The North American prairie-forest border is a major biogeographic boundary ultimately determined by the macroclimate. Climate variability during the Holocene affected the vegetation in this area, but impacts on human paleodemography are unknown. At a regional scale, community structure is partly determined by fire, however the extent to which anthropogenic burning has affected fire regimes over the Holocene is unresolved. This study investigates the interaction between climate variability, vegetation changes, fire regimes, and human population levels in the North American prairie-forest ecotone during the Holocene using information from publically-available paleoenvironmental databases. Biomass burning was associated with moisture and vegetation more than with human population size, suggesting anthropogenic burning did not significantly influence the composition and location of the prairie-forest border. Human population growth rates were impacted by sociocultural developments and environmental changes, with most changes in subsistence strategies occurring during climate regime shifts. The development of the Eastern Agricultural Complex (5.0 – 3.8 ka) and the transition to more mesic conditions after 4.0 ka facilitated long-term population growth. The arrival of maize and the bow-and-arrow at 2.2 and 1.6 ka, respectively, resulted in increased population growth, and after 1 ka, maize agriculture intensification, aided by a warmer climate, accelerated population growth. The collapse of the city of Cahokia is linked to a wider population decline across the Midwest precipitated by the Medieval Warm Period – Little Ice Age transition. Populations across a significant portion of North America were in decline at the time of European colonization. These findings provide evidence against a large-scale early Anthropocene in North America, and illustrate the importance of climate change in influencing human history.

北美草原森林边界是最终由大气候决定的主要生物地理边界。全新世期间的气候变化影响了该地区的植被，但对人类古人口统计学的影响尚不清楚。在区域范围内，群落结构部分由火决定，但人为燃烧对全新世火情的影响程度尚无定论。本研究利用公开的古环境数据库中的信息，调查了全新世期间北美草原-森林交错带的气候变异性、植被变化、火灾规律和人口水平之间的相互作用。与人口规模相比，生物质燃烧与水分和植被的相关性更大，表明人为燃烧并未显着影响草原森林边界的组成和位置。人口增长率受到社会文化发展和环境变化的影响，大多数生存策略的变化发生在气候制度转变期间。东部农业综合体（5.0 – 3.8 ka）的发展以及 4.0 ka 后向更温和条件的过渡促进了长期人口增长。玉米和弓箭分别在 2.2 和 1.6 ka 到来，导致人口增长增加，而在 1 ka 之后，在气候变暖的帮助下，玉米农业集约化加速了人口增长。卡霍基亚 (Cahokia) 市的倒塌与中西部地区更广泛的人口下降有关，这是由于中世纪暖期 - 小冰河时代的过渡导致的。在欧洲殖民时期，北美大部分地区的人口都在下降。这些发现提供了反对北美早期大规模人类世的证据，并说明了气候变化在影响人类历史方面的重要性。