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

粮食生产的出现是人类社会历史上最重要的积极变化之一。粮食生产为后来几乎所有的文化发展奠定了基础。与这些变化相一致的是，文化选择的兴起取代了自然选择，成为动植物物种生态学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粮食生产的起源，以及对4200年前开始的长达三个世纪的干旱的生态和文化反应。气候模拟、环境重建和人类适应的考古推断将用于评估这些因素与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类对环境变化的反应提供见解，并提供潜在的指导，以便后代能够更适应重大的环境变化。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变革性，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方式，以及集约化的粮食生产如何反过来影响当地的植被模式。粮食生产是人类历史上最重要的发展之一，也是许多植物和动物物种进化的决定性力量。长期以来，人们一直认为粮食生产通过增加土地的承载能力、可能的定居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。粮食生产对于保证社会内部的劳动分工也是必要的，这种分工使农民能够养活越来越多的非生产者，如政治统治者、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。重建中美洲伯利兹北部热带低地的人类活动和森林植物物种多样性将从6000-3000年前进行重建，以记录粮食生产和定居模式如何受到气候变化的影响，进而记录当地植被如何重建。这种重建将通过结合考古发掘来完成，这些考古发掘记录了人类居住和湖泊沉积物的岩心，以重建具有经济价值的物种的植物花粉的变化模式和人类燃烧当地植被以提高土壤生产力所产生的木炭。研究将集中在“4.2 ka BP事件”上，该事件在4200年至3900年前造成了三个世纪的全球气候扰动。在此之前、期间和之后的人类居住模式和饮食证据将用于评估物种可用性变化的古生态证据和通过使用火的人为干扰程度。人类居住模式和饮食的证据将根据生态位构建理论（NCT）和最优觅食理论（OFT）的期望进行评估，并与物种可用性变化的证据和火灾对景观的人为干扰程度相关。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识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.