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

The lower Yangtze, eastern China, was colonized by several Neolithic and Bronze Age cultures giving rise to possibly the highest concentration of prehistoric sites in the world. Early Neolithic cultures in the delta region cultivated rice ( Oryza sativa) and agricultural developments appear to have occurred throughout the Neolithic with abrupt socio-economic changes possibly associated with the terminal Neolithic. Given the extensive history of environmental exploitation and well-preserved archaeological sites, the Yangtze delta is an ideal setting to explore the complex interactions between humans and their environment. Multiproxies of environmental changes, namely pollen, charcoal and phytoliths, in a 14C AMS-dated sequence of sediments from an exposed profile at Qingpu, Yangtze delta, were investigated. 14C AMS dating indicates that the age range of the sedimentary sequence analysed is from c. 1800 to 6000 BP, and therefore encompasses the terminal Neolithic and subsequent Bronze Age in the region. This paper reviews this sediment-based evidence in the light of current understanding of human—environment interactions during a critical phase of the development of the Yangtze delta and associated human cultures.

Analyses of sedimentary evidence in the form of spores, pollen, freshwater algae, dinoflagellate cysts, phytoliths and charcoal from AMS 14C-dated, Holocene-aged sequences provide an excellent opportunity to examine the responses of Neolithic agriculturalists in the lower Yangtze to changing environments. Evidence from two sites close to the southern margin of the Yangtze delta and separated by what is now Hangzhou Bay attests the critical importance to early attempts at food production of access to freshwater resources. More readily, if episodically, available freshwater resources during the early to mid-Holocene on the Hangjiahu plain may have encouraged an early reliance on rice-based agriculture, which in turn facilitated the accumulation of agricultural surpluses and cultural diversification. Cultural change was relatively attenuated and human population pressures possibly lower on the Ningshao plain, seemingly because of much more profound environmental impacts of variations in local hydrological conditions, and because predominantly saline conditions, associated with rising relative sea level, hampered the early development of irrigated agriculture. The evidence, although largely dating to the early and middle parts of the Holocene, provides a timely warning of the complexity of vulnerability to climate change-induced processes of agriculture, and indeed human activities more generally, on megadeltas in Asia.

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Aim  This paper aims to reconstruct a high‐resolution fire and vegetation history from a period when humans were absent in Australia. This is then used to comment on the frequency of natural fire in high biodiversity heathland, and to compare this with historical fire regime in the same region. Methods  A section of varved sediment covering a period of c. 84 years was taken from Palaeolake Yallalie in south‐western Australia. The sediments were separated into approximately single to small multiples of years and then analysed for charcoal, pollen and sediment analysis to reconstruct the environmental conditions at the time. Results  The charcoal record indicates fire recurrence to have been roughly between 5 and 13 years, a little longer than those of the historical period. The pollen record was dominated by Casuarinaceae, Myrtaceae and a large number of Proteaceae species; these are intermixed with Araucariaceae, Nothofagus and Podocarpus. This suggests there was a mix of sclerophyll woodland and a mosaic of rain forest elements, thus conditions must have been wetter, particularly in the summers, compared with today. Conclusions  We assume that fire was most likely confined to the sclerophyll vegetation, and that fire has been a significant feature of the environment long before humans entered Australia. The slightly longer fire recurrence times compared with the present result from the intermittent nature of lightning and wetter summers at the time.

The Proteaceae family is a large Gondwanan plant family with a major centre of richness in south-western Australia. Modern pollen–vegetation relationships in the two areas of species richness in the northern and southern sandplains of south-western Australia were investigated to calibrate fossil-pollen studies concurrently conducted on Eocene, Pliocene and Quaternary sediment. Results indicated that the Proteaceae component in modern pollen rain can be quite high, contributing up to 50% of the count. Some sites showed a dominant type (such as Banksia–Dryandra), whilst others had up to six different genera represented. Exactly how and when the biodiversity of Proteaceae in south-western Australia developed is unknown. This work provides a benchmark for comparisons with studied fossil material to unravel patterns of diversity of this family in south-western Australia.

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Multiproxies of past environmental conditions, comprising 53 sediment samples analysed for their lithostratigraphic properties (mainly their charcoal, phytoliths and pollen contents) from an AMS 14C-dated sequence of sediments accumulating at Guangfulin, Yangtze delta, are presented. The oldest sediments recovered date to the Lateglacial when a mosaic of mixed (conifer-deciduous) temperate forest and wetland vegetation characterized the study area. The Lateglacial—Holocene transition and much of the early Holocene record to c. 7400 yr BP appears to be missing from the sequence. The earliest evidence possibly representing human activities in the study area (the remains of cereals and indicators of forest) date to c. 7000 yr BP. A large increase in macrocharcoal remains c. 4700 yr BP is a more certain indication of human activities close to the study site, and may indicate the first occupation of what is now the location of a major archaeological excavation at Guangfulin. Technological changes during the Eastern Zhou Dynasty (770—221 BC) may be responsible for an increased abundance of rice ( Oryza sp.), and possibly also foxtail or Chinese millet ( Setaria italica), detected in the Guangfulin record after c. 2400 yr BP. An abrupt sedimentary change at c. 4000 yr BP may represent a short-lived episode of catchment instability. Aside from this, the sediment record from Guangfulin contains no evidence of dramatic environmental changes that could have led to a major decline in agricultural productivity c. 4000 yr BP, as has been suggested for the lower Yangtze by some researchers, who associate this with the cultural transition from Liangzhu to Maqiao. The findings do, however, add weight to the argument that developments in rice-based agriculture on the Yangtze delta varied both spatially and temporally.