The impact of evolving of rice systems from China to Southeast Asia

As the world's most productive crop, the history and potential of rice is of great interest to crop scientists and archaeologists, and as a greenhouse gas producer its history is important to climatic modelling. Understanding the development, diversification and spread of rice agriculture is central not only to our understanding of the processes of human population growth, dispersal and formation of civi-lizations in Asia, it is also central to reconstructing how past agricultural activities might have im-pacted global climate through methane emissions and deforestation. Archaeobotanical evidence offers a powerful set of tools for not only documenting where and when rice was cultivated in the past, but how it was cultivated through the analysis of ecology of associated weed flora in macro-remains assemblages and phytolith assemblages. We have pio-neered the study archaeological rice weed flora and the combination of archaeological plant macro-remains and phytoliths in our recent NERC-supported research in parts of India, Sri Lanka and China (NE/G005540/1). We propose to roll out this method over a wider geographical and cultural area, as well refining the approach through some additional modern analogues. we propose to focus our work on the less known parts of Asia, especially mainland Southeast Asia and the southern parts of China, as well as further work in the eastern parts of India. These regions are central to hypotheses on the dispersal of rice cultivation, including models linking the spread of rice to major language families such as Austroasiatic and Austronesian, and yet a lack systematically-studied evidence for rice cultivation itself, or evidence as to whether early rice represented an extension of the alluvial wetland cultivation systems like those of the Neolithic Yangtze (early subspecies japonica, typical of many modern temperate japonica) or the develop-ment of upland rainfed systems (the latter typical of many modern tropical japonica rices), with a secondary later parallel evolution of irrigated wet rice systems amongst indica rices. Therefore we will use a combination of archaeobotanical seed remains, including weed flora, and phytoliths to reconstruct the earliest rice cultivation systems (Neolithic-Bronze Age) along the three hypothesized trajectories of rice diffusion southwards from the Yangtze basin towards south-east Asia, namely in Yunnan, Guangdong, and Fujian, as well as across a range of subregions, environments and periods in mainland Southeast Asia (mainly in Thailand and Vietnam) to assess the extent to which rainfed and wet irrigated systems were practiced, and whether different regional patterns or a single evolutionary trajectory can be reconstructed.On the basis of our reconstructed rice arable systems and weed flora assemblages to as-sess the likelihood of single or multiple pathways for the spread of rice into Southeast Asia, by analysing the geographical and chronological patterns of weed flora. We will then use our improved understanding of how rice was cultivated in different times and periods of southern China and Southeastern Asia to produce improved models of past wetland rice area and linked methane emissions over time, grounded in the empirical evidence for past rice cultivation. Results will be of direct relevance to prehistorians and quaternary scientists interested in Holocene Asia and rice agriculture, but such results will have a wider impact in terms of assessing the regional and global impact, and sustainability, of different traditions of rice agriculture, and its contribution to ancient anthropogenic methane emissions.

Beyond academia this research will impact on a broad demographic of potential users both locally and internationally by forging new links and building on existing partnerships developed in our previous grant.

- We have an established partnership with a local secondary school, the Hungerford School, and plan to extend this. Group visits to the archaeobotany laboratory at UCL and school visits with archaeobotanical and environmental activities where students can engage with archaeobotanical work first hand will enrich science education and encourage potential future researchers to consider a scientific path.

- Our continued presence at The Bloomsbury Festival http://www.bloomsburyfestival.org.uk/ will further engage the local community in Bloomsbury as well as the wider University community and general public. As in our current project, our archaeology student volunteers will benefit from the experience of presenting archaeobotanical related activities in a public context, while the local community will have the opportunity to participate in rice related activities, raising awareness of some of the impacts agriculture and sustainable foods can have on the environment.

- The local Bangladeshi community will benefit from events organized in collaboration with this project and the Wellcome Trust and we hope their experiences and knowledge will feed back into our project and the wider community.

- Our exhibitions at UCL and Kew Gardens will engage the UCL community and the wider public, including international visitors.

- The reconstructed ancient rice paddy at Kew Gardens will bring the project to a wide audience and raise awareness of the continuing development of farming from prehistory to the present.

International knowledge exchange through partnerships between local schools and schools in the regions we are studying will benefit all participants.

- The international exchange with schools in our research areas will provide long term benefit after the project has finished. This is also the potential basis for a wider academic network between the schools, Deccan College and UCL.

- There will be international engagement through the collaboration with our project partner's institutions. This is an opportunity for a wider international archaeological and archaeobotanical network in areas where little archaeobotanical work has taken place. There is vast and exciting potential for knowledge exchange between students and academics within our research areas.

- The website and social media feeds, along with the project blog, will provide local and international forums linking all strands of the project benefitting both academic and outreach. These will also play a part in documenting the activity and impacts of the project.

Social and economic impacts of this project arise from the development of communication and collaboration between the variety of groups and individuals within the local, university and international communities facilitated by our project. It is hoped the international exchange will provide long lasting ties between the schools and students involved and promote archaeobotany as a discipline in places where, up until now, it has been rarely practiced. This project has great potential to serve as an educational vehicle for schools, local communities and the broader general public and as a meeting point for home and international students and researchers through the creation of international networks.