基于捐赠土壤种子库的植被近自然恢复技术研究

发布时间：2018-06-02 14:16

本文选题：土壤种子库 + 捐赠种子　；参考：《河北农业大学》2015年硕士论文

【摘要】：冀北山地沙化程度日益严重,其生态系统功能的发挥受到严重制约,植被自然恢复是提高其生态系统功能的有效途径。然而,由于该地区土壤养分和水分含量低、土壤种子库中种子数量少、物种单一,采用人工造林或封育措施很难实现植被的自然恢复。基于捐赠土壤种子库的植被近自然恢复技术,是以捐赠土壤种子库为基础,以提高土壤种子库种子发芽、生长能力为目的,以天然种子库种子收集、种子发芽与生长基质配比技术,以及发芽保护等系列技术构成。该技术能够更大程度的利用相似临近地域的天然种子库,使植被的更新演替得到有效保证,又可以实现植被的近自然恢复,确保物种遗传多样性。由此可见,该技术可以克服沙化山地土壤种子库中种子数量少、水分、养分不足的缺点,从而实现对沙化山地的近自然植被恢复,与人工造林或利用封育措施自然恢复技术相比,具有明显的优越性,应用前景广阔。因此,本文以冀北沙化山地为研究对象,在了解和掌握植被恢复前沙化山地和捐赠土壤种子库林地土壤种子库特征、土壤理化性质及地上植被状况的基础上,通过比较土壤种子库土壤不同收集方式的效率和成本,研究种子发芽基质中添加木本植物种子种类和比例、保水剂和土壤粘合剂的施用量及防寒措施的必要性,总结土壤种子库收集技术、种子发芽基质配比技术和种子发芽保护技术,并利用此技术对沙化山地进行植被恢复后的效益进行分析,为今后退化山地的植被近自然恢复提供参考和技术支持,主要研究结果如下:1.相对于人工收集方式,机械收集土壤种子库的效率高、成本低,对林地土层破坏性小。机械收集土壤种子库的效率为人工收集的8倍,而成本要比人工收集方式低4.8倍。2.添加保水剂后植被生物量和木本植物的数量均明显高于未添加保水剂处理,随着保水剂施用量的增加,植被生物量和木本植物的幼苗数量显著增加。当保水剂施用量达到250 kg/m3吸足水的保水剂时,植被生物量和木本植物幼苗的数量最多,但与施用200 kg/m3保水剂的处理间差异不显著。表明每m3母土中加入200 Kg吸足水的保水剂就能满足植物种子萌发和生长的需要。3.未经任何防寒措施处理的幼苗成活率仅为9.6%,经过覆土的木本植物幼苗成活率为89%,是无防护措施的9倍。由此可以说明覆土防寒措施的必要性。4.植被恢复后的造林地土壤种子库物种数量比恢复前的沙荒地增加11种,以多年生草本植物居多;土壤种子库间相似性系数表现为恢复后造林地与恢复前沙荒地相似性系数为0.32,与捐赠土壤种子库林地相似性系数增加到0.44,相似性有所增加。5.恢复后的地上植被中出现2种常绿乔木及多种灌木树种,并增加了豆科植物,多年生草本以及一二年生草本物种数量增加明显;地上植被间相似性系数表现为恢复后造林地与恢复前沙荒地相似性系数为0.30,与捐赠土壤种子库林地相似性系数增加到0.54。6.恢复后的土壤容重达到良好水平,持水量增加,p H值接近中性,有机质、全N、全P、有效K、碱解N及速效P含量变化趋势基本一致,都是在0-10cm土壤深度时含量较高,随着土层深度增加含量有所减少,恢复后造林地较恢复前沙荒地土壤各种养分含量均显著提高。
[Abstract]:The degree of desertification in the mountainous region of northern Hebei is becoming more and more serious, and the function of its ecosystem is seriously restricted. The natural restoration of vegetation is an effective way to improve the function of its ecosystem. However, because of the low soil nutrient and water content, the number of seeds in the soil seed bank is low and the species is single, it is difficult to achieve planting by artificial afforestation or seal breeding. The natural restoration technology of the vegetation based on the donated soil seed bank is based on the donation of the soil seed bank, in order to improve the seed germination of the soil seed bank, and to improve the growth ability. It is composed of a series of techniques, such as the seed collection of the natural seed bank, the seed germination and the growth matrix ratio technique, and the germination protection. Using natural seed banks with similar adjacent regions to a greater extent, the renewal and succession of vegetation can be effectively guaranteed, and the near natural restoration of vegetation can be realized, and the genetic diversity of species can be ensured. Thus, this technique can overcome the disadvantages of small number of seeds, water and insufficient nutrients in the sandy soil seed bank of the desertification mountain area, thus realizing the desertification of desertification. The restoration of near natural vegetation in the mountain area has obvious advantages and wide application prospects compared with artificial afforestation or natural restoration techniques using seal breeding measures. Therefore, this paper takes the sandy desertification mountains in northern Hebei as the research object, and understands and grasps the characteristics of the soil seed bank of the sandy land and the donated soil seed bank before the vegetation restoration, and the soil physicochemical properties. On the basis of qualitative and aboveground vegetation conditions, by comparing the efficiency and cost of different soil collection methods in soil seed bank, the species and proportion of seeds added to the seed germination matrix, the application amount of water retention agent and soil binder and the necessity of cold prevention measures were studied, and the collection technology of soil seed bank and the ratio of seed germination matrix were summarized. Technology and seed germination protection techniques are used to analyze the benefits of vegetation restoration in sandy mountain areas, and provide reference and technical support for the near natural restoration of vegetation in degraded mountainous areas. The main results are as follows: 1. relative to artificial collection, mechanical collection of soil seed banks has high efficiency, low cost, and forest land. The soil layer is less destructive. The efficiency of the soil seed bank by mechanical collection is 8 times that of the artificial collection, and the cost of the plant is 4.8 times lower than the artificial collection method. The vegetation biomass and the number of woody plants are significantly higher than that of the non added water preserver. With the increase of the dosage of the water retention agent, the biomass of vegetation and the number of the seedlings of woody plants are increased. There was a significant increase in the amount of vegetation biomass and the number of seedlings of woody plants when the dosage of water retention agent reached 250 kg/m3 of foot water, but the difference was not significant with the treatment of the 200 kg/m3 water retention agent. It was indicated that the addition of 200 Kg absorbent water in each M3 mother soil could satisfy the needs of the plant seed germination and growth of.3.. The survival rate of the seedlings treated with no cold measures was only 9.6%, and the survival rate of the seedlings was 89%, which was 9 times as high as that of the non protective measures. Therefore, it could be explained that the necessity of the soil cold proof measures was necessary. The number of species in the soil seed bank after the restoration of.4. vegetation was increased by 11 species in the sandy land before the restoration, with the majority of perennial herbaceous plants. The similarity coefficient between the soil seed banks showed that the similarity coefficient between the reforestation and the pre recovery sand wasteland was 0.32, and the similarity coefficient increased to 0.44 with the donated soil seed bank, and the similarity increased with 2 evergreen trees and a variety of shrub species in the aboveground vegetation after.5. restoration, and increased the leguminous plants and perennial herbs. The number of one or two year old herbaceous species increased obviously. The similarity coefficient between the aboveground vegetation showed that the similarity coefficient between the reforestation and the pre recovery sand wasteland was 0.30. The similarity coefficient of the soil seed bank forestland increased to a good level after the 0.54.6. recovery, the water holding capacity increased, the p H value was close to neutral, organic matter, All N, all P, effective K, alkali solution N and quick acting P content change trend basically consistent, all is in the 0-10cm soil depth content is higher, with the soil depth increase content decreases somewhat, after recovery, the soil nutrient content of the forested land before recovery is significantly increased.
【学位授予单位】：河北农业大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：S154

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