摘要
为了对山杏在矿区生态恢复和水土保持应用中提供理论依据,用盆栽和自然耗水的方法,通过设立正常水分对照组和干旱处理试验组,研究1年生山杏苗木适应干旱胁迫的生理机制。结果表明:1)连续7个观测日对照组土壤水势(Ψs)、山杏叶水势(Ψl)变化幅度较小;而试验组Ψs和Ψl随干旱持续而下降,但Ψl的降低幅度明显小于Ψs。2)连续4个观测日对照组山杏蒸腾速率(T r)、净光合速率(P n)和胞间CO 2浓度(C i)日均值变化很小;而随干旱持续试验组T r和P n日均值显著下降、C i显著上升(P<0.05),光合作用从气孔限制转为非气孔限制时Ψs阈值为-0.27 MPa。3)试验组山杏Ψs高于永久萎蔫点(-1.5 MPa)时,Ψl日变化滞后于Ψs日变化;Ψs低于该值时,Ψl和Ψs的日变化同步。该研究结论为:山杏能通过吸收大气凝结水、气孔调节、增强水吸力和水容调节的方式抵抗干旱,可作为生态恢复和水土保持优良树种。
[Background]Many rominent problems,such as thin soil,destruction of arid vegetation,water and soil loss,and ecological deterioration present in the abandoned diggings.Artificial recovery of forests is a quick and effective approach to restore the ecology of such regions.The primary problem of vegetation restoration is to select suitable plant species.[Methods]Potted one-years-old seedlings of Prunus sibirica were used in this study,and drought stress was controled by natural evapotranspiration.The control group was conducted by normal water management.The experimental group was subjected to drought stress treatment.The soil water potential(Ψs),leaf water potential(Ψl)and the gas exchange parameters,such as net photosynthetic rate(P n),transpiration rate(T r),stomatal conductance(G s),intercellular CO 2 concentration(C i),atmosphere CO 2 concentration(C a),atmosphere relative humility(R H),air temperature(t a),leaf temperature(t l)and photosynthetic active radiation(P AR)were measured.The physiological responses of P.sibirica to drought stress were analyzed,and its drought resistance mechanism was expolored.[Results]1)The results indicated that theΨs andΨl of the control group and atmosphere water potential(Ψa)demonstrated a very small fluctuation.Furthermore,Ψs andΨl of the experimental group were on a downward trend in the consecutive 7 days of soil drought stress.The decrease range ofΨl was obviously less than that ofΨs because leaves of P.sibirica absorbed atmospheric condensation.2)The daily averages of T r,P n and C i of P.sibirica in the control group in consecutive 4 days presented little changes.With soil drought stress condition lasting,the daily averages of T r and P n of P.sibirica of the experimental group in consecutive 4 days decreased significantly and its daily averages of C i increased significantly(P<0.05),respectively.The threshold value ofΨs was-0.27 MPa in which,photosynthetic limitation was changed from stomatal to non-stomatal.3)As the effect of tissue water capacitance(C)and water suction(ΔΨs-l)of P.sibirica in the experimental group,the diurnal fluctuation ofΨl lagged those ofΨs,whenΨs was above the mean value of permanent wilting point of most plants(-1.5 MPa).In addition,diurnal fluctuation ofΨl andΨs stayed synchronously,whenΨs was below it.[Conclusions]P.sibirica has an adaption to drought environment with the mechanisms of absorbing atmospheric condensation,enhancing theΔΨs-l,tissue releasing water,and stomatal adjustment,and can be used as suitable plant species for ecological restoration and barren mountain afforestation in diggings area.
作者
谢东锋
王华田
张光灿
张才
XIE Dongfeng;WANG Huatian;ZHANG Guangcan;ZHANG Cai(Forestry College,Shandong Agricultural University,271018,Tai′an,Shandong,China;College of Agriculture and Forestry Science,Linyi University,276000,Linyi,Shandong,China;Rushan City Dry Fruit Station,264500,Weihai,Shandong,China)
出处
《中国水土保持科学》
CSCD
北大核心
2019年第4期122-129,共8页
Science of Soil and Water Conservation
基金
国家林业公益性行业科研专项“鲁东山丘区露采石矿植被恢复与重建关键技术研究与示范”(201504406-02)
关键词
山杏
干旱胁迫
大气凝结水
水容
Prunus sibirica
drought stress
atmospheric condensation
water capacitance
