Evidence of enhanced freezing damage in treeline plants during six years of CO2 enrichment and soil warming
Evidence of enhanced freezing damage in treeline plants during six years of CO2 enrichment and soil warming
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DOI：
10.1111/j.1600-0706.2011.20031.x
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发表时间：
2012-10
期刊：
影响因子：
3.4
通讯作者：
C. Rixen;M. A. Dawes;S. Wipf;F. Hagedorn
中科院分区：
文献类型：
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作者：
C. Rixen;M. A. Dawes;S. Wipf;F. Hagedorn
气候变化和大气中二氧化碳含量的升高可能会增加植物对冰冻的脆弱性。我们分析了在瑞士阿尔卑斯山（Stillberg，达沃斯）的树线进行的长期原位CO2富集（2001-2009年）和土壤变暖（自2007年以来为204 °C）实验中，植物中自然发生的冰冻事件导致的组织损伤。在2005年至2010年的六年中，有四年的夏季冰冻事件对几种丰富的亚高山和高山植物物种造成了损害。大多数冻害发生在积雪融化后两到三周气温降至21.5°C以下时。落叶落叶松和矮灌木欧洲越橘和Empetrum hermaphroditum表现出更多的冻害实验升高的CO2和/或温度下比对照条件下。土壤变暖导致50%的E.在一次冰冻事件期间，由于保护性积雪融化，两性畸形。虽然我们不能确定一个明确的机制，我们更大的冷冻敏感性相结合的先进的植物物候在春天和植物生理学的变化。自1975年以来，林木线地区的气候记录表明，夏季变暖0.58°C/10年，积雪融化提前3.5天/10年，但在植被期，冰冻事件没有显著减少。因此，在一个更温暖的气候，更高的二氧化碳水平，但不断的极端天气事件的可能性，亚高山和高山植物可能更容易受到冻结事件，这可能会部分抵消预期的增长与全球变化。因此，在预测未来大气和气候条件下高山植物的生长变化或群落组成变化时，应考虑冻害。
Climate change and elevated atmospheric CO2 levels could increase the vulnerability of plants to freezing. We analyzed tissue damage resulting from naturally occurring freezing events in plants from a long-term in situ CO2 enrichment ( 200 ppm, 2001–2009) and soil warming ( 4°C since 2007) experiment at treeline in the Swiss Alps (Stillberg, Davos). Summer freezing events caused damage in several abundant subalpine and alpine plant species in four out of six years between 2005 and 2010. Most freezing damage occurred when temperatures dropped below 21.5°C two to three weeks after snow melt. The tree Larix decidua and the dwarf shrubs Vaccinium myrtillus and Empetrum hermaphroditum showed more freezing damage under experimentally elevated CO2 and/or temperatures than under control conditions. Soil warming induced a 50% die-back of E. hermaphroditum during a single freezing event due to melting of the protective snow cover. Although we could not identify a clear mechanism, we relate greater freezing susceptibility to a combination of advanced plant phenology in spring and changes in plant physiology. The climate record since 1975 at the treeline site indicated a summer warming by 0.58°C/decade and a 3.5 days/decade earlier snow melt, but no significant decrease in freezing events during the vegetation period. Therefore, in a warmer climate with higher CO 2 levels but constant likelihood of extreme weather events, subalpine and alpine plants may be more susceptible to freezing events, which may partially offset expected enhanced growth with global change. Hence, freezing damage should be considered when predicting changes in growth of alpine plants or changes in community composition under future atmospheric and climate conditions.