The effects of nutrient limitation on the response of Plantago major to ozone.
The effects of nutrient limitation on the response of Plantago major to ozone.
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DOI：
10.1046/j.1469-8137.1998.00277.x
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发表时间：
1998-10
期刊：
影响因子：
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通讯作者：
C. Whitfield;A. Davison;T. Ashenden
中科院分区：
文献类型：
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作者：
C. Whitfield;A. Davison;T. Ashenden
大多数自然和半自然群落受到氮(N)或磷(P)等主要营养物质的限制，但大多数关于臭氧对野生植物影响的实验都使用了营养丰富的堆肥或土壤。为了研究臭氧与低营养供给之间的相互作用，人工选择了两个居群车前草（Plantago major ssp.）的两个抗臭氧系和臭氧敏感系。主要L.生长在砂壤土上，有（HN）和无（LN）施肥。土壤来自从未施肥过的半天然草地。从苗期到制种，植物分别暴露于木炭/Purafil®过滤的空气（CF=<5 nl O3 -1）或70 nl O3 -1中7 h d-1。低营养植物生长较差（约为HN的25%），叶片N和P浓度表明LN植物营养严重受限。除了影响植物的总干质量外，养分供应还改变了种子产量、繁殖努力（每总质量的种子数）和根到梢的分配。臭氧暴露对生理、生长和种子生产有显著影响，影响随种群、选择系、时间和植物发育而变化。臭氧效应与营养状况之间也存在显著的相互作用。在Lullington Heath群体中，臭氧仅在LN处理下降低了4周植株干重，在Bush群体的敏感系中，臭氧仅在LN处理下降低了种子产量。因此，与预期相反，在本实验中，给予LN处理的植物往往比在高营养条件下生长的植物对臭氧更敏感。尽管LN处理降低了气孔导度和臭氧通量，但这种敏感性仍在增加。结论是，臭氧与低营养供应之间存在潜在的重要相互作用，需要进一步调查，特别是在实地条件下。
Most natural and semi-natural communities are limited by major nutrients such as nitrogen (N) or phosphorus (P), but most experiments on the effects of ozone on wild plants have used nutrient-rich composts or soil. In order to investigate interactions between ozone and low nutrient supply, two artificially selected lines (ozone-resistant and ozone-sensitive) of two populations Plantago major ssp. major L. were grown on a sandy loam, with (HN) and without (LN) addition of fertilizer. The soil was from a semi-natural grassland that has never been fertilized. Plants were exposed to either charcoal/Purafil®-filtered air (CF=<5 nl O3 l-1 ) or 70 nl O3 l-1 7 h d-1 from the seedling stage to seed production. Poor growth (c. 25% of that in HN) of the low-nutrient plants, and leaf concentrations of N and P showed that the LN plants were severely nutrient-limited. In addition to affecting the total dry mass of the plants, the nutrient supply altered seed production, reproductive effort (number of seeds per total mass) and root-to-shoot allocation. Exposure to ozone had significant effects on physiology, growth, and seed production that varied with population, selection line, time, and plant development. There also were significant interactions between ozone effects and nutrient regime. In the Lullington Heath population, ozone reduced plant dry weight at 4 wk only in the LN treatment, and in the sensitive line of the Bush population, seed production was reduced by ozone only in LN. Therefore, contrary to what was expected, in the present experiment, plants given the LN treatment were often more sensitive to ozone than those grown under the high-nutrient regime. This increase in sensitivity was despite the fact that the LN treatment reduced stomatal conductance and ozone flux. It is concluded that there are potentially important interactions between ozone and low nutrient supply that need further investigation, particularly under field conditions.