Holocene climatic and environmental changes in the arid and semi-arid areas of China: a review

Abstract

This paper reviews recently published literature, most of which was published in Chinese, and searches for regional patterns of Holocene changes useful in depicting global patterns. The Holocene in the Xinjiang region can be divided into three stages: a warming and dry early stage (from 11 10 to 8-7 ka BP), a warm and wet middle stage (from 8-7 to 4.5-3 ka BP) and a fluctuating cool and dry late stage (since 4.5-3 ka BP). The Holocene in the northern Tibetan Plateau can also be divided into three stages: a warming and wet stage (from 10.5-10 to 5-4 ka BP), followed by a variable drying and probably warm stage (5-4 to 3 ka BP) and ending with a cool and dry stage (since 3 ka BP). In the Inner Mongolian Plateau, the early Holocene (from 10.5-9.5 to 8-7.5 ka BP) was warming and dry, and a warm and wet climate occurred from 7.5 to 3.5, during which the best time was 6.3-3.8 ka BP; the climate has been variably drying and probably cooling since 3.5 ka BP. In the northwestern part of the Loess Plateau, several Holocene palaeosols have been identified (10-9, 7.5-5, 4-3 and 2.7-2 ka BP) with the 7.5-5 ka BP palaeosol being most strongly expressed. The best-developed palaeosol-equivalent in major valleys is a swamp-wetland facies deposited between 8885 and 3805 14C yr BP under an extremely wet regime. The climate has fluctuated significantly at least three times around a dry and probably cool regime after the swamp-wetland facies-depositional period. Our summary shows that the Holocene Climatic Optimum occurred nearly contemporaneously (8-5 ka BP) at all sites in the Xinjiang region, in the Inner Mongolian Plateau and in the northwestern part of the Loess Plateau. A warming and wet early Holocene (10-8 ka BP) in the northern Tibetan Plateau is most likely related to high effective soil moisture resulting from snow and ice melting. We propose here that the middle Holocene Climatic Optimum (8-5 ka BP) in arid to semi-arid China was primarily a delayed response of the low latitude oceans to high latitude peak insolation (9-8 ka BP).

Earliest domestication of common millet ( Panicum miliaceum ) in East Asia extended to 10,000 years ago

“…8,700-5,500 cal yr BP) conditions. Many lacustrine and loess records from the Chinese Loess Plateau to Central Asia also support the scenario of a dry climate during the early Holocene (30)(31)(32)(33)(34). Under the drier climate conditions, soil development was slowed, and the soil developed on the underlying older and coarser loess of the glacial period was poor in nutrients (28).…”

Pollen Evidence of a Humid Mid-Holocene Climate from Bahar Nuur, Inner Mongolia

“…The warmer and wetter climate associated with the Holocene Climatic Optimum lead to denser vegetation cover, which might have further promoted the Optimum through the feedback mechanism related to the air-vegetation-soil coupling under the denser vegetated wetter conditions [3]. It is plausible that the humid mid-Holocene is a lagged response to Asian monsoon and peak summer insolation in the Northern Hemisphere.…”

“…Holocene solar insolation peaked at ~10 ka BP in northern semi-sphere [34]. However, the existence of substantial ice given the enhanced evaporation on west Pasific which effectively injected more water vapor into the East Asian monsoon system during ~10 ka to ~6 ka BP [3].…”

“…However, our knowledge regarding the recent climate his-tory in this area is limited. A warm and wet mid-Holocene climate has been widely reported in the East Asian Monsoon-influenced semiarid areas of northern China [3] [4]. However, other researchers suggest a dry mid-Holocene in the south Ordos Plateau based on multi-proxy data [5] [6] [7], while another study from the northwestern edge of the Ordos Plateau suggests extremely dry conditions during 8 -4 ka BP [8].…”

Phytolith evidence for rice cultivation and spread in Mid-Late Neolithic archaeological sites in central North China

“…During the Holocene optimum (early to middle Neolithic), areas in central and eastern China experienced mainly a warm and humid climate. The strengthened summer monsoon brought much more precipitation to these areas, in which vast regions of wetland and bogs occurred (Shi et al 1993;An et al 2000;Yi et al 2003;Feng et al 2004Feng et al , 2006Xiao et al 2004;An et al 2006;Rosen 2008). Guanzhong Basin was also controlled by a warm and wet climate (Lu & Zhang 2008), which was largely beneficial for the spread of rice towards the west along the Huanghe River valley.…”