Land use dynamics under the Bolsa Floresta Program: a case study of the Uatumã Sustainable Development Reserve (Amazonas, Brazil)

Original ArticleThe effectiveness of a program of payment for environmental services (PES) in the Brazilian Amazon was analyzed through an accurate mapping of deforested areas. The Bolsa Floresta Program (BFP) in Amazonas state (Brazil) was chosen as an example of a PES program that aims to compensate farmers for their commitment to zero deforestation of primary forests while opening swiddens only in secondary vegetation areas. However, the official measurement of opened swiddens is not effective since only deforested areas larger than 6.25 ha are mapped, whereas most areas opened for cassava crops are approximately 1 ha in size. The effectiveness of the BFP was evaluated in the Uatumã Sustainable Development Reserve (SDR). We tested a methodology for mapping areas from 0.45 ha upwards that have been opened for cassava swiddens. The years 2006 (before the implementation of the BFP), 2011, 2015 and 2019 were analyzed. The results indicated that 88% of the areas opened for swiddens were between 0.45 and 6.25 ha in size. After the implantation of the BFP, the cumulative total deforested area decreased, and there was a reduction in deforested areas in primary forests. An intensification of swidden cultivation was also observed, which could cause a decline in productivity. The monitoring by land-use zoning showed that the majority of opened areas were located in intensive use zones, following the rules of the SDR management plan. The results show the efforts of local families to fulfill the BFP rulesinfo:eu-repo/semantics/publishedVersio

Soil erosion from hilltribe opium swiddens in the golden triangle, and the use of karren as an erosion yardstick

[cat] El tipus de cultiu itinerant realitzat per les tribus de les muntanyes així com la cremada regular dels boscos en les àrees productores d'opi del Triangle d'Or, són responsables de seriosos danys en els recursos del sol. L'estudi de les formes exhumades de lapiaz, que presumiblement s'han desenvolupades sota la superfície en lloc de fer-ho en condicions subaèries, es presenta com a prometedor mitja per documentar l’erosió del sol; no obstant això hi ha molts de problemes que romanen sense resoldre, el que fa que encara no es puguin aconseguir resultats segurs.[eng] Shifting cultivation by hilltribes and regular burning of the forests in opium-producing areas of the Golden Triangle is responsible for serious damage to the mil resources. The study of exposed karren forms that are assumed to have developed under subsurface rather than subaerial conditions has come promise as a means of documenting soil erosion, although serious problems remain to be resolved before reliable results can be achieved

Monoculture, Polyculture, and Polyvariety in Tropical Forest Swidden Cultivation

A number of researchers have suggested that polyculture is characteristic of native tropical forest swiddens and have adduced theory from community ecology to account for its adaptiveness. Ye’kwana and Yąnomamö swidden cultivation is examined, and it is shown that polyculture is not practiced to any significant degree. Instead, the concept of polyvariety is introduced along with a number of other cultivation practices that more simply account for the adaptiveness of Ye’kwana and Yąnomamö gardening. In addition, comparative data from other parts of the tropical world indicate that polyculture is no more common than monoculture and recent advances in ecological research indicate that the diversity-stability hypothesis that underpins adaptive arguments of polyculture is in need of drastic revision

An agent-based simulation of land-use in a swidden agricultural landscape of the Kantu' in Kalimantan, Indonesia

CD-ROM contains the appendices. Append.1. User interface -- Append.2. Program documentation -- Append.3. Complete program coding -- Append.4. Thesis document (Electronic text of thesis

Culture, Envionment, and Farming Systems in Vietnam's Northern Mountain Region

この論文は国立情報学研究所の学術雑誌公開支援事業により電子化されました

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

Indigenous agroforestry in Latin America: A blueprint for sustainable agriculture?

Large-scale rainforest destruction in Latin America has occurred partly as a result of government policy incentives to colonize and clear forest for agriculture and ranching, in order to alleviate poor economic and social conditions in other regions. Inappropriate agricultural techniques have been used which are not sustainable, and the new colonist farmers are forced to clear ever more virgin forest for agriculture in order to survive. The objectives of this literature review are to assess the value of the traditional subsistence agroforestry (swidden) systems practised over centuries by the indigenous people of Latin America (Amerindians), and to suggest ways of incorporating these methods into a sustainable (non-destructive) and productive system for the new colonist farmers. In the past, researchers perceived these swidden methods as an exploitative and destructive form of agriculture, because they involved cutting and burning of the forest. However, clearings are small, and planting and protection of trees after the initial cultivation of annual crops aids the forest regrowth in the fallow phase. Specific examples of swidden agroforestry systems are described, and their contribution to sustainability, biodiversity, productivity for market, soil conservation, flexibility and population density support are discussed. Overall, they are found to be less destructive and more productive than the new colonist agriculture, and should form a basis for a sustainable system. The review then outlines the possibilities for and limits (often labour intensive, location-specific and socioeconomic constraints) to the adoption of these methods by new colonist farmers. Suggestions are made for research priorities to enable their effective transfer, including thorough documentation of existing systems and their capacity, participatory field research, the marketing potential for crops and forest products and the changes in government policy required to implement these methods. The review concludes that indigenous agroforestry systems are both ecologically and economically beneficial, but are not without some limitations. From the wealth of indigenous knowledge available and proposed new research, it should be possible to adapt these systems to produce a model or blueprint for sustainable and productive agriculture for the new colonist. Indigenous Agroforestry in Latin America: A Blueprint for Sustainable Agriculture? will not only be of interest to policy makers and donor agencies, but also to those interested in the preservation of the rainforests