Department of Environmental Sciences, Informatics and Statistics, Ca' Foscari University of Venice, Via Torino 155, 30170, Venezia Mestre, VE, Italy.
Institute for the Dynamic of Environmental Processes (IDPA-CNR), Via Torino 155, 30170, Venezia Mestre, VE, Italy.
Sci Rep. 2018 Aug 14;8(1):12113. doi: 10.1038/s41598-018-30606-3.
Deforestation associated with the initial settlement of New Zealand is a dramatic example of how humans can alter landscapes through fire. However, evidence linking early human presence and land-cover change is inferential in most continental sites. We employed a multi-proxy approach to reconstruct anthropogenic land use in New Zealand's South Island over the last millennium using fecal and plant sterols as indicators of human activity and monosaccharide anhydrides, polycyclic aromatic hydrocarbons, charcoal and pollen as tracers of fire and vegetation change in lake-sediment cores. Our data provide a direct record of local human presence in Lake Kirkpatrick and Lake Diamond watersheds at the time of deforestation and a new and stronger case of human agency linked with forest clearance. The first detection of human presence matches charcoal and biomarker evidence for initial burning at c. AD 1350. Sterols decreased shortly after to values suggesting the sporadic presence of people and then rose to unprecedented levels after the European settlement. Our results confirm that initial human arrival in New Zealand was associated with brief and intense burning activities. Testing our approach in a context of well-established fire history provides a new tool for understanding cause-effect relationships in more complex continental reconstructions.
与新西兰最初定居点相关的森林砍伐是人类如何通过火灾改变景观的一个显著例子。然而,在大多数大陆遗址中,将早期人类存在与土地覆盖变化联系起来的证据都是推论性的。我们采用多指标方法,利用粪便和植物甾醇作为人类活动的指标,利用单糖酐、多环芳烃、木炭和花粉作为湖泊沉积物核心中火和植被变化的示踪剂,在过去一千年里重建了新西兰南岛的人为土地利用情况。我们的数据为在砍伐森林时的 Kirkpatrick 湖和 Diamond 湖流域的当地人类存在提供了直接记录,并且与森林砍伐有关的人类活动的证据更加直接和有力。人类存在的首次检测与公元 1350 年左右最初燃烧的木炭和生物标志物证据相吻合。甾醇在短暂下降到表明人们偶尔存在的值后,在欧洲人定居后又上升到了前所未有的水平。我们的结果证实,新西兰的最初人类到达与短暂而强烈的燃烧活动有关。在有明确火灾历史的背景下测试我们的方法为理解更复杂的大陆重建中的因果关系提供了一个新工具。