【作者】 王磊；

【导师】 王宝山；

【作者基本信息】 山东师范大学 ， 生物工程（专业学位）， 2020， 硕士

【摘要】 土壤盐渍化成为全球严重的环境问题,人们对盐碱地的改良利用进行了多样的探索。实践证明,相比物理和化学方法,生物方法是最为有效、持久、自然友好的方法。盐生植物是在相当于或高于200 mmol·L^-1Na Cl盐渍环境中生存繁衍的一类天然植物类群。盐生植物在自然环境中分布广泛,种类繁多,是应用于盐碱地改良的宝贵资源。当前,对盐生植物的开发和利用是盐碱地改良的主要方向。我国是盐碱地分布大国,海岸线长,盐碱土壤面积广大。黄河三角洲地区是典型的滨海盐渍土壤。黄河三角洲地区现有的800万亩边际性土地多为盐碱地,土壤含盐量高、营养元素含量低,不适合于普通农作物生长;新生湿地生态系统脆弱,土壤次生盐碱化严重受海潮、风暴潮等灾害威胁较大。近年来,土壤的开垦程度增加,使原本就脆弱的人工林进一步退化,环境脆弱,问题突出。环境问题严重制约了黄河三角洲地区的城镇绿化、生态建设和经济发展。充分开发和利用好这一块东部地区少有的土地资源,培育新生的生态经济产业,对“黄河三角洲高效生态经济区”生态建设、城市绿化以及滨海地区盐碱地开发利用产生重大意义。为了提升黄河三角洲盐碱地区的生态文明程度及经济文化水平,增强其综合竞争力,必须大力发展林业,建立稳固的生态系统。前期,我们已经从全国各地收集了大量的耐盐林木品种并开展了不同类型林木耐盐性筛选指标研究,筛选出了能在重度盐碱地生存的两个树种:柽柳和沙枣。如何建立配套的盐碱地种植技术和林木立地栽培模式已成为黄河三角洲发展的关键。本研究着重研究了柽柳和沙枣两种能在黄河三角洲重度盐碱地生存的林木,探索其配套的立地栽培技术和配套的管理模式,为提升黄河三角洲地区林木成活率、保存率、森林覆盖率提供了配套的技术支持。主要结果如下:研究了柽柳和沙枣的栽培抚育技术,通过甘蒙柽柳和中国柽柳的施肥实验探索了不同的施肥量对盐渍土壤和柽柳的影响。结果表明,有机肥促进柽柳的株高伸长和生物量的积累,改善土壤含盐量、有机质含量、土壤容重和p H,3600kg·hm^-2是最合适的有机肥施肥量。相比CK,甘蒙柽柳一年内株高净增长34cm,生物量净增长500 g左右,土壤的p H值下降0.17,土壤的容重下降了5%,水解性氮和有效磷增加至原来的2倍以上,土壤中的速效钾增长了30%左右;一年内中国柽柳的株高净增长量为40 cm,地上生物量的净增长量为1500 g,土壤中水解性氮含量提高至原来的2倍以上,有效磷含量提高至原来的50%以上,速效钾增加了10%左右,土壤的p H平均降低了0.31,土壤容重降低了4.6%。通过移栽实验,筛选出合适的柽柳移栽树木的大小,柽柳的株高在60～160 cm茎围在2～8 cm之间的柽柳移栽的成活率为80%以上,显著高于其余大小的柽柳,适合移栽。通过沙枣的有机肥实验探索了施有机肥对沙枣生长和土壤理化特性的影响。结果表明,有机肥促进沙枣株高的伸长和生物量的积累,2100kg·hm^-2是最适施肥量,与对照相比,一年内的株高净增长量为30 cm,生物量的净增长量为1200g。施有机肥提高了土壤中营养成分含量,水解性氮含量提高至原来的2倍以上,有效磷的含量提高至5倍,速效钾含量提高至原来的50%以上,降低了土壤的含盐量和p H,施肥处理的土壤p H值平均下降了0.61。通过沙枣的化肥实验探索了沙枣的合适追肥浓度,化肥为每公顷187.5 kg尿素+187.5 kg过磷酸钙组合的施肥量时,一年内株高的净增长量为17.3 cm,生物量的净增长量为1001.6 g,最为合适。探索了一年生沙枣苗在不同程度盐碱地的适应能力及耐盐阈值,沙枣在含盐量为2.3%的土壤中的成活率为50%,沙枣土壤含盐量在1.5%以下时沙枣的成活率在70%左右,也就是说沙枣的耐盐阈值是2.3%,沙枣可在1.5%以下的重度盐碱地可以大范围种植。通过间苗实验探索了不同的株距对沙枣植株生长形态的影响,间距越大沙枣分枝越多、形态易弯曲,因此,密植（株距≤5cm）是沙枣的适合播种密度。另外,对濒危的红花多枝柽柳进行了组培快繁实验,获得了数百棵红花多枝柽柳幼苗并进一步优化了组培快繁的实验流程,运用MS培养基即可完成对红花多枝柽柳的生根培养和增值培养,操作简单。论文系统探索了在柽柳和沙枣的大面积种植和培育过程中的技术问题,为柽柳和沙枣工厂化育苗提供了技术支持,为柽柳和沙枣在重盐碱地生态建设及滨海盐碱城市的绿化提供了保障。更多还原

【Abstract】 Soil salinization has become a serious environmental problem in the world.Compared with physical and chemical methods,biological methods have proved to be the most effective,sustainable and environment-friendly methods.Halophytes are the native plant species that can finish their life cycles in saline environment equal to or higher than 200 mmol·L^-1Na Cl.Halophytes are widely distributed in the world,Halophytes are widely distributed and varied in natural environment,and they are valuable resources for saline-alkali land improvement.There is a large area of saline-alkali land in China.The Yellow River Delta is a typical coastal saline soil.Most of the 8 million mu of marginal land in the Yellow River Delta is saline-alkali land with high soil salinity and low nutrient content,which is not suitable for the growth of common crops.The ecosystem of newborn wetland is fragile,and the secondary salinization of soil is seriously threatened by sea tide,storm surge and other disasters.In recent years,the degree of land reclamation is increasing,which has led to the further degradation of the soil,the planted forest and the fragile environment in Yellow River Delta.Environmental problems have seriously restricted urban greening,ecological construction and economic development in the Yellow River Delta.It is of great significance to fully develop and utilize the rare land resources such as saline soil in the eastern region and to develop new ecological economic industry,which will contribute to the ecological construction,urban greening and the development and utilization of saline-alkali land in the coastal area of the Yellow River Delta.In order to improve the ecological civilization,economic and cultural level and to enhance the comprehensive competitiveness of the Yellow River Delta,we must greatly develop forestry and establish a stable ecosystem.In the past decades,we have collected a large number of salt-tolerant tree varieties from all over the country and carried out studies on the evaluation of their salt tolerances.Finally,we have screened out two tree species that can survive in the severe saline-alkali land:Tamarix chinensis and Elaeagnus angustifolia L.Now,it is the limiting factor to establish planting techniches and the planting mode of halophyes such as Tamarix chinensis and Elaeagnus angustifolia L.in saline-alkali land.In this study,Tamarix chinensis and Elaeagnus angustifolia L.were to construct the cultivation technique and supporting management mode,which provides the practical techniques for improving the survival rate,preservation rate and forest coverage rate of trees in high salinity land in the Yellow River Delta.The main results are as follows:In this study,Tamarix chinensis Lour and Elaeagnus angustifolia L.adapting to high salinity were uesed to investigate the tending techniques planting mode in saline land.The effects of different fertilizer applications on the properties of saline soil and growth parameters Tamarix chinensis Lour and Elaeagnus angustifolia were in detail studied by the experiments.The results showed that the organic fertilizer application significantly promoted the plant height and biomass accumulation of Tamarix chinensis,and markedly improved the physicochemival parameters of saline soil such as salt content,organic matter content,soil bulk density and p H.The most suitable fertilizer（N+P₅O₂+K₂O≥4%,organic matter≥30%）amount is 3600 kg·hm^-2fertilizer.Compared with control,the net growth of plant height and biomass of Tamarix austromongofica was 34 cm and about 500 g in a year,respectively.In addition,the p H value of the soil decreased by 0.17,the bulk density of the soil decreased by 5%,the hydrolyzed nitrogen and available phosphorus increased to more than twice of the original value,and the available potassium in the soil increased by about 30%.The net growth of plant height of Tamarix chinensis Lour in one year was increased by 40 cm,and the net growth of above-ground biomass was increased by1500 g.The hydrolytic N content in the soil increased to more than twice of the CK,the available P content increased to more than 50%,the available K increased by about 10%,the soil p H decreased by 0.31 on average,and the soil bulk density decreased by 4.6%.In order to take a look insight into the effect of different ages of the seedlings on the survival rate in saline soils,different ages of Tamarix chinensis seedlings were transplanted in the saline soils,and the Tamarix chinensis with a plant height of 60～160 cm and a stem diameter of 2～8 cm had a survival rate of over 80%,significantly higher than other seedlings,which was suitable for transplanting in saline land.The effects of organic fertilizer（N+P₅O₂+K₂O≥4%,organic matter≥30%）on the growth parameters of Elaeagnus angustifolia L.and the physicochemical propertyies of saline soil were studied by means of organic fertilizer application experiment.The results showed that organic fertilizer significantly promoted the elongation of plant height and the accumulation of biomass.When 2100kg·hm^-2fertilizer was applied,the net growth of plant height in one year was 30 cm,and the net average growth of biomass was 1200 g per plant,which was the optimal fertilizer application.The application of organic fertilizer increased the nutrient content in the saline soil,the content of hydrolytic nitrogen increased to more than 2 times,the content of available phosphorus increased to 5 times,the content of available potassium increased to more than 50%,and the salt content and p H of the soil were reduced.Compared with control,the p H value of the soil under fertilization decreased by 0.61 on average.The apllication of chemical fertilizers to Elaeagnus angustifolia L growing in saline soil was explored.When the fertilizer application amount was 187.5 kg urea plus 187.5 kg calcium superphosphate per hectar,the net growth rate of plant height in one year was17.3 cm and the net growth rate of biomass was 1001.6 g,which was the most suitable.In this paper,the adaptability of one-year-old Elaeagnus angustifolia seedlings in salt-alkali land was explored,the survival rate of the salt-alkali land was50%in the soil in the saline soil with a salt content of 2.3%,the survival rate of the salt-alkali land was about 70%when the soil salt content was less than 1.5%.These results indicate that the salinity threshhold of Elaeagnus angustifolia is 2.3%and Elaeagnus angustifolia can be planted in the salt-alkali land with less than 1.5%of salt content.The effect of different plant spacing on plant growth morphology was explored by means of thinning seedlings experiment.The larger plant spacing,the trunk more curved.Therefore,density of the planting（plant spacing≤5cm）is the suitable planting density for Elaeagnus angustifolia seedling propagation.Several hundred Tamarix gallica Bunge seedlings were obtained and the experimental process of tissue culture was further optimized.The root culture and increment culture of Tamarix gallica Bunge could be completed by MS medium with simple operation.In summary,the tending techniques and planting mode of Tamarix chinensis and Elaeagnus angustifolia L.in high salinity land have been constructed,which provides technical support for the large-scale forest planting in saline land and provides a guarantee for the urban greening of Tamarix chinensis and Elaeagnus angustifolia L.in the coastal cities such as Tianjin and Dongying.更多还原