不同土壤高温对梭梭幼苗生长与光合生理的影响

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中图分类号：S793.9 文献标识码：A DOI编码：10.3969/j.issn.1006—6500.2025.09.001

Abstract：ToinvestigateteectsofferentsoiligtemperaturesonthgowthandpotosyteticcharacteristicsofHloylon ammodendronsedlings，astudywasconductedusingseedlingsfromtheGurbantungutDesert.Acombinationofpotexperimentsand laboratoryanalyseswasemployed todetermine theirhigh-temperaturetolerancerange.Treatments includedrootzone warmingat40 C 45‰ ，50 C ，55 C ，and . Growth and physiological parameters such as plant height，crown area，net photosynthetic rate （ Pn ） and stomatal conductance （Gs） were measured over 4O days.Results showed that seedling height and crown area initially increased and thendecreasedacrosstemperaturegradients，exhibitingsignificantstage-specificesponses.Declinesintheseparametersafter10 days under 50-55 C treatments were more pronounced than those below 45 C . Prolonged exposure （4O days） to temperatures above 50‰ significantly reduced Pn compared to 10 days treatments，with 55 C and 60‰ treatments showing 83.06% and 85.46% reductions， respectively.After 4O days，intercellular CC ′2 concentration（ under 50‰ and 55qC treatments was1.01 fold and1.04 fold higher than at 45 C . The Ci under 50 C treatment increased by O.62-fold between 10 and 40 days.At2O days， Gs at 45‰ was 1.16 fold and 1.05 fold higher than at 50 C and 55 ΔC ，while transpiration rates （ Tr） at50 C and55 ΔC were 1.25foldandO.89 foldof that at 45qC .Both Gs and Tr under 50‰ treatment increasedby0.58foldand0.18-fold，respectively，from10to20days.Withinthe first 20 days， Pn consistently followed the order： 45 ℃>50 C> 55 C> 60 C . Short-term（10 days） high-temperature stress minimally affected seedling growthand physiology，but inhibitory effects intensified with prolonged exposure above 50‰ .The studyidentified 50- 55‰ asthecriticalhigh-temperature tolerancetresholdforsedlings，providingteoreticalfoundationsndtechnicalparametersfor artificial cultivation management of Haloxylon ammodendron forests in arid regions.

KeyWords：Haloxylonmmodendronsedlings;high-temperaturetreatment;gowth;photosyntheticphysiology;tolerancethshold

梭梭（Haloxylonammodendron）作为干旱区生态系统的关键物种，在维持生态平衡、防风固沙等方面发挥着不可替代的作用-3]。（剩余12387字）