科尔沁沙地主要经济树种茎水力功能及木质部组织和纹孔水平解剖结构研究OA

[Objective]Xylem anatomical characteristics are crucial for plant hydraulic function.This study investigates the xylem anatomy and hydraulic functions of economic tree species in Horqin Sandy Land to address two key scientific questions:(1)which anatomical structural traits determine the water transport efficiency and stress resistance in these species?Are hydraulic properties mainly governed by tissue-level structure or pit-level anatomy?(2)Does a synergistic relationship exist between tissue-level and pit-level xylem anatomical traits in economic tree species?The findings aim to provide valuable insights into their water use strategies and stress resistance mechanisms.[Method]Ten major economic tree species in Horqin Sandy Land were selected,including six diffuse-porous and four ring-porous species.Hydraulic functions and stem anatomical structures were compared both within and between functional groups.The relationships between hydraulic functions and anatomical characteristics were also examined.By examining divergent water-use strategies between diffuse-porous and ring-porous species in arid environments,this study elucidated hydraulic-based survival strategies of economic tree species under drought stress.[Result]Ring-porous species exhibited higher water transport efficiency than diffuse-porous species but had lower resistance to cavitation.Diffuse-porous species showed a significantly higher Huber value than ring-porous species.A marginally significant positive correlation was found between sapwood-specific hydraulic conductivity and vessel hydraulic diameter(0.05<P<0.10).Cavitation resistance was significantly negatively correlated with vessel hydraulic diameter and positively correlated with vessel density(P<0.05),while no significant relationship was observed between resistance to cavitation and pit anatomical traits.Vessel hydraulic diameter was negatively correlated with pit aperture area,pit membrane area,and pit aperture fraction(P<0.05).[Conclusion]The hydraulic functions of different economic tree species vary substantially,especially between the two functional groups of diffuse-porous and ring-porous species.These hydraulic differences are primarily associated with the xylem structure at the tissue level,while pit structure appears to have limited predictive ability for hydraulic safety.The relationship between xylem vessel diameter and pit size is decoupled when compared across species.