Interpreting bryophyte stable carbon isotope composition: Plants as temporal and spatial climate recorders
Interpreting bryophyte stable carbon isotope composition: Plants as temporal and spatial climate recorders
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DOI：
10.1002/2013gc005169
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发表时间：
2014-04
期刊：
影响因子：
3.7
通讯作者：
Jessica Royles;A. Horwath;H. Griffiths
中科院分区：
文献类型：
--
作者：
Jessica Royles;A. Horwath;H. Griffiths
苔藓植物无法控制组织含水量，尽管生理适应允许在广泛的生境中生长。两种藓类（Syntrichia ruralis和Chorisodontium aciphyllum）和两种地钱（Conocephalum conicum和Marchantia polymorpha）中的碳同位素信号，无论是瞬时（真实的时间，Δ 13 C）还是有机质（δ 13 COM），都提供了一个同化加权的总结。在苔藓中，δ 13 COM在Δ 13 C值的测量范围内，这表明其他代理，如化合物特异性有机信号，将代表历史光合和生长条件。苔类植物在较宽的相对含水量（RWC）范围内比藓类植物具有光合活性。C中Δ 13 C值之间存在一致的5‰偏移。conicum和M. polymorpha，暗示后者的扩散限制更大。分析了一个C. aciphyllum moss-peat岩心显示，过去200年的同位素组成反映了最近的人为CO2排放。一旦对源-CO2输入进行校正，1350年至2000年之间的季节积分Δ 13 COM与实验测量的12‰的潜在范围相比变化了1.5‰，表明大部分净同化发生的条件范围相对较窄。碳同位素识别也在空间上有差异，在低地亚马逊河流域和秘鲁安第斯山脉的上山地热带云雾林之间发现的附生branchite有机物有4‰的偏移，这与扩散限制的增加有关。
Bryophytes are unable to control tissue water content although physiological adaptations allow growth in a wide range of habitats. Carbon isotope signals in two mosses (Syntrichia ruralis and Chorisodontium aciphyllum) and two liverworts (Conocephalum conicum and Marchantia polymorpha), whether instantaneous (real time, Δ13C), or organic matter (as δ13COM), provide an assimilation‐weighted summary of bryophyte environmental adaptations. In mosses, δ13COM is within the measured range of Δ13C values, which suggests that other proxies, such as compound‐specific organic signals, will be representative of historical photosynthetic and growth conditions. The liverworts were photosynthetically active over a wider range of relative water contents (RWC) than the mosses. There was a consistent 5‰ offset between Δ13C values in C. conicum and M. polymorpha, suggestive of greater diffusion limitation in the latter. Analysis of a C. aciphyllum moss‐peat core showed the isotopic composition over the past 200 years reflects recent anthropogenic CO2 emissions. Once corrected for source‐CO2 inputs, the seasonally integrated Δ13COM between 1350 and 2000 A.D. varied by 1.5‰ compared with potential range of the 12‰ measured experimentally, demonstrating the relatively narrow range of conditions under which the majority of net assimilation takes place. Carbon isotope discrimination also varies spatially, with a 4‰ shift in epiphytic bryophyte organic matter found between lowland Amazonia and upper montane tropical cloud forest in the Peruvian Andes, associated with increased diffusion limitation.