【作者】 贺润平；

【导师】 翟明普； 牛西午；

【作者基本信息】 北京林业大学 ， 森林培育， 2007， 博士

【摘要】 甘草为常用大宗中药材,形成的植被具有重要的防风固沙作用。近年来,过度采挖甘草使我国天然分布的甘草资源面临枯竭,同时由于采掘过程中的土壤扰动带来了生态环境的恶化。柠条甘草分布有天然的混生群落,二者复合种植,一方面有助于保护和扩大我国甘草资源,另一方面通过柠条的保护作用可以减少甘草采收过程中对生态环境所产生的负面影响,对于恢复西部地区退化生态系统具有重要意义。为了探讨以柠条甘草混作条件下种间关系为基础的优化培育模式,本文首先采用PV技术等研究了柠条甘草的生理特征,而后采取根系分隔技术研究了柠条甘草的种间混生作用机制以及对甘草质量的影响,最后用施肥和控水的方法研究了水肥条件对柠条甘草种间关系的调控效应。主要研究结果如下:(1)甘草柠条水分生理特性不同,甘草的抗旱性大于柠条。柠条枝条的水势、根系和叶片保水力低于甘草,柠条的平均膨压、体积弹性模量、茎保水力大于甘草。(2)甘草柠条光合特性不同,间作后二者可以充分利用光能资源。柠条具有较高的光能转化效率和水分利用效率,甘草的净光合速率和蒸腾速率较高,柠条光补偿点大于甘草,光饱和点小于甘草,甘草耐弱光和强光的能力强于柠条,适合密植间作。(3)柠条甘草矿质营养特性不同,对矿质元素的吸收具有选择性,间作后能够充分利用养分资源。(4)根系完全分隔时甘草生长最好,甘草酸含量最高;不分隔、半分隔条件下甘草酸含量降低。网室条件下RYT=1.95-2.03,CRA=1.68-2.01,二者占有不同的生态位,适合间作,在间作中应保持适当距离。(5)施肥改变了柠条甘草生物量的分配规律,调节了种间关系。施肥后甘草N、P含量大于柠条,K含量小于柠条。柠条对N、P、K的吸收量较大。1a间作系统甘草养分吸收效率较高,2a间作系统柠条养分吸收效率较高。养分利用效率柠条NUE、PUE较高,KUE甘草较高,CaUEla时甘草高于柠条,2a时柠条高于甘草。施肥有利于甘草酸的积累,间作系统施N、K肥高水平,施P低水平时甘草酸含量高于对照。(6)土壤水分调节了种间关系。当SWC(土壤体积含水量)为30%、50%时,甘草竞争力大于柠条,SWC为50%时间作系统甘草生物量最大,根系发育最好,甘草酸含量最高。当SWC为20%、70%时,柠条竞争力大于甘草。(7)在田间试验条件下柠条甘草复合种植有益于甘草生长,边行效应明显,形成的植被能够适应极度干旱的条件。田间复合种植试验配置模式下(柠条株行距1×5 m,甘草为15×30 cm,柠条与甘草间距50 cm),种间竞争小于种内竞争,甘草能够获得较大的生物量。本研究的创新点是采用根系分隔技术研究了柠条甘草的种间作用机制,同时结合田间试验表明,二者间距较小时柠条竞争力大于甘草,随着间距的扩大,相互促进作用和边行效应逐渐增强;在盆栽条件下研究了N、P、K以及Ca肥对柠条甘草种间关系的调控作用,合理的施肥可以调节种间关系,提高甘草产量与质量;在盆栽控水条件下研究了不同土壤水分含量对种间关系的调节作用,土壤相对含水量为50%时间作系统甘草有较高的产量与质量,与施肥相比,浇水为更有效的调节种间关系的手段,最后提出了柠条甘草优化复合种植模式。更多还原

【Abstract】 Glycyrrhiza uralensis is an important medicinal plant, growing in dry area of northern China, and its vegetation plays a significant role in ecological protection. Recently over-dug made natural distribution G. uralensis resources is facing with dying out and brought out ecological environment deterioration as well. C. microphylla and G. uralensis may form natural mixed community, whose compound planting is helpful for protection and extension G. uralensis resources and restoration deteriorated vegetation in the dryland zone of western China. In order to find good mode based on water and nutrient competitive mechanism of C. microphylla and G. uralensis, physiological traits were studied by PV technique etc.; by the way of root barrier, interspecies interaction of C. microphylla and G. uralensis and effects on G. uralensis quality were studied; Effect of fertilizer and water on interspecific interaction was explored by fertilization and controlled water. Results were as following:（1） C. microphylla and G. uralensis had different water physiological traits. The whole drought-resistance of G. uralensis is stronger than C. microphylla. Branch water potential, root and leaf water retention capability of C. microphylla was lower than G. uralensis. Branch mean turgor pressure, modulus of elasticity and water retention capability of C. microphylla were bigger.（2） C. microphylla and G. uralensis had different photosynthesize traits. Their compound system can make full use of light energy. C. microphylla had a higher light energy turning and water untility effiency. Pn, Tr of G. uralensis is higher. Light compensation points of C. microphylla were higher and light saturation point lower. Ability of using weak and stronger light of G. uralensis was stronger, which was fit for closed planting and mixed planting.（3） Minal nutrient traits were different between C. microphylla and G. uralensis. They were different in absorbing mineal elements, which may make full use of nutrient resources.（4） G. uralensis grew best with most GA content under root complete barrior. No barrier and half barrier made GA content decreased. In mesh room RYT=1.95-2.03, CRA= 1.68-2.01. They had different niches, which were adequate for compound planting. In practice two should keep appropriate distance in compound planting.（5） Fertilizers adjusted biomass allocation law and adjusted interspecific interaction. N, P content of G. uralensis is higher and K content is lower than C. microphylla. N, P, K uptake of C. microphylla were bigger. In mixed system, 1a G. uralensis and 2a C. microphylla had a bigger nutrient obsorbed efficiency. NUE, PUE of C. microphylla was bigger and KUE was less. CaUE of 1a C. microphylla was less and 2a bigger. Fertilizer increased GA accumulation. When K60 g m^-2, N80 g m^-2, P40 g m^-2 were fertilized, GA content was higher than control.（6） SWC（soil water content） changed interspecial reaction. When SWC=30% or 50%, G. uralensis had more stronger competitive ability. When SWC=50%, G. uralensis accumulated most biomass withgood root and highest GA content. When SWC=20% or 70%, C. microphylla had more stronger competitive ability.（7） In the test field, compound planting of C. microphylla and G. uralensis was helpful to G. uralensis growth with obvious edge advange. This vegetation was fit for dry condition. In the condition of field （C. microphylla 1×5 m. G. uralensis 15×30 cm, their distance 50 cm） of 5 m belted planting, interspecial competition was less than inspecial competition and G. uralensis gained bigger biomass.The paper reported newly interspecific interaction mechanism of C. microphylla and G. uralensis by root barrier technology. Combination with field trial showed competitive ability of C. microphylla was bigger when distance was near and promotion action edge effects gradually increased with distance increasing; By pot trials adjustion action of N, P, K, Ca fertilizer on interspecific relationship were studied. Fittable fertilization might adjust effectively interaction relationship and improve yield and quality of G. uralensis; by control water trials, adjustion action of soil moisture on interspecific relationship were studied. Yield and quality of G. uralensis were better under SWC 50%. Compared with fertization, water was more effective measure to adjust interspecific relationship. Compound planting pattern for C. microphylla and G. uralensis was provided in the final.更多还原