巴丹吉林沙漠不同林龄梭梭(Haloxylon ammodendron)气体交换对增温的适应策略  

Adaptation strategies of gas exchange to temperature increase of different ages of Haloxylon ammodendron in Badain Jaran Desert

作　　者：杨杰 薛浩 杨淇越 冯相艳 王玉哲 Yang Jie;Xue Hao;Yang Qiyue;Feng Xiangyan;Wang Yuzhe(School of Forestry,Fujian Agriculture and Forestry University,Fuzhou 350002,China;College of Juncao Science and Technology,Fujian Agriculture and Forestry University,Fuzhou 350002,China;a.Key Laboratory of Ecological Safety and Sustainable Development in Arid Lands,Northwest Institute of Eco-Environment and Resources,Chinese Academy of Sciences,Lanzhou 730000,China;Linze Inland River Basin Research Station,Northwest Institute of Eco-Environment and Resources,Chinese Academy of Sciences,Lanzhou 730000,China)

机构地区：[1]福建农林大学林学院,福建福州350002 [2]福建农林大学菌草与生态学院,福建福州350002 [3]中国科学院西北生态环境资源研究院干旱区生态安全与可持续发展重点实验室,甘肃兰州730000 [4]中国科学院西北生态环境资源研究院临泽内陆河流域研究站,甘肃兰州730000

出　　处：《中国沙漠》2025年第1期195-203,共9页Journal of Desert Research

基　　金：国家自然科学基金面上项目(52172300);甘肃省水利科学试验研究与技术推广计划项目(24GSLK013)。

摘　　要：随着全球变暖,气温持续升高,极端干旱气候水文事件频发,对全球(特别是干旱荒漠)地区生态系统造成不利影响。梭梭(Haloxylon ammodendron)具有极强的耐干旱高温的能力,在中国西北荒漠地区被广泛种植。探究不同林龄(5、10、20、30、40 a)梭梭光合生理和水分生理特征在极端高温下的适应策略,有助于预测梭梭未来在全球变暖(极端高温)条件下的生存境况。利用LI-6800F光合-荧光全自动测量系统测量梭梭温度光合响应曲线,依据IPCC发布的增温幅度,设置了25、27.5、30、32.5、35、37.5、40℃梯度模拟升温变化,分析不同林龄梭梭气体交换差异,利用1515D压力室仪器测量不同林龄梭梭同化枝水势。结果表明:(1)不同林龄梭梭同化枝水势有显著性差异,5~30 a梭梭水势随林龄增加而升高,40 a梭梭降低且略大于20 a梭梭。(2)随着温度升高,不同林龄梭梭光合特性有明显差异,5 a梭梭由于受到水分胁迫最严重,净光合速率(P_(n))最小,10 a梭梭P_(n)呈线性增加,20、30、40 a梭梭P_(n)较高且随温度升高波动较小。不同林龄梭梭在极端高温(35~40℃)P_(n)持续升高(10 a)、保持稳定(20、30 a)或下降(5、40 a)。(3)不同林龄梭梭水分生理特征也有较大差异,特别在极端高温时的差异性与植物生存发展有紧密联系。中龄(20 a)幼龄梭梭(5、10 a)采取的水分利用策略较为保守,在极端高温时,气孔导度(G_(s))、水分利用效率(WUE)、蒸腾速率(Tr)波动较小,且保持着较高的P_(n),对极端高温环境抗逆性强;老龄梭梭(30、40 a)则采取较为激进的水分利用策略,在极端高温时仍然不断提高Tr致使WUE不断降低,虽然能保持较高的P_(n),但是也可能导致树木生长受限,长此以往也可能导致树木的死亡。不同林龄梭梭在极端高温下的气体交换特征有着较大差异,对极端高温有着不同的适应策略,尤其老龄(30、40 a)梭梭的采取适应策略较为激�With global warming,global temperatures continue to rise,extreme drought hydrological events are frequent,and they have a significant impact on ecosystems in global(especially arid and dry)regions.Haloxylon ammodendron has extremely strong tolerance to drought and high temperatures,and it is widely planted in the arid desert regions of northwest China.Exploring the adaptive characteristics of photosynthesis and water physiology in different age H.ammodendron(5,10,20,30,40 a)under extreme high temperature conditions can help predict the survival of different age H.ammodendron in the future under global.warming(extreme hightem perature).conditions.The temperature photosynthesis response curve of H.ammodendron was measured using the LI-6800F photosynthesis-fluorescence automatic measurement system.In order to simulate the warming caused by the continuous global warming,an experimental temperature gradient of 25,27.5,30,32.5,35,37.5,40℃ was set.The gas exchange differences between different age H.ammodendron were analyzed,and the Water potential of assimilating branches of different age H.ammodendron was measured using the 1515D pressure chamber instrument.The results Showed that:(1)There were significant differences in assimilating branch water potential of different age H.ammodendron.The water potential of 5-30 a H.ammodendron increased with increasing age,while that of 40a decreased slightly more than that of 20a H.ammodendron.(2)There are obvious differences in photosynthesis characteristics of different age H.ammodendron as temperature rises.The net photosynthesis rate(P_(n))of 5-year-old H.ammodendron is the smallest throughout the entire experimental temperature range due to the most severe water stress.The P_(n) of 10-year-old H.ammodendron increases linearly and does not reach a peak within the experimental temperature range.The P_(n) of 20,30,and 40-year-old H.ammodendron is higher and fluctuates less with increasing temperature.The P_(n) of different age H.ammodendron continues to increase(10-year-old),r

关 键 词：全球变暖 梭梭(Haloxylon ammodendron) 光合作用 水分利用效率 蒸腾速率 

分 类 号：O945.78[理学]