甘肃盐渍荒漠区不同草原植物群落土壤的季节性变化

发布时间：2018-06-08 18:53

本文选题：盐渍荒漠草原 + 土壤理化性质　；参考：《甘肃农业大学》2017年硕士论文

【摘要】：土壤盐渍化已成为世界性的资源问题和环境问题。全世界盐碱地面积约为9.55×10~8 hm~2,占地球陆地面积的7.26%,我国盐碱地面积约为9913×10~4 hm~2,主要分布在东北、华北、西北内陆地区以及长江以北沿海地带。如何合理开发利用这一具有巨大潜力和经济价值的土壤资源具有重要意义。近年来,对物种演替的研究表明,先锋物种对土壤条件的改善,更有利于物种的共存,增加生物多样性。那么植物与土壤之间是否存在相互作用,这些相互作用对群落的进一步发展是否起到关键性作用。为此,本研究以甘肃省河西走廊盐渍草原区主要植物类群(梭梭、白刺、鞑靼滨藜、骆驼刺)为研究对象,系统地研究了不同植物群落在不同季节土壤理化性状、土壤养分成分以及土壤微生物数量、土壤酶活性等土壤生物学性状,得到的主要结果如下:(1)梭梭群落土壤剖面盐分呈现上大下小的“T”型分布,盐分主要累积在0-60cm土层,且在7月份表层土壤盐分累积明显。研究发现梭梭群落土壤剖面盐分和Cl~-,pH和HCO_3~-,SO_4~(2-)、K~+和Na~+,Mg~(2+)和Ca~(2+)的季节性变化规律基本一致。土壤微生物数量是:细菌放线菌真菌。在梭梭群落中,真菌与放线菌之间呈显著正相关,细菌和脱氢酶呈极显著正相关、真菌和脲酶呈显著负相关、放线菌和脲酶之间呈极显著的负相关关系。真菌与速效铜之间呈显著正相关,呼吸速率与有机质之间呈显著负相关。(2)白刺群落土壤水分随土层深度的增加而增加,在0-5cm土层和5-10cm土层土壤水分均随季节的变化呈现增加的趋势。土壤剖面盐分表聚现象和季节性变化非常明显,尤其在7月份,在0-20cm土层盐分表聚高达40.7%。土壤呼吸速率随季节的变化呈现减小的趋势。土壤微生物数量是:细菌放线菌真菌。在白刺群落中,容重和土壤水分之间呈显著负相关;真菌和脲酶之间呈显著正相关;容重和速效磷呈显著负相关关系;土壤水分与速效磷之间呈显著正相关关系;脲酶与速效铜之间呈显著正相关关系;脱氢酶和速效钾之间呈极显著正相关关系;真菌与速效铜之间呈极显著正相关关系,真菌的数量直接影响速效铜的含量。(3)滨藜群落土壤水分随土层深度的增加而增加,在0-5cm土层和5-10cm土层土壤水分均随季节的变化呈现减小的趋势。土壤微生物数量:细菌放线菌真菌。土壤盐分和Cl~-,pH和HCO_3~-,SO_4~(2-)、K~+和Na~+,Mg~(2+)和Ca~(2+)的季节性变化规律基本一致,且盐分、Cl~-、HCO_3~-、SO_4~(2-)、K~+和Na~+表聚,Mg~(2+)和Ca~(2+)底聚明显。细菌与脱氢酶之间呈极显著正相关,细菌与脲酶之间呈显著正相关,脲酶和脱氢酶之间呈显著正相关,容重与速效氮呈极显著正相关,容重与速效铁之间呈显著负相关,呼吸速率与速效钾呈显著正相关。(4)骆驼刺群落土壤剖面在0-5cm土层和5-10cm土层土壤容重随着季节的变化均表现出逐渐减小的规律。盐分、Cl~-、HCO_3~-、SO_4~(2-)、K~+和Na~+具有明显表聚,Mg~(2+)和Ca~(2+)底聚明显。土壤微生物主要是细菌,其次是放线菌,真菌含量最小。呼吸速率与碱性磷酸酶呈显著正相关;真菌与脲酶、脱氢酶、有机质呈显著负相关,与速效锰、速效铜呈极显著正相关;脲酶与脱氢酶呈显著正相关、与有机质呈极显著正相关;脱氢酶和有机质呈极显著正相关;碱解氮与速效铁呈显著正相关,土壤中微量元素有效性受到土壤pH和有机质的影响。
[Abstract]:Soil salinization has become a worldwide resource and environmental problem. The area of saline alkali land in the world is about 9.55 x 10~8 hm~2, accounting for 7.26% of the earth's land area. The area of saline alkali land in China is about 9913 x 10~4 hm~2, mainly in Northeast China, North China, northwest inland area and the coastal zone of the north of the Yangtze River. The soil resources of great potential and economic value are of great significance. In recent years, the study of the succession of species shows that the improvement of soil conditions by pioneer species is more beneficial to the coexistence of species and the increase of biodiversity. In this study, the main plant groups in the saline grassland area of Hexi Corridor, Gansu Province, were studied. The soil physical and chemical properties of different plant communities in different seasons, soil nutrient components, soil microbial biomass, soil enzyme activity and other soil biological characters were systematically studied. The main results are as follows: (1) the salt of the soil profile of the Haloxylon ammodendron community has a large and lower "T" type distribution, the salt accumulation is mainly in the 0-60cm soil layer, and the salt accumulation in the surface soil is obvious in July. The salt of the soil profile in the soil profile of the Haloxylon ammodendron community and the seasonal variation rules of Cl~-, pH and HCO_3~-, SO_4~ (2-), K~+ and Na~+, Mg~ (2+) and Ca~) are found. The number of soil microbes is the same. The number of soil microbes is bacterial actinomycetes. In the Haloxylon ammodendron community, there is a significant positive correlation between fungi and actinomycetes. Bacteria and dehydrogenase have significant positive correlation, fungi and urease have significant negative correlation, and there is a significant negative correlation between actinomycetes and urease. There is a significant positive correlation between fungi and available copper, There was a significant negative correlation between the respiration rate and the organic matter. (2) the soil moisture of the white thorn community increased with the increase of soil depth, and the soil moisture in the 0-5cm soil layer and the 5-10cm soil layer showed an increasing trend with the seasonal variation. The soil profile and salt surface accumulation and seasonal changes were very obvious, especially in the July, in the 0-20cm soil layer. Soil respiration rate of up to 40.7%. decreased with seasonal variation. Soil microbial biomass was: bacterial actinomycete fungi. In white thorn communities, there was a significant negative correlation between bulk density and soil moisture; there was a significant positive correlation between fungi and urease; bulk density and available phosphorus showed a negative correlation; soil moisture and available phosphorus showed a negative correlation. There was significant positive correlation between urease and available copper; there was a very significant positive correlation between dehydrogenase and available potassium; there was a very significant positive correlation between fungi and available copper, and the number of fungi directly affected the content of quick acting copper. (3) the soil moisture of the community was increased with the increase of soil depth, and in the 0-5cm soil layer. Soil moisture in the 5-10cm soil layer decreased with the seasonal variation. Soil microbial biomass: bacterial actinomycetes. Soil salinity and Cl~-, pH and HCO_3~-, SO_4~ (2-), K~+ and Na~+, Mg~ (2+) and Ca~ (2+). There was a significant positive correlation between bacteria and dehydrogenase. There was a significant positive correlation between the bacteria and urease. There was a significant positive correlation between urease and dehydrogenase. The bulk density was significantly positively correlated with the available nitrogen. There was a significant negative correlation between the bulk density and the available iron, and the respiration rate was positively correlated with the available potassium. (4) the soil profile of the camel thorn community was in 0-5cm Soil bulk density in soil layer and 5-10cm soil layer decreases gradually with seasonal variation. Salt, Cl~-, HCO_3~-, SO_4~ (2-), K~+ and Na~+ have obvious aggregation, Mg~ (2+) and Ca~ (2+) accumulation is obvious. Soil microbes are mainly bacteria, followed by actinomycetes, and fungi are the smallest. The respiration rate is positively correlated with alkaline phosphatase; true The bacteria have significant negative correlation with urease, dehydrogenase and organic matter, which have significant positive correlation with available manganese and quick acting copper; urease and dehydrogenase have significant positive correlation with organic matter; dehydrogenase and organic matter have significant positive correlation; alkali hydrolysable nitrogen has a significant positive correlation with available iron, and the availability of trace elements in soil is pH and there is The influence of the quality of the machine.
【学位授予单位】：甘肃农业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：S812.2

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