干旱沙漠边缘地带7种沙生植物适应性机理  

Adaptive mechanisms of seven psammophytes in an arid desert margin in Shapotou area,China

作　　者：朱瑞清[1] 张志山[1] 刘立超[1] 回嵘[1] 张浩[1] 鲍婧婷[1] 

机构地区：[1]中国科学院寒区旱区环境与工程研究所沙坡头沙漠研究试验站,兰州730000

出　　处：《生态学杂志》2015年第10期2749-2756,共8页Chinese Journal of Ecology

基　　金：国家重点基础研究发展计划项目(2013CB429906)资助

摘　　要：对干旱沙区极端生境下植物适应策略的研究有助于揭示该区植物群落演替机理,预测生态系统的稳定性和演替方向,为固沙工程和生态恢复提供理论依据。本文对流动沙丘-固定沙地这一过渡带上不同群落中出现的7种优势植物种的适应策略进行了研究。结果表明:流动沙丘优势植物种沙米(Agriophyllum squarrosum)拥有高蒸腾速率(Tr)和高水分利用效率(WUE)峰值,且WUE的峰值出现在较为干旱的土壤水分条件;相反,固定沙丘优势植物种小画眉草(Eragrostis poaeoides)表现出保守的利用水分特征(低Tr,高WUE峰值,WUE的峰值出现在较为湿润的土壤水分)。我们对此过渡带的7种高等植物定义为高耗水量[沙米、花棒(Hedysarum scoparium)、油蒿(Artemisia ordosica)、刺蓬(Salsola ruthenica)]、中耗水量[蒙古虫实(Corispermum mongolicum)]和低耗水量[雾冰藜(Bassia dasyphylla)、小画眉草]3种主要的水分利用类型,并发现植物的水分消耗量(在其优势分布沙丘类型的根际土壤水分条件下)与其盖度呈显著负相关(R2=0.94,P<0.01);提示植物水分利用特征的不同和土壤水分分布的不同是两个主要的影响植被分布格局的因素,影响着土壤水分平衡和干旱沙漠绿洲生态系统的演替过程。土壤理化性质对植物的影响作用在固定和半固定沙丘上表现显著,而土壤水分的影响作用在流动和半流动沙丘中表现的更加显著。Studies on plant adaptation strategy in extreme habitats from arid desert areas help to reveal the mechanism of plant community succession, predict ecosystem stability and succession orientation, as well as provide theoretical grounds for sand-binding engineering and revegetation. In this paper, we investigated ent communities in a transitio the adaptation strategies of seven dominant plant species in differ- nal zone of shifting-fixed dunes. The pioneer annual, Agriophy- llum squarrosum, was found to possess a high transpiration rate （ Tτ, high peak of water use ef- ficiency （WUE） , with WUE peak occurring at relatively low soil moisture, while the intrusive species, Eragrostis poaeoides, behaved in conservative water use characteristics （low Tτ, low WUE peak, with WUE peak occurring at relatively high soil moisture）. For the seven species, we defined three types of water use characteristics ： lavish water use （ including Agriophyllum squar- rosum, Hedysarum scoparium, Artemisia ordosica, Salsola ruthenica ） （Corispermum mongolicum）, and conservative water use （Bassia dasyph~ moderate water use ,ylla, E. poaeoides ）. Species coverage of all the dominant species including shrubs and herbs was significantly nega- tively correlated with their diurnal transpiration under the conditions of rhizosphere moisture （ R2 = 0.94, P〈0.01 ）. The results indicate that both the water use characteristics of different spe-cies and the distribution of soil moisture are the two major factors mediating the dominance of plant species in the community, soil water balance and succession processes in arid desert-oasis ecosystems. Soil physicochemical properties play an important role in the fixed and semi-fixed dunes, while soil moisture effects are more important in shifting and semi-shifting dunes.

关 键 词：固沙植物 生态恢复 水量平衡 流动沙丘 

分 类 号：Q948.1[生物学—植物学]