Unlocking wetland ecologies and agriculture in prehistory through sulphur isotopes.

自从农业出现以来，水一直是农业生产力的核心。然而，人们过去利用自然水资源的方式，或操纵这些资源以满足他们的需求的方式，并没有得到充分的理解。虽然考古学家可以通过这些做法留下的灌溉基础设施和工具，或从详细说明农业战略的文本中找到过去使用的水管理系统的间接证据，但他们目前没有足够的方法来直接确定特定田地/作物/动物生长的水条件，特别是在可能大量使用湿地的景观中。这些信息之所以重要，有几个原因。过去对水资源的利用被认为是提高作物生产力、确保粮食安全和创造农业盈余的根本；所有这些因素都被认为使人口增长和日益复杂的社会发展成为可能。然而，水资源的利用也被认为产生了重大的环境后果，如生物多样性的丧失和温室气体排放的增加。了解这些发展和影响对我们目前的粮食生产系统具有影响，特别是在应对在日益不可预测的气候下保持农业生产力的挑战方面。为了解决这个问题，我们的项目将开发一种新的工具来检测过去人口的农业用水情况。具体地说，我们将利用动物和植物化石，通过硫同位素分析来了解农业中的水利用情况。植物和动物中的硫来自植物生长或动物喂养的土壤。目前的数据表明，土壤中的水分可能会影响植物的硫同位素值。如果这种关系能够量化，考古材料中的硫同位素就可以用来推断过去的灌溉制度。我们的项目将在受控生长实验中研究现代土壤和植物中的硫同位素。我们将在一些不同的水分条件下种植植物，并测量植物的硫同位素组成。这一分析将使我们能够量化浇水和植物同位素之间的关系，这将使我们能够将这种方法应用于考古样本。为了测试该方法在考古样本上的效果，我们将把新方法应用于两个具体的考古案例研究，其中间接证据表明，农业发展与水的可获得性或用途的变化有关。具体地说，我们将分析泰晤士河流域和泰国的考古材料，泰晤士河流域的农业实践与河流洪水的自然循环有关，泰国的水稻农业生产被认为已从低维护的干旱系统转变为高维护的湿系统，以应对气候变化。这些应用程序将使我们能够验证该方法，使其能够应用于其他考古背景。这将有助于更好地了解世界各地过去如何利用水资源，提供有关不同气候系统下农业复原力、可持续性和管理的重要信息；这些信息对于确保我们现有的粮食生产系统能够应对气候变化所面临的挑战至关重要。

Since the advent of farming, water has been central to agricultural productivity. However, the way in which people made use of natural water resources in the past, or manipulated these resources to meet their needs, is not adequately understood. While archaeologists can find indirect evidence of water management systems used in the past through the irrigation infrastructure and tools that these practices left behind, or from texts detailing agricultural strategies, they currently do not have adequate methods to directly determine the water conditions a particular field/crop/animal was raised under, particularly in landscapes where the use of wetlands may have been significant. This information is important for several reasons. The harnessing of water resources in the past are thought to have been fundamental to increasing crop productivity, ensuring food security and creating an agricultural surplus; these factors are all thought to have enabled population growth and the development of increasingly complex societies. However, the harnessing of water resources is also thought to have had significant environmental consequences such as a loss of biodiversity and increased greenhouse gas emissions. Understanding these developments and impacts has implications for our current food production systems, especially in meeting the challenges of maintaining agricultural productivity under an ever-increasingly unpredictable climate. To address this issue, our project will develop a new tool for detecting agricultural water use by past populations. Specifically, we will use fossil animal and plant remains to understand water use in agriculture through sulphur isotope analysis. Sulphur in plants and animals comes from the soil upon which the plant grew, or the animal fed. Current data shows that the amount of water in the soil likely influences plant sulphur isotope values. If this relationship can be quantified, sulphur isotopes in archaeological material can be used to infer past watering regimes. Our project will study sulphur isotopes in modern soils and plants in a controlled growth experiment. We will grow plants under a number of different water regimes and measure the plant sulphur isotope compositions. This analysis will allow us to quantify the relationship between watering and plant isotopes, which will then allow us to apply this method to archaeological samples.To test that the method works on archaeological samples we will apply the new method to two specific archaeological case studies, where indirect evidence suggests agricultural developments were linked to changing water availability or use. Specifically, we will analyse archaeological material from the Thames river valley, where agricultural practices have been linked to the natural cycle of river flooding, and from Thailand, where agricultural production of rice is thought to have shift from low-maintenance dry systems to high-maintenance wet systems in response to climate change. These applications will allow us to validate the method, enabling it to be applied to other archaeological contexts. This will facilitate better understanding of how water resources were harnessed in the past in different locations around the world, providing important information on agricultural resilience, sustainability and management under different climate systems; information that is vital to ensuring our current food production systems stand up to the challenges faced by climate change.