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作 者 ：黄瑞灵1,2,周华坤2*,刘泽华1,徐维新3,魁 武4

期 刊 ：西北植物学报 2012年 5期 页码：1021~1026

关键词：长江源区；高山嵩草；物候；生物量；气候变暖；响应；

Keywords:the Yangtze River headwaters region, Kobresia pygmaea, phenology, biomass, warming, response,

摘 要 ：利用青藏高原腹地江河源头的曲麻莱县气象站1994～2004 年观测的高寒嵩草草甸优势种高山嵩草的生育期、高度、产量等指标与同期气象资料，通过定量分析研究较长时段的物候及生物量变化特征，以揭示其对气候变化的响应。结果表明：（1）高山嵩草返青期和开花期的变化总体均呈“W”形，在区域气候变暖背景下，植物物候表现为返青期提前，开花期和枯黄期推迟，整个生长季延长。（2）高山嵩草的生物量变化在10年间呈明显的波动趋势，各月最高生物量均出现在1999年，最低生物量出现在1994年。（3）高山嵩草物候期与生长季各月气温呈显著的正相关关系(P<0.001)，与月降水量呈弱正相关关系(P>0.05)；月均气温成为本区草本植物发芽生长的先决条件，且 6～8月气温与植物萌动的相关性最大。（4）生长季6～8月高山嵩草生物量鲜重和干重均与月均气温呈显著正相关，鲜重仅与月降水量呈显著正相关关系，在青藏高原的高寒区，温度比降水对植物产量的影响更大。

Abstract:With the data of Kobresia pygmaea growth period, plant height and yield during 1994 to 2004 from Qumalai county in the Yangtze river headwater region,we investigated the relationships between climate change and K.pygmaea phenology and biomass.The results indicated that:(1)The greenup stage and florescence of K.pygmaea appeared a shape of w in general.Under the background of regional climate warming,the growth season prolonged by advanced greenup and delayed florescence and wilting.(2)Biomass of K.pygmaea changed apparently during the past 10 years.The highest biomass of K.pygmaea in each month appeared in 1999,the lowest was in 1994.(3)The phenophase of K.pygmaea showed a significantly positive correlation (P<0.001) with monthly temperature in its growing season and a weak correlation with monthly precipitation (P>0.05).Average monthly temperatures appeared to be a prerequisite in germinating and growing of local herbs,especially from June-August.(4)Fresh-and dry-weight of K.pygmaea in growing season from June to August were positively associated with monthly average temperature,while fresh weight only had positive correlation with monthly precipitation.In summary,temperature has greater influence on vegetation biomass than that of precipitation in Qinghai Tibet Plateau.

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