DOI: 10.1016/j.palaeo.2012.12.001
论文题名: Forest dynamics during the transition from the Oldest Dryas to the Bølling-Allerød at Gerzensee-a simulation study
作者: Lischke H. ; von Grafenstein U. ; Ammann B.
刊名: Palaeogeography, Palaeoclimatology, Palaeoecology
ISSN: 0031-0182
出版年: 2013
卷: 391 起始页码: 60
结束页码: 73
语种: 英语
英文关键词: δ18O
; Albedo
; Facilitation
; Forest modeling
; Migration
; Oldest Dryas-Bølling transition
; Pollen
; Scenario study
; Vegetation change
英文摘要: The aim of this study was to explore potential causes and mechanisms for the sequence and temporal pattern of tree taxa, specifically for the shift from shrub-tundra to birch-juniper woodland during and after the transition from the Oldest Dryas to the Bølling-Allerød in the region surrounding the lake Gerzensee in southern Central Europe. We tested the influence of climate, forest dynamics, community dynamics compared to other causes for delays.For this aim temperature reconstructed from a δ18O-record was used as input driving the multi-species forest-landscape model TreeMig. In a stepwise scenario analysis, population dynamics along with pollen production and transport were simulated and compared with pollen-influx data, according to scenarios of different δ18O/temperature sensitivities, different precipitation levels, with/without inter-specific competition, and with/without prescribed arrival of species. In the best-fitting scenarios, the effects on competitive relationships, pollen production, spatial forest structure, albedo, and surface roughness were examined in more detail.The appearance of most taxa in the data could only be explained by the coldest temperature scenario with a sensitivity of 0.3‰/°C, corresponding to an anomaly of - 15. °C. Once the taxa were present, their temporal pattern was shaped by competition. The later arrival of Pinus could not be explained even by the coldest temperatures, and its timing had to be prescribed by first observations in the pollen record. After the arrival into the simulation area, the expansion of Pinus was further influenced by competitors and minor climate oscillations. The rapid change in the simulated species composition went along with a drastic change in forest structure, leaf area, albedo, and surface roughness. Pollen increased only shortly after biomass.Based on our simulations, two alternative potential scenarios for the pollen pattern can be given: either very cold climate suppressed most species in the Oldest Dryas, or they were delayed by soil formation or migration. One taxon, Pinus, was delayed by migration and then additionally hindered by competition. Community dynamics affected the pattern in two ways: potentially by facilitation, i.e. by nitrogen-fixing pioneer species at the onset, whereas the later pattern was clearly shaped by competition. The simulated structural changes illustrate how vegetation on a larger scale could feed back to the climate system.For a better understanding, a more integrated simulation approach covering also the immigration from refugia would be necessary, for this combines climate-driven population dynamics, migration, individual pollen production and transport, soil dynamics, and physiology of individual pollen production. © 2012 Elsevier B.V. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/69584
Appears in Collections: 过去全球变化的重建
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作者单位: Dynamic Macroecology, Swiss Federal Research Institute for Forest, Snow and Landscape Research WSL, Zürcherstr 111., CH-8903 Birmensdorf, Switzerland; Laboratoire des Sciences du Climat et de l'Environnement (LSCE), Unité Mixte de Recherche CEA-CNRS-UVSQ, Centre de Saclay Orme des Merisiers, 91191 Gif-sur-Yvette Cedex, France; Oeschger Center for Climate Change Research, University of Bern, Zähringerstrasse 25, CH-3012 Bern, Switzerland
Recommended Citation:
Lischke H.,von Grafenstein U.,Ammann B.. Forest dynamics during the transition from the Oldest Dryas to the Bølling-Allerød at Gerzensee-a simulation study[J]. Palaeogeography, Palaeoclimatology, Palaeoecology,2013-01-01,391