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| 减光和补水对滇南喀斯特石漠化迹地迁置森林表土种子萌发和幼苗生长的影响 | |
| Alternative Title | Effects of shading and watering on seed germinationand seedling growth in translocated forest topsoil in karst rocky desertification in Southern Yunnan |
| 赵高卷 | |
| Thesis Advisor | 刘文耀 ; 沈有信 |
| 2020 | |
| Degree Grantor | 中国科学院大学 |
| Place of Conferral | 中国科学院西双版纳热带植物园 |
| Degree Name | 理学博士 |
| Degree Discipline | 生态学 |
| Keyword | 喀斯特石漠化 表土迁置 减光处理 补水处理 人工除草 种子萌发 幼苗生长 |
| Abstract | 喀斯特石漠化是我国西南地区最为严重的生态地质环境问题，石漠化区域植被恢复非常困难。表土迁置技术归还了许多维持区域特异性物种多样性和稳定性的种子和无性繁殖体，被认为是一种有效的植被恢复方法，但有关表土迁置技术在喀斯特石漠化植被恢复的应用研究鲜有报道。本研究选取位于云南省南部的建水县喀斯特石漠化区域为研究对象，在分析比较该地区供体森林（Donor forest）和受体石漠化迹地（Receiving site）地上植被和土壤种子库的基础上，开展森林表土迁置以及不同梯度减光（不减光（全光照）、轻度减光（大约30 %全光照）、中度减光（大约50 %全光照）和重度减光（大约70 %全光照））和补水处理（不补水、轻度补水（0.5倍中度补水）、中度补水和重度补水（1.5倍中度补水））对迁置表土种子萌发和幼苗生长的试验研究，定量分析减光度和补水量对种子萌发和幼苗生长的调控效应，也研究了去除草、藤本植物对乔、灌木植物萌发和生长的影响，探索喀斯特森林表土迁置后乔、灌木植物幼苗建成策略，为喀斯特石漠化地区仿自然群落构建和优良树种筛选提供科学依据。研究结果表明：（1）滇南喀斯特石漠化迹地土壤种子库中缺乏乔、灌木植物的种子，这是其自然更新和植被恢复困难的主要原因之一。周边残留森林表土迁置到石漠化迹地后，萌发出铁橡栎（Quercus baronii）、滇合欢（Albizia simeonis）、小石积（Osteomeles anthyllidifol）、假虎刺（Carissa spinarum）等一些乔、灌木植物种类，但草本植物仍占优势，其物种丰富度和密度分别占总植物（乔木+灌木+草本+藤本）丰富度和密度的58.1和68.4 %。（2）石漠化迹地迁置森林表土后，实施减光和补水显著地提高了萌发乔木和灌木植物的物种丰富度和密度，特别是物种假烟叶树（Solanum erianthum）、小石积和白枪杆（Fraxinus malacophylla），而萌发总植物、草本和藤本植物密度与减光度之间却呈抛物线关系，当减光度分别为70.0、45.0和27.5 %时，密度分别达到最大79.8、39.8和5.3株/m2。此外，减光和补水显著改善了萌发幼苗与供体森林的相似性。（3）表土迁置1年后到2年后，石漠化迹地上存活乔木植物丰富度与减光度之间的关系由正线性关系转换为抛物线关系，当减光度为37.5 %时，乔木物种丰富度为最大15.2种。存活灌木植物密度与减光度之间的关系也由正线性关系转化为抛物线关系，当减光度为51.0%时，灌木植物密度达到最大6.4株/m2。特别地，表土迁置2年后，苦刺花（Sophora davidii）、木蓝（Indigofera tinctoria）、铜钱树（Paliurus hemsleyanus）和小石积等植物的密度随减光度增加而降低。（4）表土迁置1年后到2年后，减光和补水对灌木植物平均高度和乔木植物平均地径的效应随迁置时间增加而削弱或消失。而减光对乔木植物平均高度的效应随表土迁置时间的增加而增强，特别是铁橡栎、白枪杆、滇合欢、盐肤木（Rhus chinensis）、桑树（Morus alba）、构树（Broussonetia papyrifera）和番石榴（Psidium guajave），它们的高生长随减光度和迁置时间的增加而增加。 （5）与不除草相比，除草显著增加了轻度到中度减光补水处理下乔木植物如白枪杆、铁橡栎、铜钱树和乌桕（Sapium sebiferum）等植物的密度和高生长。综上结果，喀斯特石漠化导致地上植被和土壤种子库严重破坏，植物种丰富度显著下降。森林表土迁置于石漠化迹地后，实施1-2年的中度或重度减光和补水促进了一些木本植物建群种和先锋物种的萌发和幼树建成，加快了石漠化迹地植被恢复进程。本研究结果为滇南喀斯特地区适宜的植物种类筛选、仿自然群落构建和石漠化迹地植被恢复实践提供了科学依据。 |
| Other Abstract | Karst rocky desertification is the most serious eco-geological environment problem in Southwest China. Vegetation restoration is very difficult in rocky desertification area. Topsoil translocation is considered a promising method for ecological restoration because it carries many seeds and vegetative propagates that maintains the regional species diversity and stability. However, there are few studies on the application of top soil translocation in vegetation restoration of karst rocky desertification. This study taking karst rocky desertification in Jianshui County, southern Yunnan province as the object of study, the aboveground vegetation and soil seed bank sin donor forest and karst rocky desertification were investigated and tested to explore the effect of forest topsoil translocation on the restoration of karst rocky desertification; moreover, different shading (no shading (full light), light shading (ca. 30 % full light), moderate shading (ca. 50 % full light) and heavy shading (ca. 70 % full light))and watering treatments (no watering, light watering (0.5 times moderate watering), moderate watering and heavy watering (1.5 times moderate watering))were applied to the translocated forest topsoil in karst rocky desertificationto analyze quantitatively the effects of shading degree (SD) and watering quantity (WQ) on seed germination, seedling growth and establishment. Finally, the effects of weeding herbs and lianas on seed germination and seedling growth of tree and shrub species were also analyzed. The purpose of this study is to explores the establishing strategies for seedlings of trees and shrubs after topsoil translocation, which provides scientific evidence for the construction of natural community and the selection of excellent species in rocky desertification areas. The major results are as follows:(1)There was a lack of seeds and propagules of tree and shrub species in the soil in karst rocky desertification, which was one of the main reasons for its difficulty in natural regeneration and vegetation restoration. After topsoil translocation of the karst rocky desertification site with the topsoil of surrounding donor forest, the richness and density of trees and shrubs, including some dominant woody species, such as Quercus baronii, Albizia simeonis, Osteomeles anthyllidifol,Carissa spinarum, etc. of donor forest vegetation, had been significantly increased, but herbaceous plants were still dominant. The species richness and density of herbs accounted for 58.1 and 68.4% of the total plant (tree+ shrub + herb + liana) richness and density, respectively.(2) When translocated topsoil were carried out with different shading and watering treatments in karst rocky desertification site, the richness and density of the germinated trees and shrubs species increased linearly with increasing of SD and WQ. Especially for Solanum erianthum, O. anthyllidifol and Fraxinus malacophylla. However, the relationship between density of total plants, herb and liana species and SD showed a parabolic relationship, when SD were 70.0, 45.0 and 27.5 %, the density of total plants, herb and liana species reached a maximum of 79.8, 39.8 and 5.3 seedlings/m2, respectively .Additionally, shading and watering significantly improved the similarity between germinated seedlings and donor forest. (3)From one year to two years after forest topsoil translocation, the relationship between richness of tree species and SD transformed from positive linear relationship into parabola relation and the richness of tree species reached maximum 15.2 species when SD was 37.5 %. The relationship between density of shrub species and SD also transformed from positive linear into parabola relationship, when the SDwas51.0 %, the density reached the maximum 6.4 seedlings/m2. Additionally, the density of Sophora davidii, Indigofera tinctoria, Paliurus hemsleyanusandO. anthyllidifoliadecreased with the increasing of SD after two years of topsoil translocation. (4)Fromone year to two years after topsoil translocation, the relationship between average height of shrub species and SD and WQ, the average ground diameter of tree species and WQ transformed from positive linear into no-significance relation. However, average height of tree species had a positive linear relationship with SD in both one year to two years after topsoil translocation, and the effect of SD increased with translocation time. In particular, the heights of dominant species Q.baronii, F. malacophylla, A. simeonis, Rhus chinensis,Morus alba, Broussonetia papyriferaand Psidium guajaveincreased significantly with the increasing of SD. (5)Compared with non-weeding, weeding significantly increased the density and high growth of tree species such as F. malacophylla, Q.baronii, P.hemsleyanus and Sapium sebiferum, under light to moderate shading and watering treatments. In summary, karst rocky desertification resulted in serious destruction and reduction of aboveground vegetation and soil seed bank. The forest topsoil translocation with moderate shading and watering treatments in rocky desertification site can promote the germination and seedling growth of dominant woody and pioneer species, and accelerate the rapid restoration of vegetation in rocky desertification sites. The results of this study provided a scientific evidence for the selection of suitable plant species, construction of natural community and vegetation restoration in rocky desertification sites in southern Yunnan. Key words: Karst rocky desertification; Topsoil translocation; Shading treatment; Watering treatment; Artificial weeding; Seed germination; Seedling growth |
| Pages | 152 |
| Language | 中文 |
| Document Type | 学位论文 |
| Identifier | https://ir.xtbg.ac.cn/handle/353005/11706 |
| Collection | 西双版纳热带植物园毕业生学位论文 |
| Affiliation | 1.中国科学院大学; 2.中国科学院西双版纳热带植物园 |
| Recommended Citation GB/T 7714 | 赵高卷. 减光和补水对滇南喀斯特石漠化迹地迁置森林表土种子萌发和幼苗生长的影响[D]. 中国科学院西双版纳热带植物园. 中国科学院大学,2020. |
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| 赵高卷.pdf（4689KB） | 学位论文 | 开放获取 | CC BY-NC-SA | Application Full Text | ||
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