DOI: 10.1002/2017JG004135
Scopus记录号: 2-s2.0-85042217169
论文题名: Variance and Rate-of-Change as Early Warning Signals for a Critical Transition in an Aquatic Ecosystem State: A Test Case From Tasmania, Australia
作者: Beck K.K. ; Fletcher M.-S. ; Gadd P.S. ; Heijnis H. ; Saunders K.M. ; Simpson G.L. ; Zawadzki A.
刊名: Journal of Geophysical Research: Biogeosciences
ISSN: 21698953
出版年: 2018
卷: 123, 期: 2 起始页码: 495
结束页码: 508
语种: 英语
英文关键词: carbon and nitrogen stable isotopes
; critical transitions
; diatoms
; early warning signals
; pollen
; Tasmania
Scopus关键词: Achnanthidium minutissimum
; Bacillariophyta
; Brachysira styriaca
; Eunotia diodon
; Fragilaria capucina
; Frustulia
; Gomphonema
英文摘要: Critical transitions in ecosystem states are often sudden and unpredictable. Consequently, there is a concerted effort to identify measurable early warning signals (EWS) for these important events. Aquatic ecosystems provide an opportunity to observe critical transitions due to their high sensitivity and rapid response times. Using palaeoecological techniques, we can measure properties of time series data to determine if critical transitions are preceded by any measurable ecosystem metrics, that is, identify EWS. Using a suite of palaeoenvironmental data spanning the last 2,400 years (diatoms, pollen, geochemistry, and charcoal influx), we assess whether a critical transition in diatom community structure was preceded by measurable EWS. Lake Vera, in the temperate rain forest of western Tasmania, Australia, has a diatom community dominated by Discostella stelligera and undergoes an abrupt compositional shift at ca. 820 cal yr BP that is concomitant with increased fire disturbance of the local vegetation. This shift is manifest as a transition from less oligotrophic acidic diatom flora (Achnanthidium minutissimum, Brachysira styriaca, and Fragilaria capucina) to more oligotrophic acidic taxa (Frustulia elongatissima, Eunotia diodon, and Gomphonema multiforme). We observe a marked increase in compositional variance and rate-of-change prior to this critical transition, revealing these metrics are useful EWS in this system. Interestingly, vegetation remains complacent to fire disturbance until after the shift in the diatom community. Disturbance taxa invade and the vegetation system experiences an increase in both compositional variance and rate-of-change. These trends imply an approaching critical transition in the vegetation and the probable collapse of the local rain forest system. ©2018. American Geophysical Union. All Rights Reserved. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/114604
Appears in Collections: 气候减缓与适应
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作者单位: School of Geography, University of Melbourne, Parkville, VIC, Australia; Australian Nuclear Science and Technology Organisation, Lucas Heights, NSW, Australia; Institute of Environmental Change and Society, University of Regina, Regina, SK, Canada
Recommended Citation:
Beck K.K.,Fletcher M.-S.,Gadd P.S.,et al. Variance and Rate-of-Change as Early Warning Signals for a Critical Transition in an Aquatic Ecosystem State: A Test Case From Tasmania, Australia[J]. Journal of Geophysical Research: Biogeosciences,2018-01-01,123(2)