Publication Date:
2015-11-24
Description:
Observations indicate that although average temperatures in Central Asia showed almost no increases from 1997 to 2013, they have been in a state of high variability. Despite the lack of a clear increasing trend, this 15-year period is still the hottest in nearly half a century. Precipitation in Central Asia remained relatively stable from 1960 to 1986, and then showed a sharp increase in 1987. Since the beginning of the 21st century, however, the increasing rate of precipitation has diminished. Dramatic changes in meteorological conditions could potentially have a strong impact on the region's natural ecosystems, as some significant changes have already occurred. Specifically, the NDVI of natural vegetation in Central Asia during 1982–2013 exhibited an increasing trend at a rate of 0.004 per decade prior to 1998, after which the trends reversed, and the NDVI decreased at a rate of 0.003 per decade. Moreover, our results indicate that shrub cover and patch size exhibited a significant increase in 2000–2013 compared to the 1980s-1990s, including shrub encroachment on grasslands. Over the past ten years, 8% of grassland has converted to shrubland. Precipitation increased in the 1990s, providing favorable conditions for vegetation growth, but precipitation slightly reduced at the end of the 2000s. Meanwhile, warming intensified 0.93 °C since 1997 compared to the average value in 1960–1997, causing less moisture to be available for vegetation growth in Central Asia.
Print ISSN:
0148-0227
Topics:
Geosciences
,
Physics
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