rol van die indringer mier Pheidole megacephala in die ekosisteem en evaluering van sy bedreiging vir die sisteem, 2) die evaluering van 'n lae-impak bestuursprogram vir die mier, en 3) die gebruik van 'n gemeenskaps-vlak benadering om ekosisteem reaksie op mierverwydering te assesseer. Die mier het byna 30% van die totale landoppervlak van die eiland beslaan en het in party areas baie hoë digthede bereik. Die mier was geassosieer met uitheemse dopluis spesies in mutualismes wat hoë mier en dopluis getalle gefasiliteer het. Die hoogs beskadigende dopluis Pulvinaria urbicola was een van die spesies wat bevoordeel is deur die mutualisme. Hoë vlakke van dopluis voeding het die terugsterwe van funksioneel belangrike, bedreidge inheemse Pisonia bome veroorsaak, wat ʼn groot bedreiging vir die ekosisteem verteenwoordig het. ‗n Bestuursprogram is geïmplimenteer as gevolg van hierdie bedreiging, wat bestaan het uit selektiewe hidrametielnoon-gebaseerde lokaas wat in die veld geplaas is in lokaashouers, vergesel deur intensiewe monitering voor en na lokaasplasing. Die metode was hoogs effektief in die onderdrukking van die miere en het lokaasinname deur nie-teiken organismes verhoed. Dit was ook koste-effektief en aanpasbaar volgens mierdigtheid in die veld, maar was slegs effektief oor kort afstande. Die metode mag van toepassing wees in ander sensitiewe omgewings met soortgelyke uitdagings. Na mierbeheer is die mier-dopluis mutualisme ontkoppel en die Pu. urbicola bevolking het drasties verminder. Daar was verskillende reaksies in verskillende taxa tot die verwydering van die oorvloedryke eksotiese spesies, maar die belangrikste reaksie was die herstel van Pisonia bome. Spruittoestand en blaardigtheid het verbeter en daar was ʼn afname in roetskimmel. Herbivorie op Pisonia het toegeneem as gevolg van ʼn herstel in inheemse herbivore, maar die algehele impak was veel minder as dié van die eksotiese dopluis. Grondoppervlak gelidpotiges, 'n groep wat kwesbaar kon wees vir die behandelingsmetode, was onaangeraak deur die lokaas, maar het beduidend na mierverwydering vermeerder. Mierdiversiteit het vermeerder en die Seychelles endemiese mier Pheidole flavens farquharensis is hervestig. Ander gelidpotiges het ook vermeerder, insluitend funksioneel belangrike spesies soos die Indiese kakkerlak. Natuurlike vyande wat geassosieer was met die mutualiste is beïnvloed deur die mierbestuur. Predatore van dopluis het beduidend toegeneem na mierverwydering en was hoogs betrokke by die vermindering van dopluis, terwyl parasiete van dopluis, wat voordeel getrek het uit die mutualisme, gedaal het. Daarbenewens is groepe wat onverwant was aan die mutualisme indirek beïnvloed deur mierbestuur. Die algehele natuurlike vyand gemeenskap het herstel na pre-indringing toestand. Die studie toon hoe wydverbind en invloedryk die mier was in die ekosisteem. Dit beklemtoon die bedreiging van die spesies in natuurlike stelsels asook die komplekse reaksies wat uitheemse mierverwydering volg. Tog demonstreer dit die potensiaal om die spesies veilig en doeltreffend te bestuur, en sodoende die geleentheid vir ekosisteemherstel te skep.