鄱阳湖水位波动下植被群落演替土壤碳氮时空分布及有机质的中红外光谱研究

发布时间：2018-11-23 08:21

【摘要】：本研究以鄱阳湖南矶山湿地和吴城常湖池湿地为研究区域,分析不同水位时期(平水期、枯水期和丰水期)、不同群落(裸滩、茭白、苔草、南荻、芦苇)的土壤碳、氮和活性有机质含量时空分布特征、土壤理化性质与影响因子,并利用傅立叶红外光谱技术对不同地点、植被群落演替、不同水位时期下湿地土壤有机质的结构进行分析。主要结果如下:(1)不同地点、不同群落演替、水位土壤理化性质不同。不同地点下土壤理化性质差别不大,其中南矶山湿地的含水量较高为58.21%。不同群落演替下茭白土壤的含水量最高为130.89%,其温度和pH最低分别为8.60℃、4.72,南荻土壤的温度最高为17.67℃,芦苇的含水量最低为37.94%,裸滩的pH最高为6.76。整体而言,不同水位时期下的温度表现为丰水期平水期枯水期;pH表现为枯水期丰水期平水期;含水量表现为平水期丰水期枯水期。(2)不同地点、群落演替、水位土壤碳、氮和活性有机质含量不同。不同地点土壤碳、氮含量无明显差异,两地的裸滩土壤活性有机质含量差异显著(p0.05)。不同群落演替土壤碳氮和活性有机质含量皆为茭白群落最高,分别为23.21 mg/g、2.19 mg/g、7.27 mg/g,与其他群落均有显著差异(p0.05)。不同水位下总碳、总氮含量差异显著,具体表现为平水期枯水期丰水期,总体而言,平、枯水期比丰水期时土壤活性有机质含量高。土壤碳、氮和活性有机质含量与pH值均呈显著负相关(p0.01),与温度均呈显著负相关(p0.05),和土壤的含水量均呈显著正相关(p0.01),土壤活性有机质与土壤总碳、总氮含量呈显著正相关(p0.01)。(3)各群落下的土壤红外光谱谱型基本相似,在植被群落演替下的土壤有机质在某些特征峰的强度上有着不同的差异。整体而言,植被土壤有机质在不同水位时期均表现出茭白土壤中红外光谱特征峰峰值较小,裸滩土壤中红外光谱特征峰峰值较大。不同群落演替下的土壤的红外主要峰值在3696 cm~(-1)、3622cm~(-1)、3422 cm~(-1)、2920 cm~(-1)、2840 cm~(-1)、1633 cm~(-1)、1380 cm~(-1)、1033 cm~(-1)、913cm~(-1)、798 cm~(-1)、780 cm~(-1)、694 cm~(-1)处,说明植被群落演替土壤有机质中含有羟基、芳香结构的C=C或者酰胺键、脂肪亚甲基、木质素与脂肪族化合物、粘土类矿物硅质、烯烃。(4)相同植被在鄱阳湖南矶山湿地不同水位时期的中红外光谱谱图大致相同,峰值强弱有所差异,整体而言,丰水期的土壤有机质的各个特征峰峰值较小,而平水期时各植被土壤有机质的特征峰峰值较大。不同地点下土壤有机质组成和结构上有所差异,南矶山湿地土壤二阶谱图在539 cm~(-1)、479 cm~(-1)处附近的峰普遍比吴城的强,南矶山湿地土壤中含有粘土类硅化物含量比吴城多。
[Abstract]:Taking Nanji Mountain Wetland of Poyang Lake and Changhu Lake Wetland of Wucheng as the study area, the soil carbon of different water level periods (plain, dry and abundant) and different communities (bare beach, Zizania latifolia, Carex sinensis, South Amur, Reed) were analyzed. The spatial and temporal distribution characteristics of nitrogen and active organic matter contents, soil physicochemical properties and influencing factors were analyzed by Fourier transform infrared spectroscopy (FTIR). The structure of soil organic matter in different sites, vegetation community succession and different water level periods were analyzed by Fourier transform infrared spectroscopy (FTIR). The main results are as follows: (1) the physical and chemical properties of water level soil are different in different sites, different community succession and water level. The physical and chemical properties of soil were not different in different sites, and the water content of Nanji Mountain wetland was higher than that of Nanji Mountain wetland. The highest water content of Zizania latifolia was 130.89, the lowest temperature and pH were 8.60 鈩，

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