Researchers recognize the need to better understand the factors influencing indigenous land use in order to design sustainable tropical forest management programs. A key relationship that has been long overlooked in peasant societies is the one between communal labor access through social networks and land acquisition/accumulation. This study examines land distribution and labor patterns in traditional agriculture of a lowland and a upland community on the Maranon River near Iquitos, Peru. Data were gathered through household interviews (n=76) and field visits (n=396) between June and November 2001. Results reveal marked variations in access to land and communal labor between and within communities. Household age, initial land wealth and initial inputs of labor are crucial in explaining land and labor inequalities within villages. This research contributes to a better understanding of the factors that give rise to local heterogeneity in wealth holdings and livelihood strategies, necessary tools to promote conservation throughout the region and beyond.

No description available.

This ethnoecological study of the Makushi Amerindians of Amazonian Guyana explores the place of plants in the indigenous culture and cosmology. The North Rupununi, the homeland of the Makushi people, is a bioculturally diverse mosaic of neotropical savannahs, forests, and wetlands. As subsistence hunters, fishers, and horticulturalists, the Makushi live in a constant and dynamic interaction with their ecologically rich surroundings. Against the human-faunal bias latent in much Amazonian anthropology, I place plants firmly at the centre of analysis, a positioning that mirrors their centrality in the ethnographic context. Human-plant encounters explored herein include swidden agriculture, the cultivation of bitter cassava, the fermentation of cassava drinks using a domesticated fungus, the use of a category of charm plants, and the consumption of plant substances in shamanic ritual. With the Makushi, I emphasise the status of plants as living selves and agents of semiosis, occupying perspectives on the world in and outside of their interactions with human beings. In order to investigate ethno-theories of life, I attempt to understand the constitution of the person - and associated notions of body and soul - in the indigenous cosmology. Makushi ontology can be characterised as animic - though as I argue, it also incorporates naturalistic and analogic elements. Thus, it is poly-ontological. This study pursues a dual goal: first, to pay heed to the trans-specific domain of living entities revealed in the Makushi ethnoecology, and second, to rethink conventional symbolic frameworks characteristic of anthropological approaches to culture. I explore the application of a more robust approach to sign-flows in nature - Peircian ecosemiotics - that allows for the analysis of plant communication, birdcalls, insect stings, and leaf patterns, as well as human language. In tracing these interspecific webs of signification, conclusions are drawn about the varied ways in which Makushi people engage with and think about their living environment. At the same time, many Makushi multispecies engagements are based on the physical transfer of substances between bodies of different kinds. In order to better account for this pervasive 'substance logic', greater attention must be paid to indigenous notions of corporeality and personhood. In doing so, I propose a dual analytical model that takes both the flows of signs and the flows of substances as its combined objective. This approach enables new conclusions to be drawn about multispecies relationality in indigenous Amazonian cosmologies.

Ensemble simulations of smoke aerosol radiative effects with a regional climate model in the Amazon has been conducted to investigate the radiative effects of aerosols on clouds, rainfall, and circulation from dry to wet season. The results of the ensemble simulations suggest that the radiative effect of the smoke aerosols can reduce daytime surface radiative and sensible fluxes, the depth and instability of the planetary boundary layer (PBL), consequently the clouds in the lower troposphere in early afternoon in the smoke center, where the aerosols optical depth, AOD, exceeds 0.3. The aerosol radiative forcing also appears to weaken moisture transport into the smoke center and increase moisture transport and cloudiness in the region upwind to the smoke center, namely, the northern Amazon. Anomalous wind convergence over the equatorial western Amazon occurs to compensate the anomalous wind divergence in the southern Amazon, leading to an increase of both clouds and rainfall in that region. The increased atmospheric thermodynamic stability in Southern Amazonia also appears to block synoptic cyclonic activities propagated from extratropical South America, leading to an increased synoptic cyclonic activities and rainfall in southern Brazil, Paraguay and northern Argentina. Evidently, the dynamic response of the monsoon circulation plays a major role in determining the pattern of rainfall change induced by the radiative effect of the aerosols.

Land-use change, and in particular tropical deforestation, is the leading cause of species extinctions globally, and is the second most important source of CO2 emissions after fossil fuel combustion. I examine two policy-relevant questions that relate to tropical deforestation and land use change: (1) At regional scales, what biophysical and infrastructure-related factors are associated with deforestation? and (2) At a local scale, what are some of the impacts of land use change on above- and below-ground carbon stocks and on tree-species richness? The first question was examined for the Brazilian Amazon through spatially-explicit correlation analyses of deforestation and a series of predictor variables that included highways and roads, annual rainfall, dry season length, soil characteristics, site accessibility, and population density. The proximity of a site to roads and highways was the strongest predictor of deforestation, with more accessible sites more likely to be deforested. Dry season length was also a strong, positive predictor of deforestation. The results suggest that current plans to expand road infrastructure in Amazonia will have a significant impact on the forests of the areas transected. / The second question was examined in the context of a 3,198 ha area in Eastern Panama that is managed collectively by an Indigenous Embera community.

Thesis (Ph. D.)--University of California, Berkeley, 1992. / Includes bibliographical references (leaves 136-140).

No description available.

Studies were carried out in a lowland evergreen rain forest (LERF), on an ultisol, in the 'Reserva da Campina', 45 km north of Manaus, and in two facies of the highly distinct formation called heath forest, on spodosols. The spodosols had a layer of mor humus of thickness varying from nil in some parts in the smaller facies of heath forest (SHF) to 35 cm in the taller facies (THF). The overall aim was to investigate the forest soil biota and its role in nutrient turnover by comparing the SHF, THF and LERF. Microbial biomass, soil respiration and nitrogen transformation rates were measured in the three forest types in both wet and dry seasons. Field and laboratory fertilization experiments were made to investigate potential limiting nutrients for microorganisms and plants. The role of fine roots in decomposition and litter animal colonization was assessed in litter bag studies. SHF soils have a small microbial population with no net nitrification in any season. THF soils showed a variable microbial population adapted to high acidity, which immobilises nitrogen during the wet season, but which allows a net release during the dry season. LERF showed the most diverse population which causes mineralization and nitrification in both seasons. A bioassay with nutrient addition showed that the low pH, and nitrogen and sulphur supply were likely to be limiting nitrogen dynamics in all forest types, but especially in THF and LERF. The ingrowth bags showed that despite the lower values of fine root growth in the SHF (particularly when the white sand of the spodosol was used as the substrate), the roots showed in all plots an increased production with added calcium as carbonate or sulphate. In the decomposition bioassay to evaluate the role of roots in the nutrient turnover it was shown that in all forest types there was no effect of roots on the mass loss of Clitoria leaves but there was a significant effect on concentrations of some nutrients. In general, roots contributed to the accumulation of aluminium and iron and to a faster release and uptake of calcium, magnesium and zinc. A survey of the mycorrhizal associations in all forest types showed that both VAM and ECM fungi with some unknown VAM fungal species are common. VAM and ECM adaptation to low pH and high phenolic compounds in the soils may be important in the maintenance of these ecosystems.

Thesis (Ph. D.)--Michigan State University. Dept. of Geography, 2008. / Title from PDF t.p. (viewed on July 22, 2009) Includes bibliographical references (p. 228-249). Also issued in print.

Orientador: Marlene Tiduko Ueta / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Biologia / Made available in DSpace on 2018-08-10T15:50:42Z (GMT). No. of bitstreams: 1 Muller_MariaIsabel_M.pdf: 1399889 bytes, checksum: 00a4c6b6001aa09347a576d930cde5ce (MD5) Previous issue date: 2008 / Resumo: Coletas de tucunaré (Cichla monoculus) e matrinxã (Brycon amazonicus) foram feitas quinzenalmente nas duas lagoas da Fazenda Rio das Pedras, Campinas, SP, no período de junho de 2005 a setembro de 2006, com o objetivo de pesquisar a fauna helmintológica das espécies amazônicas introduzidas nestas lagoas. Um total de 38 tucunarés e 16 matrinxãs foram coletados, os quais foram levados para o laboratório de Helmintologia do Departamento de Parasitologia, IB, Unicamp, onde foi feita a biometria, determinados os sexos dos peixes e analisados os órgãos a procura de ecto e endoparasitos. No tucunaré, cestódeos adultos da espécie Proteocephalus microscopicus (Prevalência = 76,3%, Intensidade de infecção = 280,9 vermes/peixe, Abundância média = 214,5) e Bothriocephalus cuspidatus (P= 5,3%, I=2 vermes/peixe, A=0,10) apresentaram-se parasitando o intestino. Nos olhos foram encontrados metacercárias do gênero Diplostomum sp. (P=28,9%, I=4,36 larvas/peixe, A=1,26). Monogênea do gênero Notozothecium (P= 47,4%, I=2,33 vermes/peixe, A=1,10)foi encontrado parasitando as brânquias e o nematódeo adulto Procamallanus (Spirocamallanus) inopinatus no intestino, (P = 5,3%, I= 1 verme/peixe, A=0,05). Um típico padrão de distribuição agregada foi observado em P. microscopicus, além disso observou-se correlação negativa entre intensidade de infecção e comprimento dos peixes, mostrando que peixes menores albergaram maior número deste cestódeo. Ainda para P. microscopicus, a intensidade de infecção e a transparência da água apresentaram correlação positiva. Correlação negativa entre a prevalência da infecção e pH da água foi observado para Notozothecium sp., indicando maior presença de monogêneas em águas mais ácidas. A presença deste gênero de monogênea em Cichla monoculus pode evidenciar especificidade ecológica, pois é um parasita habitual de Serrasalmidae. A espécie Bothriocephalus cuspidatus ainda não foi descrita parasitando Cichla monoculus, sendo a primeira ocorrência deste parasita em tucunaré. No matrinxã foram encontrados nematódeos adultos de Procamallanus (S.) inopinatus no intestino (P= 56,3%, I = 1,44 vermes/peixe, A= 0,81) comumente encontrado nesta espécie e monogêneas não identificadas nas brânquias / Abstract: Samples of tucunaré (Cichla monoculus) and matrinxã (Brycon amazonicus) were collected biweekly in two lakes of Rio das Pedras farm, Campinas - SP, from June 2005 to September 2006 with the objective of researching the helminthological fauna of the Amazonian species introduced at these ponds. A total of 38 tucunarés and 16 matrinxãs were collected, taken to the Laboratory of Helminthology, Parasitology Department, Biology Institute, UNICAMP, where we made the biometry and sexed the fish and analyzed the organs, searching for ecto and endoparasites. In the tucunaré, adult cestodes of the species Proteocephalus microscopicus (Prevalence = 76.3%, Intensity of infection = 280.9 worms/fish, Mean Abundance = 214.5) and Bothriocephalus cuspidatus (P= 5.3%, I = 2 worms/fish, MA= 0.10) were found in the intestine. In the eyes we have found larvae of Diplostomum sp. (P= 28.9%, I = 4.36 larvae/fish, MA= 1.26). Monogenean Notozothecium sp. (P= 47.4%, I = 2.33, worms/fish, MA= 1.10) was found parasitizing the gills and the adult nematode Procamallanus (Spirocamallanus) inopinatus (P = 5.3%, I = 1 worms/fish, MA= 0.05) in the intestine. A typical pattern of aggregate distribution were observed in P. microscopicus; the infection intensity and host length were found to be negative correlated, showing that smaller fish housed larger number of P. microscopicus. Between infection intensity and transparency of the water, there was a positive correlation. Negative correlation were found between prevalence of the infection and the water pH for Notozothecium sp, indicating higher presence of monogeneans in more acid water, in Cichla monoculus this parasite can evidences ecological specificity, because this parasite is usual in the Serrasalmidae family. The species Bothriocephalus cuspidatus is not commonly found in the Cichla monoculus, been this one its first appearance. In the matrinxã we have found adult nematodes of the species Procamallanus (Spirocamallanus) inopinatus (P = 56.3%, I = 1.44 worms/fish, MA= 0.81) in the intestine, a commom nematode for this specie and unidentified monogeneans in the gills / Mestrado / Mestre em Parasitologia