Responses to ozone in 12 provenances of European beech (Fagus sylvatica):: genotypic variation and chamber effects on photosynthesis and dry-matter partitioning
Responses to ozone in 12 provenances of European beech (Fagus sylvatica):: genotypic variation and chamber effects on photosynthesis and dry-matter partitioning
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DOI：
10.1046/j.1469-8137.1999.00518.x
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发表时间：
1999-11-01
期刊：
影响因子：
9.4
通讯作者：
Leverenz, JW
中科院分区：
文献类型：
--
作者：
Paludan-Müller, G;Saxe, H;Leverenz, JW
从1995年6月1日至10月1日，将12个欧洲山毛榉种源的幼苗暴露于环境、非过滤空气（NF）或NF + 50 nl l（-1）臭氧（NF 50）中8 h d（-1）。1996年，从5月31日至10月1日，在四个级别上继续接触：活性炭过滤空气（CF）、NF、NF 50和NF + 100 nl l（-1）臭氧（NF 100）。种源生长的两个季节外参考地块。重复所有处理。臭氧并没有影响气体交换的种源，直到第二个赛季后期。NF 100在1996年8月与CF相比减少了18%的光合作用。在9月，光合vc-as减少了22%，在NF 50和29%，在NF 100。两个季节后，臭氧降低了根：冠比24%时，比较CF和NF 100，这是由于减少根生物量。臭氧不影响树高生长和茎粗生长，也不存在臭氧与种源的互作效应。然而，有一个显着的臭氧x种源的光合作用的相互作用，显示西北欧种源是更敏感的臭氧比东南欧种源时，比较剂量响应估计。这是解释在遗传适应的光合机构的区域生长条件。室内的幼苗生长了45%，更高，并有28%以上的芽生物量和29%，更小的根生物量，导致44%的根：芽比减少相比，幼苗外。室内温度升高和PAR降低可能是造成差异的主要原因。OTC中的室效应的大小引起了对从此类室中的臭氧暴露得出的结论的怀疑。这和以前的臭氧实验与OTCs可能会得出不准确的结论，臭氧反应的大小，由于腔室的影响。
Seedlings of 12 provenances of European beech (Fagus sylvatica) were exposed to ambient, non-filtered air (NF) or NF + 50 nl l(-1) ozone (NF50) for 8 h d(-1) in open-top chambers (OTCs), from 1 June to 1 October 1995. In 1996 exposure was continued from 31 May to 1 October at four levels: charcoal-filtered air (CF), NF, NF50 and NF + 100 nl l(-1) ozone (NF100). Provenances were grown for both seasons in outside reference plots. All treatments were replicated. Ozone did not affect gas exchange in the provenances until late in the second season. NF100 reduced photosynthesis by 18% in August 1996 compared to CF. In September, photosynthesis vc-as reduced by 22%, in NF50 and by 29% in NF100. After two seasons, ozone reduced the root:shoot ratio by 24% when comparing CF and NF100; this was caused by reductions in the root biomass. Ozone did not affect height growth or stem diameter, and there mere no ozone x provenance interactions for any growth parameter. There was, however, a significant ozone x provenance interaction for photosynthesis, showing northwest European provenances to be more sensitive to ozone than southeast European provenances when comparing dose-response estimates. This is interpreted in terms of genetic adaptation of the photosynthetic apparatus to regional growing conditions. Seedlings in the chambers grew 45%, taller, and had 28% more shoot biomass and 29%, smaller root biomass, resulting in a 44% reduction of root:shoot ratios compared to seedlings outside. Increased temperature and decreased PAR inside the chambers relative to the outside were probably the main causes for the differences. The magnitude of the chamber effects in OTCs raises doubts about conclusions drawn from ozone exposures in such chambers. This and previous ozone experiments with OTCs may have reached inaccurate conclusions concerning the size of ozone responses due to chamber effects.