The search was performed in January 2016 and generated 324 articles, which we then screened for data on numbers or estimates of global or national areas influenced by shifting cultivation. (2017) A global view of shifting cultivation: Recent, current, and future extent. In our classification the occurrence for shifting cultivation was estimated at a low level, meaning 1019%, which in this case was in line with the validation data set. Shifting cultivation causes a high national waste as it converts the green land into a barren land. of Energy, grant number DE-SC0012972, and the Global Land Project Grant from the University of Copenhagen. Our predictions of future extents of shifting cultivation are, of course, speculative. Using the data and approach described above, each one-degree cell was examined visually at various zoom levels (roughly 1:100000 but, if necessary, occasionally at larger scales) to determine whether it showed the very specific spatio-temporal signature of shifting cultivation (see Fig 1). On the other hand, large areas with shifting cultivation in Central Africa, for example in the Democratic Republic of the Congo [36], are strongly under-represented in Silva et al. The earlier 15-20 years cycle of shifting cultivation on a particular land has reduced to two or three years now. We have nonetheless ventured to display our estimates in predictive maps because they are based on a spatially explicit analysis in 2010. The 270 first authors of these papers were listed and their email addresses were found. Yucatan Peninsula [66], northern South America (e.g. Human expansion throughout the world caused that agriculture is a dominant form of land management globally. The analysis presented is primarily qualitative with a supplementary quantitative analysis of the causes of forest . - The primary disadvantage of shifting cultivation is cutting down of forest, which further leads to deforestation. It does so by following natural cycles, recycling nutrients and water, while omitting excessive use of agricultural chemicals. In this specific case 1088 or 10.88% of the 1/100 degree cells within the one-degree sample cell were detected as having shifting cultivation in the validation data sets. When the soil begins to turn infertile (usually after 3-5 years) the people move on. This is called shifting cultivation. Funding: This research was supported by the Institute of Geography and the Centre for Development and Environment (CDE), University of Bern, Switzerland, as well as the Swiss Programme for Research on Global Issues for Development (r4d) supported by the Swiss National Science Foundation (SNSF) and the Swiss Agency for Development and Cooperation (SDC), grant number 400440 152167, the U.S. Dept. Shifting cultivation remains widespread, despite decreases in its extent over the last four to five decades. In some specific areas, especially in Central Africa, it is likely to increase over the next decade before it begins to decline. Shining cultivation fields are generally used not more than two years at a lime, after which . https://doi.org/10.1371/journal.pone.0184479.t001. [1]. Conceptualization, This visualization is based on the estimation of landscapes showing signs of shifting cultivation around 2010 (Fig 5) as base year and estimated decreases of shifting cultivation (Table 3) based on the expert surveys and observed trend between the Butler map and our 2010. Depletion of Nutrients The primitive style of framing like slash and burn decreases the organic matter from the soil. As the data we used (GFC as well as Bing and Google imagery) cover the period from 2000 to 2014 and 2015, respectively, our assessment of the current extent of shifting cultivation does not relate to any specific year. The Neolithic Revolutionalso referred to as the Agricultural Revolutionis thought to have begun about 12,000 years ago. Cultivation was also a traditional form of weed control. According to Olofsson et al. In eastern and southern Africa, shifting cultivation is still present, but not very common, with particularly low occurrences in Kenya and Tanzania. The map shows that shifting cultivation is still present across large areas of the humid tropics. This figure was elaborated by the first author using ArcGIS 10.4. https://doi.org/10.1371/journal.pone.0184479.g007. The difference between the Butler mapwhich is presumably based on studies dating from the 1960s and 1970s [13]and our own current investigation around 2010 is displayed in Fig 6. Regarding South and Southeast Asia, a meta-analysis by van Vliet et al. At the regional scale, an assessment by Spencer [45] provides a slightly more differentiated picture of the presence of shifting cultivation practices in Asia. The colored pixels indicate clearings in different years between 2000 and 2014 as recorded in the GFC data set [8]. The increase of shifting cultivation in Myanmar shown in Fig 6 is due to a marked underestimation in the Butler map, which can possibly be explained by the limited availability of information about Myanmar after the military government came to power in 1962. It is a serious environmental concern since it can result in the loss of biodiversity, damage to natural habitats, disturbances in the water cycle, and soil erosion. Furthermore, it should be noted that the large difference between the two spatial data sets (Fig 6) in arid and semiarid parts of Africa (Sahelian and Sudanian zones of northern Africa as well as parts of southern Africa) is partly due to the fact that Butler included other, non-shifting smallholder farming systems in his map. Formal analysis, No, Is the Subject Area "Earth systems" applicable to this article? But information about such landscapes is urgently needed to improve the . The results indicate that shifting cultivation is likely to persist longest in Africa. As growing only one kind of plant on the same piece of farmland depletes and exhausts the soil by depriving it of the biodiversity, farmers tend to artificially boost the fertility of their impacted fields by applying chemical fertilizers. The result shows that 68% of population practice shifting cultivation where out of it 69% of the locals depend on other activities other than agriculture but a high percent of people still. within global land-use models) needs spatially explicit estimates of areas under shifting cultivation at intervals lying between the status shown in the Butler map (1960s to 1970s) and our estimations for 2010 (e.g. Deforestation is also a contributor to climate change and global warming. https://doi.org/10.1371/journal.pone.0184479.g006. Nonetheless, it is more evidence-based than the 1,000 Mha of unclear origin that are repeatedly cited in the literature (e.g. Madagascar has seen only slight decreases; especially along its eastern escarpment the area under shifting cultivation has remained stable over the last two decades (e.g. In fact, they should be understood as best guesses about general patterns rather than temporally and spatially accurate predictions, as land use transitions often happen suddenly, causing abrupt changes over large areas [23]. Conceptualization, In shifting agriculture a plot of land is cleared and cultivated for a short period of time; then it is abandoned and allowed to revert to its natural vegetation while the cultivator moves on to another plot. e. The red box marks the extent of Fig 2D and Fig 2E. The areas referred to as the rural complex may be used as a proxy for the presence of shifting cultivation. Supervision, Formal analysis, Formal analysis, In Asia, we expect that continued rapid economic development and the related changes in agricultural practices and, more importantly, in the economic structure (from the primary to the secondary and tertiary sectors) may cause shifting cultivation to disappear faster than in Africa or the Americas. Fig 1 illustrates the procedure we used for this visual inspection. The spatio-temporal pattern of the annual deforestation data from 2000 to 2014 at a resolution of 30 meters provides the basis for our approximation. Nobody knows how many people today depend on shifting cultivation globally [22]. Since there have been many controversies about the impact of jhum cultivation the study was done to analyse the current situation of the practice of shifting cultivation as perceived by the local people of Mokokchung village. After analyzing the spatially differentiated changes between the status in the 1960s to 1970s as shown in the Butler map and our data for 2010 (Fig 6), we combined them with data from our expert survey about changes in areas under shifting cultivation between 1970 to 2000 and 2000 to 2010 as well as with information from the literature. Methodology, 2.2). Fig 1A shows a one-degree square of northern Laos. In order to assess both past and future land use transitions in areas currently under shifting cultivation, we identified experts with recent knowledge of these areas by searching the Web of Science (All Databases) for papers published between 2005 and 2015 whose title contained shifting cultivation or similar terms. Human influence on the land is accelerating because of rapid population growth and increasing food requirements. Intensive agriculture has dominated the global food production . For large parts of Southeast Asia, the survey results point towards that the current swift decrease in shifting cultivation continues, and that a large share of the area under shifting cultivation will have disappeared by 2030, and the remaining pockets are likely to be almost entirely gone by 2060.Moreover, the survey results indicate trends for some specific Asian countries: Humid tropical Africa is probably the region for which developments are most difficult to predict due to limited data. Is the Subject Area "Land use" applicable to this article? On the basis of archaeological evidences and radio-carbon dating, the origin of shifting cultivation could be traced back to about 8000 BC in the Neolithic period which witnessed the remarkable and revolutionary change in man's mode of production of food as from hunter and gatherer he became food producer. Regarding Central and South America, the only available source [57] used the secondary forest class as defined in FAOs Forest Resource Assessment 1990 [58] as a proxy and stated the area under shifting cultivation to be 165 Mha. broad scope, and wide readership a perfect fit for your research every time. Meanwhile, about 54% people, living in the rural areas, are engaged in practicing it. Based on existing data and knowledge, we have made a first attempt at estimating possible future trends in the distribution of shifting cultivation until 2090. Unlike intensive agriculture, sustainable farming has a great potential for benefiting the environment and preserving natural resources. Shifting Cultivation Shifting Cultivation Agricultural Geography Agricultural Hearths Agricultural Production Regions Agricultural Revolutions Agriculture and Climate Agriculture and Pollution Agrochemicals Community Supported Agriculture Extensive Farming Feeding the World Food Desert Food Insecurity Food Movements Green Revolution - West Africa (Sierra Leone, Liberia, Guinea, Cte dIvoire, Ghana): Shifting cultivation is anticipated to diminish rapidly by 2030 and to largely disappear by 2060 if peace is upheld and there is no major return of Ebola; but if conflicts resurface, shifting cultivation may persist well into the second half of this century. Lastly, it is also problematic that shifting cultivation has been subject to recycling of statements about its importance that have no basis in thorough empirical research. To date, we know little about its worldwide extent, underlying spatial patterns, or global trends in its past and future development. Myanmar [6365]), Central America (e.g. Moreover, it is not possible to know in detail how the respondents arrived at their assessment of past and future extents of shifting cultivation. Taking into consideration the stratification criteria, 328 one-degree cells were randomly selected to be validated. The evil effects of shifting cultivation are devastating and far reaching in degrading the environment and ecology of this region. IWGIA - IWGIA - International Work Group for Indigenous Affairs Data curation, Citation: Heinimann A, Mertz O, Frolking S, Egelund Christensen A, Hurni K, Sedano F, et al. There is a need to transform shifting cultivation to sustainable intensification. Shifting cultivation (SC) is a traditional land-use system to ensure livelihood in the Amazon (Villa et al., 2020).The traditional SC have small areas (0.1-0.8 ha) and short cycles of agriculture (1-3 years) with high crop diversity followed by fallow periods of 2-7 years [Fig. See also slash-and-burn agriculture. This has become more clear than ever in 2022, with war and weather extremes related to climate change wreaking havoc on farm animals, agricultural operations and food prices around the world. Moderate warming and more carbon dioxide in the atmosphere may help some plants to grow faster. The history of shifting cultivation is as old as the history of agriculture itself. These changes are not fully reflected in the above comparison between the Butler map and our own spatial investigation for 2010 because in many areas they have resulted only in a reduced occurrence of shifting cultivation but not yet in its full disappearance. Disadvantages of Shifting cultivation: Deforestation Loss of fertility of a specific site Soil erosion Tree burning generates air pollution. Yet most of the common farming techniques employed in . Click through the PLOS taxonomy to find articles in your field. In large parts of humid West Africa, shifting cultivation is still widespreadwith the exception of Nigeria, where it has all but disappeared and remains present only in small pockets. This has led to a paucity of global information on certain land use systems, including shifting cultivation at the global level. Other Causes of Deforestation Forest Fires Fires are a natural part of the lifecycle of many forests, clearing the way for younger, smaller growth. [24]). Any change in the climate of an area can affect the plants and animals living there, as well as the makeup of the entire ecosystem. - Shifting cultivation also destroys the habitat of wild animals at large. The number of estimates of areas under shifting cultivation at regional and national scales in the literature is also very limited. First, an area of fallow forest is cleared for cultivation. Extreme precipitation events can disturb plant growth, particularly in recently burned forests, and make plants more vulnerable to flooding and soils to erosion. Writing original draft, We used a search string similar to the one used for the literature review: [Title]: "Shifting cultivation" or swidden or "slash-and-burn" or "slash and burn" or "shifting agriculture" AND [Year published]: 20052015. [10] compiled available published shifting cultivation area estimates for seven countries: Thailand, Laos, Cambodia, Vietnam, Myanmar, Malaysia, and Indonesia. Each of the 328 sample one-degree cells was subdivided in cells of 1/100 degree by 1/100 degree, resulting in 10,000 verification cells per one-degree cell. https://doi.org/10.1371/journal.pone.0184479.t002. The climate of most European countries is wet This became particularly evident when Hurtt et al. They write new content and verify and edit content received from contributors. [55], citing the Wasteland Atlas [56], estimated the extent of shifting cultivation in the mid-2000s at 5.6 Mha (only area under cultivation), whereas the GLC2000-based estimate is 7.6 Mha [1]. 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. 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. As for Africa, we found only one recent national study, on the Democratic Republic of the Congo [36]. Slash-and-burn agriculture is a farming method that involves the cutting and burning of plants in a forest or woodland to create a field called a swidden.The method begins by cutting down the trees and woody plants in an area. The most important questions included: The information provided by the respondents related to very different spatial scales, ranging from village to district, provincial, and, in some cases, national scales. Sample: 2A Score: 7 This response earned full credit and demonstrates a comprehensive understanding of subsistence agriculture and the sustainability of shifting cultivation in the past and for the future. The period of cultivation is usually terminated when the soil shows signs of exhaustion or, more commonly, when the field is overrun by weeds. While an area approximation of actual shifting cultivation landscapes based on our analysis is difficult due to the estimated and not measured shared of shifting cultivation of each one-degree cell we believe that, given the high accuracy of this estimation (see Table 2), a conservative estimate can nonetheless be derived by visually inspecting the cells and allocating reasonable shares of shifting cultivation landscape (currently cultivated fields plus all stages of fallows) to them as described in the methods section. The Data behind Deforestation Causes of Deforestation Methodology, Plants, Animals, and Ecosystems. (Source of imagery in 2D and 2E: Pansharpened Landsat 8 image, acquisition date January 5 2014, available from the U.S. Geological Survey.). For each grid cell, the occurrence of shifting cultivation declined linearly by the mid-point of the estimated losses in 2030, 2060 and 2090 (see Section 3.4). 1. Forest and trees play an important role in balancing the environment. Analysis of Landsat data back to Landsat4 (launched in 1982) could provide more than 30 years of pan-tropical records, covering a time of significant change in the distribution of shifting cultivation across the humid tropics and perhaps also in the length of fallow periods. Farmers will have to shift what they grow and how they grow it to keep up with an expanding population. The ashes are then mixed with the soil. For example, the large areas of tree plantations established in Vietnam and southern China in the 1980s and 1990s can also leave a mosaic signature at a certain point in time and might therefore be incorrectly interpreted as shifting cultivation (Fig 1). For India, Goswami et al. While keeping in mind the inherent limitations of these predictions, we can identify a number of more specific patterns. Department of Geographical Sciences, University of Maryland, College Park, United States of America, Roles The plot is left alone for longer than it was cultivated, sometimes up to 10 or more years, to allow wild vegetation to grow on the plot of land. Writing original draft, Yes Predicting future trends in the development of any form of land use requires extreme caution [23,69]. The system is destabilized by long cultivation and short fallow periods. Methodology, From this, we excluded regions where shifting cultivation can safely be assumed to not have been present for centuries (e.g. As global level ground data collection is not feasible and no global data on shifting cultivation for the considered time span of 2000 to 2014 is available, we generated a validation dataset, which contains a detailed delineation of the areas under shifting cultivation for a stratified sample of one-degree cells. (Fig 2B): Location of the one-degree cell of Fig 2C - 2E. In the absence of further data to validate past estimations of the extent of shifting cultivation, the Butler map may be considered a reasonable representation of the global distribution of shifting cultivation from 1960 into the 1970s. No, Is the Subject Area "South America" applicable to this article? The comparably low user and producer accuracies of the class moderate occurrence (2039% coverage of shifting cultivation landscapes of the entire one-degree cell) is not surprising as it could have been expected that this intermediate class would be the most difficult one to estimate. There's no doubt about it: the best thing we can do to fight climate change is keep forests standing. The selection process ensured that all are experts in the field, but there may be disciplinary or personal differences in the way that especially the future of shifting cultivation was assessed. The author has visited the entire Mizoram state and observed that shifting cultivation has a severe adverse impact on the environment, forest depletion and landscape degradation. When looking at this comparison, it is important to keep in mind that only full disappearance of shifting cultivation within a one-degree cell will show as a change between the two data sets; gradual decreaseswhich normally precede full disappearanceare not captured if the occurrence of shifting cultivation in the respective cells according to our present estimate remains greater than 5%. Climate change is a leading cause of deforestation. Shifting cultivation systems are commonly associated with rural poverty and forest degradation. The search was performed in September 2015 and generated 316 results. We are very grateful to Laura Ebneter, Manuel Abebe, Lukas Wuersch and Boris Fuhrer for their support in interpreting the satellite imagery and to Marlne Tibeault for the language editing. Improvements in mapping the extent of shifting cultivation and trends in its development may be expected in the near future. However, this future may also provide better opportunities for production and income generation if development efforts are sensitive to the needs of shifting cultivators [73,74]. The period of cultivation is usually terminated when the soil shows signs of exhaustion or, more commonly, when the field is overrun by weeds. This technique serves to clear the field and enrich the soil with nutrients from the ash. The negative effects of abusing shifting cultivation are devastating and far-reaching in degrading the environment and ecology of the affected region. here. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Centre for Development and Environment, University of Bern, Bern, Switzerland, Roles Trends in humid tropical Africa vary widely. Writing original draft, Shifting cultivation, which is still prevalent in the uplands of eastern Bangladesh, contributes significantly to forest loss and is the main cause of land degradation. By zooming into areas where these clearings indicate possible shifting cultivation, we were able to determine visually whether they were accompanied by the pattern of fallows characteristic of shifting cultivation (Fig 1E) or not (Fig 1D). For this reason, the known widespread decrease in the occurrence of shifting cultivation in Southeast Asia (e.g. For more information about PLOS Subject Areas, click It is important to note that these are indeed very rough possible scenarios and should be seen as expected trends rather than fixed percentages of decline. Comparison of these figures with the GLC2000-based area estimate for Laos of almost 11 Mha [1] underlines the problem of using the GLC2000 to estimate areas under shifting cultivation. Table of Content Why are Forests Important? In addition, we used available very highresolution satellite imagery from Bing and Google (most images dating from the period between 2008 and 2015; visited between September and April 2015) in an ArcGIS Desktop 10.4 and QGIS environment to examine visually whether a given area for which the GFC data indicated a spatio-temporal pattern of small-scale clearings consistent with shifting cultivation, was indeed likely to be under shifting cultivation. For Central and South America, the survey shows a mixed picture, with some areas being quite stable or even likely to experience expansion in the near future, and other areas (e.g. Forests occupy nearly a third of Earth's land surface, providing humans and countless other species with a wide range of benefits and services from ecological functions such as water and air . e0184479. Formal analysis, Meanwhile, the area under shifting cultivation has decreased by 71.22% from 1997 and forest cover has decreased by 4.41% during the period. Given the unavailability of automated approaches to detect shifting cultivation at a global level and deliver data in a timely manner for ongoing earth system modeling, we have used a visual interpretation approach to detect shifting cultivation. Globally, sixty-two per cent of the investigated one-degree cells showed signs of shifting cultivation, with surprisingly similar shares across the 3 regions, ranging between 59 and 65% (Table 1) In absolute terms, the majority of cells with shifting cultivation are located in the Americas and Africa (almost 78%). [68]). One of the most obvious consequences is the depletion of aquifers, river systems, and downstream ground water. Climate Change. If the survey provided information about when (i.e. All answers were anonymous and cannot be traced back to the individual expert. In such environments it may be preferable to cultivate a field for a short period and then abandon it before the soil is completely exhausted of nutrients. 5 Ways Climate Change Impacts Forests. The effects of shifting cultivation are devastating and far-reaching in degrading the environment and ecology of these regions. In addition, to the extent multi-temporal very high resolution imagery was available on Google Earth, these were used to get an even better impression of the landscape and its land-use dynamics. The map shows large areas under such agriculture in Africa, tropical Central and South America, and Southeast Asia. Most plants and animals live in areas with very specific climate conditions, such as temperature and rainfall patterns, that enable them to thrive. d. It accounts for 26% of the gross domestic product. The areas newly classified as having shifting cultivation (blue in Fig 6) are more likely to have been missed in the Butler map than to represent actual new areas under shifting cultivation, as many of these regions are well known to still have significant shifting cultivation landscapes. The five classes corresponded to the following rough ranges of area shares of shifting cultivation landscapes (currently cultivated fields plus all stages of fallows) within an entire one-degree cell: none: < 1%; very low: 19%; low: 1019%; moderate: 2039%; high: 40%. It upsets the ecological balance as it disturbs many eco-systems of that region due to destruction of natural vegetation. Writing original draft, Cultivation (the preparation of land for planting crops) on the plot is done for a few years until the fertility of the formerly burned land is reduced. Writing review & editing, Affiliation Writing review & editing. A plot of land is cleared by cutting the trees and burning them. Fig 1B to Fig 1E show examples of different zoom levels used to decide whether the pattern in the GFC data is indeed related to shifting cultivation Fig 1E (showing pattern of clearing for the current year of cultivation and different stages of fallow) or not Fig 1D (larger scale clearings with young rubber). While our estimates are based on non-automated methods and expert information from different parts of the world, we argue that our work nonetheless advances the state of knowledge considerably, especially with regard to earth system modeling scenarios, which have proved sensitive to the inclusion of shifting cultivation and up to now have used shifting cultivation data based on a hand drawn map from the 1980s. The major disadvantage of Shifting Cultivation is that many trees in the forest are cut and this increases soil infertility and leads to soil . 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. The impacts of traditional agriculture on Environment are discussed below: 1. current practice of shifting cultivation in the region is an extravagant and unscientific form of land use. An area of 1,000 Mha was mentioned by Davidson et al. As for the entire global level assessment of all the 2,817 one degree cells considered, the GEFC and available very high resolution imagery (i.e. The present study is a first step towards a future in which we will know more about the global distribution of shifting cultivation; we hope it opens the door to quantifying shifting cultivations importance for local as well as the global socio-ecological systems. (Fig 2A): the global distribution of the stratified sample of the 328 one-degree cells used in the validation data set. With 62% of the investigated one-degree cells in the humid and sub-humid tropics currently showing signs of shifting cultivationthe 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.
