DOI: 10.1016/j.palaeo.2015.02.018
论文题名: Plant architecture and spatial structure of an early Permian woodland buried by flood waters, Sangre de Cristo Formation, New Mexico
作者: Rinehart L.F. ; Lucas S.G. ; Tanner L. ; John Nelson W. ; Elrick S.D. ; Chaney D.S. ; DiMichele W.A.
刊名: Palaeogeography, Palaeoclimatology, Palaeoecology
ISSN: 0031-0182
出版年: 2015
卷: 424 起始页码: 91
结束页码: 110
语种: 英语
英文关键词: Dicranophyllum
; Fossil forest
; Permian
; Self thinning
; T0 assemblage
英文摘要: Natural molds of 165 stems were found in life position in a 1m-thick sandstone bed, lower Permian (Wolfcampian), Sangre de Cristo Formation, northern New Mexico. The sandstone represents a single flood event of a river sourced in the Ancestral Rocky Mountains. Most of the flood-buried plants survived and resumed growth. The stem affinities are uncertain, but they resemble coniferophytic gymnosperms, possibly dicranophylls. Stem diameters (N=135) vary from 1 to 21cm, with three strongly overlapping size classes. Modern forest studies predict a monotonically decreasing number (inverse square law) of individuals per size class as diameter increases. This is not seen for fossil stems ≤6cm diameter, reflecting biases against preservation, exposure, and observation of smaller individuals. Stems ≥6cm diameter obey the predicted inverse square law of diameter distribution. Height estimates calculated from diameter-to-height relationships of modern gymnosperms yielded heights varying from ~0.9m to >8m, mean of ~3m. Mean stand density is approximately 2 stems/m2 (20,000 stems/hectare) for all stems >1cm diameter. For stems >7.5cm or >10cm diameter, density is approximately 0.24 stems/m2 (2400 stems/hectare) and 0.14 stems/m2 (1400 stems/hectare). Stem spatial distribution is random (Poisson). Mean all-stem nearest-neighbor distance (NND) averages 36cm. Mean NND between stems >7.5cm and >10cm diameter is approximately 1.02m and 1.36m. NND increases in approximate isometry with stem diameter, indicating conformation to the same spatial packing rules found in extant forests and other fossil forests of varying ages. Nearest-neighbor distance distribution passes statistical testing for normality, but with positive skew, as often seen in extant NND distributions. The size-frequency distribution of the stems is similar to those of Jurassic, early Tertiary, and extant woodlands; the early Permian woodland distribution line has the same slope, but differs in that the overall size range increases over time (Cope's rule). The early Permian woodland is self-thinning; its volume versus density relationship shows a self-thinning exponent between -1.25 and -1.5, within the range seen in some extant plant stands (-1.21 to -1.7). © 2015 Published by Elsevier B.V. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/68994
Appears in Collections: 过去全球变化的重建
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作者单位: New Mexico Museum of Natural History and Science, 1801 Mountain Rd. NW, Albuquerque, NM, United States; Department of Biology, Le Moyne College, Syracuse, NY, United States; Illinois State Geological Survey, 615 E. Peabody Drive, Champaign, IL, United States; Department of Paleobiology, NMNH Smithsonian Institution, Washington, DC, United States
Recommended Citation:
Rinehart L.F.,Lucas S.G.,Tanner L.,et al. Plant architecture and spatial structure of an early Permian woodland buried by flood waters, Sangre de Cristo Formation, New Mexico[J]. Palaeogeography, Palaeoclimatology, Palaeoecology,2015-01-01,424