https://doi.org/10.1371/journal.pone.0184479.t003. Warum funktioniert convert2mp3net nicht mehr. 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. At the regional scale, an assessment by Spencer [45] provides a slightly more differentiated picture of the presence of shifting cultivation practices in Asia. This figure was elaborated by the first author using ArcGIS 10.4. https://doi.org/10.1371/journal.pone.0184479.g007. 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. 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%. here. This approach, however, suffers from the shortcoming that land cover data are of very limited use in estimating land use practices, which is acknowledged by Silva et al. Australia, the Gulf States, arid areas in Africa) or where it disappeared several decades ago (e.g. (Homeschool) - würde mich über sehr Hilfe freuen. In that there is the there is the change of the place is take place that means if there is the cultivation of the land is get reduced then by shifting it we can increase this. Shifting cultivation, called “shwe pyaung taung ya,” is the dominant agricultural system in Myanmar’s upland areas. Writing – review & editing, Affiliation We estimate that shifting cultivation landscapes currently cover roughly 280 million hectares worldwide, including both cultivated fields and fallows. 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. Was soll man da schreiben..?? 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: 1–9%; low: 10–19%; moderate: 20–39%; high: ≥ 40%. Writing – original draft, 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. Ich weis es auch nicht :D, Hallo, ich hab in geo eine Hausaufgabe, und zwar muss ich anhand einer Abbildung erklären, welche Rolle das Klima für den Pflanzenwachstum im tropischen Regenwald hat, jedoch weiss ich nicht wie ich da vorgehen soll. At the same time, shifting cultivation was one of the most sensitive variables in their model runs (along with wood harvesting). The area of interest ranges from 30°S and 30°N (6,704 one-degree cells on landmass), while the area investigated includes 2,817 cells. It is known as Jhoom in Assam, Onam in Kerala, Podu in Andhra Pradesh and Odisha. This trend, which was also identified by van Vliet et al. We did not perform any detailed spatial delineation of the actual area under shifting cultivation, as the goal of our study was to provide a global one degree–gridded product. - Borneo and Sulawesi: Shifting cultivation is expected to disappear sometime between 2030 and 2060. Conceptualization, Department of Geographical Sciences, University of Maryland, College Park, United States of America, Roles Visualization, Shifting cultivation, rough grazing of livestock, and crop rotation systems were the dominant agricultural methods until the 1950s, when these were largely superceded by intensive agricultural techniques in Europe and North America. Formal analysis, 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. Moreover, even if GFC deforestation data processing using the Google Earth engine might enable this automation in the future, the visual approach will still be highly valuable for validating the robustness of automated approaches. Data curation, December 10, 2017 by Study Mentor Leave a Comment Shifting cultivation is a type of cultivation in which an area is cultivated temporarily for a period of time which differs from place to place and then abandoned for some time so that it restores nutrients in the plot naturally. Both conditions apply to considerable parts of Central Africa. The remaining cells (3,887) were excluded from the analysis as shifting cultivation can be assumed to have never existed or disappeared decades ago (see Fig 5 and Method section). decadal), the areas newly classified as having shifting cultivation (blue in Fig 6) should be added to the original Butler map, thereby producing an updated estimated extent of shifting cultivation for this earlier period. India, Bangladesh), comparison of the maps (Fig 6) and the survey responses point to similar trends. Discover a faster, simpler path to publishing in a high-quality journal. On this basis, we can provide a preliminary overview of regional and national trends in the development of the extent of shifting cultivation over the past 40 to 50 years. Nomina [en] shifting cultivation. Der tropische Regenwald wird trotz seiner ungünstigen Umweltbedingungen seit Jahrtausenden von Menschen besiedelt und genutzt, die sich in ihrer Lebensweise an die vorherrschenden Bedingungen angepasst haben. Hence, the occurrence level was estimated and not measured and the classification was based on a coarse assessment of the landscape (also see accuracy assessment below). No source is reported for the map, but most likely it builds on a number of regional studies that was carried out between the 1940s and the 1970s, as well as “general knowledge” of where shifting cultivation and other extensive smallholder farming systems were found. The period of cultivation is usually terminated when the soil shows signs Yes The main outcomes presented in this study are maps showing the estimated presence of shifting cultivation at a one-degree resolution for the present, as well as, for the first time, estimations for 2030, 2060, and 2090. We initiated occurrence at a one-degree resolution in 2010 (base year) at the mean of the above-stated ranges for each occurrence category in the assessment of current landscape with signs of shifting cultivation based on the GFC data (c.f. Wenn du damit "Stockwerk Anbau" meinst, ja. Könnt ihr mir etwas zur Biozönose im tropischen Regenwald sagen? Accordingly, they emphasized that “the need for global data on annual global gridded land-use transitions from past-to-future presents a large and underdetermined problem” [2]. Zu welcher Jahreszeit ist es im tropischen Regenwald am kältesten? Citation: Heinimann A, Mertz O, Frolking S, Egelund Christensen A, Hurni K, Sedano F, et al. The classic studies on shifting cultivation in Africa [46–48] do not provide any area data for the continent, and for Central and South America we were unable to find any regional-scale past area estimation. Researchers are currently developing automated approaches that are capable of processing decades of Landsat data and detecting the spatio-temporal patterns of shifting cultivation. 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. The respondents were asked to estimate the current spatial extent of shifting cultivation as well as past and future trends in the development of this extent in their area of interest. Shifting cultivation is an agricultural system in which plots of land are cultivated temporarily, then abandoned while post-disturbance fallow vegetation is allowed to freely grow while the cultivator moves on to another plot. PLoS ONE 12(9): Was soll man da schreiben..? 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. These misconceptions and their policy implications need to be challenged. Shifting cultivation forms part and parcel of day-today life of the people living in Nam Nane watershed area. 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. - India and Bangladesh: Shifting cultivation is estimated to disappear by 2030. 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 cultivation’s importance for local as well as the global socio-ecological systems. - Indicate shifting cultivation area changes in the following periods of the past (no change, expansion, decline, disappearance): 1900–1970; 1970–2000; 2000–2015. Yes - Papua New Guinea: Shifting cultivation may persist well into the second half of this century, perhaps even until 2090. https://doi.org/10.1371/journal.pone.0184479.s001. 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 high–resolution satellite imagery. For India, Goswami et al. Our predictions of future extents of shifting cultivation are, of course, speculative. https://doi.org/10.1371/journal.pone.0184479.g006. Copyright: © 2017 Heinimann et al. The area approximation of actual shifting cultivation landscapes was performed based on the average occurrence rates in the one-degree cells for each of the five classes above (>1% class: 0%; 1–9%: 5%; 10–19%: 15%; 20–39%: 30%; ≥40%:70%). In West and Central Africa, shifting cultivation is largely continuing and has even been expanding in certain areas. The stratified validation sample design was chosen considering the distribution of the validation samples per occurrence class and the spatial distribution per continents. The red box marks the extent of Fig 2D and Fig 2E. 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 use–related 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. Yes The map shows that shifting cultivation is still present across large areas of the humid tropics. 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 Laos—where the largest share of shifting cultivation in the country is found—are 3.1 Mha [33] and 2.6 Mha [34]. The shifting cultivation is briefly known as agriculture in the cultivate manner that is in the form of the Jhum. Yucatan Peninsula [66], northern South America (e.g. - Vietnam and Laos: Shifting cultivation is likely to be greatly reduced by 2030 and completely gone by 2060. However, adequate prediction of land use–based emissions requires an improved understanding of megatrends in land use systems change [2,5]. Writing – review & editing, Affiliation Writing – original draft, Spencer [45] indicates an approximate area under shifting cultivation (currently cultivated fields plus all stages of fallows) of around 110 million hectares (Mha) for Asia. Methodology, shifting cultivation. The study by Silva et al. Methodology, Nehme kritisch Stellung zu der Aussage dass Shifting Cultivation eine dem tropischen Regenwald angepasste Nutzungsform sein. Institute for the Study of Earth, Oceans, and Space, University of New Hampshire, Durham, United States of America, Roles - West Africa (Sierra Leone, Liberia, Guinea, Côte d’Ivoire, 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. However, the expert survey confirms that shifting cultivation has fully disappeared between the 1970s and the 2000s in various areas of mainland Southeast Asia, such as southern Thailand, Peninsular Malaysia, and China. archeological studies or historical studies of shifting cultivation in Europe), duplicates, and papers whose authors had deceased in the meantime, 282 papers remained. For more information about PLOS Subject Areas, click Ich frage mich halt, ob es überhaupt geht im tropischen Regenwald Bäume oder Pflanzen einzupflanzen, da der Boden so nährstoffarm ist? Secondly, the detection and monitoring of complex shifting cultivation mosaics using automated remote sensing approaches remains challenging [33,38,39] and the mentioned small spatio-temporal signature of vegetation clearings and regrowth is very specific to shifting cultivation and visual interpretation is therefore suitable [40]. [1]. Its authors detected changes in what they call “the rural complex” for the period from 2000 to 2010. broad scope, and wide readership – a perfect fit for your research every time. Our main objectives in this study are therefore 1) to review published knowledge about current status and past trends in the development of the global extent of shifting cultivation; 2) to assess the recent global distribution of shifting cultivation and, based on these trends and expert statements, 3) to provide a first estimation of the future extent and spatial distribution of shifting cultivation until 2090. These are areas of heavy rainfall and quick regenerating of vegetation. Silva et al. 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. Shifting cultivation since its inception is identified with rotation of fields rather than rotation of crops, absence of draught animals and manuring, use of human labour only, employment of dibble sticks or hoe, and short period of occupancy alternating with long fallow periods to assist the regeneration of vegetation, culminating in … We analyzed a few spatial patterns and processes of a shifting cultivation landscape in the Garo Hills of Meghalaya state in North East India, where about 85 % of land belongs to native community. Was ist gut, wenn man den Regenwald nutzt und was nicht? Shifting Cultivation Veränderung in den letzten Jahrhunderten Pro/ Kontra Bevölkerungswachstum Geringere Bevölkerung = ausreichende Regenerationszeit Grundlegende Versorgung wird sicher gestellt Keine Anwendung von chemichen Dünger Streben nach mehr Einnahmen Steigende Instagram: Warum sind Nachrichten bei manchen blau? Shifting Cultivation (frage unten)? The recently launched Sentinel-2 instruments with their augmented repeat frequency will generally help to improve remote sensing–based analyses of the humid tropics, which are complicated by frequent and persistent cloud cover. The comparably low user and producer accuracies of the class “moderate” occurrence (20–39% 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. Writing – review & editing, Affiliations Validation, Peninsular Malaysia, central and southern Thailand) [28]. While the literature offers good representations of the major natural land covers and human land uses [6–8], mosaic landscapes with a dynamic mix of managed and natural land covers often fall through the cracks in global land cover and land use classifications, as these are unable to adequately capture such landscapes’ dynamic nature and complex spectral signatures [9–12]. Consequently, if further research (e.g. An area of 1,000 Mha was mentioned by Davidson et al. 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). According to our tentative predictions, shifting cultivation—which has been a globally important form of human crop cultivation for millennia—may be gone by the end of this century. northern Zambia and in the Democratic Republic of the Congo), parts of southeastern Africa (e.g. These approaches, however, are still in the making and will require substantial resources. Shifting agriculture, system of cultivation that preserves soil fertility by plot (field) rotation, as distinct from crop rotation. According to Olofsson et al. No, Is the Subject Area "Africa" applicable to this article? Furthermore we wish to express our gratitude to the two reviewers as well as the editor for the very useful comments and inputs. Investigation, Myanmar [63–65]), Central America (e.g. Overall, a decrease after 2030 and disappearance after 2060 is expected. No, Is the Subject Area "Asia" applicable to this article? - Madagascar: Shifting cultivation is expected to remain widespread, especially along the eastern escarpment, until well beyond 2030. We then made an estimate of trends in occurrence of shifting cultivation for these aggregated regions for 2030, 2060 and 2090 also taking into account the historical trends between the Butler map and our 2010 classification. Conceptualization, This is reflected both in the comparison of the two spatial data sets (Fig 6) and in the survey responses. Was sind Vorteile und was sind Nachteile der Nutzung des Tropischen Regenwaldes? https://doi.org/10.1371/journal.pone.0184479.t002. It is practiced by tribal and also known as Burn and Slash cultivation. The pattern of destruction associated with shifting cultivation is described as follows: Farmers cut and burn forests. Is the Subject Area "Land use" applicable to this article? Centre for Development and Environment, University of Bern, Bern, Switzerland, Roles Shifting cultivation ist heute noch in den feuchten südamerikanischen, südostasiatischen (starker Rückgang) und vor allem … [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]. We have nonetheless ventured to display our estimates in predictive maps because they are based on a spatially explicit analysis in 2010. Based on the spatio-temporal pattern of the GFC data (different colours denoted different year of clearings) and the patterns of clearing and regrowth in the very high resolution imagery (here Bing), a 1/100-degree cell is being classified as showing shifting cultivation or not. In English, the terms shifting cultivation, swidden, and rotational agriculture are all used to refer to this cultivation method. gutefrage ist so vielseitig wie keine andere. Writing – original draft, There was a bias towards responses from researchers who worked in Southeast Asia (see Fig 3); but this is also the world region where most research on shifting cultivation has been done, whereas Africa has the fewest studies and is clearly under-represented in light of the considerable occurrence of shifting cultivation there [17,44]. For this reason, the known widespread decrease in the occurrence of shifting cultivation in Southeast Asia (e.g. ich muss bis morgen eine frage beantworten und zwar, charakterisiere die Wirtschafsweise der Shifting cultivation in den immerfeuchten Tropen, Meine Tochter hat in Erdkunde eine Aufgabe bekommen: Zu welcher Jahreszeit ist es im Tropischen regenwald am kältesten und WIE kalt ist es dann? This is the case for Peninsular Malaysia [28], parts of Sumatra [60], Yunnan Province in southern China [61]and the southern part of the Brazilian Amazon [62], for example. The map shows large areas under such agriculture in Africa, tropical Central and South America, and Southeast Asia. Department of Geosciences and Natural Resource Management, University of Copenhagen, Copenhagen K, Denmark, Roles bahasa Inggris . Formal analysis, Panama, Guatemala) well into the 2000s. 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. Writing – original draft, 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. 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. 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 decreases—which normally precede full disappearance—are not captured if the occurrence of shifting cultivation in the respective cells according to our present estimate remains greater than 5%. More and more land is being used for subsistence farming by shifting cultivation, large forest areas are being converted to the cultivation of food and agricultural products for export, cleared for industrial and energy projects or for settlement, as well as used to provide wood for building and fuel. Our point of departure is a global map of the distribution of “primitive subsistence agriculture” produced by Butler in 1980 [13], a visual inspection of the distribution of shifting cultivation based on the 2000–2014 Global Forest Change (GFC) data set [8] and very high–resolution satellite imagery, as well as an expert survey. 1 Antwort agrabin 20.09.2019, 04:48. 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. Writing – original draft, Roles 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 high–resolution imagery from Bing and Google. If and when the occurrence of shifting cultivation in a grid cell fell below 5% (mean value for “very low”), shifting cultivation was assumed to disappear in that grid cell. https://de.wikipedia.org/wiki/Stockwerkanbau. The accuracy levels of our classification were high with an overall accuracy above 87%. Taking into consideration the stratification criteria, 328 one-degree cells were randomly selected to be validated. Given that biomass regrows very quickly in the humid tropics, the GFC data set treats large shares of a field cleared for shifting cultivation and kept fallow for a relatively short period as deforestation. 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. 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. 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. 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. Danke im voraus ...komplette Frage anzeigen. The period of cultivation is usually terminated when the soil shows signs of exhaustion or, more commonly, … 2.2). Methodology, was ist der Unterschied zwischen Regenwald und tropischer Regenwald? 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. was versteht man unter shifting cultivation? South America shows mixed trends: Areas under shifting cultivation have clearly decreased in the southern Brazilian Amazon, whereas survey responses indicate that they are expanding in other parts of the Brazilian Amazon and in Peru. Shifting cultivation supports around 200 million people in the Asia-Pacific region alone. (2017) A global view of shifting cultivation: Recent, current, and future extent. In Central Africa, shifting cultivation also remains very widespread, with an even higher occurrence than in West Africa; in certain areas it is still expanding, such as in the Democratic Republic of the Congo [36]. The arrangement of shifting cultivation is primarily practiced by an individual or a family. https://doi.org/10.1371/journal.pone.0184479, Editor: Benjamin Poulter, Montana State University Bozeman, UNITED STATES, Received: September 2, 2016; Accepted: August 24, 2017; Published: September 8, 2017. Warum ist der Wanderfeldbau keine angepasste Wirtschaftsform im tropischen Regenwald mehr? In shifting cultivation systems, farmers clear land [24], who in turn had cited Dixon et al. 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. The shifting cultivation is a kind of agrarian system, where lands are cultivated on a temporary basis and the cultivated lands are shifted at a regular interval. This became particularly evident when Hurtt et al. The aforementioned map produced by Butler [13] (Fig 4) is a hand-drawn representation of areas where both shifting and non-shifting “primitive subsistence agriculture exists,” as Butler put it. Fig 2 illustrates this process for one sample cell. The search was performed in September 2015 and generated 316 results. [52]; the latter source, however, does not provide this information, so the 1,000 Mha claim seems to be unfounded. Trends in humid tropical Africa vary widely. 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. No, PLOS is a nonprofit 501(c)(3) corporation, #C2354500, based in San Francisco, California, US, https://doi.org/10.1371/journal.pone.0184479, ftp://ftp.fao.org/docrep/fao/003/y1860e/y1860e00.pdf, https://www.cia.gov/library/publications/the-world-factbook/geos/cg.html.