發(fā)布時間：2018-05-17 12:01

  本文選題：豬毛蒿 + 沙-土界面��； 參考：《寧夏大學(xué)》2017年碩士論文

【摘要】：在人為活動和自然干擾下,荒漠草原大塊連續(xù)分布的自然景觀,被其他非適宜生境分隔成許多面積較小的生境斑塊,導(dǎo)致斑塊破碎分離并由簡單趨向復(fù)雜。豬毛蒿在這些破碎斑塊中占重要地位,而且沿著沙性土與壤質(zhì)土的過渡界面呈現(xiàn)有規(guī)律的分布,研究這種規(guī)律的形成機(jī)理能夠?yàn)椴菰�改良和生態(tài)恢復(fù)提供理論基礎(chǔ)。本文采用野外樣帶調(diào)查、室內(nèi)物理和化學(xué)分析以及冗余分析和地統(tǒng)計學(xué)等方法,研究了毛烏素沙地西南緣一個典型沙性土斑塊與壤質(zhì)土斑塊過渡帶(簡稱沙-土斑塊界面)的豬毛蒿分布格局及其與土壤、植被的相互關(guān)系。主要結(jié)論如下:1.沙-土斑塊界面植物主要為禾本科、豆科、菊科,是其廣適性的表現(xiàn)。本研究的野外調(diào)查物種調(diào)查結(jié)果中共有植物28種,分屬12科27屬,多年生草本占優(yōu)勢,多為禾本科、豆科、菊科物種。界面植被呈現(xiàn)為針茅群落與豬毛蒿群落的交錯分布,短花針茅、豬毛蒿在各自群落中占優(yōu)勢地位,物種豐富度最高出現(xiàn)在界面上。土壤沙化程度的增加,針茅、胡枝子的重要值逐漸減小,豬毛蒿由于其卓越的抗逆性,其重要值逐漸增加最終發(fā)展為群落建群種,其中有20個樣方豬毛蒿重要值超過1/3,甚至有些超過一半以上。生物量也有類似的變化趨勢。2.豬毛蒿群落特征與土壤因子都存在界面變化,有空間自相關(guān)界面豬毛蒿群落樣帶平均高度、蓋度、生物量、密度、豐富度、香農(nóng)威納指數(shù)、均勻度指數(shù)、優(yōu)勢度指數(shù)隨樣帶延伸而變化�；哪�草原存在大量叢生植物如短花針茅、糙隱子草等,導(dǎo)致群落密度與生物量相關(guān)性不高。土壤水分、養(yǎng)分和粒徑也隨樣帶表現(xiàn)出梯度變化,體現(xiàn)了界面效應(yīng),且有較強(qiáng)的空間自相關(guān)。豬毛蒿與與土壤各層粒徑都表現(xiàn)出極度相關(guān)。3.影響豬毛蒿群落物種多樣性和功能群多樣性的主要因子是底層土壤質(zhì)地與養(yǎng)分。對針茅-豬毛蒿過渡群落分布及其物種多樣性變化有顯著影響的主要土壤環(huán)境因子分別為20-40cm 土層黏粉粒和20-40cm 土層有機(jī)碳。對植被功能群有顯著影響的主要土壤環(huán)境因子分別為20-40cm粗砂粒和10-20cm全磷。表層土壤養(yǎng)分和質(zhì)量的變化也有植物分布格局的形成有顯著相關(guān),但解釋量不高。主要還是20-40cm 土壤粒徑約束下物種擴(kuò)散競爭的空間格局。植物群落隨土壤粒徑增大多樣性逐漸降低,植物分布越呈密集的小片狀分布,物種豐富度也降低。4.荒漠草原沙-土斑塊界面土壤底層粗砂粒的分布格局決定豬毛蒿群落的空間分布。研究發(fā)現(xiàn)各土層有機(jī)碳與生物量均呈現(xiàn)極顯著相關(guān)性,且相關(guān)性由表層到深層遞減。表層土由于外界干擾較多,其相關(guān)性不明顯。不同土層粒徑含量與群落蓋度、生物量的相關(guān)性對比發(fā)現(xiàn)由于荒漠草原土壤受侵蝕作用強(qiáng),土壤表層粒徑與蓋度生物量的相關(guān)性不顯著,越往底層反而越顯著;土壤中局部粗砂粒含量高使土壤團(tuán)粒結(jié)構(gòu)喪失、土壤孔隙減小,滲透阻力增大,導(dǎo)致水分散失增大,限制物種進(jìn)入,形成單優(yōu)先鋒物種群落。表現(xiàn)出地上植被群落與土壤下伏地層或成土母質(zhì)的相關(guān)性更為明顯。研究結(jié)果表明底層土壤質(zhì)地是決定荒漠草原地區(qū)島狀板塊豬毛蒿群落的構(gòu)建的主要因子。
[Abstract]:Under human activities and natural disturbances, the continuous distribution of natural landscapes in large desert grassland is separated by other unsuitable habitats into many smaller habitats, resulting in fragmented patches and simple tendency to complex. Artemisia porcine is important in these fragmented patches, and along the transition interface between sandy soil and loam soil In this paper, a typical sandy soil patch in the southwest margin of the Maowusu Sandy Land and the transition zone of the loamy soil patch are studied by field sampling, indoor physical and chemical analysis, redundancy analysis and geostatistics. The distribution pattern of Artemisia Artemisia and its relationship with soil and vegetation. The main conclusions are as follows: 1. sand soil patch interface plants are mainly gramineaceae, Leguminosae, and Compositae. There are 28 species of plant species in this study, belonging to 12 families, 27 genera, and perennial herbs. The interface vegetation is the interlaced distribution of the Stipa community and the Artemisia annua community, and the species richness of the species is the highest in the community. The soil desertification degree increases, the important value of the Stipa, the Lespedeza is gradually reduced, and the Artemisia Artemisia is due to its excellent resistance. The important value of its important value gradually increased to the community construction, among which 20 samples were more than 1/3, even some more than half. There was a similar trend in the biomass of.2., and there was an interface change between the community characteristics and soil factors of the Artemisia Artemisia, and the average height and coverage of the spatial autocorrelation interface of the community sample zone of Artemisia Artemisia. The biomass, density, richness, Shannon Wiener index, evenness index and dominance index vary with the sample belt. There are a large number of cluster plants such as Stipa short and saphenous weed in desert steppe, which leads to the low correlation between the density and biomass of the community. Soil moisture, nutrients and grain sizes also show gradient changes with the sample zone, reflecting the interfacial effect. The main factors affecting the species diversity and functional group diversity of the Artemisia hairy Artemisia community are the underlying soil texture and nutrient. The main soil environment which has significant influence on the distribution of the Transitional Community and the variety of species diversity of the Artemisia hairy Artemisia Artemisia is the main factor affecting the diversity of the species and functional groups of the Artemisia annua community..3. The factors are 20-40cm soil layer clay particle and 20-40cm soil layer organic carbon respectively. The main soil environmental factors that have significant influence on the vegetation functional groups are 20-40cm coarse sand grains and 10-20cm total phosphorus, respectively. The change of soil nutrient and quality also has significant correlation with the formation of plant distribution pattern, but the amount of interpretation is not high. It is mainly the 20-40cm soil. The spatial pattern of species diffusion competition under the restriction of particle size. The diversity of plant communities gradually decreased with the increase of soil particle size, and the more dense small flaky distribution of plant distribution. The species richness also reduced the distribution pattern of the coarse sand grains at the bottom of the sandy soil patch interface of.4. desert grassland. There is a significant correlation between organic carbon and biomass, and the correlation is decreasing from the surface to the deep. The correlation of the surface soil is not obvious because of the more external interference. The correlation of the grain size and the community coverage and the biomass of the different soil layers shows that the soil surface grain size and the cover biomass are strong due to the strong erosion of the desert grassland soil. The correlation is not significant, and the more significant it goes to the bottom. The high content of coarse sand grains in the soil causes the loss of soil aggregate structure, the decrease of soil porosity and the increase of osmotic resistance, which leads to the increase of water loss, limiting the entry of species and forming a single superior pioneer species community. The results show that the texture of the underlying soil is the main factor determining the construction of the Artemisia annua community in the desert grassland area.
【學(xué)位授予單位】：寧夏大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2017
【分類號】：Q948

【參考文獻(xiàn)】

相關(guān)期刊論文 前10條

1 楊秉s，

本文編號：1901285