Late-Glacial and Holocene forest dynamics at Steregoiu in the Gutaiului Mountains, Northwest Romania
Late-Glacial and Holocene forest dynamics at Steregoiu in the Gutaiului Mountains, Northwest Romania
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DOI：
10.1016/s0034-6667(02)00249-x
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发表时间：
2003-04-01
影响因子：
1.9
通讯作者：
Wohlfarth, B
中科院分区：
文献类型：
--
作者：
Björkman, L;Feurdean, A;Wohlfarth, B
对罗马尼亚西北部Gutaiului山脉中等海拔地区前火山口湖Steregoiu的湖泊沉积物和泥炭沉积进行了花粉分析和AMS C-14测量，以详细重建该地区在冰后期和全新世期间的植被发展。底部的沉积物是硅质碎屑，可能是在整个冰川时期沉积的，冰川的特点是开阔的斑驳植被，由灌木、草本植物和未生长的土地组成的马赛克。大约14700年前，随着富含有机质的湖泊沉积物开始沉积，一片开阔的松桦林扩大了。这一变化可能是对GRIP事件地层学中沸腾时期开始时的第一个去冰川变暖阶段(GI-1e)的反应。在13750至12950年间，该地区形成了以桦树、云杉、松树和榆树为主的疏林。森林组成意味着相当温暖的气候条件，这可能对应于Allerod或Gi-1c-Gi-1a。大约在12950卡尔·年前，森林开始收缩，到12600卡尔·年·BP时，开阔的斑驳植被得以重建。这些变化意味着回到明显更冷的条件，这可能对应于年轻的仙女木，或GS-1。在11500卡年BP时，白桦树、松树和赤杨树对温度上升做出了迅速的反应，这是全新世开始的特征。在几百年的时间里，大约11300年前，榆树和云杉重新建立起来，一种混合森林类型扩大了。Quercus、Tilia和Fraxinus可能在10750卡·BP左右到达，大约从这个时候开始，桦木和松树开始减少。距今10500年左右，该地区形成了以榆属、云杉、栎属、梧桐和白蜡树为主的茂密混交林。Corylus可能在公元前10500年左右在当地建立，但直到公元10200年才扩大。Tilia和Fraxinus在当地一直很重要，直到公元前8600年，云杉重新变得重要起来，湖泊变得完全杂草丛生。云杉可能是该遗址卡尔森林以及高地森林的重要组成部分。大约4800卡尔·BP·费格斯和马尾松在当地的林分中变得重要起来，显然没有对森林造成任何重大干扰。在公元前3400年左右之前，这片森林高度多样化，但当费格斯最终扩张时，榆属、丁香、云杉和梧桐属都减少了。从大约2200年开始，费格斯一直是当地森林的优势种，但也有一些栎属和Carpinus个体存在。人类影响当地植被的花粉证据相对较少。该地区可能从公元前1050年左右就被用于森林放牧，但直到公元前300年左右，放牧压力可能都很低。(C)2002 Elsevier Science B.V.保留所有权利。
Pollen analyses and AMS C-14 measurements were performed on lacustrine sediments and peat deposits from the former crater lake Steregoiu in a mid-altitude area in the Gutaiului Mountains in NW Romania in order to provide a detailed reconstruction of the vegetational development of the area during the Late-Glacial and Holocene. The bottom sediments are siliciclastic and were deposited probably during the Full Glacial, which is characterised by open patchy vegetation consisting of a mosaic of shrubs, herbs, and ungrown grounds. Around 14 700 cal yr BP an open Pinus-Betula forest expanded, at the same time as organic-rich lake sediments started to be deposited. This change was likely a response to the first deglacial warming phase at the beginning of the Boiling period, or GI-1e, in the GRIP event stratigraphy. Between 13 750 and 12 950 cal yr BP an open forest dominated by Betula, Picea, Pinus, and Ulmus developed in the area. The forest composition implies rather warm climatic conditions, which may correspond to the Allerod, or GI-1c-GI-1a. Around 12950 cal yr BP the forest retracted, and at 12600 cal yr BP open patchy vegetation became re-established. These changes imply a return to significantly colder conditions, which may correspond to the Younger Dryas, or GS-1. At 11500 cal yr BP Betula, Pinus, and Alnus quickly responded to the temperature rise, characterising the beginning of the Holocene. Within a few hundred years, around 11300 cal yr BP, Ulmus and Picea became re-established and a mixed forest type expanded. Quercus, Tilia, and Fraxinus likely arrived at around 10 750 cal yr BP, and from about this time Betula, and Pinus started to diminish. Around 10 500 cal yr BP a dense mixed forest dominated by Ulmus, Picea, Quercus, Tilia, and Fraxinus had developed in the area. Corylus probably became locally established around 10 500 cal yr BP, but it did not expand until 10 200 cal yr BP. Tilia and Fraxinus were locally important until 8600 cal yr BP, when Picea gained renewed importance and the lake became completely overgrown. Picea was probably an important constituent in the carr forest at the site as well as in the upland forest. Around 4800 cal yr BP Fagus and Carpinus became important in the local stand, apparently without any major disturbance of the forest. Until around 3400 cal yr BP the forest was highly diverse, but when Fagus eventually expanded, Ulmus, Tilia, Picea, and Corylus diminished. From about 2200 cal yr BP onwards Fagus has been the local forest dominant, but some Quercus and Carpinus individuals have been present as well. Pollen evidence for human influence on the local vegetation is comparatively scant. The area may have been used for forest grazing from about 1050 cal yr BP, but the grazing pressure was probably low until ca. 300 cal yr BP. (C) 2002 Elsevier Science B.V. All rights reserved.