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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.
1

Intera??o abelha-planta em sistemas agr?colas: for?as de intera??o e nichos tr?ficos

Carvalho, Danielle Mendes 04 February 2013 (has links)
Submitted by Ricardo Cedraz Duque Moliterno (ricardo.moliterno@uefs.br) on 2016-02-29T22:55:34Z No. of bitstreams: 1 Disserta??o Danielle Mendes Carvalho.pdf: 1158711 bytes, checksum: b9a8e1c6f59d19bb451209ed9144c6f5 (MD5) / Made available in DSpace on 2016-02-29T22:55:34Z (GMT). No. of bitstreams: 1 Disserta??o Danielle Mendes Carvalho.pdf: 1158711 bytes, checksum: b9a8e1c6f59d19bb451209ed9144c6f5 (MD5) Previous issue date: 2013-02-04 / Funda??o de Amparo ? Pesquisa do Estado da Bahia - FAPEB / Different strategies of resource exploitation can lead to divergences in species niche realized. Niche differentiation may involve several niche dimensions, which can differ, especially in the diet, in space, and time. In this study, we measured the redundancy level or complementarity in the interaction network in a bee community associated with an agricultural system. The hypothesis is that the degree of trophic overlap on the diet axis in the community is low, with high complementarity, since there is difference in the resource supply over the vintages and, that the overlap on time axis is high with high redundancy at the time of the use of floral resources. The overlap niche on diet axis was low (NOih = 0.18) and 88% of pairs showed overlap values below 30%. Niche overlap on time axis was intermediate (NOih = 0.49), and 65% of pairs showed overlap values between 30 and 60%. The network analysis showed that the bees separate its niche on diet axis and presented additional intermediate specialization (H2 '= 0.46). And on the time axis (H2 '= 0.12) bees were considered generalists, with high temporal redundancy. When we tested whether environmental requirements determined the high redundancy at the time of use of floral resources, we verified that the temperature was not a guiding factor to structure the niche overlap in relation to the time of use. The results indicate that the low niche overlap on the diet axis and the intermediate overlap on the time axis should be reflecting the plurality of floral resources choices by different bee species, which used broad resource spectrum. / Diferentes estrat?gias de explora??o dos recursos podem levar a diverg?ncias no nicho realizado das esp?cies. Diferencia??es de nicho podem envolver diversas dimens?es do nicho, podendo diferir, sobretudo na dieta, no espa?o e no tempo. Neste estudo mensuramos o n?vel de redund?ncia ou complementaridade na rede de intera??o em uma comunidade de abelhas associada a um sistema agr?cola. Nossa hip?tese de trabalho ? que o n?vel de sobreposi??o tr?fica no eixo da dieta na comunidade seja baixo, com alta complementaridade, visto que h? diferen?a na oferta de recurso ao longo das safras e, que a sobreposi??o no eixo temporal seja alta com alta redund?ncia nos hor?rios de uso dos recursos florais. A sobreposi??o de nicho no eixo da dieta foi baixa (NOih= 0,18), e 88% dos pares apresentaram valores de sobreposi??o abaixo de 30%. A sobreposi??o de nicho no eixo temporal foi intermedi?ria (NOih= 0,49), e 65% dos pares apresentaram valores de sobreposi??o entre 30 e 60%. A an?lise de rede mostrou que as abelhas separam seu nicho no eixo da dieta e apresentaram especializa??o complementar intermedi?ria (H2?=0,46). E no eixo temporal (H2?=0,12) as abelhas foram consideradas generalistas, com alta redund?ncia temporal. Ao testarmos se requerimentos ambientais determinaram a alta redund?ncia nos hor?rios de uso dos recursos florais verificamos que a temperatura n?o foi um fator norteador para estruturar a sobreposi??o de nicho em rela??o ao hor?rio. Os nossos resultados indicam que a baixa sobreposi??o do nicho no eixo da dieta e a intermedi?ria sobreposi??o no eixo temporal devem ser reflexo da pluralidade das escolhas de recursos florais por diferentes esp?cies de abelhas, que utilizaram amplo espectro de recursos.

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