中国戈壁针茅（Stipa gobica）草原植物群落特征及其地理分布

发布时间：2018-01-23 18:17

本文关键词： 戈壁针茅草原群落特征植物区系地理群落多样性土壤微量元素　出处：《内蒙古大学》2017年硕士论文　论文类型：学位论文

【摘要】：戈壁针茅(Stipa gobica)为多年生旱生丛生小型草本,属针茅属(Stipa)羽针组(Sect.Smirnvia),区系地理成分为亚洲中部分布种。戈壁针茅草原是一种小型针茅为建群种的草原,主要分布于荒漠草原区的石质丘陵或石质山坡,向东可以分布在典型草原区的石质丘陵或山地,向西也可以分布在荒漠区的石质山坡上。由于戈壁针茅与石生针茅(Stipa klemenzii)在分布区上近重合,在形态上又相似,在我国及蒙古国主要著作中记载的由二者分别建群构成的草原类型出现完全颠倒(主要是由于学名的颠倒造成的),导致群落学上的描述与实际不相符。所以,系统深入地研究中国戈壁针茅草原植物群落基本特征及其地理分布有助于区别戈壁针茅草原和石生针茅草原的群落特征,订正主要植被著作中的混乱,拓展草原植被生态学研究领域,可为中国草原的植被区划,合理地制定综合自然区划方案提供科学依据,并对荒漠草原区植被保育和合理的安排放牧及畜牧生产具有重要的实践指导意义。在系统了解中国戈壁针茅草原的群落特征及其空间分布规律,并对中国戈壁针茅草原116个样地进行详细样方调查、分析的基础上,得出下结论:1、建群种戈壁针茅虽然与石生针茅的分布区相似,但形态特征与天山针茅更相近,与石生针茅在形态特征上存在较大的差异。戈壁针茅与近缘种天山针茅在颖片长、外稃长度、芒长、芒针长度、外稃先端是否具毛环等特征上均具有明显差别,在地理分布上戈壁针茅与天山针茅(Stipatianschanica)的分布中心也相对独立,因此可得出结论:天山针茅和戈壁针茅在种间存在多个独立的、变异间断的形态性状,且两个物种具有各自独立的多度分布中心,符合"形态-生物学物种Morphology-biology pecies"的概念,是形态鲜明有别,地理分布独立的两个物种。2、根据已有样方资料统计中国戈壁针茅草原共有维管植物303种,隶属于40科,139属。其中裸子植物5种,隶属于2科,2属;被子植物298种,隶属于38科,137属,含物种数大于10种的科分别为:菊科(Compositae)、禾本科(Gramineae)、豆科(Leguminosae)、蔷薇科(Rosaceae)、百合科(Liliaceae)、藜科(Chenopodiaceae)、石竹科(Caryophyllaceae);戈壁针茅草原植物区系的生活型谱以地面芽植物为主,共189种植物、占总种数的62.38%;水分生态类型以旱生植物为主,共127种,占总种数的41.91%;植物区系地理成分上以亚洲中部分布种(含其变型)最多,共95种,占总种数的31.35%;盖度等级划分上以0.1%-1%的盖度最多,占总种数的64.1%;恒有度等级划分上以I级(0%-20%)的物种数最多,共259种植物,占所有植物种数的94.87%。3、基于群落调查数据、按照群落-外貌分类原则,将戈壁针茅群系划分为8个群丛组、106个群丛,并对每个群丛的分布区、群落特征进行了描述,以及对戈壁针茅草原植物群落的生态演替关系进行了分析。4、中国戈壁针茅草原群落多样性沿海拔和经度梯度表现出有规律的变化,随着经度的升高,群落的α多样性整体水平呈直线或波动性上升趋势,随着海拔的升高,α多样性中物种丰富度呈先增后减的趋势,其他多样性指数呈整体上升的趋势;而β多样性指数随经度的升高,呈现波动性的上升趋势,在108-109°E处,Cody多样性指数达到最高值,而Jaccard相似性系数达到最低值;β多样性指数随海拔的增大呈现出先增后减的趋势,在海拔1700m左右处达到最大值。5、通过戈壁针茅草原与地带性群落石生针茅草原、短花针茅(Stipa breviflora)草原和克氏针茅(Stipa krylovii)草原的土壤微量元素和土壤pH值的对比研究,得出土壤微量元素中对戈壁针茅草原群落的分布影响最大的两个微量元素分别为Cr元素和Cu元素含量,其原因可概括为以下几点:第一,戈壁针茅草原的土壤pH值要显著低于其他草原类型的土壤,而有研究表明土壤pH值与Cr元素和Cu元素的含量是呈显著负相关的;第二,有可能是戈壁针茅物种本身对于这两种元素的选择性吸收能力要强于对其他土壤微量元素,因此戈壁针茅的根从砾石质化严重的岩石风化物中吸取这两种元素,随着植株体的死亡,将植株内吸收的这两种元素又归还到土壤当中,使得群落土壤中这两种元素的含量显著高于其他草原类型的土壤;第三,戈壁针茅草原所处的生境砾石质化明显高于其地带性草原类型,所受风蚀的程度也明显高于其他草原类型,使得土壤中矿物的风化和分解的速度也自然显著快于其他草原类型的土壤,而随着土壤中矿物的风化和分解,其中的土壤微量元素含量自然升高,这也可能成为戈壁针茅草原的土壤微量元素整体水平高于其他草原类型且Cr元素和Cu元素的含量显著高于其他草原类型的一个原因。
[Abstract]:Gobi (Stipa gobica) is a perennial species with small genus of xerophytic herbaceous, Stipa (Stipa) group (Sect.Smirnvia), feather needle flora for the Asian part of cloth. Gobi steppe is a small Stipa as edificators grassland, desert grassland is mainly distributed in the rocky hills or stony hill, to the East can be distributed in the typical steppe area of rocky hills or mountains to the west can be distributed in the desert region of the rocky hillside. Because Gobi Stipa and Stipa klemenzii (Stipa klemenzii) nearly coincide in the distribution area, and similar in morphology, the two group of grassland types respectively. The main works recorded in China and Mongolia in China appear upside down (mainly due to name upside down), resulting in the school community description does not match with the actual system. Therefore, in-depth study of Gobi plant communities of Stipa steppe China basic characteristics Sign is helpful to distinguish between community characteristics of Gobi steppe and Stipa klemenzii steppe and its geographical distribution, the main vegetation in the works of correction of confusion, expand the research field of grassland vegetation ecology, vegetation regionalization for Chinese grassland, reasonably establish the comprehensive natural zoning program to provide a scientific basis, and has important practical significance to the grassland vegetation the desert area conservation and reasonable arrangement of grazing and livestock production. In the system to understand the distribution characteristics of community and space China Gobi steppe, and the Chinese Gobi steppe 116 plots detailed investigation, based on the analysis, draw the conclusion: 1, edificators of Stipa in Gobi although the distribution area and stone students of Stipa are similar, but morphological characteristics and the Stipa is more similar, and Stipa klemenzii have great differences in morphological characteristics of Stipa and related species. Gobi Tianshan needle Mao Zaiying Length, lemma length, awn length, awn needle length, lemma apex ciliate ring features whether have obvious differences in the geographical distribution of Stipa in Gobi and Tianshan Stipa (Stipatianschanica) distribution center is relatively independent, we can draw a conclusion: Tianshan and Gobi in Stipa species of Stipa has more than one independent. Morphological variation and discontinuous, two species abundance distribution center has independent, accord with the concept of "form - biological species Morphology-biology pecies", is a distinctive form of two species are different, the geographical distribution of.2 independent, according to statistics Gobi Chinese Stipa grassland plots there are vascular plants of 303 species. Belonging to 40 families and 139 genera. Among them there are 5 species gymnosperm belonging to 2 families, 2 genera; 298 species of angiosperms, belonging to 38 families, 137 genera, including more than 10 species of Compositae were: (Compositae), Gramineae (Gramineae), beans Science (Leguminosae), Rosaceae and Liliaceae (Rosaceae) (Liliaceae), Chenopodiaceae and Caryophyllaceae (Chenopodiaceae) (Caryophyllaceae); spectrum hemicrypotophyte live in Gobi grassland flora, 189 species, accounting for 62.38% of the total species; water ecological types xerophytes mainly, a total of 127, accounting for 41.91% of the total species; the geographical composition of the flora in the Asian part of cloth (including its variants) most, a total of 95, accounting for 31.35% of the total species; the coverage classification based on 0.1%-1% coverage up to 64.1% of the total species; the constant degree classification to I (0%-20%) species, 259 species, accounting for all species of the 94.87%.3 community, based on survey data, according to the classification principle of community appearance, Gobi Stipa is divided into 8 cluster groups, 106 groups, and the distribution area of each cluster, community characteristics are described, and the The relationship between ecological succession in steppe plants in Gobi were analyzed by.4, China Gobi steppe community diversity along altitudinal gradient and longitude show regular changes, with the longitude increased, community diversity overall level is linear or volatility upward trend, with the increase of altitude, diversity in species richness first increased and then decreased, other diversity index showed an upward trend; while the index of beta diversity with increasing latitude, the rise in volatility, 108-109 ~ E, Cody diversity index reached the highest value, while the Jaccard similarity coefficient reaches the minimum value; diversity index with altitude the increase showed increased firstly and then decreased, reached the maximum value of.5 at an altitude of about 1700m, and through the Gobi steppe zone group students rockfall Stipa steppe, Stipa breviflora STEPPE (Stipa breviflora) and Kirschner wire Mao (Stipa krylovii) Comparative Study of grassland soil trace elements and soil pH value, the distribution of Gobi steppe communities of trace elements in soil affect the two largest trace element were Cr and Cu elements content, the reason can be summarized as follows: first, the soil pH in Gobi steppe the value was lower than that of other types of grassland soil, and studies have shown that the pH value of soil and the content of Cr and Cu elements are negatively related; second, there may be a species of Stipa in Gobi for the two elements of the selective absorption ability is stronger than that of other trace elements in the soil, thus draw the two elements Gobi Stipa rock weathering serious root from gravel quality, with the plant's death, the two kinds of elements in plants to absorb and return to the soil, making the two kinds of elements in the soil containing community The amount was significantly higher than that in other types of grassland soil; third, Gobi steppe where habitat of gravel is significantly higher than that of the steppe type, the erosion degree is significantly higher than that of other types of grassland, the weathering of minerals in the soil and the rate of decomposition is significantly faster than other natural grassland types and soil. With the soil mineral weathering and decomposition of soil trace elements in the natural increase, which may be the content of the overall level of soil trace elements in Gobi grassland is higher than other types of grassland and the Cr and Cu elements were significantly higher than that of a reason other types of grassland.

【学位授予单位】：内蒙古大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：S812

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