【作者】 万勤琴；

【导师】 丁国栋；

【作者基本信息】 北京林业大学 ， 水土保持与荒漠化防治， 2008， 硕士

【摘要】 呼伦贝尔沙地是我国四大沙地之一,近些年来,由于受自然条件变化和不合理人为活动的影响,造成了该沙地大面积草场退化、沙漠化,目前成为我国四大沙地中沙漠化唯一仍在扩展的沙地。恢复呼伦贝尔沙地植被、防止沙漠化进一步扩展已经迫在眉睫。因此本文在对呼伦贝尔沙地形成的历史背景进行系统分析的基础上,以沙漠化发展最为严重的陈巴尔虎旗作为研究区,通过考察近几十年的气候变化规律和主要社会经济情况,探讨沙漠化扩展原因。同时,通过大量的野外调查,研究了呼伦贝尔沙地植被资源状况、特征及植被演替规律,为天然植被的保护利用和建立稳定的人工植被提供科学依据。通过研究得出如下主要结论:1.呼伦贝尔沙地的沙漠化是由自然因素和人为因素共同造成的。温度的持续升高和降水量的不断减少,使得气候更加趋于干旱化,构成沙漠化过程的基本背景,而随着当地人口的增加,以及对资源需求的扩大,对土地产生愈来愈大的压力,加速了沙漠化的进程。2.调查结果显示,研究区所见植物共有种子植物54科,146属,199种。常以建群种或优势种出现的有菊科的蒿属,禾本科的针茅属(Stipa)、蝇子草属(Cleistogenes)、芨芨草属(Achnatherum)、碱茅属(Puccinellia)、拂子茅属(Calamagrostis)、赖草属(Leymus)、芦苇属(Phragmites),豆科的锦鸡儿属(Caragana)、棘豆属(Oxytropis)、岩黄耆属(Hedysarum),藜科的碱蓬属(Suaeda)、莎草科的薹草属(Carex),鸢尾科的鸢尾属(Iris)等。3.在过度放牧所引起的逆行演替中,固定沙地,半固定沙地和流动沙地的植物群落物种组成从31种锐减到了2种,盖度从61%降低到8%,群落的物种丰富度逐渐降低,流动沙地的的物种丰富度分别是半固定沙地和固定沙地的0.25、0.065倍,多样性指数分别为2.464、1.584、0.554,固定沙地最大,为流动沙地的4.45倍;物种均匀度0.497、0.528、0.554。流动沙地最大,是固定沙地的1.11倍。高度及生物量亦均呈递减趋势,优势种和建群种发生更迭,群落结构趋于简单。4.在人工干预状态下的恢复演替中,植物的进展演替规律为:以沙米为优势种的一年生先锋植物群落以糙隐子草为优势种其他多年生禾草伴生的过渡型植被群落冰草+糙隐子草过渡型植被群落羊草+冷蒿亚稳定型群落。与此同时,土壤的结构、理化性质得到改善。更多还原

【Abstract】 The Hulunbeier sandy land is our country one of four big sands. Recent year, because natural environment’s worsening adds fells, opens up wasteland, herds, excavates and excessively human’s unreasonable activity caused the Hulunbeier sand big area pasture to the sandy land to desertification. It’s the only expanding land in china. Combat desertification becoming more and more important in china. This paper choose Chenbaerhu Banner as the trail area based on almost 20 year’s climate’date and vegetation date to investigate the reason of desertification, the vegetation constructs and sandy land restored method. Through this research the main purpose of this paper is to give the effective suggestion on restores with the reconstruction degeneration ecosystem. The main conclusion is as follows:1. The Hulunbeier sand’s desertification is created together by the natural factor and the human factor. The temperature continues to elevate with the precipitation reduction, the climate is getting drier, along with local population’s increase, as well as resource demand’s expansion has put more and more tremendous pressure to the land, which accelerated the desertification advancement.2. There are 54 families, 146 genera and 199 species seed plants in the research area. The dominant genera are Artemisia of Asteraceae family, Stipa, Cleistogenes, Achnatherum, Puccinellia, Calamagrosti, Leymus, Phragmites of Gramineae family, Caragana, Oxytropis, Hedysarum of leguminosae family,Suaeda of Chenopodiaceae family, Carex of sedge family and Iris of Iridaceae family.3. In plant’s retrogression of succession, the plant community species composition changed. Species decreased from 31 to 2, coverage from 61% to 8%, species richness in shifting sandy land is 0.25 times of that in semi-fixed sandy land, 0.065 times of that in fixed sandy land. diversity index in Fixed sandy land, semi-fixed sandy land ,shifting sandy land are 2.464, 1.584 and 0.554.diversity index in Fixed sandy land was the biggest which is 4.45 times of that in shifting sandy land. Species evenness is 0.497, 0.528 and 0.554. Species evenness in shifting sandy land is the biggest which is 1.11 times of that in fixed sandy land. At the same time, the biomass also assumes the decreasing progressively tendency, the dominant species and constructs the group kind to occur alternates, the community structure tends to be simple.4. Manual intervention in the restoration of state in succession, the progress of succession law: annual species such as Agriophyllum squarrosum as the dominant species in vegetation community. Cleistogenes squarrosa as the dominant species with another Perennial Grass in this kind of transition vegetation community Agropyron cristatum and Cleistogenes squarrosa together as the dominant species in the transition vegetation community Leymus chinensis and Artemisia frigida together as the dominant species in the metastable vegetation community. At the same time, the soil structure, improve physical and chemical properties.Plant’s progression of succession rule is: the stage of Agriophyllum squarrosum & Corispermum stauntonii -> the stage of Agropyron cristatum & Artemisia frigida -> Caragana microphylla & Stipa grandis & Cleistogeness quarrosa -> Carex rigescens & Agropyron cristatum. Meanwhile, the soil structure, the physics and chemistry nature are improved.更多还原