【作者】 张俊佩；

【导师】 张建国；

【作者基本信息】 中国林业科学研究院 ， 森林培育， 2009， 博士

【摘要】 本文以贵州黄果树石漠化地区主要造林树种为研究对象,从生理生态学的角度,采用盆栽试验与野外试验相结合的方法,深入系统地探讨了石漠化地区主要造林树种在不同环境条件下的蒸腾耗水特性、光合和水分生理生态特性,以及生长状况,并运用隶属函数法和逐步回归法,综合评价了供试树种的耐旱性和野外条件下影响树种光合作用的主要因子,旨在为该区域植被恢复提供科学理论与实践依据。主要结论体现在如下几个方面:1、主要造林树种的耐旱性苗木连日蒸腾耗水量、土壤水势和叶水势随干旱处理天数呈线性下降,苗木叶水势随土壤水势呈幂函数下降,但不同苗木下降的速率和幅度不一样。基于叶水势与土水势关系,将供试的19个树种的耐旱性分为四类:I、高水势延迟脱水的有马尾松和夹竹桃;II、低水势忍耐脱水的仅有喜树;III、亚高水势延迟脱水的有车桑子、杜英、苦楝、乌桕、香椿、银鹊、香樟、川含笑、金叶女贞、侧柏、栾树;IV、亚低水势忍耐脱水的有桂花、大叶女贞、花椒、滇湫、滇柏。随干旱处理天数的增加,净光合速率呈线性下降,气孔导度主要呈指数函数下降,蒸腾速率呈线性和幂函数两种下降趋势,而水分利用效率则呈现出先增加后降低的趋势。说明在干旱胁迫初期由于气孔关闭,蒸腾速率对干旱胁迫的反应更敏感,而在干旱胁迫的后期净光合速率由于受到严重的非气孔限制因素的影响,下降幅度高于蒸腾速率。在干旱胁迫下,苗木净光合速率随叶水势呈对数函数下降,蒸腾速率和气孔导度随叶水势呈指数函数下降。由于树种的不同,其下降幅度有显著的差异。夹竹桃属于典型的高水势延迟脱水植物,不能仅以叶水势的值来判断夹竹桃受胁迫的程度。苗木叶片光合速率与气孔导度成线性关系或者成幂函数关系,苗木的蒸腾速率与气孔导度呈幂函数关系;蒸腾速率与净光合速率的下降呈显著线性相关。而且净光合速率随蒸腾速率和气孔导度的下降幅度在树种间存在显著的差异。下降相同幅度的蒸腾速率,大叶女贞和桂花的净光合速率受影响最大,银鹊最小。干旱胁迫下各苗木叶片的电子传递、光合的潜在活性和原初光能转换效率受到了明显的抑制,部分苗木叶片的叶绿素含量也明显减少;供试苗木的根量、根茎的生物量和生长量出现了明显的不同。中度胁迫下,控水耐旱能力由强到弱为:杜英、香樟、乌桕、车桑子、滇湫、金叶女贞、马尾松、苦楝、香椿、喜树、桂花、侧柏、滇柏、大叶女贞、银鹊、川含笑、花椒、栾树。重度胁迫下,供试树种控水耐旱性的排序从大到小为:香椿、香樟、杜英、滇湫、银鹊、川含笑、苦楝、金叶女贞、马尾松、喜树、车桑子、乌桕、滇柏、栾树、侧柏、大叶女贞、花椒。2、主要造林树种光合、水分生理生态适应机制各坡向和坡位的含水量和土壤水势有明显的差异,阴坡和半阴坡要大于阳坡。在干旱胁迫下,气孔导度、净光合速率和水分利用效的峰值提前,并在中午时刻出现“午休”现象,是植物对干旱条件的一种适应。叶水势、水分利用效率、净光合速率的日均值在阴坡要高于阳坡,而蒸腾速率和PSII原初光能转换效率日均值阴坡却低于阳坡;叶水势和蒸腾速率日均值上坡位高于下坡位。不同坡向叶水势的差异主要由土壤水势的差异引起,高坡位具有较高的叶水势与其较强的根系供水能力和较轻的蒸腾失水相关。另外,水分利用效率和净光合速率日均值的坡向差异主要是由于叶水势日均值的差异引起的。应用系统聚类的方法,依据不同的指标,将供试树种分为高、亚高、低和亚低四类,具体分类如下:侧柏为高水分利用效率、亚高净光合速率、亚低PSII原初光能转换效率和低蒸腾速率;香樟为高净光合速率和蒸腾速率、亚低水分利用效率和PSII原初光能转换效率;小叶女贞为高PSII原初光能转换效率、亚高净光合速率和蒸腾速率、亚低水分利用效率;大叶女贞为高蒸腾速率、亚低净光合速率、低PSII原初光能转换效率和水分利用效率;滇柏为亚高水分利用效率和净光合速率、亚低PSII原初光能转换效率和蒸腾速率;夹竹桃为亚高水分利用效率和PSII原初光能转换效率、低净光合速率和蒸腾速率;乌桕为亚高水分利用效率、亚低PSII原初光能转换效率和净光合速率、低蒸腾速率;白花刺和火棘均属于亚低水分利用效率、净光合速率、PSII原初光能转换效率和蒸腾速率;车桑子为亚低水分利用效率和PSII原初光能转换效率、低净光合速率和蒸腾速率;金叶女贞为亚低水分利用效率和PSII原初光能转换效率、亚高净光合速率和蒸腾速率。旱季条件下,水分利用效率的变化主要受蒸腾速率的影响;随着气孔导度和蒸腾速率的增加,净光合速率的增加受限,可能与干旱胁迫相关。Pn与Gs、WUE和Tr的关系密切,成正相关,叶水势仅在五个方程中成为主要因子,表明所选样地的树种受到了严重的干旱胁迫。由于坡向坡位和树种的不同,供试树种的生长量、生物量和根量存在显著差异。更多还原

【Abstract】 Taking tree species for vegetation in Stone Dissertation District of Huangguoshu in Guizhou as study object, in the view of physiological ecology, this paper deeply studied the characteristics of water consumption, photosynthesis and water physiological ecology and growth of the main tree species through potted plant trial and plantation survey, and the comprehensive evolution of drought tolerance and the main reason of restricting Pn were done using membership function and regression equation and provide theoretical ad practical base for ecological forestation in Stone Dissertation District. The main conclusions were below:1、Drought tolerance of the main tree species for forestationWith increase in days of the drought treatment , water consumption by transpiration, water potential of soil (WS) and water potential of plant (WP) decreased lineally, power function correlation between WP and WS, but speed and extent of decrease was different among tree species. According to the mathematical relationship between WP and WS, systematical classification method was applied to divide 19 kings of tree species into four sorts: a drought tolerance of dehydration postponement with high tissue water potential, including Pinus massoniana Lamb. and Nerrium indicum Mill.; a drought tolerance of sub-dehydration postponement with high tissue water potential, including Dodonaea viscosa (Linn.) Jacq., Elaeocarpus decipiens Hemsl., Melia azedarach L., Sapium sebiferum (Linn.) Roxb., Toona sinensis (A. Juss.) Roem., Tapiscia sinensis Olivx., Cinnamonum camphora L., Michelia szechuanica Dandy., Ligustrum vicaryi Mill., Platycladus orientalis (Linn.) Franco., and Koelreuteria paniculata Laxm.; a drought tolerance of dehydration tolerance with low tissue water potential, including Camptotheca acuminata Decne.; a drought tolerance of sub-dehydration tolerance with low tissue water potential, including Elaeocarpus decipiens Hemsl., Ligustrun lucidum Ait., Zanthoxylum bungeanum Maxim., Catalpa fargesii Bur. f. duclouxii (Dode) Gilmour, and Fokienia hodginsii (Dunn) Henry et Thomas.With increase in days of the drought treatment, photosynthesis (Pn) decreased linearly, stomatal conductance (Gs) decreased exponentially, transpiration rated (Tr) decreased linearly and power, while water use efficiency (WUE) increased in initial stages then decreased. This indicated that Tr reacted sensitively to drought stress in initial stages due to stomatal close, while the decrease extent of Pn was larger than that of Tr because of the increase in non stomatal restriction.Under drought stress, with the decrease in WP, Pn deceased logarithmically, Tr and Gs decreased exponentially. There was a significant difference among tree species. BecauseNerrium indicum Mill.belonged to a classic drought tolerance of dehydration postponement with high tissue water potential, stress extent of Nerrium indicum Mill. did not judge by WP.Linear and power function correlation between Pn and Gs, power function correlation between Tr and Gs, linear correlation between Pn and Tr. With the Tr and Gs decrease, there was different in extent of Pn among tree species. The same extent of decrease in Tr, Pn of Ligustrun lucidum Ait. and Osmanthus fragrans Lours. decreased largest, and Pn of Tapiscia sinensis Olivx. smallest.PSII electronic transmit rate (Fm/Fo), potential activity and photosynthesis efficiency were restrained by drought stress, chlorophyll content of partial tree species decreased notably. There was significant different in root amount, root and shoot biomass, growth amount among tested tree species.Under middle-drought stress, the capability of drought tolerance and water control from strong to feeble: Elaeocarpus decipiens Hemsl., Cinnamonum camphora L., Sapium sebiferum (Linn.) Roxb., Dodonaea viscosa (Linn.) Jacq., Catalpa fargesii Bur. f. duclouxii (Dode) Gilmour, Ligustrum vicaryi Mill., Pinus massoniana Lamb., Melia azedarach L., Toona sinensis (A. Juss.) Roem., Camptotheca acuminata Decne., Osmanthus fragrans Lours., Platycladus orientalis (Linn.) Franco., Fokienia hodginsii (Dunn) Henry et Thomas., Ligustrun lucidum Ait., Tapiscia sinensis Olivx., Michelia szechuanica Dandy., Zanthoxylum bungeanum Maxim. And Koelreuteria paniculata Laxm.; Under heavy-drought stress, the capability of drought tolerance and water control from strong to feeble: Toona sinensis (A. Juss.) Roem., Cinnamonum camphora L., Elaeocarpus decipiens Hemsl., Catalpa fargesii Bur. f. duclouxii (Dode) Gilmour, Tapiscia sinensis Olivx., Michelia szechuanica Dandy., Melia azedarach L., Ligustrum vicaryi Mill., Pinus massoniana Lamb., Camptotheca acuminata Decne., Dodonaea viscosa (Linn.) Jacq., Sapium sebiferum (Linn.) Roxb., Fokienia hodginsii (Dunn) Henry et Thomas., Koelreuteria paniculata Laxm., Platycladus orientalis (Linn.) Franco., Ligustrun lucidum Ait. and Zanthoxylum bungeanum Maxim.2、Photosynthetic and water ecophysiology adaptation mechanism of main tree species for vegetation restoration There were notable difference in SWC and Ws among AS/SP, those of northern slope was higher than southern slope. Under drought stress, the peak time of Gs, Pn and WUE moved up and presentation of“sleep at noon”was the adaptation mechanism of tree to drought.Daily average values of WP, WUE and Pn in northern slope were higher than those in southern slope, on the contrary, daily average values of Tr and Fv/Fm in southern slope were higher than those in northern slope; daily average values of WP and Tr on the higher SP were higher than on the lower SP. The difference of WP resulting from AS was related to SW, and the higher WP on the higher SP related to stronger water uptake capability and smaller water consumption by Tr. And, the AS effect on the daily average value of WUE and Pn arose mainly from the difference in daily average value of WP.The tested tree species were divided into four sort in terms of different parameters using hierarchical clustering method, high, sub-high, sub-low and low, respectively. As followed: Platycladus orientalis (Linn.) Franco., high WUE, sub-high Pn, sub-low WUE and Fv/Fm; Cinnamonum camphora L., high Pn and Tr, sub-low WUE and Fv/Fm; Ligustrum quihoui Carr., high Fv/Fm, sub-high Pn and Tr, sub-low WUE; Ligustrun lucidum Ait., high Tr, sub-low Pn, low Fv/Fm and WUE; Fokienia hodginsii (Dunn) Henry et Thomas., sub-high WUE and Pn, sub-low Fv/Fm and Tr; Nerrium indicum Mill., sub-high WUE and Fv/Fm, low Pn and Tr; Sapium sebiferum (Linn.) Roxb., sub-high WUE, sub-low Fv/Fm and Pn, low Tr; Sophora viciifolia Hance. and Pyracantha fortuneana (Maxim.) Li., sub-low WUE, Pn, Fv/Fm and Tr; Dodonaea viscosa (Linn.) Jacq., sub-low WUE and Fv/Fm, low Pn and Tr; Ligustrum vicaryi Mill., sub-low WUE and Fv/Fm, sub-high Pn and Tr.Under drought season, WUE affected mainly by Tr; with the increase in Gs and Tr, the restriction of Pn increase was related to drought stress. There was positive correlation between Pn and Gs, WUE, Tr. WP become a main reason only in 5 equation, which indicated these plant subjected from great drought stress.There were significant difference in growth amount, biomass and root amount of tested tree species among AS/SP.更多还原