Holocene-aged sedimentary records of environmental changes and early agriculture in the lower Yangtze, China

Abstract

Sedimentary evidence from a total of 21 AMS 14 C dates and 192 pollen and charcoal and 181 phytolith samples from three study sites in the archaeologically rich lower Yangtze in China provides an indication of interactions between early agriculturalists and generally highly dynamic environmental conditions. Results suggest that environmental changes influenced agricultural development, and attest the localised environmental impacts of incipient agriculture. Evidence of human activity, in the form of indicators of deforestation and possibly food production, is apparent by ca 7000 BP (early Neolithic or Majiabang). Clearer evidence of human activity dates to ca 4700 BP (late Neolithic or Liangzhu). Extensive, profound and apparently widespread human impacts do not appear until the Eastern Zhou (Iron Age, ca 2800-2200 BP), however, which in the lower Yangtze was a period associated with technological advances in agriculture, increased urbanisation and relatively stable hydro-geomorphological conditions. r

Environmental history, palaeoecology and human activity at the early Neolithic forager/cultivator site at Kuahuqiao, Hangzhou, eastern China

“…This is despite the propensity for dates on alluvial sediment to yield anomalous results because of the incorporation of material reworked and transported by fluvial action from areas away from the site of deposition. Such dating effects have been reported from the Yangtze system (Stanley and Chen, 2000;Stanley and Hait, 2000) and from the Hangzhou lowlands (Atahan et al, 2008). But the Kuahuqiao site, despite its closeness to the head of a significant river estuary, appears to have escaped such adulteration, because its sheltered location and its deposition as an organic marsh soil rather than as natural alluvial accumulation comprising material eroded from higher in the catchment.…”

“…Gramineae (grass) pollen has been divided into two size classes in order to differentiate grains likely to be of cereal (Oryza) type (40 μm and above) from other wild grasses (<40 μm), following and Chatuvedi et al (1998), and as adopted by previous investigators, e.g. Atahan et al (2008). Microscopic charcoal particles (microcharcoal) were counted upon the microscope slides relative to the standard pollen sum, providing a pollen/microcharcoal ratio.…”

“…A multi-core study (Waller, 1998) would have been necessary to reconstruct fully the vegetational and palaeoenvironmental history of the marshland landscape around Kuahuqiao but this is not the purpose of this research and so such a study has not been undertaken. Single-core studies elsewhere in the Taihu region (Okuda et al, 2003;Atahan et al, 2008) have provided high-quality information regarding geographical changes and human activity.…”

Domestication as innovation: the entanglement of techniques, technology and chance in the domestication of cereal crops

“…Willcox et al 2009). For the Lower Yangtze these include the evidence for land management and some domesticated spikelet bases from Kuahuqiao (Zheng et al 2007;Zong et al 2007), and more questionably the microcharcoal record at Loujiang (LJ) (Atahan et al 2008), and the archaeobotanically poor Shangshan (Liu et al 2007); for discussion see Fuller and Qin (2009). The approximate durations of incipient and intensifying pre-domestication, referred to in the text, are indicated.…”

Ecology and hydrology of early rice farming: geoarchaeological and palaeo-ecological evidence from the Late Holocene paddy field site at Maoshan, the Lower Yangtze

“…This indicates that these locations were on low topography and subject to long inundations. The Middle to Late Holocene climate in the Yangtze Delta and nearby regions was humid and wet as consistently shown by several pollen and geochemical studies (Atahan et al 2008;Tao et al 2006;Yi et al 2003;Yu et al 2000). This climate condition promoted the expansion of 'subtropical evergreendeciduous broadleaved forests' (Yi et al 2003) between c. 7600 and 4800 cal.…”