James Angus Fraser

Dark Earths and manioc cultivation in Central Amazonia: a window on pre-Columbian agricultural systems?

Many commentators highlight the fertility of Anthropogenic Dark Earths (ADE), emphasizing their potential for sustainable agriculture. Some scholars believe that terra mulata (the less fertile, more extensive form of ADE) was created by means of agricultural practices used by large settled populations of pre-Columbian farmers. But what was it that these Amerindian farmers were growing? Until recently, scholarly consensus held that manioc does not perform well on ADE. New research on the middle Madeira River is showing, however, that this consensus was premature. In this region, the most common crop in ADE fields is bitter manioc. Farmers there have various landraces of manioc that they believe yield particularly well on ADE, and logically plant more of these varieties on ADE. Aspects of the behaviour and perception of manioc cultivation among 52 farmers at the community of Barro Alto were measured quantitatively on four terra firme soil types (Terra Preta, Terra Mulata, Oxisols and Ultisols). These farmers plant different configurations of landraces in different soils, according to their perception of the suitability of particular landraces and their characteristics to certain soil types and successional processes. This, in turn, shapes selective pressures on these varieties, as new genetic material incorporated from volunteer seedlings is more likely to contain traits present in the most prevalent landrace(s) in each soil type. Owing to localized population pressure at Barro Alto, manioc is under more intensive cultivation systems, with shorter cropping periods (5-10 months) and shorter fallow periods (1-2 years). The outcome of these processes is different co-evolutionary dynamics on ADE as opposed to non-anthropogenic soils. Further anthropological study of manioc swiddening in one of the richest agricultural environments in Amazonia can fill a gap in the literature, thus opening an additional window on the pre-Columbian period.

Convergent adaptations: bitter manioc cultivation systems in fertile anthropogenic dark earths and floodplain soils in Central Amazonia.

Shifting cultivation in the humid tropics is incredibly diverse, yet research tends to focus on one type: long-fallow shifting cultivation. While it is a typical adaptation to the highly-weathered nutrient-poor soils of the Amazonian terra firme, fertile environments in the region offer opportunities for agricultural intensification. We hypothesized that Amazonian people have developed divergent bitter manioc cultivation systems as adaptations to the properties of different soils. We compared bitter manioc cultivation in two nutrient-rich and two nutrient-poor soils, along the middle Madeira River in Central Amazonia. We interviewed 249 farmers in 6 localities, sampled their manioc fields, and carried out genetic analysis of bitter manioc landraces. While cultivation in the two richer soils at different localities was characterized by fast-maturing, low-starch manioc landraces, with shorter cropping periods and shorter fallows, the predominant manioc landraces in these soils were generally not genetically similar. Rather, predominant landraces in each of these two fertile soils have emerged from separate selective trajectories which produced landraces that converged for fast-maturing low-starch traits adapted to intensified swidden systems in fertile soils. This contrasts with the more extensive cultivation systems found in the two poorer soils at different localities, characterized by the prevalence of slow-maturing high-starch landraces, longer cropping periods and longer fallows, typical of previous studies. Farmers plant different assemblages of bitter manioc landraces in different soils and the most popular landraces were shown to exhibit significantly different yields when planted in different soils. Farmers have selected different sets of landraces with different perceived agronomic characteristics, along with different fallow lengths, as adaptations to the specific properties of each agroecological micro-environment. These findings open up new avenues for research and debate concerning the origins, evolution, history and contemporary cultivation of bitter manioc in Amazonia and beyond.

Homegardens on Amazonian Dark Earths, Non-anthropogenic Upland and Floodplain Soils along the Brazilian Middle Madeira River Exhibit Diverging Agrobiodiversity

Homegardens on Amazonian Dark Earths, Non-anthropogenic Upland, and Floodplain Soils along the Brazilian Middle Madeira River Exhibit Diverging Agrobiodiversity. We test the hypothesis that the agrobiodiversity associated with homegardens on three different soils—upland Amazonian Dark Earths (ADE) and Oxisols (OX), and Fluvent Entisols (FL)—commonly found along the middle Madeira River in the municipality of Manicoré, Amazonas State, Brazil, is different due to the contrasting biotic, abiotic, and cultural settings specific to each of these soils. Using data from interviews with 63 farmers about food and utility species, we compare structural and floristic characteristics of homegarden agrobiodiversity. The density of individuals is higher on ADE than on the other soils (mean ± standard deviation: 715 ± 363 on ADE, 474 ± 283 on OX, 642 ± 399 on FL). ADE and OX have higher species richness (28.2 ± 5.6 on ADE, 25 ± 3.7on OX, 23.6 ± 5 on FL), while ADE and FL have a greater degree of domestication (2 ± 0.6 on ADE, 1.3 ± 0.5 on OX, 2.3 ± 0.6 on FL). ADE and OX have greater proportions of richness, density, and coverage composed of South American species, while FL has greater proportions of richness and density composed of Old World species. ADE has higher proportions of density and coverage of Mesoamerican species. Floristic composition is also different between soils: ADE occupies an intermediate position, composed of species associated with each of the other soil types and species that are most common on ADE. These differences in agrobiodiversity emerge through the interaction of human agency, plant responses, and the unique properties of soils in relation to socioeconomic and historical trajectories over time.Quintais agroflorestais em solos antrópicos, solos não-antrópicos na terra firme e em solos de várzea ao longo do médio Rio Madeira divergem quanto à agrobiodiversidade. Nós testamos a hipótese de que a agrobiodiversidade associada a quintais em três diferentes tipos de solo—solos antrópicos (ADE), latossolos (OX) na terra firme, e gleissolos de várzea (FL)—comumente encontrados ao longo do médio Rio Madeira no município de Manicoré, Amazonas, Brasil, é diferente devido às características bióticas, abióticas e culturais específicas de cada um desses solos. Utilizando dados de entrevistas com 63 agricultores sobre espécies comestíveis e úteis nós comparamos características florísticas e estruturais da agrobiodiversidade de quintais agroflorestais. A densidade de indivíduos é maior em ADE do que em outros tipos de solo (média ± desvio padrão: 715 ± 363 em ADE, 474 ± 283 em OX, 642 ± 399 em FL). ADE e OX possuem maior riqueza de espécies (28.2 ± 5.6 em ADE, 25 ± 3.7em OX, 23.6 ± 5 em FL), enquanto ADE e FL possuem um maior grau de domesticação (2 ± 0.6 em ADE, 1.3 ± 0.5 em OX, 2.3 ± 0.6 em FL). ADE e OX têm maiores proporções de riqueza, densidade e cobertura compostas de espécies Sul-Americanas, enquanto FL têm maiores proporções de riqueza e densidade compostas de espécies do Velho Mundo. ADE possui maiores proporções de densidade e cobertura de espécies Mesoamericanas. A composição florística também é diferente entre os tipos de solo: ADE ocupa uma posição intermediária, composta por espécies associadas a cada um dos outros tipos de solo e espécies que são mais comuns em ADE. Essas diferenças na agrobiodiversidade emergem a partir da interação entre ação humana, respostas das plantas e propriedades dos solos em relação às trajetórias sócio-econômicas e históricas ao longo do tempo.

Anthropogenic Dark Earths in the Landscapes of Upper Guinea, West Africa: Intentional or Inevitable?

Drawing on the recent identification of anthropogenic dark earths (ADEs) in West Africas Upper Guinea forest region, this article engages with Amazonian debates concerning whether such enriched soils were produced intentionally or not. We present a case study of a Loma settlement in Northwest Liberia in which ethnography, oral history, and landscape mapping reveal subsistence practices and habitus that lead African dark earths (AfDEs) to form inevitably around settlements and farm camps. To consider the question of intentionality and how the inevitability of AfDE is experienced, we combine historical and political ecology with elements of nonrepresentational theory. The former show how the spatial configuration of AfDEs in the landscape reflect shifting settlement patterns shaped by (1) political and economic transformations, mediated by (2) enduring ritual practices and social relations between first-coming and late-coming social groups that are symbolically related as uncles and nephews. We use nonrepresentational theory to show how the Loma phenomenological experience of these soils and their origins is better conceptualized in terms of sensual objects, the formation of which is inflected by these social and political processes. We thus reframe the debate away from intentionality, to theorize enriched anthropogenic soils and landscapes in terms of shifting sociocultural, political, and historical factors interplaying with the practical, sensually experienced, and inevitable effects of everyday life.

Cultural valuation and biodiversity conservation in the Upper Guinea Forest, West Africa

The cultural valuation of biodiversity has taken on renewed importance over the last two decades as the ecosystem services framework has become widely adopted. Conservation initiatives increasingly use ecosystem service frameworks to render tropical forest landscapes and their peoples legible to market-oriented initiatives such as REDD+ and biodiversity offsetting schemes. Ecosystem service approaches have been widely criticized by scholars in the social sciences and humanities for their narrow focus on a small number of easily quantifiable and marketable services and a reductionist and sometimes simplistic approach to culture. We address the need to combine methods from each of the “three cultures” of natural science, quantitative social science, and qualitative social science/humanities in conceptualizing the relationship between cultural valuation and biodiversity conservation. We combine qualitative data with forest inventories and a quantitative index of cultural value to evaluate the relationship between cultural valuation and biodiversity conservation in Upper Guinea forest in Liberia, West Africa. Our study focuses on “sacred agroforests,” spaces that are associated with Mande macro-language speaking groups such as the Loma. We demonstrate that sacred agroforests are associated with different cultural values compared with secondary forests. Although biodiversity and biomass are similar, sacred agroforests exhibit a different species composition, especially of culturally salient species, increasing overall landscape agro-biodiversity. Sacred agroforests are also shaped and conserved by local cultural institutions revolving around ancestor worship, ritual, and the metaphysical conceptual category “salɛ.” We conclude that to understand the relationship between cultural valuation and biodiversity conservation, interpretivist approaches such as phenomenology should be employed alongside positivist ecosystem service frameworks.

Amazonian peasant livelihood differentiation as mutuality-market dialectics

ABSTRACT Economistic approaches to the study of peasant livelihoods have considerable academic and policy influence, yet, we argue, perpetuate a partial misunderstanding – often reducing peasant livelihood to the management of capital assets by rational actors. In this paper, we propose to revitalize the original heterodox spirit of the sustainable livelihoods framework by drawing on Stephen Gudeman’s work on the dialectic between use values and mutuality on the one hand, and exchange values and the market on the other. We use this approach to examine how historically divergent mutuality-market dialectics in different Amazonian regions have shaped greater prominence of either extractivism or agriculture in current livelihoods. We conclude that an approach centered on the mutuality-market dialectic is of considerable utility in revealing the role of economic histories in shaping differential peasant livelihoods in tropical forests. More generally, it has considerable potential to contribute to a much-needed re-pluralization of approaches to livelihood in academia and policy.