Influence of Little Ice Age on New England Vegetation from 2000 BP to Present

This multi-proxy study uses paleoecological, paleolimnological, and historical approaches to reconstruct climate, vegetation, and cultural dynamics over the past 1500 years at sites arrayed across the climatic and forest gradients of New England and to place these results in a regional framework through analysis of pollen records from the North American Pollen Database. High resolution records were obtained using pollen to interpret vegetation history; chironomids, stable isotopes, geochemistry, and diatoms, supplemented by historical reconstructions, to interpret climate history; charcoal and land-use data to document the human impacts; and Pb-210 and C-14 for chronological control. Results will provide: (1) an objective characterization of the Little Ice Age and climate history in New England, (2) comparison of pre- and post-European forest dynamics in relationship to independent environmental and land-use histories, (3) a reexamination of historical vegetation dynamics in light of prior climate an vegetation change, and (4) widespread availability of data and results through publications, symposium presentation, and the Harvard Forest Archives and web pages.

本多代用指标研究采用古生态学、古湖沼学与历史学研究方法，针对分布于新英格兰地区气候与森林梯度带的多个遗址，重建过去1500年的气候、植被及文化动态；并通过北美花粉数据库（North American Pollen Database）的花粉记录分析，将研究结果纳入区域研究框架。本研究通过以下手段获取高分辨率记录：利用花粉解析植被历史；借助摇蚊（chironomids）、稳定同位素、地球化学与硅藻，并辅以历史重建结果，解析气候历史；采用木炭与土地利用数据记录人类活动影响；利用铅-210（Pb-210）与碳-14（C-14）测年实现年代学控制。本研究预期产出以下成果：（1）对新英格兰地区小冰期（Little Ice Age）与气候历史的客观特征刻画；（2）对比欧洲殖民前后森林动态与独立环境及土地利用历史的关联；（3）结合既往气候与植被变化，对历史植被动态进行重新审视；（4）通过学术发表、研讨会展示以及哈佛森林档案馆（Harvard Forest Archives）与官方网页，实现数据与研究成果的广泛共享。