It coincided with the end of the last ice age and the beginning of the. 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. First, an area of fallow forest is cleared for cultivation. Formal analysis, This indicates that, despite the subjectivity involved on estimating the landscape level of occurrence of shifting cultivation in our classification, the method led to reproducible and accurate results. The accuracy levels of our classification were high with an overall accuracy above 87%. [3037]) such approaches cannot yet be up-scaled to global level due to data availability as well as computational limitations. - Madagascar: Shifting cultivation is expected to remain widespread, especially along the eastern escarpment, until well beyond 2030. Fig 5 presents the results of our own visual approximation of the global extent of shifting cultivation around 2010 at a one-degree resolution, based on Hansen et al.s (2013) GFC data and very highresolution satellite imagery. However, it is important to underline that this assessment is based on very few survey responses (Fig 3) due to the small number of existing studies on shifting cultivation in Africa. Writing original draft, 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]. The land takes many years to replenish just at the cost of providing yield for 2 to 3 years. The length of time that a field is cultivated is usually shorter than the period over which the land is allowed to regenerate by lying fallow. Despite the limited number of survey responses on Central and South America, it appears that here, unlike in Southeast Asia, areas under shifting cultivation have not seen a strong decline over the last 20 years. 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. broad scope, and wide readership a perfect fit for your research every time. Environment; Why poison ivy is an unlikely climate change winner. No, Is the Subject Area "Surveys" applicable to this article? Laos, Vietnam) over the past 15 to 25 years is not reflected in this comparison. In addition to searching the Web of Science, we also consulted three major book publications that could be assumed to contain relevant information [2426]. The number of estimates of areas under shifting cultivation at regional and national scales in the literature is also very limited. 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]. Shifting cultivation is the major occupation and the main source of income of the marginal farmers ( Jhumias) in Mizoram. 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). To assess published scientific material on the current extent of shifting cultivation, we searched the Web of Science (All Databases) using the following search string: [Title]: "shifting cultivation" or swidden* or "slash and burn" or "slash-and-burn" or "shifting agriculture" AND [Year published]: 20052016. As for Africa, we found only one recent national study, on the Democratic Republic of the Congo [36]. The validation of the estimation of landscapes showing signs of shifting cultivation revealed that 95.1% of the one-degree cells showing signs of shifting cultivation in the validation data correspond to the results in our classification. Copyright: 2017 Heinimann et al. 70% of global freshwater withdrawals are used for agriculture 2. Generally, the two approximations of areas under shifting cultivation are in fairly good agreement, especially when considering that the large differences in the arid areas of northern Africa, southern Angola, and Zambia and the high-mountain areas of eastern Bolivia are largely explained by the fact that Butler included other, non-shifting forms of extensive smallholder agriculture and that shifting cultivation in these areas based on the climatic condition never could have been widespread. To get a first estimation of the occurrence of shifting cultivation, we classified each cell under investigation into one of five shifting-cultivation occurrence classes: none, very low, low, moderate, or high. This is only the case if, in addition to a pattern of small-scale clearings in the GFC data, a spatio-temporal pattern of different stages of fallow and regrowth is visible in the very highresolution imagery from Bing and Google. Yes Deforestation is also a contributor to climate change and global warming. Conceptualization, 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. At present, net area sown in Mizoram State is only 5.5%, of which, 16.9% area is devoted to shifting cultivation. 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. This trend, which was also identified by van Vliet et al. Table of Content Why are Forests Important? However, the areas indicated for each country vary greatly depending on the source. Fig 1 illustrates the procedure we used for this visual inspection. The colored pixels indicate clearings in different years between 2000 and 2014 as recorded in the GFC data set [8]. Department of Geographical Sciences, University of Maryland, College Park, United States of America, Roles For example, data for Laos indicate between 2 and over 6 Mha, while more recent figures based on remote sensing (multi-temporal Landsat) for northern Laoswhere the largest share of shifting cultivation in the country is foundare 3.1 Mha [33] and 2.6 Mha [34]. No, Is the Subject Area "South America" applicable to this article? - Vietnam and Laos: Shifting cultivation is likely to be greatly reduced by 2030 and completely gone by 2060. Also when considering the different levels of occurrence of shifting cultivation estimated based on the overall impression of the landscape per one-degree cell, the accuracies were high (see confusion matrix in Table 2), with an overall classification accuracy of 87.8%. current practice of shifting cultivation in the region is an extravagant and unscientific form of land use. Validation, Letting it dry and burning it off. More widespread signs of shifting cultivation were found mostly in small pockets, with the exception of larger areas in Central Africa (e.g. Forest and trees play an important role in balancing the environment. Institute of Geography, University of Bern, Bern, Switzerland, The system is destabilized by long cultivation and short fallow periods. Meanwhile, the area under shifting cultivation has decreased by 71.22% from 1997 and forest cover has decreased by 4.41% during the period. Moderate warming and more carbon dioxide in the atmosphere may help some plants to grow faster. In Central America, shifting cultivation is still widespread, and both Fig 6 and the survey results indicate an increase in some areas (e.g. According to our tentative predictions, shifting cultivationwhich has been a globally important form of human crop cultivation for millenniamay be gone by the end of this century. Articles with data at subnational scales were only considered if the subnational area studied constituted the main area of shifting cultivation in the given country (and thus a reasonable estimate of the national extent of shifting cultivation). The evil effects of shifting cultivation are devastating and far reaching in degrading the environment and ecology of this region. This article first questions the share of responsibility assigned to traditional agriculture it may well be overestimated because of unclear definitions, uncertain estimates, and potential political biases. Disadvantages of Shifting cultivation: Deforestation Loss of fertility of a specific site Soil erosion Tree burning generates air pollution. [68]). https://doi.org/10.1371/journal.pone.0184479.g004. Writing original draft, Roles Fig 2 illustrates this process for one sample cell. Let us know if you have suggestions to improve this article (requires login). Cultivation of the earth after clearing is usually accomplished by hoe or digging stick and not by plow. 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. 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. here. - Indicate how you expect the shifting cultivation occurrences to change in the future for the following periods (no change, expansion, decline, disappearance): 20152030; 20302060; 20602090. There's no doubt about it: the best thing we can do to fight climate change is keep forests standing. 1,063 likes, 4 comments - Simran IAS Academy (@simranias) on Instagram: "#Learnbymaps is here to explain you about #Slash and #Burn Cultivation Slash and burn #agricultu." Simran IAS Academy on Instagram: "#Learnbymaps is here to explain you about #Slash and #Burn Cultivation Slash and burn #agriculture is also called the shifting cultivation. [43] when using the same source material for the classification as for the reference or validation data, it is essential to create the reference/validation data with a more accurate process than the classification. Intensive agriculture has dominated the global food production . 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. Writing original draft, Writing original draft, Each of these samples was visually examined in detail at scale of 1:20,000 or lower for the presence or absence of the above mentioned shifting cultivation specific spatio-temporal signs of clearing and regrowth on the landscape. We estimate that shifting cultivation landscapes currently cover roughly 280 million hectares worldwide, including both cultivated fields and fallows. Writing review & editing, Affiliation In a second cluster of countriesLaos, Cambodia and Myanmarshifting cultivation areas have decreased drastically since 2000. The Neolithic Revolutionalso referred to as the Agricultural Revolutionis thought to have begun about 12,000 years ago. It does so by following natural cycles, recycling nutrients and water, while omitting excessive use of agricultural chemicals. Peninsular Malaysia, central and southern Thailand) [28]. Writing review & editing, Affiliation (Source of imagery in 2D and 2E: Pansharpened Landsat 8 image, acquisition date January 5 2014, available from the U.S. Geological Survey.). Extreme weather. Outlines the natural features of Mizoram climate, flora, fauna. A review focusing on Southeast Asia found little aggregate information about the areas under shifting cultivation there [10], and we were unable to find information about shifting cultivation areas in Africa and Latin America. 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). [1]. Yes Industrialized agriculture is highly concentrated and mechanized, relying on chemical inputs like fertilizers, pesticides and non-therapeutic antibiotics. The area of interest ranges from 30S and 30N (6,704 one-degree cells on landmass), while the area investigated includes 2,817 cells. As our aim was to provide, in a timely manner, a global-scale overview of landscapes showing signs of shifting cultivation for use in global land userelated earth system modeling scenarios [27], we worked at an aggregated level using one-degree cells, which corresponds approximately to the scale of current earth system model analyses. 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. PLoS ONE 12(9): Taking into consideration the stratification criteria, 328 one-degree cells were randomly selected to be validated. https://doi.org/10.1371/journal.pone.0184479.t003. [17], contrasts with developments in other parts of Africa, where decreases and the disappearance of areas under shifting cultivation have dominated over the last two decades. This will be useful in improving the characterization of land surface and land use dynamics for earth system models and large-scale carbon and greenhouse gas accounting. This number certainly requires further validation before it can be claimed to be an adequate estimate of the global area under shifting cultivation. In West and Central Africa, shifting cultivation is largely continuing and has even been expanding in certain areas. 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. Benefits of sustainable agriculture for the environment and our wellbeing. (2017) A global view of shifting cultivation: Recent, current, and future extent. This figure was elaborated by the first author using ArcGIS 10.4. https://doi.org/10.1371/journal.pone.0184479.g003. Eutrophication is considered to be a serious environmental concern since it often results in the .