地下水埋深对幼龄梭梭功能性状的影响  

Effects of groundwater depth on functional traits of young Haloxylon ammodendron

作　　者：刘深思 徐贵青[1,2] 陈图强 米晓军 刘燕[1,2] 马健[1,2] 李彦[1,2] LIU Shen-si;XU Gui-qing;CHEN Tu-qiang;MI Xiao-jun;LIU Yan;MA Jian;LI Yan(State Key Laboratory of Desert and Oasis Ecology,Xinjiang Institute of Ecology and Geography,Chinese Academy of Sciencesy Urumqi 830011,China;Fukang Station of Desert Ecology,Chinese Academy of Sciences,Fukang 831505,Xinjiang,China;University of Chinese Academy of Sciences,Beijing 100049,China;Chengbei Reclaimed Water Co.,Ltd.Urumqi,Urumqi S30013,China)

机构地区：[1]中国科学院新疆生态与地理研究所荒漠与绿洲生态国家重点实验室,乌鲁木齐830011 [2]中国科学院阜康荒漠生态国家野外科学观测研究站,新疆阜康831505 [3]中国科学院大学,北京100049 [4]乌鲁木齐城北再生水有限公司,乌鲁木齐830013

出　　处：《应用生态学报》2022年第3期733-741,共9页Chinese Journal of Applied Ecology

基　　金：新疆维吾尔自治区天山青年计划项目(2020Q025);国家自然科学基金项目(32171874);新疆维吾尔自治区自然科学基金项目(2019D01A98);中国科学院前沿科学重点研究项目(QYZDJ-SSW-DQC014)资助。

摘　　要：地下水是干旱荒漠区潜水灌丛植物的重要水分来源,为认识地下水埋深对潜水植物功能性状的影响,利用蒸渗仪群配备的全自动补水仪设置两组地下水埋深(2和3.5 m),测定幼龄梭梭生长季同化枝水力性状、气体交换特征和根系形态参数。结果表明:与地下水埋深2 m相比,地下水埋深3.5 m处理幼龄梭梭黎明前同化枝水势、饱和膨压渗透势和根长比分别显著降低48.2%、41.5%、56.7%,生长季后期最大净光合速率、根体积、细根比根长和细根比根面积分别显著增加75.7%、41.0%、273.7%、67.7%,正午同化枝水势和同化枝含水量先降低后升高。在两组地下水埋深下,幼龄梭梭根系在土壤剖面的分布特征均表现为根平均直径与土壤深度呈显著正相关,而细根表面积比例与土壤深度呈显著负相关。幼龄梭梭地上同化枝水力性状与光合能力和地下根系形态指标存在协同性。在地下水埋深增加的条件下,幼龄梭梭采取降低黎明前同化枝水势和饱和膨压渗透势,增大根系直径和长度的生态策略,以增强水分缺失的耐受性和扩大水分吸收的面积来维持其生存。Groundwater is an important water source for phreatophytic shrubs in arid desert areas.In order to understand the impacts of groundwater depth on functional traits of phreatophytic shrubs,two groups of groundwater levels(2 and 3.5 m)were set up using lysimeter with automatic water replenishing instrument.We measured hydraulic traits,gas exchange characteristics,and root morphological parameters of young Haloxylon ammodendron during the growing season.The results showed that predawn assimilating branch water potential,osmotic potential at full turgor,and root length ratio of young H.ammodendron in the groundwater depth of 3.5 m were lower by 48.2%,41.5%and 56.7%than that under groundwater depth of 2 m,respectively,while maximum net photosynthetic rate of late growing season,root volume,specific root length and specific root area of fine root were 75.7%,41.0%,273.7%and 67.7%higher,respectively.Midday water potential and water content of assimilating branch tended to decrease first in the early growing season and then increase in the late growing season.Root distribution of young H.ammodendron along soil profile showed a significant positive correlation between the average root diameter and soil depth,while the proportion of fine root surface area showed a significant negative correlation with soil depth at both groundwater levels.There was synergy of aboveground assimilating branch hydraulic traits and photosynthetic capacity with belowground root morphological traits in young H.ammodendron.Under the condition of increasing groundwater depth,young H.ammodendron adopted the ecological strategies of reducing predawn assimilating branch water potential and osmotic potential at full turgor,and increasing root diameter and length to enhance water deficit tolerance and expanding the area of water uptake to sustain their survival.

关 键 词：地下水埋深 水力性状 气体交换 根系形态 梭梭 

分 类 号：S792.99[农业科学—林木遗传育种]