江陵地区全新世早期人类活动的孢粉记录

江陵剖面沉积物孢粉提供全新世早期人类活动的证据。早期人类活动始于6 200 a B.P.,人类大规模活动始于3 400 a B.P.。随着定居点扩大和人类活动加强,地表土壤侵蚀严重,入湖的陆源粗颗粒物质和营养物质增多。湖泊沉积物表现为粗颗粒含量迅速增加,各粒径波动频繁,TOC、TN和C/N的高值以及有机质δ¹³C的低值。2 500 a B.P.以后,沉积环境发生了显著变化,由湖泊及湖沼堆积转化为洪水漫滩堆积,气候变干,人类逐渐撤离该地区。

Palynological Records of Early Human Activities in Holocene at Jiangling Area,Hubei Province

The evidence of human activities around Jiangling area was revealed by sporo-pollen records from sediments in the Jiangling section, Hubei Province. The preliminary human activities started from about 6 200 yr B.P., marked by cultivation on economic crop Papaverraceae and the increased occurrence of pasture plant, such as Labiatae and Plantago. The increased herbs of pasture and crop suggested the primitive stockbreeding and agriculture in the study region. The human activities increased from about 4 700 yr B.P. The broad-leaved trees of Betula and Ulmus, and the aquatic herbs of Myriophyllum, and the spore of Selaginella and Microlepria, started to appear continuously in large amounts, and the weed plants of Artemisia had a speedy increase. The human activities were mainly agricultural planting and grazing near settlement, yet with small piece of economic trees. The large-scale human activities started from 3 400 yr B.P., the Gramineae content ascended fleetly, suggesting the extension of farmland around the lake shore. The broad-leaved trees of Betula, Ulmus, and the herbs of Papaverraceae, Labiatae, Plantago, Artemisia, Chenopodiaceae, Myriophyllum, and the spore of Selaginella, Microlepria had a evident increase. The increases in broad-leaved trees and weed herbs indicate the expansion of settlement around which broad-leaved trees were replanted. The extension of settlement and the enhancement of human activities resulted in the enhanced erosion of surface soil and the increase of coarse particle matters from land and nutritive material. The lacustrine sediments were characterized by the prompt increase of coarse materials, and frequent fluctuation of different forms of grain size, and high value of TOC, TN, and C/N, and low value of organic matter δ¹³C. The sedimental environment came to evident variance after 2 500 yr B.P., that is, lacustrine and limnic deposit became to floodplain deposit, and human evacuate from Jiangling area by degrees.