【作者】 王玉涛；

【导师】 李吉跃；

【作者基本信息】 北京林业大学 ， 森林培育学， 2008， 博士

【摘要】 北京市属于严重缺水的地区,随着林木数量的增加和绿地覆盖率的增加,北京市缺水的问题势必会进一步加剧。为缓解北京城市绿化建设上规模和水分严重缺乏这一矛盾,筛选和应用抗旱节水的绿化植物材料成为关键因子。本文根据北京市近年来绿地建设的现状和城市缺水的实际状况,选取北京市常见的63种主要绿化植物材料(包括常绿针叶乔木6种、落叶阔叶乔木16种、灌木20种、木本地被5种、草本地被9种、藤本7种),从植物的解剖结构特征(主要包括上下表皮角质层厚度、上下表皮厚度、叶片厚度、海绵组织层数和厚度、栅栏组织层数和厚度、栅栏组织厚度与海绵组织厚度比值、叶片组织结构的紧密度和疏松度、气孔密度和气孔大小等)、生理特征(主要是植物春夏秋3个季节的长期和瞬时的水分利用效率及对环境因素的响应等)和苗木对水分胁迫的响应入手,进行多目标、多植物下的综合选择,从中选择一些具有一定抗旱潜力且观赏价值较高的绿化植物,并且对抗旱节水的指标进行综合评价,确定一些简便易操作并且指示抗旱节水比较可靠的指标,在此基础上建立北京城市绿化植物抗旱节水评价指标体系。本文主要有以下几个方面的研究结论:(1)通过叶片解剖结构指标初步确定4种类型绿化植物的抗旱性差异。常绿乔木树种的耐旱性为侧柏>桧柏,油松>白皮松>雪松>华山松;16种落叶乔木树种抗旱性强弱为馒头柳>玉兰、杜仲、柿树和元宝枫>国槐、栾树、毛白杨、刺槐、臭椿、山楂、白蜡、椴树和楸树>银杏和杂种马褂木;20种灌木抗旱性强弱为沙棘>Ⅰ类较抗旱的中生灌木(包括黄栌、金银木、银芽柳、珍珠梅、丁香、太平花、贴梗海棠、红玉海棠、紫穗槐、棣棠、醉鱼草和紫叶李)>Ⅱ类相对不抗旱的中生灌木(糯米条、碧桃、榆叶梅、海仙花和天目琼花)>大叶黄杨和红王子锦带;木本地被植物抗旱性强弱为平枝栒子>金叶女贞>紫叶小檗、金叶莸和月季;9个草本地被植物抗旱性强弱为八宝景天>萱草>孔雀草和金鸡菊>美国薄荷、婆婆那、玉簪、二月兰和紫花地丁;攀援绿化植物中小叶扶芳藤为最耐旱的一类,其次是金银花、紫藤和美国凌霄,再次为五叶地锦和南蛇藤,抗旱性最差的是山荞麦。(2)不同类型植物3个季节叶片碳同位素比率表明,常绿乔木叶片碳同位素比率种间差异达到极显著水平和季节差异未达到显著水平,而落叶乔木树种、灌木、地被和攀援植物叶片碳同位素比率值均是春季大于夏季和秋季,且落叶乔木树种、灌木和攀援植物季节间差异达到了极显著水平,种间差异(除木本地被植物外)也达到显著或极显著水平。由于水分利用效率与叶片碳同位素比率呈正比,可见落叶乔木树种、灌木、地被和攀援植物春季的水分利用效率大于夏秋两季,且通常夏季最小。木本植物的水分利用效率大于草本植物。瞬时水分利用效率的结果与长期水分利用效率的结果存在一致性,即春季和秋季瞬时水分利用效率大于夏季。(3)综合分析不同类型植物3个季节叶片碳同位素比率、植物的光合速率及瞬时水分利用效率表明:桧柏水分利用效率高于侧柏,水分利用效率高说明植物节水性强,白皮松和油松节水性都较高,而雪松相反;银杏和杂种马褂木抗旱性较差,但水分利用效率较高,即节水性较强。馒头柳属于深根抗旱耗水型植物,白蜡、玉兰、柿树、杜仲和元宝枫是节水性都较强的绿化植物,国槐、毛白杨、臭椿和山楂属于节水较低的树种,其余居中等水平。对于灌木树种,金银木、红王子锦带、海仙花和天目琼花的长期水分利用效率较高,即较节水,大叶黄杨抗旱性和节水性均较低;木本地被中平枝栒子和金叶女贞在节水性方面表现较好，其次是月季；八宝景天以其独特的结构和景天酸代谢途径,表现出较好地抗旱节水性,玉簪和婆婆那节水性较高;金银花、紫藤为抗旱性和节水都比较好的攀援植物,山荞麦则正好相反。(4)对4种类型的典型植物苗木进行水分胁迫试验表明,随着水分胁迫逐渐加剧,乔木树种白蜡苗木对干旱的适应性强于银杏、桧柏强于雪松;灌木树种天目琼花苗木抗旱性强于醉鱼草、碧桃和红王子锦带;地被植物中金叶女贞苗木的表现出较好的抗旱性,攀援植物小叶扶芳藤苗木抗旱性强于山荞麦。从苗木的水分胁迫试验来看,除天目琼花外其它植物均与前面的结论基本一致。(5)建立城市园林绿化树种抗旱节水评价指标体系。经灰色关联分析,各类型与抗旱节水关联度大的指标都非常相近,主要是春夏秋3个季节的叶片碳同位素比率、叶片的厚度、比叶面积、气孔密度、气孔长径、单个气孔的大小、叶片的紧密度和叶片的疏松度,这些指标在反映抗旱方面贡献较大。利用灰色关联分析综合比较苗木的对水分胁迫的适应性与与苗木实际抗旱能力较吻合。更多还原

【Abstract】 Beijing is a city short of water severely. And the water shortage problem will be further deteriorated with the increase of forest and green space cover rates. To solve this problem, it is the key factor to select and apply plant species with characteristics of drought resistance and water-saving in Beijing. In this paper, according to present situation of the green space construction and the shortage of urban water resource in Beijing, the common 63 landscape plant species in Beijing (6 evergreen conifers, 16 deciduous trees, 20 shrubs, 5 wood ground cover plants and 9 herb ground cover plants, 7 climbers) were used to examined their anatomical characteristics (the leaves anatomical structure: thickness of both upper and lower epidermis cuticle, the thickness of both upper and lower epidermis, thickness of leaf, layers and thickness of spongy tissue, layers and thickness of the palisade tissue, width of spongy tissue cell and palisade cell, the ratio of thickness of palisade tissue versus thickness of spongy tissue, cell tense ratio, spongy ratio, stomatal density and size, etc), physiological characteristics (long-term and instantaneous water use efficiency in spring, summer and autumn and relationships betweenδ13C with soil temperature, humidity and the other weather variables) as well as responses of plant seedlings to water stress. Some potentially drought resistant greenism plant species with high ornamental value were selected by multi-objective, multi-plant comprehensive selection, and the indicators of selecting drought resistant and water-saving plants were also evaluated. Evaluation indicator system of Beijing urban landscape plants with characteristics of drought resistance and water-saving was established based on this. Main conclusions are as follows:(1) The differences of drought resistance characteristics among four kinds of greenism plant species were preliminarily identified by analyzing the leaf anatomical indicators. The order of drought resistant capability in evergreen trees was Platycladus orientalis>Sabina chinensis, Pinus tabulaeformis > Pinus bungeana>Pinus armandi>Cedrus deodara; while, that in the 16 kinds of hardwood plants was S. matsudana f.Umbraculifera>Magnolia denudate, Eucommia ulmoides, Diospyros kaki, Acer truncatum>Sophora japonica, Koelreuteria paniculata, Populus tomentos, Robinia pseudoacacia, Ailanthus altissima, Crataegus pinatifida, Fraxinus chinesis, Tilia mandshurica and Catalpa bungei>Ginkgo biloba and Liriodendron chinense×L.tulipifera; and the sequence of drought resistant capability for shrubs was Hippophae rhamnoides>groupⅠof shrubs with greater drought resistant capability (Cotinus coggygria, Lonicera maackii, S. leaucopithecia, Sorbaria sorbifola, Syringa oblata, Philadephus pekinensis, Chaenomeles speciosa, Malus‘Red jude’, Amorpha fruticosa, Kerria japonica var.pleniflora, Buddleja lindleyana and Prunus cerasifera f. atropurea)>groupⅡof shrubs with relatively weaker drought resistant capability (Abelia chinensis, Prunus persica f.duplex, Prunus triloba, Weigela coraeensis and Viburnum sargentii)>Euonymus japonicus and Weigela florida cv.Red Prince; the order in wood cover ground plants was Cotoneaster horizontalis>Ligustrum×vicaryi>Berberis thunbergii cv. Atropurpurea, Caryopteris clandonensis‘Worcester Gold’and Rosa chinensis, and that in herb cover ground plants, Sedum spectabile>Hemerocalis fulva>Tagetes patula and Corepsis grandiflora>Monarda didyma, Veronica didyma, Hosta plantaginea, Orychophragmus viloaceus and Viola philippcia; in the climbers, Euonymus var.microphyllus>Lonicera japonica, Wisteria sinensis, Campsis radicans>Parthenocissus quinquefolia and Celastrus orbiculatus>Polygonum aubertii.(2) The results inδ13C value of different plants during the 3 different season showed thatδ13C value in evergreen trees differed significantly among tree species and did not vary among seasons; whileδ13C value in deciduous hardwood trees, shrubs, ground cover and climber plants in spring were greater than that in summer and autumn, and differed significantly among seasons and plant species (except wood ground cover species). As there was a positive relationship between water use efficiency andδ13C value, the above results indicated that water use efficiency in deciduous hardwood trees, shrubs, ground cover and climber plants in spring was larger than that in summer and autumn, with the smallest in summer. The result of instantaneous water use efficiency was consistent with that of long term water use efficiency, that is, instantaneous water use efficiency in spring was greater than that in summer.(3) Comprehensive analysis ofδ13C, photosynthetic rate and instantaneous water use efficiency of different plants during the 3 seasons showed that water use efficiency of Sabina chinese was higher than that of Platycladus orientalis, higher water use efficiency suggesting stronger water saving characteristics. And water-saving capability of Pinus bungeana and Pinus tablaeformis were greater, and Cedrus deodara was the opposite, Drought resistance capability of Ginkgo biloba and Liriodendron chinense×L.tulipifera was weaker, but their WUE was higher, Salix matusdana f. Umbraculifera was a kind of plant with deep roots and strong drought resistant capability. Fraxinus chinese, Magnolia denudate, Diospyros kaki, Eucommia ulmoides and Acer truncatum were greater water-saving landscape plants, while Sophora japonica, Populus tomentosa, Ailanthus altissima and Crataegus pinatifida were lower water-saving landscape plants, and the rest species were in the middle level. For shrubs, Lonicera maackii, Weigela florida cv.Red Prince, Weigela coraeensis and Viburnum sargentii were higher water - saving landscape shrubs with higher long term water use efficiency, but drought resistant capability and water use efficiency of Euonymus japonicus were lower; In wood ground cover plants, Cotoneaster horizontalis and Ligustrum×vicaryi were better at water saving, next was Rosa chinensis; Sedum spectabile with special structure and CAM metabolic pathway showed the strongest drought resistance and water- saving capabilities, water use efficiency in Hosta plantaginea and Veronica didyma were higher; Drought resistance and water-saving of Lonicera japonica and Wisteria sinensis were higher among the climbers, Polygonum aubertii was the opposite.(4) The water stress experiment on typical plants among four types of plant species showed that the adaptability to drought in Fraxinus chinese was better than that in Ginkgo biloba, Sabina Chinese, with Cedrus deodara the weakest, for shrubs, Viburnum sargentii was stronger than Buddleja lindleyana, Prunus persica and Weigela florida cv.Red Prince; drought resistance of Ligustrum×vicaryi was the strongest among the ground cover plants; For climbers, the adaptability to drought in Euonymus var.microphyllus was better than that in Polygonum aubertii. Thus, it can be concluded that the drought adaptability of seedlings was consistent with the above results except that in V. sargentii.(4) Evaluating indicators system of drought-resistant and water-saving urban landscape plants in Beijing was established. The grey correlative degree analysis showed that the indicators that highly associated with drought-resistant and water-saving plants in various groups were very close, mainly includingδ13C value in spring, summer and autumn, the thickness of leaves, specific leaf area, stomatal density, stomatal long diameter, the size of a single stoma, cell tense ratio and spongy ratio of leaves, The conclusion reflected that these indicators contributed more than the others to drought-resistant and water-saving capability. The grey correlative degree analysis showed the drought adaptability of seedlings to water stress was consistent with actual drought resistant capability of seedlings.更多还原