Untitled

该 花 粉 组 合 信 息 可 用 以 重 建 古 植 被 、
古 气 候 及 古 环 境 的 变 化 。
2010010057
全 新 世 泥 炭 中 花 粉 百 分 比 与 稳 定 碳 同
位 素 之 间 相 似 的 变 化 趋 势 -- 古 气 候 研
究 的 可 能 诠 释 = Analogous trends in
pollen percentages and carbon stable
isotope composition of Holocene peat —
Possible interpretation for palaeoclimate
studies. ( 英 文 ). Skrzypek G;
Baranowska-Kącka A; Keller-Sikora A;
Jędrysek M. Review of Palaeobotany
and Palynology, 2009, 156(3-4): 507-
518
Pollen and spore analysis and analysis
of carbon stable isotope composition in
a peat core from Hala Izerska (SW Poland)
were used for palaeoclimate studies
of the Holocene over the last ~ 8.5 ka.
The results of these two methods have
been compared and variations of the
δ 13 C value show a clear relationship
with the pollen percentages of tree taxa,
such as Carpinus, Fagus, Picea, and
Pinus as well as with spores of Sphagnum
and akinetes of Cyanophyta. However,
lags of up to ~ 200 years of pollen
maxima and minima versus δ 13 C were
observed. The δ 13 C value in the peat
core varied between − 23.47 and
− 27.58‰ and is interpreted here as reflecting
temperature control of the carbon
isotope composition of the peat. According
to this interpretation and pollen
analysis of the study area, the following
climatic periods for the Holocene can be
described: Atlantic–beginning warm
(8.50–7.90 ka cal. BP) followed by
moderated cold (7.90–5.75 ka cal. BP),
Subboreal–beginning moderated cold
(5.75–5.40 ka cal. BP) then warm (5.40–
2.55 ka cal. BP), Subatlantic–beginning
warm (2.55–2.20 ka cal. BP) then cold
and moderate cold (2.20 ka–0.40 ka cal.
BP) with a climatic minimum ~ 1.60 ka
cal. BP. The highest relative difference
between growing season temperatures
was about 3.6 °C, which has been observed
between the Subboreal temperature
maximum (5.00 ka cal. BP) and the
Subatlantic temperature minimum
(1.60 ka cal. BP).
2010010058
中 寒 武 世 至 早 泥 盆 世 孢 型 壁 的 纹 层 =
Laminae in palynomorph walls from the
Middle Cambrian–Early Devonian. ( 英
文 ). Taylor W A. Review of Palaeobotany
and Palynology, 2009,
156(1-2): 7-13 2 图 版 .
This study was undertaken to examine
the wall ultrastructure of widely dispersed,
mainly lower Paleozoic palynomorphs/cryptospores.
Many of these palynomorphs
have walls that are at least
partially composed of laminae. The
walls and their constituent laminae are
variable in their construction, but show
certain similarities to one another and to
some extant land plants (e.g., sphaerocarpalean
liverworts). Careful examination
with transmission electron microscopy
reveals that: 1) Cambrian–Early
Devonian laminate palynomorphs have
laminae that are fairly uniform in their
thickness, 2) most contemporaneous
acritarchs have walls that are thicker
than individual laminae in these putatively
land-derived palynomorphs and
cryptospores, 3) extant algae have lamellae,
not laminae, in their cyst walls,
and in smaller numbers than the laminae
in these palynomorphs/cryptospores, and
4) extant liverworts have laminae whose
thickness overlaps that of these palynomorphs/cryptospores,
but also have
some laminae that are much thicker. The
antiquity of these palynomorphs clearly
establishes the plesiomorphic state of
laminate wall construction among land
plants. While it is not possible to assign
the producers of these palynomorphs to
any specific group of organisms based
on the ultrastructure of the wall, they
clearly produced spores with thicker,
more complex walls than any fossil or
extant alga known to date.
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