signature=5dd921e127ca4260f7a83c6b9e1f8542,A DNA signature for the expansion of irrigation in Bali?

摘要：

We mapped the temple, the irrigation canals that flow out of it, and the fields that depend on this flow (Figure 17.2). We also sank 18 soil cores to a depth of up to 5 meters and carried out analyses of sediment, pollen, and phytoliths on the samples thus extracted. We found that, as predicted, before the advent of irrigated rice cultivation, the valley bottom was a swampy forest dominated by palms and bananas. Taro was probably also grown but because it does not produce pollen, this could not be directly confirmed. Later, irrigated rice was grown in the small concave depression immediately downstream from the water temple. Sedimentology indicated a very rapid buildup of sediments after the appearance of irrigation systems. For example, a radiocarbon date from a core extracted from a currently unutilized terrace surface north of the temple showed that nearly 3 meters of soil had been deposited at this location in the past 500 years. Local farmers showed us how the predictable buildup of sediments could be managed to contour the landscape, enlarging the area suitable for terracing and facilitating the flow of water in small canals. The little basin located south of the temple widened as a result of sediment buildup, but even today it is much too small to use more than a small fraction of the water that flows from the springs. So at some point, the farmers began to construct a series of small tunnels, aqueducts, and canals, which now transport most of the flow 4 km downstream to the subak of Dlod Blungbang. Three of our 16 cores struck defunct irrigation tunnels, evidence for the frequency

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