【作者】 刘宇；

【导师】 卜兆君；

【作者基本信息】 东北师范大学 ， 湿地科学， 2019， 硕士

【摘要】 泥炭地具有重要的生态功能,但因为气候变化和人类活动等多方面因素,普遍面临退化问题。目前,退化泥炭地的恢复研究主要包括复湿后自然恢复和原有植物引入恢复两类,探讨泥炭藓（Sphagnum）繁殖体的离体扩增以及引入恢复对于泥炭地恢复将有重要应用价值,然而,这两方面研究在我国均十分缺乏。本研究使用中位泥炭藓（S.magellanicum）、喙叶泥炭藓（S.flexuosum）和粗叶泥炭藓（S.squarrosum）为室内实验物种,以长白山区白江河泥炭地作为恢复样地,使用中位泥炭藓为引入物种,采用水位提升和小灌木去除的手段,从以下两方面对退化泥炭地苔藓地被生态恢复技术展开探讨:（1）对中位泥炭藓的离体培养展开研究,探讨在室内培育用于泥炭地恢复中所需的泥炭藓繁殖体的可行性（2）对水位提升、小灌木去除和泥炭藓繁殖体移植密度三个因素在泥炭地恢复中的影响和作用机理进行研究,为野外恢复工作的实施提供依据。研究所得的主要结果和结论如下:（1）抗生素对泥炭藓孢子萌发具有抑制作用,且在从孢子开始的离体培养中效果不明显,在培养中不使用抗生素为宜。（2）培养基的浓度和元素比例影响泥炭藓孢子萌发和原丝体生长。Rudolph培养基对泥炭藓孢子萌发有利,且有利于原丝体进行分枝生长。而钙离子影响丝状原丝体伸长能力,含钙离子的Knop培养基能促进原丝体伸长,适合用与原丝体培养。（3）生长素类似物2,4-D和细胞分裂素6-BA可刺激喙叶泥炭藓孢子萌发,而中位泥炭藓孢子对植物激素刺激不敏感。使用2,4-D和6-BA刺激喙叶泥炭藓和中位泥炭藓原丝体,均无法诱导其产生愈伤组织。（4）将泥炭藓原丝体粉碎后可以进行传代培养,达到快速扩增的目的。停止传代后泥炭藓原丝体会自然发育成配子体植株。在这一阶段施加植物激素处理,发现使用浓度为0.01⁰.2mg·L^-1的生长素类似物2,4-D和细胞分裂素6-BA刺激后,泥炭藓高度均有所降低。（5）使用泥炭块和木板搭建高度不同的堤坝堵截排水沟,可以显著将实验样地内不同水位埋深区的水位埋深区分开来,堵截排水沟是经济而有效的调控退化泥炭地水位条件的手段。（6）提升水位能显著提高两个生长季结束后的泥炭藓盖度,水位提升对泥炭藓生长的影响主要是在泥炭藓繁殖体的建植阶段中体现,泥炭藓繁殖体对水分有着强烈的需求,充分湿润的环境可以使泥炭藓繁殖体存活率显著提高,从而达到更好的恢复效果。（7）小灌木去除使两个生长季结束后的泥炭藓盖度显著提高。因为在越冬时小灌木会阻挡降雪形成雪被,其下的泥炭藓盖度在冬季结束后显著降低。因此在泥炭地恢复过程中应当优先提升水位的前提下去除小灌木,以提高泥炭藓盖度。（8）提高繁殖体移植密度能显著增大两个生长季之后的泥炭藓盖度,但是在深水位埋深的干燥条件或是越冬时的寒冷条件下,提高泥炭藓繁殖体移植密度会使泥炭藓存活率下降。（9）野外实验中,水位提升和小灌木去除处理均使样地内的草本植物盖度显著提高,但引入泥炭藓繁殖体则对草本植物生长没有显著影响。综上所述,本研究得出的恢复方案为:使用Rudolph培养基进行泥炭藓孢子萌发获取原丝体,之后再Knop培养基上对泥炭藓原丝体进行反复破碎分瓶培养实现泥炭藓繁殖体快速扩增,从而得到泥炭藓繁殖体,泥炭藓繁殖体可用于野外恢复中。在野外恢复工作中应优先进行提升水位,保证水位达到地表附近后使用机械设备完全去除小灌木,之后进行泥炭藓繁殖体引入,控制泥炭藓繁殖体移植密度在1:10左右比较有效率。更多还原

【Abstract】 The climate change and anthropogenic activities are putting the peatlands at high risk of degradation.Currently,the restoration of degraded peatlands had gained a lot of focus and the restoration is progressing by using two different approaches:natural restoration after rewetting and transplantation of native species for vegetation restoration.In China,there are few studies on peatland vegetation restoration by using Sphagnum.Long-term studies on bryophytes tissue cultures,in vitro culture of Sphagnum and the relatively mature technical system,had been formed,however,there is a lack of study on using plant hormones to initiate callus growth from Sphagnum.The species used for in vitro experiment were as S.magellanicum,S.flexuosum and S.squarrosum,whereas,the in-situ experiment was conducted in Baijianghe peatland in Changbai Mountains.The intermediate Sphagnum was introduced into the species,and the water level elevation and dwarf shrub removal were used in peatland vegetation restoration.There were two experiments in this study:（1）In vitro culture of S.magellanicum was studied to explore the feasibility of indoor cultivation of the Sphagnum propagule used in the restoration of peatland.（2）The effects of water level elevation,dwarf shrub removal and propagation transplant density on the restoration of peatland and its mechanism were studied to provide a basis for the implementation of field restoration.The main results and conclusions are as follows:（1）Antibiotics imposed an inhibitory effect on the germination of Sphagnum spores,and the effect was not obvious in in-vitro culture from spores.Therefore,it is recommended to avoid the usage of antibiotics in culture.（2）The concentration of the medium and the proportion of the elements affected the spore germination and growth of the protonema.The low concentration of Rudolph medium was beneficial for the germination of Sphagnum spores and branching growth of the protonema.Calcium ions affected the elongation of filamentous protonema,and Knop medium containing calcium ions promoted the elongation of the protonema.（3）The auxin analogues 2,4-D and cytokinin 6-BA stimulated the spore germination of Sphagnum flexuosum,while the Sphagnum magellanicum spores were not sensitive to phytohormone stimulation.Both 2,4-D and 6-BA were used to stimulate S.flexuosum and Sphagnum magellanicum,which could not induce callus production.（4）After pulverizing the Sphagnum protonema,it can be subcultured to achieve rapid expansion.After stopping the subculture,the Sphagnum protonema will naturally develop into gametophyte plants.At this stage,phytohormone treatment was applied and it was found that the Sphagnum height was reduced after stimulation with the auxin analogues 2,4-D and cytokinin 6-BA at a concentration of 0.01-0.2 mg·L^-1.（5）Peat blocks and planks were used to block the drainage ditches and to construct dams at different heights.Blocking the drainage ditch is an economical and effective way to regulate the water table depth conditions of degraded peatlands.（6）Water level elevation significantly increased the Sphagnum cover after the end of the two growing seasons.The effect of water level elevation on the growth of Sphagnum was mainly reflected in the colonization stage of the Sphagnum breeding body.A fully humid environment could significantly improve the survival rate of Sphagnum propagules,thus achieving better recovery.（7）Dwarf shrub removal significantly increased the Sphagnum cover after the end of the two growing seasons.The shrub cover blocks the snowfall to form snow cover,therefore,in the process of peatland restoration,the dwarf shrub should be removed so that water level could rise and increase the cover of the Sphagnum.（8）Increasing the transplant density of the propagule significantly increased the Sphagnum coverage after two growing seasons,but increasing the transplant density of the Sphagnum propagules under the dry conditions with low water table or cold conditions during winter decreased the survival rate of Sphagnum.（9）In the field experiment,the elevation of water table level and the removal of small shrubs significantly increased the coverage of herbaceous plants in the plot,but the introduction of Sphagnum propagules had no significant effect on the growth of herbaceous plants.In summary,the use of Rudolph medium for germination of Sphagnum spores to obtain protonema,followed by a subculture of Sphagnum protonema achieved the purpose of rapid expansion of Sphagnum propagules.The rising of water level and removal of dwarf shrubs in the peatland restoration was beneficial to the growth of Sphagnum,and it is more effective to control the transplant density of Sphagnum propagules around 1:10.更多还原