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1.
Sci Total Environ ; 859(Pt 1): 160194, 2023 Feb 10.
Article in English | MEDLINE | ID: mdl-36395830

ABSTRACT

The spatial transformation of cultivated land is an important element in the study of land use transformation. Analyzing the characteristics and direction of the global spatial transformation of cultivated land is of great significance in clarifying the spatial extent and quality of global cultivated land and ensuring global food security. In this context, this paper uses the global spatial data of cultivated land from 1992 to 2015 to analyze the characteristics of global cultivated land spatial transformation from the perspectives of cultivated land quantity, cultivated land landscape pattern, and cultivated land management pattern, applying the Mann-Kendall trend tests, trend analysis, landscape pattern index measures, and global rural per capita cultivated indicators. The global cultivated land area increased, followed by a decrease, during the study period; there were three distinct phases of change, with the years 1995 and 2005 as turning points. During the first phase, the global cultivated land area increased at an average annual rate of 0.19 %, in the second phase, the increase rate was 0.30 %, and in the third phase, the increase rate was -0.003 %. Based on the trend of cultivated land change during the study period, the areas with a dramatic change in cultivated land area were classified into six typical hotspot areas, involving the increase and decrease of area change in 10 different countries. The two countries with the largest increases in cultivated land area are Sweden and Brazil (24.82 % and 24.43 %, respectively), whereas Ukraine's cultivated land area decreased throughout the study period.


Subject(s)
Conservation of Natural Resources , Brazil , Sweden , China
2.
J Environ Manage ; 188: 73-84, 2017 Mar 01.
Article in English | MEDLINE | ID: mdl-27930958

ABSTRACT

The conversion of natural ecosystems to agricultural land and urban areas plays a threat to the protected areas and the natural ecosystems conservation. The aim of this paper is to provide an analysis of the agricultural expansion and its impact on the landscape spatial and temporal patterns in a buffer zone of a protected area located in the transition zone between the Atlantic Forest and Cerrado, in the State of São Paulo, Brazil. The land use and land cover were mapped between 1971 and 2008 and landscape metrics were calculated to provide a spatiotemporal analysis of the forest structure and the expansion of the croplands. The results showed that the landscape patterns were affected by the economic cycles. The predominant crop surrounding the protected area is sugar cane, which increased by 39% during this period, followed by citrus. This landscape change is connected to the Brazilian oil crisis in 1973. The rapid expansion of sugar cane was largely driven by Brazil's biofuel program, the "Proálcool" (pro-alcohol), a project in 1975 that mixed ethanol with gas for automotive fuel. The forest loss occurred mainly between 1971 and 1988, decreasing the forest cover from 17% in 1971 to 12.7% in 2008. Most of the forest patches are smaller than 50 ha and has low connectivity. Throughout the years, the fragments in the buffer zone have become smaller and with an elongated shape, and the park has become isolated. This forest fragmentation process and the predominance of monoculture lands in the buffer zone threaten the protected areas, and can represent a barrier for these areas to provide the effective biodiversity conservation. The measures proposed are necessary to ensure the capability of this ecosystem to sustain its original biodiversity.


Subject(s)
Agriculture , Biodiversity , Conservation of Natural Resources/methods , Economic Development , Brazil , Crops, Agricultural , Ecosystem , Environment , Forestry/statistics & numerical data , Forests , Saccharum
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