114,450 research outputs found

    A global view of shifting cultivation: Recent, current, and future extent

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    Mosaic landscapes under shifting cultivation, with their dynamic mix of managed and natural land covers, often fall through the cracks in remote sensing–based land cover and land use classifications, as these are unable to adequately capture such landscapes’ dynamic nature and complex spectral and spatial signatures. But information about such landscapes is urgently needed to improve the outcomes of global earth system modelling and large-scale carbon and greenhouse gas accounting. This study combines existing global Landsat-based deforestation data covering the years 2000 to 2014 with very high-resolution satellite imagery to visually detect the specific spatio-temporal pattern of shifting cultivation at a one-degree cell resolution worldwide. The accuracy levels of our classification were high with an overall accuracy above 87%. We estimate the current global extent of shifting cultivation and compare it to other current global mapping endeavors as well as results of literature searches. Based on an expert survey, we make a first attempt at estimating past trends as well as possible future trends in the global distribution of shifting cultivation until the end of the 21st century. With 62% of the investigated one-degree cells in the humid and sub-humid tropics currently showing signs of shifting cultivation—the majority in the Americas (41%) and Africa (37%)—this form of cultivation remains widespread, and it would be wrong to speak of its general global demise in the last decades. We estimate that shifting cultivation landscapes currently cover roughly 280 million hectares worldwide, including both cultivated fields and fallows. While only an approximation, this estimate is clearly smaller than the areas mentioned in the literature which range up to 1,000 million hectares. Based on our expert survey and historical trends we estimate a possible strong decrease in shifting cultivation over the next decades, raising issues of livelihood security and resilience among people currently depending on shifting cultivation

    The impact of shifting cultivation in the forestry ecosystems of timor-leste

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    Every year thousands of hectares of forest are destructed as a result of the practice of swidden agriculture, shifting cultivation or "slush and burn" causing changes in forest ecosystems. In Timor- Leste shifting cultivation is still practiced nowadays as a form of subsistence agriculture. Swidden agriculture is characterized by slash and burn clearing, by a rotation of fields rather than of crops, and by short periods of cropping (1-3 years) alternating with long fallow periods. Based on the characterization of shifting cultivation in two Sucos of Bobonaro district, a reflection is made on the impact of this practice in the sustainable development of forest ecosystems of Timor- Leste. Primary data collection was performed using a questionnaire survey of farmers practicing shifting cultivation. The questionnaire characterized shifting cultivation, and asked farmers’ opinion on slash and burning of forest areas and on the importance of forests. According to the results obtained, in most situations the existing vegetation before the slash was composed of dense forest, the slash is made by the family group, the majority of farmers have been doing the “slush and burn” for more than ten years and the size of the plots where slash is made is less than 2 hectares. The materials resulting from the slash are used for firewood, building materials and fencing. The burning of vegetable residues is done before planting and soil preparation and sowing is done with a lever. Land and forest, despite having an individual use, have a tenure regime of ownership and access in which its nature of common pool good prevails. Every year thousands of hectares of forest are destructed as a result of the practice of swidden agriculture, shifting cultivation or "slush and burn" causing changes in forest ecosystems. In Timor-Leste shifting cultivation is still practiced nowadays as a form of subsistence agriculture

    Economic models of shifting cultivation: a review

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    This chapter reviews farm-level economic models of shifting cultivation and those of deforestation and soil conservation related to shifting cultivation. Although economists have made significant progress in modeling shifting cultivation over the last two decades, extant economic models neither clearly distinguish between primary and secondary forests nor address potential roles of on-farm soil conservation in shifting cultivation. Developing a unified farm model of primary forest clearing, forest fallowing, and on-farm soil conservation is needed to examine effective policies for protecting primary forest and maintaining sustainable secondary fallow forest. The chapter points to promising avenues for future modeling.

    Dynamics of Shifting Cultivation Landscapes in Northern Lao PDR Between 2000 and 2009 Based on an Analysis of MODIS Time Series and Landsat Images

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    The rotational nature of shifting cultivation poses several challenges to its detection by remote sensing. Consequently, there is a lack of spatial data on the dynamics of shifting cultivation landscapes on a regional, i.e. sub-national, or national level. We present an approach based on a time series of Landsat and MODIS data and landscape metrics to delineate the dynamics of shifting cultivation landscapes. Our results reveal that shifting cultivation is a land use system still widely and dynamically utilized in northern Laos. While there is an overall reduction in the areas dominated by shifting cultivation, some regions also show an expansion. A review of relevant reports and articles indicates that policies tend to lead to a reduction while market forces can result in both expansion and reduction. For a better understanding of the different factors affecting shifting cultivation landscapes in Laos, further research should focus on spatially explicit analyse

    No-till cultivation suppresses broad-leaved weeds but favours grasses

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    When shifting from traditional ploughing to no-till cultivation there will be new possibilities to weeds. However, the changes in weed population are more dependent on each field than on cultivation method. We had two field trials in southern Finland (Jokioinen and Mietoinen) on heavy clay for four years (2001-2004). The main treatment was direct seeding or conventional sowing after autumn ploughing combined with spring rotary hoeing

    Socio-Economic Perspectives on Shifting Cultivation Landscapes in Northern Laos

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    Despite the rapid agricultural transition that has occurred in the past decade, shifting cultivation remains a widespread agricultural practice in the northern uplands of Lao PDR. Little information is available on the basic socio-economic situation and respective possible patterns in shifting cultivation landscapes on a regional level. On the basis of a recent approximation of the extent of shifting cultivation landscapes for two time periods and disaggregated village level census data, this paper characterizes these landscapes in terms of key socioeconomic parameters for the whole of northern Laos. Results showed that over 550,000 people live in shifting cultivation regions. The poverty rate of this population of 46.5% is considerably higher than the national rural rate. Most shifting cultivation landscapes are located in remote locations and a high share of the population comprises ethnic minorities, pointing to multi-dimensional marginality of these areas. We discuss whether economic growth and increased market accessibility are sufficient to lift these landscapes out of povert

    Diversity of soil macroarthropods in shifting cultivation and forest ecosystem of Mizoram, Northeast India

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    Soil organisms are an integral part of agricultural ecosystems and are essential for the maintenance of healthy productive soils. Little is known about soil arthropods assemblages in shifting cultivation system. Therefore, we compared the diversity of soil macroarthropods in shifting cultivation (EXPTL) system and its adjacent natural forest (CTRL) ecosystem in Mizoram, northeast India and assessed the impact of shifting cultivation on the diversity. The study was conducted from 2013 to 2015, and the period was divided as pre-cultivation, cultivation and post-cultivation phases. Traditional shifting cultivation was practised in EXPTL site in the year 2014. Sampling was done by handpicking and digging from a quadrat (25×25×30 cm) located at least 10 m apart at monthly intervals. Specimens were preserved in 4% formalin and were identified up to the lowest possible taxa. A total of 97 taxa of arthropods belonging to five classes were recorded. 88 taxa and 48 taxa were recorded in CTRL and EXPTL respectively. Order-wise Shannon diversity index was significantly higher (p < .001) in CTRL as compared to EXPTL site. There were significant differences in both cultivation (p <.001) and post-cultivation (p <.001) phases between CTRL and EXPTL sites. There was a significant effect of shifting cultivation on the diversity of soil macroarthropods at the p <.05 level for the three cultivation phases in EXPTL site. Therefore, it was concluded that shifting cultivation system negatively affected soil macroarthropod diversity at least for a short duration. This study provided the first baseline data of soil macroarthropod diversity and its interaction with land-use system from Mizoram, northeast India

    Strategi Peladang Berpindah di Routa Dalam Rangka Menguatkan Klaim Hak Atas Tanah Bekas Areal Perladangan Berpindah di Masa Lalu

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    Claims of rights to land formerly shifting cultivation areas in the past, as referred to by the terms orawu, anahoma, laliwata and osambu are now increasingly ineffective - one of which is because the former shifting cultivation area has been abandoned for a long time where the trees have grown as usual, until hardly leaving the slightest sign of former swidden cultivation areas. As a result, lands in the former shifting cultivation areas in the past are now being taken over and controlled by other parties. This research, which lasted for six months, was conducted in Routa District, Konawe Regency, Southeast Sulawesi Province, considering that in this area a new phenomenon has developed in which land formerly cultivated areas in the past was re-opened by their descendants of current shifting cultivators in order to strengthen land rights claims. There are …. informants participated in this study, including shifting cultivators and descendants of shifting cultivators, government officials, and local law enforcers. Data collection techniques were carried out through interviews and observations. The study shows that the current strategy of the descendants of shifting cultivators in Routa is to re-open their parents' former shifting cultivation areas - this strategy is increasingly emphasized through planting growing crops, creating boundaries and legalizing land rights with both SKT and SHM. These strategies have proven to be quite successful in overcoming the encroachment of former shifting cultivation areas as well as providing new economic bases for shifting cultivators in the form of land and gardens

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

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    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
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