贝加尔针茅响应降水变化敏感指标及关键阈值  

Thresholds of Stipa baicalensis sensitive indicators response to precipitation change

作　　者：石耀辉[1] 周广胜[1] 蒋延玲[2] 王慧[2] 许振柱[2] 麻雪艳[1] 

机构地区：[1]中国气象科学研究院,北京100081 [2]中国科学院植物研究所植被与环境变化国家重点实验室,北京100093

出　　处：《生态学报》2017年第8期2620-2630,共11页Acta Ecologica Sinica

基　　金：公益性行业(气象)科研专项(重大专项)(GYHY201506001-3);国家重点基础研究发展计划(973计划)(2010CB951301)

摘　　要：降水是影响中国北方草原群落结构和生产力的关键环境因子,弄清植物响应降水变化敏感指标,确定关键阈值,可为草原的科学管理与制定应对气候变化措施提供依据。以贝加尔针茅为材料,基于不同降水的模拟实验,采用正态总体统计容忍区间及容忍限的估算方法,对测定的叶面积、株高、叶绿素和叶N含量等14个植物生理生态指标响应降水变化的敏感性及其阈值进行了研究。结果表明,植株总叶面积、水势(或叶绿素含量)和地上生物量可分别从形态、生理和生物量积累三方面较好地指示贝加尔针茅对降水变化的敏感性,受到胁迫时的降水量(6、7和8月3个月份总降水量)阈值分别是283、276(276)mm和280 mm。研究结果可为客观辨识贝加尔针茅草原干旱的发生发展与监测预警提供参考。Precipitation is a crucial environmental factor that determines the community structure and productivity of temperate grasslands in northern China, located in the arid to semi-arid regions. As a result of the increase in greenhouse gases, precipitation patterns are projected to be changed, and the extreme weather events might become more common. Although many studies have focused on the effects of precipitation change on plant growth characteristics, none has quantified the relationship between precipitation and sensitive indicator （ leaf area, plant height, chlorophyll content, etc. ）. Understanding this relationship is essential to a comprehensive appreciation and accurate prediction of the effects of climate change on plants. Stipa baicalensis, a high quality forage grass, is a dominant species in the meadow steppe in eastern Inner Mongolia, an area that has experienced severe degradation during recent decades and is therefore sensitive to climate 30% ）, based on the average monthly （June, July and August） natural precipitation of the seed provenances from 1978 to2007, were used to simulate the effects of precipitation change on 14 eco-physiological indicators, including leaf area, plant height, chlorophyll and leaf N content, etc., in S. baicalensis. There were six replicates （ i.e., six pots with four plants per pot） for each precipitation treatment. Each precipitation regime was converted to irrigation amounts for each month, which were then divided and applied every three days after 4：00 P.M. Each pot of plants was destructively harvested and separated into two parts （leaves and roots） at the end of the experiment. Plant height, tiller and leaf number, and leaf area were measured. Leaves and roots were dried and weighed to measure the aboveground biomass, belowground biomass, and leaf N concentration. The changes in precipitation strongly affected the biomass, leaf area, leaf number, plant height, chlorophyll, and leaf N content, etc., but did not influence leaf mass per area （LMA）.

关 键 词：贝加尔针茅 降水变化 敏感指标 阈值 

分 类 号：S812[农业科学—草业科学]