【作者】 王晶英；

【导师】 赵雨森；

【作者基本信息】 东北林业大学 ， 水土保持与荒漠化防治， 2007， 博士

【摘要】 水源涵养林主要功能包括水源涵养、水土保持、水质改善三部分内容，水源涵养林体系应当是一种以水源涵养、水土保持为核心的，兼顾经济、用材林的综合防护林体系。随着现代社会的发展，人口和经济的增长，水资源紧缺已成为世人共同关注的全球性问题。因此作为以涵养水源为主要目的的水源涵养林也越来越引起人们的重视。本研究以盆栽苗木为试验材料对黑龙江省水源涵养林12个树种进行了水分适应性研究，研究内容主要包括：(1)探讨了黑龙江东部山区水源涵养林树种的光合和耗水特性；(2)测定了水源涵养林树种的萎蔫系数，比较了不同树种的抗旱能力，并以银中杨为材料，在模拟干旱条件下，研究了林木的抗旱机理；(3)研究了水源涵养林树种的淹水适应性，比较了不同树种的抗淹水能力，探讨了淹水危害机理，筛选出了抗淹水指标。12个树种分别为：银中杨(Populus alba×Populus berolinensis)、水曲柳(Fraxinus maudshurica)、紫丁香(Syringa oblata)、白桦(Betula platyphylla)、白榆(Ulmus pumila)、暴马丁香(Syringa amurensis)、紫椴(Tilia amurensis)、胡桃楸(Juglans mandshurica)、旱柳(Salix matsudana)、黄菠萝(Phellodendron amurense)、云杉(Picea koraiensis Nakai)和樟子松(Pinus sylvesris L.var.mongolica Litvin)。通过对不同树种光合和耗水特性的分析发现：5月至9月的日均净光合速率，旱柳＞银中杨＞紫丁香＞白榆＞白桦＞水曲柳＞胡桃楸＞暴马丁香＞黄菠萝；日均蒸腾速率：旱柳＞白榆＞银中杨＞黄菠萝＞紫丁香＞水曲柳＞白桦＞胡桃楸＞暴马丁香＞紫椴；单株年耗水量，银中杨＞旱柳＞白桦＞紫丁香＞白榆＞水曲柳＞暴马丁香＞紫椴＞胡桃楸＞黄菠萝；日均水分利用率，银中杨＞紫丁香＞白桦＞旱柳＞暴马丁香＞紫椴＞白榆＞水曲柳＞胡桃楸＞黄菠萝。不同树种荧光参数日变化规律比较明显，φPSⅡ与Fv/Fm日变化中具有早晨和晚上高、中午低的趋势，Fo有早晨和晚上低、中午高的趋势。不同树种荧光参数季节变化有较大的差异。在干旱适应性方面研究发现，不同树种的萎蔫系数：胡桃楸＞黄菠萝＞旱柳＞白桦＞紫椴＞银中杨＞水曲柳＞暴马丁香＞云杉＞白榆＞紫丁香＞樟子松。银中杨具有较强的抗旱性，适度干旱有利于银中杨光合作用。逐渐干旱过程中，土壤含水量在40.1％～20.2％范围内，光合速率随着含水量的减少而降低，但降低幅度较小；土壤含水量为15.5％时的光合能力则大幅度下降；光饱和点随着土壤含水量的下降而降低。银中杨在干旱胁迫条件下发生一系列生理生化变化，以提高其抗旱性。干旱胁迫导致叶绿素含量降低，SOD在轻度干旱胁迫的初期，其活性提高，随着胁迫时间的延长、胁迫强度的加剧其活性降低，但降低幅度较小；类胡萝卜素、脯氨酸含量和电解质含量略微增加，可溶性糖含量显著增加。对银中杨的抗旱性贡献较大的指标是，可溶性糖、脯氨酸、类胡萝卜素积累，SOD下降幅度较小，MDA和膜透性没有明显变化，可以考虑将他们作为抗旱指标。在淹水适应性方面研究发现，不同树种的抗淹水能力：银中杨和旱柳＞紫椴＞樟子松＞白桦、白榆和云杉＞暴马丁香＞水曲柳＞紫丁香。淹水导致林木光合速率及叶绿素含量下降，但叶绿素含量与光合速率没有直接关系。抗淹水性较强的树种蒸腾速率、气孔导度、Fv/Fm变化较小。淹水后期抗淹水树种Fo变化平稳，中等抗性树种Fo降低，抗性差的树种升高，在淹水条件下，树种的光化学淬灭(qP)、实际光化学效率(φPSⅡ)和净光合速率三者同步变化，抗淹水性强的树种淹水后虽然实际光化学效率(φPSⅡ)和净光合速率降低，但非光化学猝灭(qN)增加。淹水胁迫后苗木发生一系列的生理生化变化以适应淹水胁迫。淹水初期叶片含水量提高的树种，淹水适应性较强。抗淹水性强的树种类胡萝卜素含量在淹水初期有较大的提高。较长时间淹水后煮沸电导率降低幅度越小抗淹水性越强，但阔叶树与针叶树没有可比性。抗淹水的树种的脯氨酸含量随着淹水时间的延长而增加，但银中杨的升高幅度大于旱柳。抗淹性较强的树种随着淹水时间的延长可溶性蛋白含量逐渐升高或维持较高的水平，对淹水具有中等抗性的树种可溶性蛋白含量基本不变或在淹水初期下降之后缓慢下降，抗淹水较差的树种则是先升高后降低；较长时间淹水后抗淹水性较强的树种超氧化物歧化酶活性比对照增加，抗性弱则降低，抗性极差的紫丁香除外。不同树种的抗淹水能力不同，不同生理指标对不同树种的抗淹水性具有不同响应特性，总的看来，淹水后光合速率、Fo、Fv/Fm、类胡萝卜素含量、煮沸电导率、脯氨酸含量、可溶性蛋白含量和超氧化物歧化酶活性的变化与树种的抗淹水能力有着直接的关系，它们均可以作为抗淹水指标。根据以上试验结果，可以为黑龙江不同生境、不同经营目的的水源涵养林的树种选择提供参考。(1)从涵养水源角度考虑，需要蒸腾速率低，年耗水量少，水分利用率高的树种，白桦、水曲柳、暴马丁香、紫椴、胡桃楸、黄菠萝、云杉、樟子松较为合适；(2)旱柳、银中杨的光合能力较强，有较大的生长量，是速生树种。白榆和紫丁香次之；(3)抗旱性较强的树种为：樟子松、紫丁香、白榆、云杉、暴马丁香、水曲柳、银中杨、紫椴和白桦；(4)在水库、河岸带和集水区经营的水源涵养林经常处于淹水环境，抗淹水能力较强的树种为：银中杨、旱柳和紫椴。本论文全面系统地研究了黑龙江东部山区多个水源涵养林树种苗木在不同水分条件下的光合特性、耗水特性及水分适应性机理，揭示了林木抗水分胁迫机理，确定了林木抗淹水能力的衡量因子，其研究结果不但为黑龙江水源涵养林构建提供了依据，而且丰富了树木水分生理内容。更多还原

【Abstract】 The chief function of water resource conservation forest contains three parts, water conservation, soil and water conservation and improvement of water quality. The water resource conservation system should be a comprehensive protective forest system whose main objectives are water conservation, soil and water conservation. At the same time it gives attention to commercial timber forest. With the development of modern society and the growth of population and economic, water resources shortage has been becoming a global problem which attracted the attention all over the world. And more and more attention is being paid to water resource conservation forest which main objective is water conservation.Water adaptability of 3-year-seedlings was investigated using pot experiment of 12 tree species in this paper. The 12 tree species included Populus alba×Populus berolinensis, Fraxinus maudshurica, Syringa oblate, Betula platyphylla, Ulmus pumila, Syringa amurensis, Tilia amurensis, Juglans mandshurica, Salix matsudana, Phellodendron amurense, Picea koraiensis Nakai, Pinus sylvesris L.var.mongolica Litvin. The research contained three parts: (1) Photosynthetic and water consuming characteristics of the tree species of water conservation forest was researched in Heiiongjiang Province (2) Wilting coefficient of tree species in water conservation forest was determined and drought-resistance of different tree species was compared. Also, drought-resistance mechanism under simulated drought stress was researched using Populus alba×Populus berolinensis as experimental material. (3)Waterlogging adaptability of tree species was studied and waterlogging-resistance of different tree species was compared Mechanism of waterlogging harm was probed into and waterlogging-resistance indices had been screened.Through the analyses of the photosynthetic and water consuming characteristics of the trees the results showed that net photosynthesis rate per day from May to September decreased as follow sequence: Salix matsudana＞Populus alba×Populus berolinensis＞Syringa oblata＞Ulmus pumila＞Betula platyphylla＞Fraxinus maudshurica＞Juglans mandshurica＞Syringa amurensis＞Phellodendron amurense; Transpiration rate per day as follows: Salix matsudana＞Ulmus pumila＞Populus alba×Populus berolinensis＞Phellodendron amurense＞Syringa oblata＞Fraxinus maudshurica＞Betula platyphylla＞Juglans mandshurica＞Syringa amurensis＞Tilia amurensis; Water consumption every year per plant: Populus alba×Populus berolinensis＞Salix matsudana＞Betula platyphylla＞Syringa oblata＞Ulmus pumila＞Fraxinus maudshurica＞Syringa amurensis＞Tilia amurensis＞Juglans mandshurica＞Phellodendron amurense; Water use efficiency per day: Populus alba×Populus berolinensis＞Syringa oblata＞Betula platyphylla＞Salix matsudana＞Syringa amurensis＞Tilia amurensis＞Ulrnus pumila＞Fraxinus maudshurica＞Juglans mandshurica＞Phellodendron amurense. Fluorescence parameters of different tree species vary regularly,ΦPSII and Fv/Fm were higher in the morning and evening while lower at noon, which wais converse to the changes of PAR and air temperature per day. Fo was lower in the morning and evening while higher at noon. The seasonal varieties of fluorescence parameters of different tree species were quite different.The study from the aspect of drought adaptability mechanism showed that the wilting coefficients of tree species from strong to weak were as follows: duglans mandshurica, Phellodendron amurense, Salix matsudana, Betula platyphylla, Tilia amurensis, Populus alba×P opulus berolinensis, Fraxinus maudshurica, Syringa amurensis, Picea koraiensis Nakai, Ulmus pumila, Syringa oblata and Pinus sylvesris L.varmongolica Litvin. Populus alba×Populus berolinensis presented strong drought resistance and moderate drought was favorable to photosynthesis, in given soil moisture content (40.1%～20.2%), the rate of photosynthesis decreased with the soil moisture and the decreased degree was smaller. The rate of photosynthesis decreased tempestuously when the soil moisture lowered to 15.5%. The light saturation point of Poplar reduces with the reducing of soil moisture content. There would be a series of changes in physiology and biochemistry in Poplar under drought stress so that its drought-resistance was stronger. Drought stress would lead to the reduction of chlorophyll content. SOD activity increased at the beginning of soil slight drought and decreased with soil water stress degree ascending and days prolonging. Freeproline and carotenoind and electrolyte matter content increased slightly and soluble sugar increased obviously. The indices which could make the drought resistance of Poplar much stronger are the accumulation of soluble sugar, praline and carotenoid, smaller descending range of SOD and unobvious changes of MDA and membrane permeability. In terms of that we could take them as drought-resistance indices.The study from the aspect of water-logging adaptability mechanism showed that the waterlogging-resistances of tree species from the best to the worst were as follows: Populus alba xPopulus berolinensis and Salix matsudana＞Tilia amurensis＞Pinus sylvesris L.varmongolica Litvin＞Betula platyphylla, Ulmus pumila and Picea koraiensis Nakai＞Syringa amurensis＞Fraxinus maudshurica＞Syringa oblate. Water-logging leaded to the descend of photosynthetic rate and the decrease of chlorophyll content, but there was no direct relation between them. There is few changes of transpiration rate, stomatal conductance and Fv/Fm in the trees which has good waterlogging-resistance. In the late stage of waterlogging, Fo variation of tree species of good waterlogging-resistance keet stable, and Fo of the tree species of middling waterlogging-resistance decreased, while that of the tree species of bad waterlogging-resistance increased. Under the waterlogging condition, the Photochemical Quenching(qP), practice photosynthetic rate(ΦPSII) and net photosynthetic rate of tree species changed in the same step. Although practice photosynthetic rate(ΦPSII) and net photosynthetic rate of tree species of good waterlogging-resistance decreased, qN of them increased. There should be a series of changes in physiology and biochemistry in seedlings after waterlogging stress, which helps adapt to waterlogging stress. Tree species whose leaf water content increased at the beginning of wateriogging had better waterlogging-resistance. There was much relationship between the variation of carotenoid contents and waterlogging-resistance of tree species whose waterlogging-resistance was strong. Its waterlogging-resistance increased a lot and with less reduction of boiling conductivity after being subjected to longtime water stress it became stronger. But there is no comparability between conifer and broadleaf trees. Proline content increased gradually with days prolonging. The praline content of Poplar whose waterlogging-resistance was strong increased obviously while much less in Salix matsudana instead。Soluble protein contents of the tree species which had good waterlogging-resistance increased gradually or kept a high level and that of the tree species of middling wateriogging-resistance kept stable or decreased gradually after the decline at the beginning of waterlogging, while soluble protein contents of the tree species which had bad waterlogging-resistance decreased gradually after increased. SOD activity of the tree species which had good waterlogging-resistance increased while that of the ones whose waterlogging-resistance was worse decreased after being subjected to longtime water stress, except for Syringa oblata of the worst waterlogging-resistance.Different tree species have different waterlogging-resistance and different indexes have different influences on waterlogging. Taking every aspect into consideration show that the variation of photosynthetic rate, Fo, Fv/Fm, carotenoind content, boiling conductivity, proline content, soluble protein contents and SOD activity make direct effect on the waterlogging-resistance of tree species. They all can be taken as waterlogging-resistance indexes. The study on water-logging adaptability shows the water-logging adaptability mechanism of forest trees and fixes the factors that can reflect trees’ waterlogging-resistance.Basing on the test results, electable tree species could be provided for the water conservation forests in different habitats and their different purposes of management. (1)From the aspect of water conservating, the tree species which has lower transpiration rate, less water consumption per year and higher water use efficiency was needed, such as Betula platyphylla, Fraxinus maudshurica, Syringa amurensis, Tilia amurensis, Juglans mandshuricam, Phellodendron amurense, Pieea koraiensis Nakai and Pinus sylvesris L.var.mongolica Litvin. (2)Salix matsudana and Populus alba×Populus berolinensis who have good photosynthetic ability and great growth increment are fast-growing tree species, with Ulmus pumila and Syringa oblate second to them. (3)The ones which have stronger drought-resistance are Pinus sylvesris L.var.mongolica Litvin, Syringa oblate, Ulmus pumila, Picea koraiensis Nakai, Syringa amurensis, Fraxinus maudshurica, Populus alba×Populus berolinensis, Tilia amurensis and Betula platyphylla. (4)The water conservation forests around the reservoir and on the riverside and catchment are always under the condition of water-logging. The tree species which have stronger waterlogging-resistance are Populus alba×Populus berolinensis, Salix matsudana and Tilia amurensis.There had been a comprehensive research on photosynthetic characteristic, fluorescence characteristic, water consuming characteristic and water adaptability mechanism of some different tree species in water conservation forest under different water conditions in this paper. The water-logging adaptability mechanism of trees had showed and the factors that can reflect trees’ waterlogging-resistance had fixed. The results of the research not only provide the evidence for the construction of water conservation forest in Heilongjiang Province. but also enrich the water physiology of trees.更多还原