滨海湿地不同植被类型下土壤中氮与磷的积聚特征

发布时间：2018-07-17 08:34

【摘要】：湿地土壤中氮(N)和磷(P)与湿地群落演替生态系统的稳定密切相关。然而,对滨海湿地植被如何影响其覆盖下土壤中不同赋存形态N、P的积聚,以及典型滨海湿地植被芦苇Phragmites australis (Cav.) Trin. ex Steud是否存在沃岛效应等知之甚少。本研究以威海市月湖滨海湿地芦苇、三棱草Scirpus planiculmis Fr.Schmidt、狭叶香蒲Typha angustifolia L覆盖下的土壤为研究对象,研究了湿地不同植被覆盖下不同赋存形态N、P的积聚特征、生态化学计量学特征,以及芦苇群落存在沃岛效应的可能性。主要结果如下：1)不同植被覆盖下土壤理化性质。土壤容重在1.06-1.53 g/cm3之间,在植被类型间的差异因季节的变化而变化。春季,狭叶香蒲覆盖下的土壤容重为1.06±0.25 g/cm3,小于芦苇覆盖下的土壤容重(1.40±0.25 g/cm3)和三棱草覆盖下的土壤容重(1.51±0.17g/cm3)(p5%)；夏季,三棱草覆盖下土壤的容重为1.21±0.20 g/cm3,显著小于芦苇覆盖下的土壤容重(1.40±0.11 g/cm3)和狭叶香蒲覆盖下的土壤容重(1.44±0.22 g/cm3)(p5%)。土壤容重整体表现为随土壤深度的增加而增大的趋势。春、秋季,土壤有机质含量在植被类型间的变化规律相同,狭叶香蒲覆盖下的土壤有机质含量显著大于芦苇和三棱草覆盖下的土壤的有机质含量(p5%)。土壤含水率的变化范围为8.43-38.96%,在植被类型间的差异性极为显著(p5%),各季度间不同植被覆盖下土壤含水率也大致表现为同一规律,狭叶香蒲覆盖下土壤的含水率大于芦苇和三棱草覆盖下土壤的含水率(p5%)。0-10 cm土壤含水率和有机质含量大于10 cm以下的土壤含水率和有机质含量。2)土壤有机氮(ON)和有机磷(OP)是N和P的主要赋存形态,分别占土壤总氮(TN)的94.67%和土壤总磷(TP)的97.16%。土壤无机磷(IP)和TP含量在植被间的差异相似,均表现为狭叶香蒲覆盖下的土壤TP和IP含量大于三棱草和芦苇覆盖下的土壤TP和IP含量(p5%),三棱草覆盖下在0-2 cm处土壤IP和TP含量较多,狭叶香蒲覆盖下土壤IP和TP含量较高的区域为10-20cm。土壤无极氮(IN)和TN含量在植被类型间的差异不显著。土壤可交换氮(Ex-N)和可交换磷(Ex-P)含量在植被类型间的差异因季节而不同。春、夏季,狭叶香蒲覆盖下土壤Ex-P含量较小,显著小于芦苇和三棱草覆盖下土壤Ex-P含量(p5%),秋、冬季,芦苇覆盖下土壤Ex-P含量显著小于三棱草和狭叶香蒲覆盖下土壤Ex-P含量(p5%)。夏、冬季,土壤Ex-N在植被类型间的差异较为显著(p5%)。夏季,各植被覆盖下土壤Ex-N含量的大小排列顺序为三棱草狭叶香蒲芦苇(p5%)；冬季,各植被覆盖下土壤Ex-N含量的大小排列顺序为狭叶香蒲三棱草芦苇(p5%)。3)春、夏、冬季,芦苇覆盖下土壤的Ex-N/Ex-P比分别为15.20±6.31、7.31±2.44、36.76±9.24,均小于三棱草和狭叶香蒲覆盖下土壤的Ex-N/Ex-P比。除春、夏季的芦苇外,其余各季度各植被覆盖下土壤的Ex-N/Ex-P比均大于16,植被的生长均受到土壤中P的限制。春季和冬季,碳(C)氮比在植被类型间存在显著差异,狭叶香蒲覆盖下土壤的C/N比显著大于芦苇和三棱草覆盖下土壤的C/N比(p5%)。各季度各植被覆盖下土壤的C/N比均小于25,表明本地区微生物对有机质的分解加快,有利于N的积累。4)芦苇群落对土壤含水率、C/N比的影响范围为0-2 m,分别体现在16-18cm和6-8 cm深度的土壤。对土壤有机质的影响范围则在群落中心和距中心0.5 m处,且所处的土层较为分散。土壤Ex-N、TN含量和Ex-N/Ex-P、TN/TP比在芦苇和裸地间的差异表现在距中心0.5 m处,体现在12-14 cm深度的土壤。土壤IN、IP含量在芦苇和裸地间的差异表现在距中心1.5 m处,体现在14-18 cm深度的土壤。此外,芦苇对Ex-P、IN、TN有积聚作用,对水分、Ex-N、IP、TP有疏散作用。在滨海湿地,芦苇可能具有反沃岛效应,其指标是土壤含水率和土壤C/N比。
[Abstract]:Nitrogen (N) and phosphorus (P) in wetland soils are closely related to the stability of wetland community succession ecosystems. However, little is known about how coastal wetland vegetation affects the accumulation of N, the accumulation of P, and the existence of the fertile island effect of the typical coastal wetland vegetation, Phragmites australis (Cav.) Trin. ex Steud, and so on. The soil of reed, Scirpus planiculmis Fr.Schmidt and narrow leaf cattail Typha angustifolia L covered by Weihai Moon Lake wetland was studied. The accumulation characteristics of P, ecological chemometrics characteristics and the possibility of the existence of fertile island effect in reed community were studied under different vegetation coverage. The main results are as follows: 1) the physical and chemical properties of soil under different vegetation coverage. The soil bulk density is between 1.06-1.53 g/cm3, the difference between the vegetation types and the season changes. In spring, the soil bulk density under the narrow leaf cattail is 1.06 + 0.25 g/cm3, less than the soil soil bulk density (1.40 + 0.25 g/cm3) under the reed and the soil covered by Prisma Soil bulk density (1.51 + 0.17g/cm3) (p5%); in summer, the bulk density of soil under mulching was 1.21 + 0.20 g/cm3, significantly less than the soil bulk density (1.40 + 0.11 g/cm3) under reed mulching and soil bulk density (1.44 + 0.22 g/cm3) under the narrow leaf cattail (1.44 + 0.22 g/cm3). Soil bulk density overall showed a trend of increasing with the increase of soil depth. The organic matter content of soil organic matter is the same among the vegetation types. The content of soil organic matter under the cover of cattail is significantly greater than that of reed and PRISMA (p5%). The variation range of soil water content is 8.43-38.96%, and the difference between the vegetation types is very significant (p5%), and the different vegetation covers each quarter. The soil moisture content under the covered soil is also approximately the same. The water content of soil under the cover of the narrow leaf cattail is greater than the soil moisture content of the soil under the reed and prism covered soil (p5%).0-10 cm soil moisture content and the organic matter content is greater than 10 cm soil moisture content and organic matter content.2). Soil organic nitrogen (ON) and organophosphorus (OP) are the main contents of N and P. The difference of soil inorganic phosphorus (IP) and TP content in soil total nitrogen (TN) 94.67% and soil total phosphorus (TP) was similar to that of TP, which showed that the content of TP and IP in the soil under the narrow leaf cattail was greater than that of the soil TP and IP (p5%) under the mulching and reed covered soil. The soil IP and the content of the soil under the mulching at the 0-2 cm were compared. The areas with higher soil IP and TP content under the narrow leaf cattail were no significant difference between 10-20cm. soil non polar nitrogen (IN) and TN content among vegetation types. The difference of soil exchangeable nitrogen (Ex-N) and exchangeable phosphorus (Ex-P) content between vegetation types varied from season to season. In spring and summer, the soil Ex-P content was smaller and significantly smaller under the narrow leaf cattail. Soil Ex-P content (p5%) under reed and PRISMA mulching, autumn, winter, and reed covered soil Ex-P content was significantly less than the soil Ex-P content (p5%) under the mulching and narrow leaf cattail. In summer and winter, the difference of soil Ex-N between vegetation types was significant (p5%). In summer, the order of the size of soil Ex-N content under the cover of each vegetation was three prism. Grass narrow leaf cattail reed (p5%); in winter, the order of soil Ex-N content under the cover of each vegetation covers the narrow Ye Xiangpu trisse reed (p5%).3) spring, summer and winter, and the Ex-N/Ex-P ratio of the soil under the reed is 15.20 + 6.31,7.31 + 9.24 respectively, which is less than the Ex-N/Ex-P ratio of the soil under the mulching and the narrow leaf cattail, except for spring and summer. The Ex-N/Ex-P ratio of the soil under the rest of the season was more than 16, and the growth of the vegetation was limited by the P in the soil. In spring and winter, the carbon (C) nitrogen was significantly different between the vegetation types. The C/N ratio of the soil under the narrow leaf cattail was significantly greater than the C/N ratio of the soil under the reed and the mulching grass (p5%). The C/N ratio of the soil under vegetation cover is less than 25, indicating that the decomposition of organic matter in the local area is accelerated and the accumulation of N is.4). The influence range of reed community to soil water content and C/N ratio is 0-2 m, which is reflected in the depth of 16-18cm and 6-8 cm respectively. The influence range of the soil organic matter is at the center of the community and the 0.5 m at the center of the distance, and the soil organic matter is at the center of the community and the center of the distance from the center. Soil Ex-N, TN content and Ex-N/Ex-P, Ex-N/Ex-P, TN/TP than in reeds and bare land in the difference between the center 0.5 m, 12-14 cm depth of the soil. Soil IN, IP content between reeds and bare land at 1.5 m from the center, reflected in 14-18 cm depth of the soil. In addition, the reed to Ex-P, IN, accumulate the product Aggregation plays an important role in dispersing water, Ex-N, IP and TP. In coastal wetlands, Phragmites australis may have an anti fertile island effect, and its index is soil water content and soil C/N ratio.
【学位授予单位】：山东大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：S153

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