摘要
【目的】比较科尔沁沙地典型生境上生长的刺榆木质部水力结构特征、叶片水分关系与光合气体交换特征,探讨刺榆适应不同土壤水分环境的内在生理机制,为科尔沁沙地防风固沙造林和植被修复的适地适树提供理论依据。【方法】以生长在科尔沁沙地丘间低地和沙丘上部2种土壤水分环境中的刺榆为研究对象,从树木水力结构角度,分析不同生境刺榆枝条水分传输效率与安全性的差异,结合叶片水分关系、光合生理特性以及木质部解剖结构等进行对比研究。【结果】与沙丘上部相比,丘间低地土壤水分条件较好,刺榆枝条木质部导管直径较大、水分传输效率(Ks)更高(P<0.05),叶片和枝条水势均更高(P<0.05)。尽管2种生境上生长的刺榆叶片光合碳同化速率无明显差异,但气孔导度(g_(s))和水分利用效率(WUE_(i))明显不同,沙丘上部刺榆的g_(s)更低(P<0.05),WUEi更高(P<0.05)。丘间低地刺榆枝条末端叶面积和边材面积的比值(LA/SA)显著高于沙丘上部(P<0.05),地径、树高和地上生物量等指标也显著高于沙丘上部(P<0.05);但沙丘上部刺榆木材密度更高,抗气穴化栓塞能力更强,水力安全边界(HSM)也较宽(Ψ_(S-md)-P_(50)和Ψ_(S-md)-P_(80)较大)。【结论】在土壤水分条件较好的丘间低地生长的刺榆,导管直径较大,水分传输效率更高,可保证较高的生长速率和竞争力;而在土壤水分条件较差的沙丘上部生长的刺榆,木质部导管直径变小,虽然水分传输效率降低,但有助于获得更强的木质部抗气穴化栓塞能力,从而保证植株能在水分胁迫较严重的生境中长期存活。刺榆水力结构特征随水分生境变化而调整的策略,反映出其较强的抗旱性和适应性。
【Objective】The aim of this study was to investigate the internal physiological mechanisms of Hemiptelea davidii adapting to different soil water environments by comparing the effect of microenvironments(interdune and upperdune)with different soil water conditions on the characteristics of xylem hydraulic architecture,leaf water relations and photosynthetic gas exchange of H.davidii,in order to provide a theoretical basis for windproof and sand fixation afforestation and vegetation restoration in Horqin sandy land.【Method】In this study,the H.davidii inhabiting in the interdune and upperdune with different soil water conditionsin Horqin sandy land was targeted.The differences in water transport efficiency and safety of H.davidii in the two habitats were analyzed from the perspective of trees hydraulic architecture,and a comparative study on leaf water relation,photosynthetic gas exchange and xylem anatomical structure was conducted.【Result】Soil water status in interdune was much better than that in upperdune,thus H.davidii growing in interdune presented the larger conduits,and significantly higher stem water transport efficiency(K_(s))and leaf and stem water potential(P<0.05).Although,there was no significant difference in leaf photosynthetic carbon assimilation rate between the two habitats,the stomatal conductance(g_(s))and intrinsic water use efficiency(WUE_(i))showed significantly different.gs of the upperdune was significantly lower(P<0.05),and its WUEi was significantly higher(P<0.05).Different soil water content in habitats also had significant impacts on the ratio of leaf area to sapwood area(LA/SA)of H.davidii,the value of LA/SA was significantly higher ininterdune than that of upperdune habitat(P<0.05).Growth indicators such as basal diameter,tree height and aboveground biomass were also significantly higher in interdune than those of the upperdune habitat(P<0.05).H.davidii in the upperdune showed higher wood density and stronger resistance to cavitation,and the hydraulic safety margin(HSM)was
作者
曹宇
巢林
安宇宁
吴德东
张学利
李红
刘艳艳
Cao Yu;Chao Lin;An Yuning;Wu Dedong;Zhang Xueli;Li Hong;Liu Yanyan(Liaoning Institute of Sandy Land Control and Utilization,Fuxin 123000;Key Laboratory of Environment Change and Resources Use in Beibu Gulf of Ministry of Education Guangxi Key Laboratory of Earth Surface Processes and Intelligent Simulation, Institute of Geography and Oceanography, Nanning Normal University,Nanning 530001;Department of Horqin Sandy Land Ecosystem National Positioning Observatory, Zhanggutai, Liaoning Province,Zhangwu 123203;Institute of Sand-Fixation and Afforestation Research of Liaoning Province,Fuxin 123000)
出处
《林业科学》
EI
CAS
CSCD
北大核心
2021年第7期32-42,共11页
Scientia Silvae Sinicae
基金
国家自然科学基金项目(31800333)
辽宁省公益研究基金项目(2020JH4/10100047)
辽宁省自然科学基金项目(2019-MS-201)。
关键词
刺榆
水分传输
抗气穴化栓塞
脆弱性
水力安全边界
水分利用效率
Hemiptelea davidii
water transport
resistance to cavitation/embolism
vulnerability
hydraulic safety margin
water use efficiency
