京都大学 / 0048 / 新制・課程博士 / 博士(地球環境学) / 甲第21236号 / 地環博第172号 / 新制||地環||35(附属図書館) / 京都大学大学院地球環境学舎地球環境学専攻 / (主査)教授 山下 洋, 教授 柴田 昌三, 教授 宮下 英明 / 学位規則第4条第1項該当 / Doctor of Global Environmental Studies / Kyoto University / DFAM

As interações tróficas de 31 espécies de peixes e 2 de lulas da Baía do Araçá, São Sebastião (SP), foram investigadas por meio dos isótopos estáveis de carbono (δ13C) e nitrogênio (δ15N). Os valores de δ13C das espécies variaram entre -17,2‰ e -12,1‰, e os de δ15N, entre 10,0‰ e 14,5‰. Os valores de δ13C dos produtores e consumidores permitiram indicar que as espécies analisadas participam das teias tróficas, pelágica e bentônica, e têm como base da cadeia alimentar o fitoplâncton, os microfitobentos e a matéria orgânica dos sedimentos. Maiores valores de δ13C nos peixes e lulas foram registrados no verão, associados a valores mais altos na base. As posições tróficas das espécies variaram entre 3,18 e 4,72, indicando que atuam como consumidores secundários e terciários. A composição da dieta dos peixes, avaliada pelo modelo de mistura isotópica, apontou elevada contribuição de presas como Polychaeta, Tanaidacea e Ophiuroidea, grupos com alta abundância na Baía do Araçá e no Canal de São Sebastião. A ingestão de presas disponíveis no interior da baía e no canal evidenciou a importância desses peixes e lulas como carreadores de nutrientes, realizando tanto acoplamento pelágico-bentônico, como entre as regiões sublitoral e entremarés da Baía do Araçá. / The trophic interactions of 31 fish species and 2 squid species of the Araçá Bay, São Sebastião (São Paulo, Brazil), were investigated through carbon (δ13C) and nitrogen (δ15N) stable isotopes. The δ13C of the species ranged from -17.2‰ to -12.1‰, and the δ15N, from 10.0‰ to 14.5‰. The δ13C data of the producers and consumers indicated that the species analysed are part of the pelagic and benthic trophic webs, and have phytoplankton, microphytobenthos and organic matter from the sediment as the base of the food web. Higher values of δ13C were registered in the summer, linked to the higher values at the base. The trophic positions of the species varied between 3.18 e 4.72, an indication that they act as secondary and tertiary-quaternary consumers. The diet composition of fish, evaluated trough the isotope mixing model, showed high contribution of prey, such as Polychaeta, Tanaidacea and Ophiuroidea, groups highly abundant in the Bay and the adjacent São Sebastião Channel. The intake of available prey in the intertidal region and in the Channel revealed the importance of the fish and squid as nutrient pathway links, coupling the pelagic-benthic systems and the sublittoral and intertidal regions of the Araçá Bay.

As interações tróficas de 31 espécies de peixes e 2 de lulas da Baía do Araçá, São Sebastião (SP), foram investigadas por meio dos isótopos estáveis de carbono (δ13C) e nitrogênio (δ15N). Os valores de δ13C das espécies variaram entre -17,2‰ e -12,1‰, e os de δ15N, entre 10,0‰ e 14,5‰. Os valores de δ13C dos produtores e consumidores permitiram indicar que as espécies analisadas participam das teias tróficas, pelágica e bentônica, e têm como base da cadeia alimentar o fitoplâncton, os microfitobentos e a matéria orgânica dos sedimentos. Maiores valores de δ13C nos peixes e lulas foram registrados no verão, associados a valores mais altos na base. As posições tróficas das espécies variaram entre 3,18 e 4,72, indicando que atuam como consumidores secundários e terciários. A composição da dieta dos peixes, avaliada pelo modelo de mistura isotópica, apontou elevada contribuição de presas como Polychaeta, Tanaidacea e Ophiuroidea, grupos com alta abundância na Baía do Araçá e no Canal de São Sebastião. A ingestão de presas disponíveis no interior da baía e no canal evidenciou a importância desses peixes e lulas como carreadores de nutrientes, realizando tanto acoplamento pelágico-bentônico, como entre as regiões sublitoral e entremarés da Baía do Araçá. / The trophic interactions of 31 fish species and 2 squid species of the Araçá Bay, São Sebastião (São Paulo, Brazil), were investigated through carbon (δ13C) and nitrogen (δ15N) stable isotopes. The δ13C of the species ranged from -17.2‰ to -12.1‰, and the δ15N, from 10.0‰ to 14.5‰. The δ13C data of the producers and consumers indicated that the species analysed are part of the pelagic and benthic trophic webs, and have phytoplankton, microphytobenthos and organic matter from the sediment as the base of the food web. Higher values of δ13C were registered in the summer, linked to the higher values at the base. The trophic positions of the species varied between 3.18 e 4.72, an indication that they act as secondary and tertiary-quaternary consumers. The diet composition of fish, evaluated trough the isotope mixing model, showed high contribution of prey, such as Polychaeta, Tanaidacea and Ophiuroidea, groups highly abundant in the Bay and the adjacent São Sebastião Channel. The intake of available prey in the intertidal region and in the Channel revealed the importance of the fish and squid as nutrient pathway links, coupling the pelagic-benthic systems and the sublittoral and intertidal regions of the Araçá Bay.

North American grassland birds show long-term population declines that generally exceed the declines of other bird groups. Efforts to conserve grassland birds require knowledge of diet and habitat requirements during both the breeding and nonbreeding periods of annual life cycles. This dissertation investigated sparrow habitat associations within two defined plant communities of the dry prairie ecosystem, the dry-mesic and wet-mesic prairie, for four prescribed fire treatments over two consecutive winters. Grasshopper and Henslow’s sparrows showed higher relative abundance in wet-mesic prairie and Bachman’s Sparrows were more abundant in dry-mesic prairie across all fire treatments. Abundances of Grasshopper and Bachman’s sparrows were best predicted by plant community association and secondly by time since fire; whereas for Henslow’s Sparrows, habitat and time since fire were equally important. Fall molt-period diets and diet overlap were modeled for resident Florida Grasshopper and Bachman’s sparrows using stable carbon and nitrogen isotope ratios of bird feathers and potential food sources, e.g., arthropods and seeds. Grasshoppers (Orthoptera, including a variety of species foraging on both C3 and C4 herbs), spiders, dragonflies, flies, beetles and weevils comprised the majority of the diets of adult and juvenile Florida Grasshopper Sparrows and Bachman’s Sparrows, but in differing proportions. Despite the similarity in reconstructed diets for the two sparrow species, analysis of diet overlap suggested that approximately half of the Florida Grasshopper Sparrows had diets consisting of higher trophic level prey than Bachman’s Sparrows. Winter diets and diet overlap among Grasshopper, Henslow’s, and Bachman’s sparrows were reconstructed using stable carbon and nitrogen isotope ratios of feathers and potential arthropod and seed food sources. Sparrows were captured and recaptured in winter iv 2007-2008 using systematic flush-netting, removing a tail feather at first capture and then removing the regrown feather when birds were recaptured. Winter diets of all three sparrows included a variety of arthropods, grass seeds, and sedge seeds, but Bachman’s Sparrow winter diets spanned greater trophic diversity than either of the migratory sparrows. Estimated diets of Henslow’s and Grasshopper sparrows differed from that of Bachman’s Sparrow but Henslow’s Sparrow diets did not differ from Grasshopper Sparrow diets. This is the first study of fall and winter sparrow diets in Florida based on stable isotopes and the first study in peninsular Florida on habitat associations of ground-dwelling sparrows.

Social Impact Assessment (SIA) identifies the intended and unintended impacts that proposed projects or developments are likely to have on a community or individuals and suggest mitigation measures to prevent these impacts and enhance the positive impacts. The main aim of this dissertation is to explore the significance and the status of SIA in a South African context. EIA is currently in its third era of mandatory practice and with an increasing number of SIAs, it is essential that the practice of SIA should be investigated. The aim of this dissertation was firstly reached by exploring the perspectives of SIA practitioners in South Africa through a questionnaire. The practitioners’ perspectives showed that despite distinct weaknesses in the practice of SIA, i.e. the lack of a fixed set of guidelines and a shortage of SIA skill in the practitioner community, SIA practice has improved since 1997 with the promulgation of ECA, although there is still room for improvement. Secondly a quality review was conducted on a sample of SIARs in South Africa using an adapted review package. The results revealed relatively weak report quality compared to EIA report quality, but with an improvement, in report quality since 1997. The quality review findings appear to confirm the perspectives of the practitioners regarding the state of SIA practice in South Africa. Despite the weaknesses in the SIA process, it appears that the SIA practitioner community is driven by best practice considerations, and that SIA practice is in line with international trends. It appears therefore that despite the observed weaknesses, SIA practice in South Africa is relatively healthy. It is recommended that instead of seeking to strengthen SIA practice by means of regulation and guidelines, SIA practitioners should rather ensure that SIA delivers what it is intended to deliver by ongoing pursuance of best practice, and by improved training and skills development. / Thesis (MSc (Geography and Environmental Studies))--North-West University, Potchefstroom Campus, 2013

Social Impact Assessment (SIA) identifies the intended and unintended impacts that proposed projects or developments are likely to have on a community or individuals and suggest mitigation measures to prevent these impacts and enhance the positive impacts. The main aim of this dissertation is to explore the significance and the status of SIA in a South African context. EIA is currently in its third era of mandatory practice and with an increasing number of SIAs, it is essential that the practice of SIA should be investigated. The aim of this dissertation was firstly reached by exploring the perspectives of SIA practitioners in South Africa through a questionnaire. The practitioners’ perspectives showed that despite distinct weaknesses in the practice of SIA, i.e. the lack of a fixed set of guidelines and a shortage of SIA skill in the practitioner community, SIA practice has improved since 1997 with the promulgation of ECA, although there is still room for improvement. Secondly a quality review was conducted on a sample of SIARs in South Africa using an adapted review package. The results revealed relatively weak report quality compared to EIA report quality, but with an improvement, in report quality since 1997. The quality review findings appear to confirm the perspectives of the practitioners regarding the state of SIA practice in South Africa. Despite the weaknesses in the SIA process, it appears that the SIA practitioner community is driven by best practice considerations, and that SIA practice is in line with international trends. It appears therefore that despite the observed weaknesses, SIA practice in South Africa is relatively healthy. It is recommended that instead of seeking to strengthen SIA practice by means of regulation and guidelines, SIA practitioners should rather ensure that SIA delivers what it is intended to deliver by ongoing pursuance of best practice, and by improved training and skills development. / Thesis (MSc (Geography and Environmental Studies))--North-West University, Potchefstroom Campus, 2013