CNH2-L: Climate Change and the Coupled Dynamics of Tropical Forest Ecology and Human Food Production

粮食生产的出现代表着人类社会历史上最重大的积极变化之一。粮食生产为几乎所有随后的文化发展奠定了基础。与这些变化相一致的是，文化选择取代了自然选择，成为动植物物种生态和进化的决定性力量。粮食生产与气候和干旱密切相关，这些因素的重大变化往往导致生产中断和文化崩溃。该奖项调查了3000-6000年前中美洲伯利兹热带低地的粮食生产起源，以及对4200年前开始的三个世纪干旱的生态和文化反应。将使用气候建模、环境重建和人类适应的考古推断来评估这些因素和不断变化的社会环境动态之间的长期关系。这项研究将为数千代人应对环境变化的经验提供洞察力，并提供潜在的指导，使子孙后代能够更好地适应重大环境变化。这项研究在促进对人类如何养活自己和热带森林生态之间相互作用的基本理解方面具有革命性意义，以应对深刻的环境变化。该奖项将研究干燥的环境条件如何影响人类的生存实践，以及集约化的粮食生产反过来如何影响当地的植被模式。粮食生产是人类物种历史上最重大的发展之一，也是某些动植物物种进化的决定性力量。长期以来，粮食生产一直被认为是通过增加土地的承载能力、可能的封建程度以及更大的人口密度，为几乎所有随后的文化发展奠定了基础。因此，粮食生产是建立城市生活的必要先决条件。粮食生产也是保障社会分工的必要因素，这种分工使农民能够支持越来越多的非生产者，如政治尺子、牧师、工程师和科学家。环境变化常常被认为是导致文化崩溃的原因。中美洲伯利兹北部热带低地人类占领和森林植物物种多样性的重建将重建6000-3000年前，以记录气候变化如何影响粮食生产和定居模式，进而记录当地植被是如何重建的。这一重建将通过结合考古挖掘和湖泊沉积物取心来完成，这些考古挖掘记录了人类居住和湖泊沉积物取心，以重建经济有用物种的植物花粉和木炭的变化模式，这些植物花粉是人类燃烧当地植被以提高土壤生产力的结果。研究将集中在4200至3900年前在全球范围内造成三个世纪气候扰动的“4.2 ka BP事件”。这一时期之前、期间和之后的人类聚居地模式和饮食的证据将被用来评估物种可获得性变化的古生态证据以及通过使用火造成的人为干扰的程度。人类居住模式和饮食的证据将根据生态位构建理论(NCT)和最佳觅食理论(OFT)的预期进行评估，并与物种可获得性变化的证据和火对景观的人为干扰程度相关。该奖项反映了NSF的法定使命，并通过使用基金会的智力价值和更广泛的影响审查标准进行评估，被认为值得支持。

The emergence of food production represents one of the most significant positive changes in the history of human society. Food production set the stage for virtually all subsequent cultural developments. Coincident with these changes was the rise of cultural selection replacing natural selection as the determining force in the ecology and evolution of plant and animal species. Food production was tightly tied to climate and drought and significant changes in these factors often resulted in disruption of production and cultural collapse. This award investigates the origins of food production in the tropical lowlands of Belize, Central America occurring from 3000-6000 years ago and the ecological and cultural response to a three-century drought that began 4200 years ago. Climate modeling, environmental reconstruction and archaeological inference of human adaptation will be used to evaluate the long-term relationships among these factors and changing socio-environmental dynamics. This study will provide insights to the experience of thousands of generations of human responses to environmental change and potential guidance so that future generations can be more resilient to major environmental changes. This research is transformative in advancing basic understanding of interactions between how human populations feed themselves and tropical forest ecology in response to profound environmental change. This award will examine how drying environmental conditions affect human subsistence practices and how intensified food production, in turn, affect local vegetation patterns. Food production is one of the most significant developments in the history of the human species and as the determining force in the evolution of a select number of plant and animal species. Food production has long been acknowledged as setting the stage for virtually all subsequent cultural developments by increasing the carrying capacity of land, the degree of sedentism that is possible as well as greater population density. As a result, the production of food was a required prerequisite for the establishment of urban life. Food production is also necessary to underwrite the division of labor within society that allowed farmers to support ever-increasing numbers of non-producers such as political rulers, priests, engineers and scientists. Environmental change is often posited as resulting in cultural collapse. The reconstruction of human occupation and forest floral species diversity in the tropical lowlands of northern Belize, Central America will be reconstructed from 6000-3000 year ago to document how food production and settlement patterns were affected by climate change and, in turn, how local vegetation was reconstituted. This reconstruction will be accomplished by combining archaeological excavation that document human habitation and lake sediment coring to reconstruct changing patterns of plant pollen from economically useful species and charcoal that result from human burning of local vegetation to increase soil productivity. Research will focus on the "4.2 ka BP event" that caused three centuries of climate disturbance world-wide between 4200 and 3900 years ago. Evidence of human settlement patterns and diet from before, during and after this period will be used to evaluate paleoecological evidence of changing species availability and the extent of anthropogenic disturbance through the use of fire. Evidence of human settlement patterns and diet will be evaluated in light of expectations of niche construction theory (NCT) and optimal foraging theory (OFT) and related to evidence of changing species availability and the extent of anthropogenic disturbance on the landscape with fire.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.